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Trapezium implant arthroplasty
Trapezium implant arthroplasty Long-term evaluation of 150 cases Arthritis of the joints at the base of the thumb can be painful and severely disabling, interfering with normal functional activity. The trapezium implant, which acts as a replacement for the removed patholigic bone, must have certain features if it is to be tolerated by the host tissue and be stable and durable. Implant resection arthroplasty of the trapezium, with careful correction of other associated deformities, has resulted in long-term, excellent functional and cosmetic results in this group of cases.
A. B. Swanson, M.D., G. deGoot Swanson, M.D., and J. J. Watermeier, M.D., Grand Rapids, Mich.
An
arthroplasty method for treatment of arthritic disorders of the basal joints of the thumb consisting of a trapeziectomy and replacement with a silicone implant was first performed in 1965 by Swanson. 1 Since that time, this procedure has been used by many surgeons throughout the world in thousands of cases. 2 - 5 Long term review of the method has proven worthy, and it is the purpose of this review to describe a group of pa- · tients operated on in our clinic and relate the develop ment of the surgical technique to the results.
Disabilities of thumb basal joints Clinical course. Arthritic and posttraumatic dis abilities often interfere with normal thumb function, especially when the basal joints are involved. Pain and swelling at the base of the thumb are the most common early complaints. As the disease progresses, instability, crepitation, deformity, and loss of motion and strength are also noted. The condition most often occurs in postmenopausal women and is most commonly caused by osteoarthritis and rheumatoid arthritis; the disability may also be a sequel to Bennett's fracture, or it can develop as a result of fixed contractures around the base of the thumb after soft tissue injuries. The severity of the symptoms and deformity depends From the Departments of Orthopedic and Hand Surgery Training and Orthopedic Research, Blodgett and Butterworth Hospitals, Grand Rapids, Mich., and the Department of Surgery, Michigan State University. Presented at the meeting of the American Society for Surgery of the Hand, Las Vegas, Nevada, February 3, 1977. Received for publication Sept. 29, 1979; revised Sept. 8, 1980. Reprint requests: Alfred B. Swanson, M.D., Blodgett Professional Bldg., Ste. 290, 1900 Wealthy St., S.E., Grand Rapids, MI 49506.
on the degree of destructive changes that occur at the basal joints and the secondary imbalancing forces ap plied across the thumb ray. 7 • 8 The radially subluxating base of the first metacarpal produces a prominence which we call a "shoulder deformity." Arthritis at the base of the thumb may be the initiating cause of adduc tion contracture of the first metacarpal and associated collapse of the thumb into severe swan-neck deformity. It may also be associated with compression of the me dian nerve in the carpal tunnel; tendonitis of the flexor carpi radialis, abductor pollicis longus, and extensor pollicis brevis tendon; recurrent radial palmar degen erative ganglia; and arthritis of the finger joints. Radiographic findings. The radiograms of a series of 200 osteoarthritic thumbs of patients who were being considered for reconstructive surgery of the thumb basal joints were evaluated to demonstrate the inci dence of lesions found around the articulations of the trapezium. 9 Typical changes were noted in the osteoar thritic thumbs, including narrowing of the joint space, subchondral condensation of bone, osteophyte forma tion, and radial and proximal subluxation of the first metacarpal. This survey and that of others 10 showed that the trapezium was usually the center of a generalized or pantrapezial arthritic process as shown in Fig. 1. Rheumatoid patients may show a similar involve ment, localized at the basal joints; they may also ex hibit absorptive changes in the trapezium and metacar pal base and in other carpal bones, producing a result not unlike a resection arthroplasty.
Trapezium implant resection arthroplasty Design and development. The trapezium implant was developed by Swanson 1 in 1965 to help preserve the anatomic relationships of the thumb basal joints
0363-5023/81/020125+ 17$01.70/0 © 1981 American Society for Surgery of the Hand
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1st
METACARPAL
SCAPHOID
INCIDENCE OF OSTEOARTHRITIC CHANGES AROUND THE TRAPEZIUM Fig. 1. Diagram of incidence of osteoarthritic changes around
trapezium. Trapezium is center of generalized arthritic pro cess with most frequent involvement of trapezium-first meta carpal joint, and also of trapezio-scaphoid, trapezio-trape zoid, and trapezium second metacarpal joints. This suggests that total excision of trapezium will be necessary in most cases to eliminate all arthritic pain. after resection arthroplasty of the trapezium. 11 This im plant is maintained in proper alignment by a triangular intramedullary stem that fits into the first metacarpal and by capsuloligamentous reconstruction around the implant. Design of this implant was based on a study of cadaver bones and radiograms of normal hands. The original implant design had a convex head and was made of silicone rubber No. 372. The shape was then modified, giving it a slightly concave surface to provide a more stable fit on the rounded articular sur face of the scaphoid (Fig. 2). The silicone elastomer* *High Performance Silicone Elastomer, Dow Coming Corp., Mid land, MI.
The Journal of HAND SURGERY
was later improved to offer a 400% greater tear resis tance. Mechanical testing of the implant in the labora tory to 140 million compression and sheer stress movements without failure has demonstrated adequate durability of the implant. Evolution of surgical technique. Since the begin ning of the trapezium implant arthroplasty procedure, attempts have been made to make the surgical tech nique simple, dependable, predictable, and reproduc ible by other surgeons. A critical analysis of the results obtained has demonstrated the importance of a firm capsuloligamentous support around the implant and of adequate postoperative immobilization. Ligamentous reconstruction. In 1969, reinforce ment of the capsule around the implant with a slip of abductor pollicis longus tendon was initiated for pa tients who had inadequate capsular tissue; the con straining effect of this technique was not completely satisfactory. In 1971, in an effort to replace the support of the frequently inadequate anterior oblique ligament, a distally based slip of the flexor carpi radialis tendon, was used to reinforce the volar capsule and form an ulnar check ligament to hold the base of the first meta carpal to the base of the second metacarpal; the latter may be especially important for manual workers or for patients who present a subluxation of the trapeziometa carpal joint. A slip of the flexor carpi radialis tendon has been used for capsular reinforcement in all our cases since that time. In some cases, the abductor pol licis longus tendon was also used to reinforce the radial capsule. In one case of revision of a dorsal dislocation of the implant, a slip of the extensor carpi radialis lon gus tendon was used to successfully reinforce the dorsal capsular area. Postoperative immobilization. From the beginning, the importance of adequate abduction of the metacarpal to at least 45° and correction of an occasionally associ ated hyperextension deformity of the metacarpophalan geal (MP) joint was recognized. Release of the abduc tor pollicis muscle origin may be carried out to obtain sufficient abduction. However, the use of a scaphoid type cast alone did not always maintain the desired position of the first metacarpal, even when a Kirschner wire was used to immobilize the MP joint. In 1973, a temporary Kirschner wire fixation was placed between the first and second metacarpals. At first, the wire was placed through the distal portion of the metacarpals; however, because of an unfavorable lever placed on the metacarpal base, the wire was subsequently inserted more proximally. This was a good technique, but pre sented a hazard of inadvertent puncture of the radial artery in this area.
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Fig. 2. Intramedullary stemmed implant to improve results of excision arthroplasty of trapezium by acting as space-filler and preserving joint space relationships.
When the high-performance silicone elastomer im plant became available in 197 4, a temporary fixation wire could be placed through the implant into the trape zoid bone with less fear of tears resulting. Because of the potential problem from pin tract infection, which might occur following transcutaneous wire fixation, temporary fixation of the implant to the scaphoid facet with an absorbable suture is now preferred. The high-performance silicone elastomer has been tested for suture pull-out strength. If the needle passes through at least 5 mm of material, up to 30 pounds of force can be applied before the suture will pull out. A 0.045 inch Kirschner wire passed through the implant will hold up to 80 pounds of force before the silicone tears. The use of a suture or pin through the implant for temporary fixation is then feasible. We have selected a TR 5 needle with a No. 0 synthetic absorbable suture which has a breaking strength of 20 pounds and main tains its tensile strength for 3 weeks. It loses its holding strength at an average of 6 weeks, which coincides with the time of firm encapsulation and cast immobilization. When the patient starts movement, the suture will have been absorbed and will not interfere with the implant and the concept of circumferential encapsulation. Clinical advantages. Definite advantages are de rived from the trapezium implant arthroplasty method. The implant acts as a space filler to preserve the rela tionships of the basal joints of the thumb after resection of the trapezium. Meticulous and firm capsuloligamen tous reconstruction around the implant and correction of associated deformities of the thumb are possible and essential for a good result. 12 ~ 16 Biologically 17 and me chanically well tolerated, the implant is rapidly sur rounded by a fibrous supporting capsule which helps further preserve a normal joint space relationship. 18
Contrary to simple resection arthroplasty, trapezium implant arthroplasty helps maintain the important mo tion at the base of the thumb without loss of stability; it also obviates the disadvantages of rigidity and poor positioning which may follow fusion procedures. 19 Re lief of pain and crepitation are excellent, and a good strength of grip and pinch are preserved. Preservation of motion at the thumb basal joints allows stabilization or fusion of the distal joints in position of function. Indications. Trapezium implant resection arthro plasty is indicated when the following conditions are present, whether the disability is due to degenerative, posttraumatic (following an old Bennett's fracture, for example), or rheumatoid arthritis with localized bony changes: (1) localized pain and palpable crepitation during circumduction movements, with axial compres sion of the thumb ("grind test"), (2) loss of motion, with decrease of normal pinch and grip strength, (3) radiologic evidence of arthritic changes of the trapezio metacarpal, trapezioscaphoid, trapeziotrapezoid, and trapezium-second metacarpal joints, singly or in combi nation, (4) unstable, stiff, or painful distal joints of the thumb or swan-neck collapse deformity. We have described a "grind test" which may be useful in localizing the cause of the patient's complaint. To perform this test, the patient's thumb is held se curely in the examiner's right hand, and the base of the patient's thumb is held in the examiner's left thumb and index finger. If the test is positive, passive circumduc tion of the thumb while axial compression is applied will produce pain and palpable crepitation or subluxa tion at the carpometacarpal joint. We now prefer the use of the convex condylar im plant arthroplasty of the trapeziometacarpal joint for advanced cases of rheumatoid arthritis where there is
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Swanson, deGoot Swanson, and Watermeier
EKtensor Pollieis Lonous Extensor PoUicis Brevis
-J.JW~~
Abductor Pcllicit LOnQUI --4~~~~-~~f:l
Fig. 3. A and B. A, Longitudinal incision parallel to extensor pollicis brevis has short transverse and palmarward arm to continue proximally parallel to flexor carpi radialis tendon. 8, Anatomic rela tionships of abductor pollicis longus, extensor pollicis brevis and extensor pollicis longus tendons, superficial radial nerve, vein, and artery at base of thumb. (From Swanson AB: J Bone Joint Surg [Am] 54:456, 1972, reprinted by permission.)
severe displacement, absorption, or fusion of the con tiguous carpal bones as discussed later. Surgical technique. Various incisions can be used. A transverse incision over the basal joints can provide reasonable exposure; however, the approach is facili tated with a longitudinal incision. A straight longitu dinal incision is not recommended; the incision should preferably be curved palmarward. A 7 to 8 em longitu dinal incision centered over the trapezium is started 2 em above the trapeziometacarpal joint parallel to the extensor pollicis brevis tendon; the incision is then di rected proximally and ulnarward to the distal wrist crease. To expose the flexor carpi radialis tendon at the wrist, it is curved palmarward and continued proxi mally for 3 to 4 em parallel to this tendon (Fig. 3, A). A 2.5 em bridge of skin can also be preserved at the distal wrist crease before running the incision proximally. The branches of the superficial radial nerve are care fully identified and mobilized in the proximal portion of the wound (Fig. 3, B). Small transverse veins may be ligated; however, longitudinal veins are spared. The retinaculum of the first dorsal compartment is incised longitudinally to expose the abductor pollicis longus and extensor pollicis brevis tendons. The dissection is carried down between these tendons to expose the ad ventitial tissue and fatty layer overlying the radial ar tery. This artery is carefully dissected from the underly
ing capsular tissues around the dorsal surface of the trapeziometacarpal joint and mobilized for proximal retraction. One or more small arterial branches going into the trapeziometacarpal joint are ligated. The artery can be retracted safely with a small rubber tube. The capsule over the scaphoid, trapezium, and base of the first metacarpal is incised longitudinally or in a ''T'' fashion, and the flaps are carefully incised off the un derlying bone to retain all capsular tissue. The trapezia scaphoid and trapeziometacarpal joints are identified and, with traction on the thumb, further free ing of the dorsal capsular attachments around the trapezium can be done. It is important to stay close to the bone during the dissection to avoid injury to the artery, underlying tendons, or capsule. The trapezium is removed, preferably by sectioning the bone into pieces with a small sharp osteotome which is directed distally towards the depths of the wound to avoid injuring the underlying flexor carpi radialis tendon and capsule. The bone is removed piecemeal with a rongeur, including the ulnar distal projection often seen between the first and second metacarpals. Traction on the thumb or distal retraction with a small two-prong rake retractor on the base of the metacarpal will facilitate the exposure. Frequently, small flecks of bone are left with the underlying capsule to preserve a good palmar capsuloligamentous support.
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Fig. 3. C and D. C, Proper exposure and retraction of radial artery over scaphoid bone essential for proper exposure. Adequate excision of trapezium bone including projection between first and second metacarpals is most important. When necessary, radial aspect of trapezoid bone is removed to improve fit of implant over scaphoid facet. D, Palmar carpal ligaments. Complete excision of carpal bones (trapezium, scaphoid, or lunate) may leave "holes" or defects in palmar carpal ligaments, because they firmly attach to carpal bones. Small shell of bone should be left on palmar capsule to preserve its continuity.
This is especially true on the radial palmar aspect of the trapezium where it attaches to the transverse carpal lig ament and to the underlying thenar musculature. Any osteophytes or irregularities on the distal end of the scaphoid or trapezoid can be trimmed. Care should be taken to selectively identify the trapezium bone to pre vent removing portions of adjacent bones. Frequently, there is a radial shift of the trapezoid that prevents adequate seating of the implant over the scaphoid facet. A portion of the radial aspect of the trapezoid should be removed to improve this fit (Fig. 3, C). The base of the metacarpal is brought up into the wound and squared off with a rongeur, leaving most of its cortical and subchondral bone intact. Any os teophytes, especially on its medial portion, should be removed. The intramedullary canal of the metacarpal should not be entered initially with the drill, but should be probed first with a thin broach or small curette to prevent inadvertent perforation through its sidewall and consequent extrusion of the implant stem through this defect. The preparation is completed using special burrs with a smooth leader point by developing a trian gular space just large enough to receive the implant stem easily. The proper sized implant should fit the trapeziectomy
space, with its collar seating properly on the metacarpal base and its base well over the distal scaphoid facet to allow full and stable circumduction of the thumb. Test implants are used to select the proper size from the five available sizes; implant sizes Nos. 2 and 3 are most commonly used. The wound must be thoroughly irri gated with saline to remove all debris before inserting the implant. At the end of the procedure it is important to secure the implant in place over the scaphoid by reconstruction of the preserved capsular ligamentous structures and by temporary fixation. Before inserting the implant, the palmar capsule and ligaments should be inspected in the depths of the wound for inadvertent tears or "holes" (Fig. 3, D). If present, these should be sutured so that there is firm supporting capsule on the palmar surface of the implant. If there are only mild destructive changes around the trapezium, the normal capsular struc tures will suffice to maintain the implant in position. The dorsal capsular structures are firmly sutured over the implant with a No. 3-0 Dacron suture, or other nonabsorbable material, using multiple interrupted su tures with inverted knots. The integrity of the proximal capsular reflection off the scaphoid is of outmost impor tance to secure the radial capsular repair. As the radial
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Fig. 3. E to G. E, Trapeziectomy and partial trapezoidectomy completed. Flexor carpi radialis (FCR) tendon slip dissected to its insertion on second metacarpal, passed under FCR tendon, and sutured to FCR tendon and palmar capsule to exit radially through abductor pollicis brevis muscle. F, Flexor carpi radialis slip passed anteriorly through abductor pollicis longus (APL) tendon and
lateral capsule. Sutures passed through capsular reflections off scaphoid bone to secure capsular closure. G, After implant insertion and temporary fixation are completed, capsule is sutured. FCR slip is brought over and through radial capsule and over implant to exit through ulnar capsule. Slip is then pulled, folded over and across dorsal capsule, and sutured in position.
artery is retracted proximally, three No. 3-0 Dacron sutures are usually placed through this capsular reflection and if necessary, through I mm drill holes made in the edge of the scaphoid bone. Ligamentous reinforcement. If the capsular struc tures are inadequate on either the palmar or dorsal areas, particularly if the original condition has been associated with a subluxation of the trapeziometacarpal joint, a ligamentous reconstruction using a slip from the abductor pollicis longus, extensor carpi radialis longus, or (preferably) the flexor carpi radialis tendon is indicated. The flexor carpi radialis tendon is exposed at the wrist, its radial half is incised, and a 7 to 8 em slip is dissected distally to the fibro-osseous canal. The tendon slip is pulled up into the site of the trapeziectomy and further dissected to its insertion on the second metacar pal which is carefully preserved. Great care should be taken to avoid transverse lacerations of the tendon slip. A small hemostat is passed through the abductor pol lids brevis muscle to pull the tendon slip under the residual portion of the flexor carpi radialis tendon and then through the abductor pollicis brevis muscle (Fig. 3, E). The slip is brought anteriorly through the abduc
tor pollicis longus tendon and the lateral portion of the capsular tissues (Fig. 3, F). It is important that the slip not be pulled too tightly, as it may have a tendency to lift the implant from the floor of the wound; this can be prevented by placing the tendon slip under the flexor carpi radialis tendon and suturing it to this tendon and the palmar capsule. Three No. 3-0 Dacron sutures should be placed as described through the capsular reflection off the scaphoid bone to secure the closure of the radial capsule. The implant is placed in the meta carpal with a no-touch technique and temporarily fixed in position as will be described later. The remaining portion of the tendon slip is then brought over and through the radial capsule, over the implant, to exit through the ulnar capsule. The tendon slip may also be passed through the distal portion of the extensor carpi radialis longus tendon avoiding the overlying radial ar tery. It is then pulled out and folded over and across the dorsal capsular repair and sutured in position (Fig. 3, G). The longitudinal capsular incision is repaired. This ligamentous repair provides a firm capsular reinforce ment on the palmar, ulnar, and radial sides. The first dorsal compartment may be loosely closed over the abductor pollicis longus and extensor pollicis
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Fig. 4. Method of temporary fixation of trapezium implant using No. 0 synthetic absorbable suture on TR-5 needle. A, Radial artery is retracted; curved needle is passed under and around waist of scaphoid and picked up distally in depths of wound. Suture is then passed through insertion of the flexor carpi radialis tendon on base of second metacarpal to prevent slipping of suture. Needle is straightened for passage through implant from middle of its concave facet to run out distally, adjacent to stem. B, Implant stem is placed in intramedullary canal of first metacarpal and reduced in proper position, suture is tied securely with multiple surgical knots.
brevis tendons. Dorsal bowstringing of the extensor pollicis brevis tendon could result in an increased mo ment arm and produce hyperextension of the MP joint of the thumb; however, increasing the moment arm of the abductor pollicis longus tendon can improve thumb abduction and can be accomplished by advancing its distal insertion on the metacarpal. Temporary fixation of the implant. The use of temporary fixation to further stabilize the position of the implant during the early healing phase has been an important technical advancement in this method. This can be achieved with an absorbable suture through the implant and/ or with a small Kirschner wire. The implant may be secured to the scaphoid with a No. 0 synthetic absorbable suture on a TR-5 needle. The radial artery must be retracted to expose the area of the dorsal radial portions of the scaphoid. The curved needle is passed under and around the waist of the scaphoid and picked up distally in the depths of the wound. The needle may then also be passed through the insertion of the flexor carpi radialis tendon on the base of the second metacarpal to prevent slipping of the suture. The needle may then be straightened further with two needle holders to run through the trapezium implant from the middle of its concave surface exiting distally adjacent to the stem. Alternatively, it may be passed transversely through the body of the implant (Fig. 4). The implant stem is placed in the in tramedullary canal of the first metacarpal, the implant
is reduced in position, and the suture is securely tied with the multiple surgical knots (Fig. 4). The implant must seat securely on the scaphoid facet. The appro priate capsular closure, with or without tendon rein forcement, is carried out after the implant is positioned. An alternate method for temporary fixation is to pin the implant in position over the scaphoid bone by run ning a 0.045 inch Kirschner wire under direct vision through the long abductor tendon and the capsule, transversely through the head of the implant, and into the trapezoid bone (Fig. 5). On closure, the tip of the wire should perforate the skin approximately I em from the edge of the wound. This should be accomplished without tension, taking care to avoid branches of the superficial radial nerve which must not lie over the tendon edges or directly underneath the wound. The tip of the wire is left protruding 1.5 em from the skin. Closure and postoperative care. The wound is closed in layers, using No. 6-0 Dexon sutures for the subcutaneous tissues. To avoid adhesions, the branches of the superficial radial nerve are carefully rerouted away from the skin closure. This is done during the subcutaneous closure by transferring this nerve slightly dorsally or palmarly away from the line of skin closure with No. 6-0 Dexon sutures. The skin is closed with No. 5-0 nylon sutures, and small silicone rubber drains are inserted subcutaneously. A secure dressing, includ ing an anterior and posterior plaster splint, is then applied. It is possible to apply a full plaster dressing,
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Fig. 5. Trapezium implant temporarily fixed in position with 0.045 inch Kirschner wires into trapezoid bone. Pin was left protruding I em from skin and window made in cast over pin-exit site. Pin was removed after 3 weeks. Note partial trapezoidectomy and excellent fit over distal scaphoid facet.
but it should be bivalved and the extremity elevated because of the potential postoperative swelling. If the tourniquet is left on for more than 90 minutes, a stellate ganglion block is usually given unless previously con traindicated. The extremity is kept elevated for 3 to 5 days, and the drains are removed in approximately 48 hours. After 4 to 5 days, depending on the amount of soft tissue swelling, a short arm thumb spica type plaster is applied. If Kirschner wire is used, a small window is made over the area of exit of the pin. The window may be covered with adhesive tape. In 2 to 3 weeks the wire is extracted, and a soft dressing is placed over the win dow. The plaster is worn for 6 weeks. When it is re moved, the patient is instructed to start a guarded range of motion including pinch and grasp activities. A small 2.5 to 5 em diameter dowel is a good exercise device; it can be grasped in the web space between the first and
HAND SURGERY
second metacarpals to improve abduction and build strength in the hand and forearm. Special considerations. Adduction contracture of the first metacarpal is an occasionally associated prob lem in arthritic disabilities of the basal joints of the thumb. If severe and untreated, it will unbalance the thumb and seriously affect the result of trapezial ar throplasties. If the angle of abduction between the first and second metacarpals does not reach at least 45°, the origin of the adductor pollicis muscle should be re leased from the third metacarpal through a separate palmar incision. 20 • 21 Once sufficient abduction has been achieved, proper seating of the implant on the scaphoid should be established. A Kirschner wire can be passed through the first and second metacarpals for temporary maintenance of abduction in severe cases. Hyperextension deformity of the MP joint contrib utes to the adduction tendency of the metacarpal and prevents proper abduction of the metacarpal and seating of the implant. This deformity should be corrected at the same time as the basal joint reconstruction. If the MP joint hyperextends less than 10°, no treatment other than application of a postoperative cast is necessary. This abducts only the metacarpal, not the proximal phalanx. If the MP joint hyperextends from 10° to 20°, it is pinned in 10° of flexion with an obliquely placed Kirschner wire for 4 to 6 weeks to help maintain the abduction of the metacarpal during the healing phase. If hyperextension of the MP joint is greater than 20o, with near normal flexion and good lateral stability of the joint, a palmar capsulodesis of the MP joint may be indicated to preserve available flexion and to restrict the hyperextension. Fusion of the MP joint to 10o of flex ion, 5° of abduction, and slight pronation should be done for hyperextension deformities with no available flexion, for lateral instability due to collateral ligament disruption, or for articular destruction. The distal interphalangeal joint may be involved in the arthritic process and, if unstable, may require fu sion. If there is a flexible hyperextension deformity of this joint with good lateral stability and articular sur faces, a flexor tendon hemitenodesis may be indicated. If there is articular destruction with reasonably good stability and motion, a condylar replacement or a small flexible hinged implant may be used to preserve a pain-free joint movement. A boutonniere deformity of the thumb is usually not associated with arthritis of the basal joints of the type that would require implant arthroplasty. However, when this situation does occur, fusion of the MP joint and release of the extensor pollicis longus at the distal joint may be indicated.
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Rheumatoid arthritic basal joints Many patients who have disabilities of the basal joints of the thumb due to rheumatoid arthritis have destructive changes of the contiguous carpal bones which make trapezium resection arthroplasty difficult. Frequently, the trapezium may be fused to the scaphoid, or the scaphoid may be absorbed or shifted ulnarly. In some of our early cases, the trapezium im plant was allowed to articulate with the distal radius, resulting in a satisfactory arthroplasty. More recently, a specially designed intramedullary stemmed convex condylar implant with a thinner head (similar to the single-stem great toe implant) has been used (Fig. 6). Instead of carrying out a trapeziectomy, a limited re section of the base of the metacarpal and concave shap ing of the distal surface of the trapezium is done. Enough bone must be removed to provide a joint space of 4 mm and radial abduction of the metacarpal to 45o. The implant stem fits in the intramedullary canal of the first metacarpal. A distally based slip of the abductor pollicis longus tendon is interwoven through the meta carpal, trapezium, and capsule to provide an excellent stabilizing effect. The usual attention must be given to correction of deformities of the distal joints. This nar row implant can maintain the joint space in these difficult cases, although, the usual range of motion that can be attained with the standard trapezium implant arthroplasty cannot be expected. A stable, pain-free, functioning thumb joint will be obtained if the recom mended surgical technique is followed.
Fig. 6A. Silicone convex condylar implant.
Table I. Distribution of 150 trapezium implant arthroplasty cases according to diagnosis, age, and sex Sex
Material and methods This is a review of 121 consecutive patients with 150 thumbs treated from 1965 to 1976 by flexible implant resection arthroplasty of the trapezium. The distribu tion of patients according to diagnosis, age, and sex is given in Table I. All patients were disabled by pain and loss of thumb motion. None had responded to conser vative therapy. Of the 150 operated thumbs, 60 were followed from 6 months to 2 years, 56 were followed from 2 to 5 years, and 34 were followed from 5 to 12 years. Over all average follow-up was 42 months. Results were evaluated in terms of pinch and grasp strength, stability and mobility of the thumb in activities of daily living, relief of pain, and restoration of abduction and op position. 22 Functional evaluation included assessment of pre hensile patterns and strength. Function of the thumb in the activities of daily living was assessed by observa tion and direct questioning of the patient, as was the relief of pain. Strength of grip and pinch was recorded
Diagnosis
No. of patients
Osteoarthritis
93
83
Rheumatoid arthritis Traumatic arthritis Systemic lupus ery thematosis
23
21
4
2
Total
121
Fematej Male
107
No. of thumbs
Average age
60
120 (27 bilateral) 2 25 (2 bilateral) 2 4
44
0
44
10
14
150
55
54
preoperatively and postoperatively for both hands of each patient, using a Jamar hydraulic dynamometer for the former and an electronic pinchmeter for the latter. Abduction was measured with a goniometer as the angle formed by the first and second metacarpals during maximum active radial abduction in the palmar plane. Opposition was measured as the greatest distance at
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Fig. 6. B to D. Arthroplasty of trapezia-metacarpal joint with convex condylar, single-stem silicone implant. B, Resection should include distal surface of trapezium and its articulating projection to second metacarpal base. Sufficient resection of base of metacarpal is carried out to provide adequate joint space. Stem of convex condylar implant is introduced into prepared intramedullary canal of first metacarpal. Implant head seats on prepared surface of trapezium. C, An 8 em slip of abductor pollicis longus tendon is prepared, and its insertion to radial aspect of metacarpal is preserved. Slip is then looped into intramedullary canal, and end of slip is extracted through 2 to 3 em hole in radiodorsal aspect of metacarpal. Similar hole is made in trapezium. End of slip is then drawn from inside of bone to outside. It can be noted when this slip is pulled up tight, this arrangement forces the metacarpal slightly ulnarward, providing an excellent check-rein to radial subluxation of base of metacarpal. Previously sized implant is inserted, and tendon slip is pulled tight. D, Remaining tendon slip is securely interwoven and secured to reinforce capsular closure. Distal end of slip is passed through or under insertion of abductor pollicis longus and sutured to radial capsular struc tures of trapezium.
which the distal flexion crease of the thumb could be actively held away from the palm in the plane perpen dicular to the palm and passing through the base of the long finger. A review of radiograms made from 6 months to 12 years after operation will be discussed.
Results We will describe our results to demonstrate the influence that changes in our surgical technique had on our results. The evaluation of strength, mobility, pre hensile patterns, performance of activities of daily liv ing and pain relief was done for all 150 trapezium im plant arthroplasties. However, the results relating to the stability of the arthroplasty and the positions of the implant over the scaphoid were chronologically sub divided according to the major modifications of our surgical technique. Strength. All patients showed improvement in strength of pinch and grasp postoperatively, with some approaching normal values. Meaningful data from these measurements, however, could only be deter mined for the patients with osteoarthritis, whose pre operative and postoperative strengths were compared.
In the patients with rheumatoid arthritis, there was often such severe involvement of other joints that the effect of the arthroplasty on the recorded strength could not be reasonably determined. An average of 3.4 pounds (1.5 kg) in pulp pinch strength, 3.9 pounds (1.8 kg) in key pinch strength, and 12.9 pounds (5.9 kg) in grip strength was gained after surgery in cases of os teoarthritis (Figs. 7 and 8). Range of motion. Patients who had lost some thumb motion because of pain or deformity gained a func tional range of movement postoperatively. Radial ab duction ranged from 30° to 90° postoperatively with an average of 50° in osteoarthritic patients, 47° in rheuma toid patients, and 69° in posttraumatic arthritic thumbs (Fig. 9). The postoperative opposition ranged from 4 to 9 em for an average of 5.9 em in osteoarthritic thumbs, 5.7 em in rheumatoid thumbs, and 7.7 em in posttrau matic cases (Fig. 10). The average opposition was ade quate for normal activities in all patients postoperatively; 80% of the activities of daily living could be per formed, with a thumb-palm opening of 4 em. Functional evaluation. Fifty-one consecutive pa tients were randomly selected, 39 with osteoarthritis
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and 12 with rheumatoid arthritis. Their entire preop erative and postoperative profiles were evaluated by a computer. The average follow-up time for this group was 28 months. Their ability to perform specific ac tivities of daily living was compared before and after operation (Fig. 11). Fifty-three percent of those who were unable to perform these activities became inde pendent in their performance postoperatively, and 25% of this group became capable of performing the same activities with assistance. Thus 78% of these patients were improved, and 22% showed no change in their performance. Of particular significance was their in creased ability to do the pick-up test without assistance, to tum door knobs, to open car doors, and to unscrew jar tops. Previously, these patients were unable to per form such vital routine activities. The patients with osteoarthritis gained greater functional improvement than those with rheumatoid arthritis; the latter disease affects more joints and can be progressive. Radiographic review. The condition of the bone adjacent to the implant and a classification of the ar ticulating position of the implant relative to the scaphoid bone was made on serial radiograms using standard anteroposterior, oblique, and lateral pro jections. In the stable positions, the implant was ar ticulating with adjacent bone. This position was defined as neutral when the implant was perfectly placed over the scaphoid bone (Fig. 12). Mild displacement indi cated that the implant had approximately one-third of its width not articulating on the scaphoid (Fig. 13). Moderate displacement indicated that two-thirds of the implant was off the scaphoid (Fig. 14). In some cases, articulation of the implant was over the distal end of the radius (Fig. 15). Unstable positions were noted as dis locations, indicating that the implant was not articulat ing with any bone (Fig. 16). Dislocations were divided into palmar, radial, and dorsal. The shape of the implant, the technique of capsulo ligamentous reinforcement, and the seating and main tenance of the implant position on the distal scaphoid facet in the early postoperative period are critical factors affecting the final implant position on the scaphoid as viewed on the radiograms. For this reason, radiographic results were divided into six groups (Table II). The initial convex head implant was used in the first 32 cases (group I). There were seven mild displace ments and one moderate (radial) displacement of the implant; there were three dislocations. A surgical revi sion to a neutral position was needed for two of the cases of radial dislocations. An asymptomatic case of palmar dislocation was not revised. A stable articula tion of the implant with the radial styloid was obtained
Trapezium implant arthroplasty
•
FEMALE
135
-MALE
uj ID ...J
Y PINC:H----' PINCH STRENGTH IN 120 OSTEOARTHRITIC THUMBS 109 FEMALES
11 MALES
Fig. 7. Preoperative and postoperative pinch strength for 120 trapezium implant arthroplasties in patients with osteoar thritis. Values are shown separately for men and women.
II
FEMALE
-MALE
ui ....
Ill
PRE·OP
POST·OP
GRIP STRENGTH IN 120 OSTEOARTHRITIC THUMBS 109 FEMALES
11 MALES
Fig. 8. Preoperative and postoperative grip strength for 120 osteoarthritic thumbs.
in two cases where severe absorption of the scaphoid bone was present. One patient had rheumatoid arthritis and the other severe erosive osteoarthritis. There were 118 thumbs reconstructed with the con cave head model implant; of these, 70 thumbs were reconstructed with No. 372 silicone elastomer, and 48 thumbs were reconstructed with the high-performance silicone elastomer. A slip of the abductor pollicis longus was used for reinforcement around the first 31 concave head model trapezium implants (group II). There were six mild (four radial, one palmar, and one dorsal) and two
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HAND SURGERY
0'
0'
RHEUMATOlD ARTHRITIS (25 THUMBS!
OSTEOARTHRITIS ( 120 THUMBS)
RADIAL ABDUCTION AVERAGES Fig. 9. Preoperative and postoperative average radial abduction.
7
IIPRE-OP
~
POST·OP
6
2 1 RHEUMATOID ARTHRITIS <25 THUMBS)
OSTEOARTH RITIS ( 120 THUMBS!
OPPOSITI ON AVERAGES
Fig. 10. Preoperative and postoperative average opposition.
%o moderate (radial) displaceme nts of the implants; in four rheumatoid thumbs, the implant articulated with the radial styloid. A slip of the flexor carpi radialis tendon was used for reconstruct ion around the next 18 trapezium implants (group III). There were one mild (palmar) and one moderate (palmar) displaceme nts of the implant, articu lation with the radial styloid in one thumb with severe erosive osteoarthri tis, and two dislocation s (one dorsal and one palmar); both dislocation s were revised to a neutral position. In the next 21 thumbs, a single or double slip of
UNCHANGED
IMPROVED
PATIENTS RATED UNABLE PRE-OP IN ADL
Fig. 11. Postoperative profile of performance of daily ac tivities in 51 randomly selected patients who were rated as unable to perform these same activities preoperatively. flexor carpi radialis tendon was used in conjuction with intermetaca rpal temporary wire fixation (group IV). There were two mild (radial) and one moderate (pal mar) implant displaceme nts, articulation with the radial styloid in one rheumatoid thumb, and one asympto matic palmar dislocation of the implant which did not require revision.
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Fig. 12. A, Preoperative radiogram showing subluxation of trapeziometacarpal joint and severe joint destruction in patient with osteoarthritis. Note osteophytic projection between first and second metacarpal and trapezoid shift. B, Five years following trapezium implant resection arthroplasty, this patient continues to have excellent position of implant and, clinically, has an essentially normal thumb. Note partial trapezoidectomy.
The group of 48 thumbs reconstructed with the high-performance silicone elastomer trapezium implant were analyzed in two separate groups. The first 18 cases were operated using a single or double slip of flexor carpi radialis around the implant and temporary intermetacarpal wire fixation (group V). There were two palmar subluxations of the implant; one remained asymptomatic, and the other was surgically revised to a neutral position. In one rheumatoid thumb, the implant formed a stable articulation with the radial styloid. In addition to the ligamentous slip reconstruction, a small Kirschner wire was inserted through the head of the implant into the trapezoid bone for temporary fixation in the last 30 thumbs analyzed in this series (group VI). There was only one case of mild displacement of the implant due to a prominent trapezoid bone and a narrow scaphoid facet. There were no incidences of disloca tion. This immobilization technique has been used in 47 other cases in our clinic since that time, with excel lent results obtained in 46 cases. One case presented a dorsal subluxation 1 year postoperatively because of inadequate capsule repair. Temporary fixation of the implant to the scaphoid facet with an absorbable suture is the method currently preferred. Excellent position of the implant was main
tained on a minimum of 6 months follow-up in 55 cases operated with this method. These cases were done sub sequent to the tabulation of the 150 cases reported here and are not included in these series. The most common indication for the trapezium im plant arthroplasty procedure is reconstruction of basal thumb joints affected by osteoarthritis, as seen in 120 of the 150 operated thumbs in this series (Table 1). However, this procedure was also done for 25 thumbs affected by rheumatoid arthritis. Of these, 10 were operated in our earlier series with the convex head im plant; 13 thumbs were reconstructed with the later con cave head model made of the original silicone elas tomer; and, in the last 3 years of our survey, only two thumbs affected by rheumatoid arthritis were recon structed with this method. The implant was allowed to articulate with the distal radius in seven cases of rheu matoid arthritis and in two cases of severe erosive os teoarthritis. This position of the implant did not seem to present a problem as the patients had good pain relief, range of motion, and stability. However, in cases pre senting severe erosive changes or displacement of the contiguous carpal bones, we now prefer to perform an arthroplasty of the trapeziometacarpal joint using a convex condylar implant as described earlier.
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Fig. 13. Mild displacement. One-third of trapezium implant width is not seated over scaphoid. These patients have good stable and mobile thumbs in spite of this radiographic finding. This can be obviated by meticulous attention to surgical technique, taking care to prepare good seating of scaphoid facet, including occasional trimming of some trapezoid bone, and securing capsuloligamentous reinforcement around im plant with adequate immobilization and temporary fixation.
Fig. 14. Moderate displacement. Two-thirds of trapezium implant surface is not articulating with scaphoid. Position of implant on this radiogram is not mechanically ideal. How ever, clinically, patient has good pain-free motion of thumb. Good stability is dependent on excellent encapsulation around implant.
The condition of the bone next to the implant was evaluated on radiograms taken from 6 months to 12 years after surgery. There was no incidence of bone absorption or unusual reactive bone formation except in two cases of palmar dislocation of the implant, present ing a progressive widening of the intramedullary canal. This bone response was explained by the fact that the thumb motion occurred around the stem of the implant rather than at the normal implant scaphoid location (Fig. 16). We have previously noted that the in tramedullary canal has a poor tolerance for excessive movement of an implant stem. There was some in crease in the erosive changes in the scaphoid bone on long-term radiologic follow-up in two patients origi nally presenting pantrapezial erosive osteoarthritis with
severe involvement of the trapezioscaphoid joint; how ever, this did not seem to affect the good clinical results. Complications. Symptomatic complications follow ing trapezium implant arthroplasty were noted as fol lows. (1) Sympathetic dystrophy developed in one pa tient; however, following stellate ganglion blocks and conservative treatment, all symptoms regressed within 3 months. (2) Neuritis along the distribution of the radial nerve damaged during surgery was noted in two patients; they complained of numbness over the scar and hyperesthesia when the skin was rubbed or touched over the area. (3) Fatigue pain at the basal joints of the thumb was present in two patients who had a moderate radial displacement of the implant.
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Dislocation of the implant remained asymptomatic clinically and did not require a revision procedure in three of the eight patients with this problem. These patients had a good range of motion, and their only apparent problem was a slight prominence at the base of the palm. Resorption of bone in the intramedullary canal around the implant stem was seen in two cases of nonrevised palmar dislocations as discussed above. There were no postoperative infections. One patient referred to us with a postoperative infection did well following removal of the implant, because the implant had acted as a good spacer for a resection arthroplasty, and an adequate capsule had formed around it. There was partial protrusion of the implant stem through the metacarpal shaft in two cases due to inadvertent perfo ration of the cortex during preparation of the in tramedullary canal. There were no subsequent changes due to this. There was one asymptomatic fracture of a small convex head implant in a patient with severe lupus erythematosis. There were no fractures in the concave style implants nor in the high performance implants although 30 of these were transfixed with a Kirschner wire. Discussion
The ad vantages of this implant design and method are well proven in the clinical and radiographic surveys of our cases. Almost all patients (147 of 150) have had a painfree, mobile, and functioning basal thumb joint reconstruction. The potential for instability of the im plant in its articulation with the scaphoid has been solved in our cases by consideration of these special details: (1) good implant articulation on the scaphoid facet, possibly requiring a partial removal of the trape zoid, (2) provision of a strong capsuloligamentous re construction, (3) maintainence of a perfect position of the implant during the important early capsular healing phase by temporary fixation either to the adjacent trap ezoid bone with a Kirschner wire, or, preferably, to the scaphoid facet with an absorbable suture. We have demonstrated in the long-term study of our various implants that permanent fixation of a silicone implant results in localization of forces which can cause a breakdown in either the implant or bony tissue. An example of this is the marked bone absorption that oc curs in the intramedullary canal when the head of the trapezium implant is fixed and the majority of move ment between implant and bone occurs in the in tramedullary canal. Our experiences with implant re placement of carpal bones have also demonstrated that great care must be taken to provide fixation of an im plant when a normal carpal bone is invaded. Aseptic
Fig. 15. Radial articulation. Radiogram illustrates radial ar ticulation of trapezium implant in case of severe erosive os teoarthritis. Except for small cosmetic deformity presenting as radial prominence, these patients have had stable, pain free, mobile thumbs.
necrosis and degeneration can occur if the blood supply is compromised. The silicone trapezium implant is softer than bone and, when it is properly positioned and stabilized by a firm capsuloligamentous reconstruction and temporary fixation, it will be well tolerated by the adjacent tissues. Movement of the implant occurs mainly at the articulation with the scaphoid. It is impor tant however, that some slight movement occur all around the implant to properly distribute the forces that occur with normal thumb use. Summary
Arthritis of the joints at the base of the thumb can be a painful and severely disabling condition, interfering with the normal functional activity of the hand. The
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Fig. 16. A, Palmar dislocation of implant due to unrepaired hole in capsule after trapeziectomy. Implant is anterior to carpus and is angled at body-stem junction. There is minimal movement of body of implant, with most movement occuring between stem and intramedullary canal. B, Bone absorption is noted, demonstrating phenomenon of poor tolerance of endosteal bone to this move ment pattern.
Table II. Radiographic position of implant in 150 thumbs classified according to implant style, capsuloligamentous reinforcement method, and implant fixation technique Implant model
APL
Procedure No. thumbs Displacement Mild Moderate Radial articulation Dislocation Revision of dislocation*
Concave silicone No. 372
Convex
32 8 7
2 3 2*
31 8 6 2 4 0 0
I
FCR
18 2
l
FCR and intermetacarpal wire
Intermetacarpal wire fixation
21 3
18
2
1
2 2*
Concave high-peiformance silicone
0
0 0 0 1
2 1*
l
Implant transjixation with wire 30 1
0 0 0 0
APL = Adductor pollicis long slip; FCR = flexor carpi radialis slip. *Indicates number that has been surgically revised. For example, under the column heading Convex, 2 of the 3 dislocations were surgically revised.
trapezium implant, which acts as a replacement for the removed pathologic bone, must have certain features if it is to be tolerated by the host tissue and be stable and durable. It must not be permanently fixed, because this will result in eventual breakdown of the fixation and the
tissue involved. The spacer must be accurately placed and be completely and securely encapsulated. The flexible material should be tear resistant, chemically inert, and biologically unaffected by the host. Implant resection arthroplasty of the trapezium, with
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careful correction of other associated deformities, has resulted in long-term, excellent functional and cosmetic results in this group of cases. A mobile, stable, pain free, durable arthroplasty resulted in 147 of 150 thumbs. Patients have been able to return to normal activities, including physically stressful work and sports. If certain technical considerations in the treat ment program are carefully adhered to, predictably good and reproducible results will be easily obtained.
REFERENCES 1. Swanson AB: Silicone rubber implants for replacement of arthritic or destroyed joints in the hand. Surg Clin North Am 48:1113-27, 1968 2. Burton R: Basal joint arthrosis of the thumb. Orthop Clin North Am 4:331-47, 1973 3. Eiken 0: Prosthetic replacement of the trapezium in sur gery of the hand. Scand J Plast Reconstr Surg 5:131, 1971 4. Haffajee D: One hundred cases of trapeziometacarpal joint arthrosis treated by silicone arthroplasty. (Mono graph) Lund, Sweden, Feb 1976 5. Lister GO, Kleinert HE, Kutz JE, Atasoy E: Arthritis of the trapezial articulations treated by prosthetic replace ment. Hand 9:117-29, 1977 6. Bennett EH: Fracture of the metacarpal bone of the thumb. Br Med J 12:2, 1886 7. Boyes JH: Bunnell's surgery of the hand, ed 5. Philadel phia, 1970, JB Lippincott Co 8. Nalebuff EA: Diagnosis, classification, and management of rheumatoid thumb deformities. Bull Hosp Joint Dis 29:119-37, 1968 9. Swanson, AB: Disabling arthritis of the base of the thumb. Treatment by resection of the trapezium and flexible (silicone) implant arthroplasty. J Bone Joint Surg [Am] 54:456-71, 1972 10. Cars tam N, Eiken 0, Andren L: Osteoarthritis in the trapezioscaphoid joint. Acta Orthop Scand 39:354-8, 1968
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11. Swanson AB: Flexible implant resection arthroplasty of the hand and extremities. St. Louis, 1973, The CV Mosby Co 12. Swanson AB: Disabilities of the thumb joints and their surgical treatment including flexible implant arthro plasty. Instructional Course Lectures, AAOS, St. Louis, The CV Mosby Co 12:89-104, 1973 13. Swanson AB: Flexible implant arthroplasty in the hand. Clin Plast Surg 3:141-57, 1976 14. Swanson AB, deGroot Swanson G: Thumb disabilities in rheumatoid arthritis: Classification and treatment. In Symposium on tendon surgery of the hand, AAOS, St. Louis, 1975, The CV Mosby Co, pp 233-54 15. Swanson AB, deGroot Swanson G: Disabling osteoar thritis in the hand and its treatment. In Symposium on osteoarthritis, St. Louis, 1976, The CV Mosby Co, pp 196-232 16. Swanson AB, deGroot Swanson G: Flexible implant re section arthroplasty: A method for reconstruction of small joints in the extremities. Instructional Course Lec tures, AAOS, St. Louis, The CV Mosby Co, 27:27-60, 1978 17. Swanson AB, Meester WD, deGroot Swanson G, Ran gaswamy L, Schut GED: Durability of silicone im plants-An in vivo study. Orthop Clin North Am 4: 1097-112, 1973 18. Swanson AB: Finger joint replacement by silicone rubber implants and the concept of implant fixation by encapsu lation. Ann Rheum Dis [Br] 28:47-55, 1969 19. Eaton RG, Littler JW: A study of the basal joint of the thumb, treatment of its disabilities by fusion. J Bone Joint Surg [Am] 51:661-8, 1969 20. Matev IB: Surgical treatment of the spastic "thumb-in palm" deformity. J Bone Joint Surg [Br] 45:703, 1963 21. Swanson AB: Surgery of the hand in cerebral palsy and muscle origin release procedures. Surg Clin North Am 48:1129-38, 1968 22. Swanson AB, Mays J, Yamauchi Y: A rheumatoid ar thritis evaluation record for the upper extremity. Surg Clin North Am 48:1003-13, 1968
A. B. Swanson, M.D., G. deGoot Swanson, M.D., and J. J. Watermeier, M.D., Grand Rapids, Mich.
An
arthroplasty method for treatment of arthritic disorders of the basal joints of the thumb consisting of a trapeziectomy and replacement with a silicone implant was first performed in 1965 by Swanson. 1 Since that time, this procedure has been used by many surgeons throughout the world in thousands of cases. 2 - 5 Long term review of the method has proven worthy, and it is the purpose of this review to describe a group of pa- · tients operated on in our clinic and relate the develop ment of the surgical technique to the results.
Disabilities of thumb basal joints Clinical course. Arthritic and posttraumatic dis abilities often interfere with normal thumb function, especially when the basal joints are involved. Pain and swelling at the base of the thumb are the most common early complaints. As the disease progresses, instability, crepitation, deformity, and loss of motion and strength are also noted. The condition most often occurs in postmenopausal women and is most commonly caused by osteoarthritis and rheumatoid arthritis; the disability may also be a sequel to Bennett's fracture, or it can develop as a result of fixed contractures around the base of the thumb after soft tissue injuries. The severity of the symptoms and deformity depends From the Departments of Orthopedic and Hand Surgery Training and Orthopedic Research, Blodgett and Butterworth Hospitals, Grand Rapids, Mich., and the Department of Surgery, Michigan State University. Presented at the meeting of the American Society for Surgery of the Hand, Las Vegas, Nevada, February 3, 1977. Received for publication Sept. 29, 1979; revised Sept. 8, 1980. Reprint requests: Alfred B. Swanson, M.D., Blodgett Professional Bldg., Ste. 290, 1900 Wealthy St., S.E., Grand Rapids, MI 49506.
on the degree of destructive changes that occur at the basal joints and the secondary imbalancing forces ap plied across the thumb ray. 7 • 8 The radially subluxating base of the first metacarpal produces a prominence which we call a "shoulder deformity." Arthritis at the base of the thumb may be the initiating cause of adduc tion contracture of the first metacarpal and associated collapse of the thumb into severe swan-neck deformity. It may also be associated with compression of the me dian nerve in the carpal tunnel; tendonitis of the flexor carpi radialis, abductor pollicis longus, and extensor pollicis brevis tendon; recurrent radial palmar degen erative ganglia; and arthritis of the finger joints. Radiographic findings. The radiograms of a series of 200 osteoarthritic thumbs of patients who were being considered for reconstructive surgery of the thumb basal joints were evaluated to demonstrate the inci dence of lesions found around the articulations of the trapezium. 9 Typical changes were noted in the osteoar thritic thumbs, including narrowing of the joint space, subchondral condensation of bone, osteophyte forma tion, and radial and proximal subluxation of the first metacarpal. This survey and that of others 10 showed that the trapezium was usually the center of a generalized or pantrapezial arthritic process as shown in Fig. 1. Rheumatoid patients may show a similar involve ment, localized at the basal joints; they may also ex hibit absorptive changes in the trapezium and metacar pal base and in other carpal bones, producing a result not unlike a resection arthroplasty.
Trapezium implant resection arthroplasty Design and development. The trapezium implant was developed by Swanson 1 in 1965 to help preserve the anatomic relationships of the thumb basal joints
0363-5023/81/020125+ 17$01.70/0 © 1981 American Society for Surgery of the Hand
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1st
METACARPAL
SCAPHOID
INCIDENCE OF OSTEOARTHRITIC CHANGES AROUND THE TRAPEZIUM Fig. 1. Diagram of incidence of osteoarthritic changes around
trapezium. Trapezium is center of generalized arthritic pro cess with most frequent involvement of trapezium-first meta carpal joint, and also of trapezio-scaphoid, trapezio-trape zoid, and trapezium second metacarpal joints. This suggests that total excision of trapezium will be necessary in most cases to eliminate all arthritic pain. after resection arthroplasty of the trapezium. 11 This im plant is maintained in proper alignment by a triangular intramedullary stem that fits into the first metacarpal and by capsuloligamentous reconstruction around the implant. Design of this implant was based on a study of cadaver bones and radiograms of normal hands. The original implant design had a convex head and was made of silicone rubber No. 372. The shape was then modified, giving it a slightly concave surface to provide a more stable fit on the rounded articular sur face of the scaphoid (Fig. 2). The silicone elastomer* *High Performance Silicone Elastomer, Dow Coming Corp., Mid land, MI.
The Journal of HAND SURGERY
was later improved to offer a 400% greater tear resis tance. Mechanical testing of the implant in the labora tory to 140 million compression and sheer stress movements without failure has demonstrated adequate durability of the implant. Evolution of surgical technique. Since the begin ning of the trapezium implant arthroplasty procedure, attempts have been made to make the surgical tech nique simple, dependable, predictable, and reproduc ible by other surgeons. A critical analysis of the results obtained has demonstrated the importance of a firm capsuloligamentous support around the implant and of adequate postoperative immobilization. Ligamentous reconstruction. In 1969, reinforce ment of the capsule around the implant with a slip of abductor pollicis longus tendon was initiated for pa tients who had inadequate capsular tissue; the con straining effect of this technique was not completely satisfactory. In 1971, in an effort to replace the support of the frequently inadequate anterior oblique ligament, a distally based slip of the flexor carpi radialis tendon, was used to reinforce the volar capsule and form an ulnar check ligament to hold the base of the first meta carpal to the base of the second metacarpal; the latter may be especially important for manual workers or for patients who present a subluxation of the trapeziometa carpal joint. A slip of the flexor carpi radialis tendon has been used for capsular reinforcement in all our cases since that time. In some cases, the abductor pol licis longus tendon was also used to reinforce the radial capsule. In one case of revision of a dorsal dislocation of the implant, a slip of the extensor carpi radialis lon gus tendon was used to successfully reinforce the dorsal capsular area. Postoperative immobilization. From the beginning, the importance of adequate abduction of the metacarpal to at least 45° and correction of an occasionally associ ated hyperextension deformity of the metacarpophalan geal (MP) joint was recognized. Release of the abduc tor pollicis muscle origin may be carried out to obtain sufficient abduction. However, the use of a scaphoid type cast alone did not always maintain the desired position of the first metacarpal, even when a Kirschner wire was used to immobilize the MP joint. In 1973, a temporary Kirschner wire fixation was placed between the first and second metacarpals. At first, the wire was placed through the distal portion of the metacarpals; however, because of an unfavorable lever placed on the metacarpal base, the wire was subsequently inserted more proximally. This was a good technique, but pre sented a hazard of inadvertent puncture of the radial artery in this area.
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Fig. 2. Intramedullary stemmed implant to improve results of excision arthroplasty of trapezium by acting as space-filler and preserving joint space relationships.
When the high-performance silicone elastomer im plant became available in 197 4, a temporary fixation wire could be placed through the implant into the trape zoid bone with less fear of tears resulting. Because of the potential problem from pin tract infection, which might occur following transcutaneous wire fixation, temporary fixation of the implant to the scaphoid facet with an absorbable suture is now preferred. The high-performance silicone elastomer has been tested for suture pull-out strength. If the needle passes through at least 5 mm of material, up to 30 pounds of force can be applied before the suture will pull out. A 0.045 inch Kirschner wire passed through the implant will hold up to 80 pounds of force before the silicone tears. The use of a suture or pin through the implant for temporary fixation is then feasible. We have selected a TR 5 needle with a No. 0 synthetic absorbable suture which has a breaking strength of 20 pounds and main tains its tensile strength for 3 weeks. It loses its holding strength at an average of 6 weeks, which coincides with the time of firm encapsulation and cast immobilization. When the patient starts movement, the suture will have been absorbed and will not interfere with the implant and the concept of circumferential encapsulation. Clinical advantages. Definite advantages are de rived from the trapezium implant arthroplasty method. The implant acts as a space filler to preserve the rela tionships of the basal joints of the thumb after resection of the trapezium. Meticulous and firm capsuloligamen tous reconstruction around the implant and correction of associated deformities of the thumb are possible and essential for a good result. 12 ~ 16 Biologically 17 and me chanically well tolerated, the implant is rapidly sur rounded by a fibrous supporting capsule which helps further preserve a normal joint space relationship. 18
Contrary to simple resection arthroplasty, trapezium implant arthroplasty helps maintain the important mo tion at the base of the thumb without loss of stability; it also obviates the disadvantages of rigidity and poor positioning which may follow fusion procedures. 19 Re lief of pain and crepitation are excellent, and a good strength of grip and pinch are preserved. Preservation of motion at the thumb basal joints allows stabilization or fusion of the distal joints in position of function. Indications. Trapezium implant resection arthro plasty is indicated when the following conditions are present, whether the disability is due to degenerative, posttraumatic (following an old Bennett's fracture, for example), or rheumatoid arthritis with localized bony changes: (1) localized pain and palpable crepitation during circumduction movements, with axial compres sion of the thumb ("grind test"), (2) loss of motion, with decrease of normal pinch and grip strength, (3) radiologic evidence of arthritic changes of the trapezio metacarpal, trapezioscaphoid, trapeziotrapezoid, and trapezium-second metacarpal joints, singly or in combi nation, (4) unstable, stiff, or painful distal joints of the thumb or swan-neck collapse deformity. We have described a "grind test" which may be useful in localizing the cause of the patient's complaint. To perform this test, the patient's thumb is held se curely in the examiner's right hand, and the base of the patient's thumb is held in the examiner's left thumb and index finger. If the test is positive, passive circumduc tion of the thumb while axial compression is applied will produce pain and palpable crepitation or subluxa tion at the carpometacarpal joint. We now prefer the use of the convex condylar im plant arthroplasty of the trapeziometacarpal joint for advanced cases of rheumatoid arthritis where there is
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EKtensor Pollieis Lonous Extensor PoUicis Brevis
-J.JW~~
Abductor Pcllicit LOnQUI --4~~~~-~~f:l
Fig. 3. A and B. A, Longitudinal incision parallel to extensor pollicis brevis has short transverse and palmarward arm to continue proximally parallel to flexor carpi radialis tendon. 8, Anatomic rela tionships of abductor pollicis longus, extensor pollicis brevis and extensor pollicis longus tendons, superficial radial nerve, vein, and artery at base of thumb. (From Swanson AB: J Bone Joint Surg [Am] 54:456, 1972, reprinted by permission.)
severe displacement, absorption, or fusion of the con tiguous carpal bones as discussed later. Surgical technique. Various incisions can be used. A transverse incision over the basal joints can provide reasonable exposure; however, the approach is facili tated with a longitudinal incision. A straight longitu dinal incision is not recommended; the incision should preferably be curved palmarward. A 7 to 8 em longitu dinal incision centered over the trapezium is started 2 em above the trapeziometacarpal joint parallel to the extensor pollicis brevis tendon; the incision is then di rected proximally and ulnarward to the distal wrist crease. To expose the flexor carpi radialis tendon at the wrist, it is curved palmarward and continued proxi mally for 3 to 4 em parallel to this tendon (Fig. 3, A). A 2.5 em bridge of skin can also be preserved at the distal wrist crease before running the incision proximally. The branches of the superficial radial nerve are care fully identified and mobilized in the proximal portion of the wound (Fig. 3, B). Small transverse veins may be ligated; however, longitudinal veins are spared. The retinaculum of the first dorsal compartment is incised longitudinally to expose the abductor pollicis longus and extensor pollicis brevis tendons. The dissection is carried down between these tendons to expose the ad ventitial tissue and fatty layer overlying the radial ar tery. This artery is carefully dissected from the underly
ing capsular tissues around the dorsal surface of the trapeziometacarpal joint and mobilized for proximal retraction. One or more small arterial branches going into the trapeziometacarpal joint are ligated. The artery can be retracted safely with a small rubber tube. The capsule over the scaphoid, trapezium, and base of the first metacarpal is incised longitudinally or in a ''T'' fashion, and the flaps are carefully incised off the un derlying bone to retain all capsular tissue. The trapezia scaphoid and trapeziometacarpal joints are identified and, with traction on the thumb, further free ing of the dorsal capsular attachments around the trapezium can be done. It is important to stay close to the bone during the dissection to avoid injury to the artery, underlying tendons, or capsule. The trapezium is removed, preferably by sectioning the bone into pieces with a small sharp osteotome which is directed distally towards the depths of the wound to avoid injuring the underlying flexor carpi radialis tendon and capsule. The bone is removed piecemeal with a rongeur, including the ulnar distal projection often seen between the first and second metacarpals. Traction on the thumb or distal retraction with a small two-prong rake retractor on the base of the metacarpal will facilitate the exposure. Frequently, small flecks of bone are left with the underlying capsule to preserve a good palmar capsuloligamentous support.
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Fig. 3. C and D. C, Proper exposure and retraction of radial artery over scaphoid bone essential for proper exposure. Adequate excision of trapezium bone including projection between first and second metacarpals is most important. When necessary, radial aspect of trapezoid bone is removed to improve fit of implant over scaphoid facet. D, Palmar carpal ligaments. Complete excision of carpal bones (trapezium, scaphoid, or lunate) may leave "holes" or defects in palmar carpal ligaments, because they firmly attach to carpal bones. Small shell of bone should be left on palmar capsule to preserve its continuity.
This is especially true on the radial palmar aspect of the trapezium where it attaches to the transverse carpal lig ament and to the underlying thenar musculature. Any osteophytes or irregularities on the distal end of the scaphoid or trapezoid can be trimmed. Care should be taken to selectively identify the trapezium bone to pre vent removing portions of adjacent bones. Frequently, there is a radial shift of the trapezoid that prevents adequate seating of the implant over the scaphoid facet. A portion of the radial aspect of the trapezoid should be removed to improve this fit (Fig. 3, C). The base of the metacarpal is brought up into the wound and squared off with a rongeur, leaving most of its cortical and subchondral bone intact. Any os teophytes, especially on its medial portion, should be removed. The intramedullary canal of the metacarpal should not be entered initially with the drill, but should be probed first with a thin broach or small curette to prevent inadvertent perforation through its sidewall and consequent extrusion of the implant stem through this defect. The preparation is completed using special burrs with a smooth leader point by developing a trian gular space just large enough to receive the implant stem easily. The proper sized implant should fit the trapeziectomy
space, with its collar seating properly on the metacarpal base and its base well over the distal scaphoid facet to allow full and stable circumduction of the thumb. Test implants are used to select the proper size from the five available sizes; implant sizes Nos. 2 and 3 are most commonly used. The wound must be thoroughly irri gated with saline to remove all debris before inserting the implant. At the end of the procedure it is important to secure the implant in place over the scaphoid by reconstruction of the preserved capsular ligamentous structures and by temporary fixation. Before inserting the implant, the palmar capsule and ligaments should be inspected in the depths of the wound for inadvertent tears or "holes" (Fig. 3, D). If present, these should be sutured so that there is firm supporting capsule on the palmar surface of the implant. If there are only mild destructive changes around the trapezium, the normal capsular struc tures will suffice to maintain the implant in position. The dorsal capsular structures are firmly sutured over the implant with a No. 3-0 Dacron suture, or other nonabsorbable material, using multiple interrupted su tures with inverted knots. The integrity of the proximal capsular reflection off the scaphoid is of outmost impor tance to secure the radial capsular repair. As the radial
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Fig. 3. E to G. E, Trapeziectomy and partial trapezoidectomy completed. Flexor carpi radialis (FCR) tendon slip dissected to its insertion on second metacarpal, passed under FCR tendon, and sutured to FCR tendon and palmar capsule to exit radially through abductor pollicis brevis muscle. F, Flexor carpi radialis slip passed anteriorly through abductor pollicis longus (APL) tendon and
lateral capsule. Sutures passed through capsular reflections off scaphoid bone to secure capsular closure. G, After implant insertion and temporary fixation are completed, capsule is sutured. FCR slip is brought over and through radial capsule and over implant to exit through ulnar capsule. Slip is then pulled, folded over and across dorsal capsule, and sutured in position.
artery is retracted proximally, three No. 3-0 Dacron sutures are usually placed through this capsular reflection and if necessary, through I mm drill holes made in the edge of the scaphoid bone. Ligamentous reinforcement. If the capsular struc tures are inadequate on either the palmar or dorsal areas, particularly if the original condition has been associated with a subluxation of the trapeziometacarpal joint, a ligamentous reconstruction using a slip from the abductor pollicis longus, extensor carpi radialis longus, or (preferably) the flexor carpi radialis tendon is indicated. The flexor carpi radialis tendon is exposed at the wrist, its radial half is incised, and a 7 to 8 em slip is dissected distally to the fibro-osseous canal. The tendon slip is pulled up into the site of the trapeziectomy and further dissected to its insertion on the second metacar pal which is carefully preserved. Great care should be taken to avoid transverse lacerations of the tendon slip. A small hemostat is passed through the abductor pol lids brevis muscle to pull the tendon slip under the residual portion of the flexor carpi radialis tendon and then through the abductor pollicis brevis muscle (Fig. 3, E). The slip is brought anteriorly through the abduc
tor pollicis longus tendon and the lateral portion of the capsular tissues (Fig. 3, F). It is important that the slip not be pulled too tightly, as it may have a tendency to lift the implant from the floor of the wound; this can be prevented by placing the tendon slip under the flexor carpi radialis tendon and suturing it to this tendon and the palmar capsule. Three No. 3-0 Dacron sutures should be placed as described through the capsular reflection off the scaphoid bone to secure the closure of the radial capsule. The implant is placed in the meta carpal with a no-touch technique and temporarily fixed in position as will be described later. The remaining portion of the tendon slip is then brought over and through the radial capsule, over the implant, to exit through the ulnar capsule. The tendon slip may also be passed through the distal portion of the extensor carpi radialis longus tendon avoiding the overlying radial ar tery. It is then pulled out and folded over and across the dorsal capsular repair and sutured in position (Fig. 3, G). The longitudinal capsular incision is repaired. This ligamentous repair provides a firm capsular reinforce ment on the palmar, ulnar, and radial sides. The first dorsal compartment may be loosely closed over the abductor pollicis longus and extensor pollicis
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Fig. 4. Method of temporary fixation of trapezium implant using No. 0 synthetic absorbable suture on TR-5 needle. A, Radial artery is retracted; curved needle is passed under and around waist of scaphoid and picked up distally in depths of wound. Suture is then passed through insertion of the flexor carpi radialis tendon on base of second metacarpal to prevent slipping of suture. Needle is straightened for passage through implant from middle of its concave facet to run out distally, adjacent to stem. B, Implant stem is placed in intramedullary canal of first metacarpal and reduced in proper position, suture is tied securely with multiple surgical knots.
brevis tendons. Dorsal bowstringing of the extensor pollicis brevis tendon could result in an increased mo ment arm and produce hyperextension of the MP joint of the thumb; however, increasing the moment arm of the abductor pollicis longus tendon can improve thumb abduction and can be accomplished by advancing its distal insertion on the metacarpal. Temporary fixation of the implant. The use of temporary fixation to further stabilize the position of the implant during the early healing phase has been an important technical advancement in this method. This can be achieved with an absorbable suture through the implant and/ or with a small Kirschner wire. The implant may be secured to the scaphoid with a No. 0 synthetic absorbable suture on a TR-5 needle. The radial artery must be retracted to expose the area of the dorsal radial portions of the scaphoid. The curved needle is passed under and around the waist of the scaphoid and picked up distally in the depths of the wound. The needle may then also be passed through the insertion of the flexor carpi radialis tendon on the base of the second metacarpal to prevent slipping of the suture. The needle may then be straightened further with two needle holders to run through the trapezium implant from the middle of its concave surface exiting distally adjacent to the stem. Alternatively, it may be passed transversely through the body of the implant (Fig. 4). The implant stem is placed in the in tramedullary canal of the first metacarpal, the implant
is reduced in position, and the suture is securely tied with the multiple surgical knots (Fig. 4). The implant must seat securely on the scaphoid facet. The appro priate capsular closure, with or without tendon rein forcement, is carried out after the implant is positioned. An alternate method for temporary fixation is to pin the implant in position over the scaphoid bone by run ning a 0.045 inch Kirschner wire under direct vision through the long abductor tendon and the capsule, transversely through the head of the implant, and into the trapezoid bone (Fig. 5). On closure, the tip of the wire should perforate the skin approximately I em from the edge of the wound. This should be accomplished without tension, taking care to avoid branches of the superficial radial nerve which must not lie over the tendon edges or directly underneath the wound. The tip of the wire is left protruding 1.5 em from the skin. Closure and postoperative care. The wound is closed in layers, using No. 6-0 Dexon sutures for the subcutaneous tissues. To avoid adhesions, the branches of the superficial radial nerve are carefully rerouted away from the skin closure. This is done during the subcutaneous closure by transferring this nerve slightly dorsally or palmarly away from the line of skin closure with No. 6-0 Dexon sutures. The skin is closed with No. 5-0 nylon sutures, and small silicone rubber drains are inserted subcutaneously. A secure dressing, includ ing an anterior and posterior plaster splint, is then applied. It is possible to apply a full plaster dressing,
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Fig. 5. Trapezium implant temporarily fixed in position with 0.045 inch Kirschner wires into trapezoid bone. Pin was left protruding I em from skin and window made in cast over pin-exit site. Pin was removed after 3 weeks. Note partial trapezoidectomy and excellent fit over distal scaphoid facet.
but it should be bivalved and the extremity elevated because of the potential postoperative swelling. If the tourniquet is left on for more than 90 minutes, a stellate ganglion block is usually given unless previously con traindicated. The extremity is kept elevated for 3 to 5 days, and the drains are removed in approximately 48 hours. After 4 to 5 days, depending on the amount of soft tissue swelling, a short arm thumb spica type plaster is applied. If Kirschner wire is used, a small window is made over the area of exit of the pin. The window may be covered with adhesive tape. In 2 to 3 weeks the wire is extracted, and a soft dressing is placed over the win dow. The plaster is worn for 6 weeks. When it is re moved, the patient is instructed to start a guarded range of motion including pinch and grasp activities. A small 2.5 to 5 em diameter dowel is a good exercise device; it can be grasped in the web space between the first and
HAND SURGERY
second metacarpals to improve abduction and build strength in the hand and forearm. Special considerations. Adduction contracture of the first metacarpal is an occasionally associated prob lem in arthritic disabilities of the basal joints of the thumb. If severe and untreated, it will unbalance the thumb and seriously affect the result of trapezial ar throplasties. If the angle of abduction between the first and second metacarpals does not reach at least 45°, the origin of the adductor pollicis muscle should be re leased from the third metacarpal through a separate palmar incision. 20 • 21 Once sufficient abduction has been achieved, proper seating of the implant on the scaphoid should be established. A Kirschner wire can be passed through the first and second metacarpals for temporary maintenance of abduction in severe cases. Hyperextension deformity of the MP joint contrib utes to the adduction tendency of the metacarpal and prevents proper abduction of the metacarpal and seating of the implant. This deformity should be corrected at the same time as the basal joint reconstruction. If the MP joint hyperextends less than 10°, no treatment other than application of a postoperative cast is necessary. This abducts only the metacarpal, not the proximal phalanx. If the MP joint hyperextends from 10° to 20°, it is pinned in 10° of flexion with an obliquely placed Kirschner wire for 4 to 6 weeks to help maintain the abduction of the metacarpal during the healing phase. If hyperextension of the MP joint is greater than 20o, with near normal flexion and good lateral stability of the joint, a palmar capsulodesis of the MP joint may be indicated to preserve available flexion and to restrict the hyperextension. Fusion of the MP joint to 10o of flex ion, 5° of abduction, and slight pronation should be done for hyperextension deformities with no available flexion, for lateral instability due to collateral ligament disruption, or for articular destruction. The distal interphalangeal joint may be involved in the arthritic process and, if unstable, may require fu sion. If there is a flexible hyperextension deformity of this joint with good lateral stability and articular sur faces, a flexor tendon hemitenodesis may be indicated. If there is articular destruction with reasonably good stability and motion, a condylar replacement or a small flexible hinged implant may be used to preserve a pain-free joint movement. A boutonniere deformity of the thumb is usually not associated with arthritis of the basal joints of the type that would require implant arthroplasty. However, when this situation does occur, fusion of the MP joint and release of the extensor pollicis longus at the distal joint may be indicated.
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Rheumatoid arthritic basal joints Many patients who have disabilities of the basal joints of the thumb due to rheumatoid arthritis have destructive changes of the contiguous carpal bones which make trapezium resection arthroplasty difficult. Frequently, the trapezium may be fused to the scaphoid, or the scaphoid may be absorbed or shifted ulnarly. In some of our early cases, the trapezium im plant was allowed to articulate with the distal radius, resulting in a satisfactory arthroplasty. More recently, a specially designed intramedullary stemmed convex condylar implant with a thinner head (similar to the single-stem great toe implant) has been used (Fig. 6). Instead of carrying out a trapeziectomy, a limited re section of the base of the metacarpal and concave shap ing of the distal surface of the trapezium is done. Enough bone must be removed to provide a joint space of 4 mm and radial abduction of the metacarpal to 45o. The implant stem fits in the intramedullary canal of the first metacarpal. A distally based slip of the abductor pollicis longus tendon is interwoven through the meta carpal, trapezium, and capsule to provide an excellent stabilizing effect. The usual attention must be given to correction of deformities of the distal joints. This nar row implant can maintain the joint space in these difficult cases, although, the usual range of motion that can be attained with the standard trapezium implant arthroplasty cannot be expected. A stable, pain-free, functioning thumb joint will be obtained if the recom mended surgical technique is followed.
Fig. 6A. Silicone convex condylar implant.
Table I. Distribution of 150 trapezium implant arthroplasty cases according to diagnosis, age, and sex Sex
Material and methods This is a review of 121 consecutive patients with 150 thumbs treated from 1965 to 1976 by flexible implant resection arthroplasty of the trapezium. The distribu tion of patients according to diagnosis, age, and sex is given in Table I. All patients were disabled by pain and loss of thumb motion. None had responded to conser vative therapy. Of the 150 operated thumbs, 60 were followed from 6 months to 2 years, 56 were followed from 2 to 5 years, and 34 were followed from 5 to 12 years. Over all average follow-up was 42 months. Results were evaluated in terms of pinch and grasp strength, stability and mobility of the thumb in activities of daily living, relief of pain, and restoration of abduction and op position. 22 Functional evaluation included assessment of pre hensile patterns and strength. Function of the thumb in the activities of daily living was assessed by observa tion and direct questioning of the patient, as was the relief of pain. Strength of grip and pinch was recorded
Diagnosis
No. of patients
Osteoarthritis
93
83
Rheumatoid arthritis Traumatic arthritis Systemic lupus ery thematosis
23
21
4
2
Total
121
Fematej Male
107
No. of thumbs
Average age
60
120 (27 bilateral) 2 25 (2 bilateral) 2 4
44
0
44
10
14
150
55
54
preoperatively and postoperatively for both hands of each patient, using a Jamar hydraulic dynamometer for the former and an electronic pinchmeter for the latter. Abduction was measured with a goniometer as the angle formed by the first and second metacarpals during maximum active radial abduction in the palmar plane. Opposition was measured as the greatest distance at
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Fig. 6. B to D. Arthroplasty of trapezia-metacarpal joint with convex condylar, single-stem silicone implant. B, Resection should include distal surface of trapezium and its articulating projection to second metacarpal base. Sufficient resection of base of metacarpal is carried out to provide adequate joint space. Stem of convex condylar implant is introduced into prepared intramedullary canal of first metacarpal. Implant head seats on prepared surface of trapezium. C, An 8 em slip of abductor pollicis longus tendon is prepared, and its insertion to radial aspect of metacarpal is preserved. Slip is then looped into intramedullary canal, and end of slip is extracted through 2 to 3 em hole in radiodorsal aspect of metacarpal. Similar hole is made in trapezium. End of slip is then drawn from inside of bone to outside. It can be noted when this slip is pulled up tight, this arrangement forces the metacarpal slightly ulnarward, providing an excellent check-rein to radial subluxation of base of metacarpal. Previously sized implant is inserted, and tendon slip is pulled tight. D, Remaining tendon slip is securely interwoven and secured to reinforce capsular closure. Distal end of slip is passed through or under insertion of abductor pollicis longus and sutured to radial capsular struc tures of trapezium.
which the distal flexion crease of the thumb could be actively held away from the palm in the plane perpen dicular to the palm and passing through the base of the long finger. A review of radiograms made from 6 months to 12 years after operation will be discussed.
Results We will describe our results to demonstrate the influence that changes in our surgical technique had on our results. The evaluation of strength, mobility, pre hensile patterns, performance of activities of daily liv ing and pain relief was done for all 150 trapezium im plant arthroplasties. However, the results relating to the stability of the arthroplasty and the positions of the implant over the scaphoid were chronologically sub divided according to the major modifications of our surgical technique. Strength. All patients showed improvement in strength of pinch and grasp postoperatively, with some approaching normal values. Meaningful data from these measurements, however, could only be deter mined for the patients with osteoarthritis, whose pre operative and postoperative strengths were compared.
In the patients with rheumatoid arthritis, there was often such severe involvement of other joints that the effect of the arthroplasty on the recorded strength could not be reasonably determined. An average of 3.4 pounds (1.5 kg) in pulp pinch strength, 3.9 pounds (1.8 kg) in key pinch strength, and 12.9 pounds (5.9 kg) in grip strength was gained after surgery in cases of os teoarthritis (Figs. 7 and 8). Range of motion. Patients who had lost some thumb motion because of pain or deformity gained a func tional range of movement postoperatively. Radial ab duction ranged from 30° to 90° postoperatively with an average of 50° in osteoarthritic patients, 47° in rheuma toid patients, and 69° in posttraumatic arthritic thumbs (Fig. 9). The postoperative opposition ranged from 4 to 9 em for an average of 5.9 em in osteoarthritic thumbs, 5.7 em in rheumatoid thumbs, and 7.7 em in posttrau matic cases (Fig. 10). The average opposition was ade quate for normal activities in all patients postoperatively; 80% of the activities of daily living could be per formed, with a thumb-palm opening of 4 em. Functional evaluation. Fifty-one consecutive pa tients were randomly selected, 39 with osteoarthritis
Vol. 6, No. 2 March 1981
and 12 with rheumatoid arthritis. Their entire preop erative and postoperative profiles were evaluated by a computer. The average follow-up time for this group was 28 months. Their ability to perform specific ac tivities of daily living was compared before and after operation (Fig. 11). Fifty-three percent of those who were unable to perform these activities became inde pendent in their performance postoperatively, and 25% of this group became capable of performing the same activities with assistance. Thus 78% of these patients were improved, and 22% showed no change in their performance. Of particular significance was their in creased ability to do the pick-up test without assistance, to tum door knobs, to open car doors, and to unscrew jar tops. Previously, these patients were unable to per form such vital routine activities. The patients with osteoarthritis gained greater functional improvement than those with rheumatoid arthritis; the latter disease affects more joints and can be progressive. Radiographic review. The condition of the bone adjacent to the implant and a classification of the ar ticulating position of the implant relative to the scaphoid bone was made on serial radiograms using standard anteroposterior, oblique, and lateral pro jections. In the stable positions, the implant was ar ticulating with adjacent bone. This position was defined as neutral when the implant was perfectly placed over the scaphoid bone (Fig. 12). Mild displacement indi cated that the implant had approximately one-third of its width not articulating on the scaphoid (Fig. 13). Moderate displacement indicated that two-thirds of the implant was off the scaphoid (Fig. 14). In some cases, articulation of the implant was over the distal end of the radius (Fig. 15). Unstable positions were noted as dis locations, indicating that the implant was not articulat ing with any bone (Fig. 16). Dislocations were divided into palmar, radial, and dorsal. The shape of the implant, the technique of capsulo ligamentous reinforcement, and the seating and main tenance of the implant position on the distal scaphoid facet in the early postoperative period are critical factors affecting the final implant position on the scaphoid as viewed on the radiograms. For this reason, radiographic results were divided into six groups (Table II). The initial convex head implant was used in the first 32 cases (group I). There were seven mild displace ments and one moderate (radial) displacement of the implant; there were three dislocations. A surgical revi sion to a neutral position was needed for two of the cases of radial dislocations. An asymptomatic case of palmar dislocation was not revised. A stable articula tion of the implant with the radial styloid was obtained
Trapezium implant arthroplasty
•
FEMALE
135
-MALE
uj ID ...J
Y PINC:H----' PINCH STRENGTH IN 120 OSTEOARTHRITIC THUMBS 109 FEMALES
11 MALES
Fig. 7. Preoperative and postoperative pinch strength for 120 trapezium implant arthroplasties in patients with osteoar thritis. Values are shown separately for men and women.
II
FEMALE
-MALE
ui ....
Ill
PRE·OP
POST·OP
GRIP STRENGTH IN 120 OSTEOARTHRITIC THUMBS 109 FEMALES
11 MALES
Fig. 8. Preoperative and postoperative grip strength for 120 osteoarthritic thumbs.
in two cases where severe absorption of the scaphoid bone was present. One patient had rheumatoid arthritis and the other severe erosive osteoarthritis. There were 118 thumbs reconstructed with the con cave head model implant; of these, 70 thumbs were reconstructed with No. 372 silicone elastomer, and 48 thumbs were reconstructed with the high-performance silicone elastomer. A slip of the abductor pollicis longus was used for reinforcement around the first 31 concave head model trapezium implants (group II). There were six mild (four radial, one palmar, and one dorsal) and two
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HAND SURGERY
0'
0'
RHEUMATOlD ARTHRITIS (25 THUMBS!
OSTEOARTHRITIS ( 120 THUMBS)
RADIAL ABDUCTION AVERAGES Fig. 9. Preoperative and postoperative average radial abduction.
7
IIPRE-OP
~
POST·OP
6
2 1 RHEUMATOID ARTHRITIS <25 THUMBS)
OSTEOARTH RITIS ( 120 THUMBS!
OPPOSITI ON AVERAGES
Fig. 10. Preoperative and postoperative average opposition.
%o moderate (radial) displaceme nts of the implants; in four rheumatoid thumbs, the implant articulated with the radial styloid. A slip of the flexor carpi radialis tendon was used for reconstruct ion around the next 18 trapezium implants (group III). There were one mild (palmar) and one moderate (palmar) displaceme nts of the implant, articu lation with the radial styloid in one thumb with severe erosive osteoarthri tis, and two dislocation s (one dorsal and one palmar); both dislocation s were revised to a neutral position. In the next 21 thumbs, a single or double slip of
UNCHANGED
IMPROVED
PATIENTS RATED UNABLE PRE-OP IN ADL
Fig. 11. Postoperative profile of performance of daily ac tivities in 51 randomly selected patients who were rated as unable to perform these same activities preoperatively. flexor carpi radialis tendon was used in conjuction with intermetaca rpal temporary wire fixation (group IV). There were two mild (radial) and one moderate (pal mar) implant displaceme nts, articulation with the radial styloid in one rheumatoid thumb, and one asympto matic palmar dislocation of the implant which did not require revision.
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Fig. 12. A, Preoperative radiogram showing subluxation of trapeziometacarpal joint and severe joint destruction in patient with osteoarthritis. Note osteophytic projection between first and second metacarpal and trapezoid shift. B, Five years following trapezium implant resection arthroplasty, this patient continues to have excellent position of implant and, clinically, has an essentially normal thumb. Note partial trapezoidectomy.
The group of 48 thumbs reconstructed with the high-performance silicone elastomer trapezium implant were analyzed in two separate groups. The first 18 cases were operated using a single or double slip of flexor carpi radialis around the implant and temporary intermetacarpal wire fixation (group V). There were two palmar subluxations of the implant; one remained asymptomatic, and the other was surgically revised to a neutral position. In one rheumatoid thumb, the implant formed a stable articulation with the radial styloid. In addition to the ligamentous slip reconstruction, a small Kirschner wire was inserted through the head of the implant into the trapezoid bone for temporary fixation in the last 30 thumbs analyzed in this series (group VI). There was only one case of mild displacement of the implant due to a prominent trapezoid bone and a narrow scaphoid facet. There were no incidences of disloca tion. This immobilization technique has been used in 47 other cases in our clinic since that time, with excel lent results obtained in 46 cases. One case presented a dorsal subluxation 1 year postoperatively because of inadequate capsule repair. Temporary fixation of the implant to the scaphoid facet with an absorbable suture is the method currently preferred. Excellent position of the implant was main
tained on a minimum of 6 months follow-up in 55 cases operated with this method. These cases were done sub sequent to the tabulation of the 150 cases reported here and are not included in these series. The most common indication for the trapezium im plant arthroplasty procedure is reconstruction of basal thumb joints affected by osteoarthritis, as seen in 120 of the 150 operated thumbs in this series (Table 1). However, this procedure was also done for 25 thumbs affected by rheumatoid arthritis. Of these, 10 were operated in our earlier series with the convex head im plant; 13 thumbs were reconstructed with the later con cave head model made of the original silicone elas tomer; and, in the last 3 years of our survey, only two thumbs affected by rheumatoid arthritis were recon structed with this method. The implant was allowed to articulate with the distal radius in seven cases of rheu matoid arthritis and in two cases of severe erosive os teoarthritis. This position of the implant did not seem to present a problem as the patients had good pain relief, range of motion, and stability. However, in cases pre senting severe erosive changes or displacement of the contiguous carpal bones, we now prefer to perform an arthroplasty of the trapeziometacarpal joint using a convex condylar implant as described earlier.
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Fig. 13. Mild displacement. One-third of trapezium implant width is not seated over scaphoid. These patients have good stable and mobile thumbs in spite of this radiographic finding. This can be obviated by meticulous attention to surgical technique, taking care to prepare good seating of scaphoid facet, including occasional trimming of some trapezoid bone, and securing capsuloligamentous reinforcement around im plant with adequate immobilization and temporary fixation.
Fig. 14. Moderate displacement. Two-thirds of trapezium implant surface is not articulating with scaphoid. Position of implant on this radiogram is not mechanically ideal. How ever, clinically, patient has good pain-free motion of thumb. Good stability is dependent on excellent encapsulation around implant.
The condition of the bone next to the implant was evaluated on radiograms taken from 6 months to 12 years after surgery. There was no incidence of bone absorption or unusual reactive bone formation except in two cases of palmar dislocation of the implant, present ing a progressive widening of the intramedullary canal. This bone response was explained by the fact that the thumb motion occurred around the stem of the implant rather than at the normal implant scaphoid location (Fig. 16). We have previously noted that the in tramedullary canal has a poor tolerance for excessive movement of an implant stem. There was some in crease in the erosive changes in the scaphoid bone on long-term radiologic follow-up in two patients origi nally presenting pantrapezial erosive osteoarthritis with
severe involvement of the trapezioscaphoid joint; how ever, this did not seem to affect the good clinical results. Complications. Symptomatic complications follow ing trapezium implant arthroplasty were noted as fol lows. (1) Sympathetic dystrophy developed in one pa tient; however, following stellate ganglion blocks and conservative treatment, all symptoms regressed within 3 months. (2) Neuritis along the distribution of the radial nerve damaged during surgery was noted in two patients; they complained of numbness over the scar and hyperesthesia when the skin was rubbed or touched over the area. (3) Fatigue pain at the basal joints of the thumb was present in two patients who had a moderate radial displacement of the implant.
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Dislocation of the implant remained asymptomatic clinically and did not require a revision procedure in three of the eight patients with this problem. These patients had a good range of motion, and their only apparent problem was a slight prominence at the base of the palm. Resorption of bone in the intramedullary canal around the implant stem was seen in two cases of nonrevised palmar dislocations as discussed above. There were no postoperative infections. One patient referred to us with a postoperative infection did well following removal of the implant, because the implant had acted as a good spacer for a resection arthroplasty, and an adequate capsule had formed around it. There was partial protrusion of the implant stem through the metacarpal shaft in two cases due to inadvertent perfo ration of the cortex during preparation of the in tramedullary canal. There were no subsequent changes due to this. There was one asymptomatic fracture of a small convex head implant in a patient with severe lupus erythematosis. There were no fractures in the concave style implants nor in the high performance implants although 30 of these were transfixed with a Kirschner wire. Discussion
The ad vantages of this implant design and method are well proven in the clinical and radiographic surveys of our cases. Almost all patients (147 of 150) have had a painfree, mobile, and functioning basal thumb joint reconstruction. The potential for instability of the im plant in its articulation with the scaphoid has been solved in our cases by consideration of these special details: (1) good implant articulation on the scaphoid facet, possibly requiring a partial removal of the trape zoid, (2) provision of a strong capsuloligamentous re construction, (3) maintainence of a perfect position of the implant during the important early capsular healing phase by temporary fixation either to the adjacent trap ezoid bone with a Kirschner wire, or, preferably, to the scaphoid facet with an absorbable suture. We have demonstrated in the long-term study of our various implants that permanent fixation of a silicone implant results in localization of forces which can cause a breakdown in either the implant or bony tissue. An example of this is the marked bone absorption that oc curs in the intramedullary canal when the head of the trapezium implant is fixed and the majority of move ment between implant and bone occurs in the in tramedullary canal. Our experiences with implant re placement of carpal bones have also demonstrated that great care must be taken to provide fixation of an im plant when a normal carpal bone is invaded. Aseptic
Fig. 15. Radial articulation. Radiogram illustrates radial ar ticulation of trapezium implant in case of severe erosive os teoarthritis. Except for small cosmetic deformity presenting as radial prominence, these patients have had stable, pain free, mobile thumbs.
necrosis and degeneration can occur if the blood supply is compromised. The silicone trapezium implant is softer than bone and, when it is properly positioned and stabilized by a firm capsuloligamentous reconstruction and temporary fixation, it will be well tolerated by the adjacent tissues. Movement of the implant occurs mainly at the articulation with the scaphoid. It is impor tant however, that some slight movement occur all around the implant to properly distribute the forces that occur with normal thumb use. Summary
Arthritis of the joints at the base of the thumb can be a painful and severely disabling condition, interfering with the normal functional activity of the hand. The
140
The Journal of HAND SURGERY
Swanson, deGoot Swanson, and Watermeier
Fig. 16. A, Palmar dislocation of implant due to unrepaired hole in capsule after trapeziectomy. Implant is anterior to carpus and is angled at body-stem junction. There is minimal movement of body of implant, with most movement occuring between stem and intramedullary canal. B, Bone absorption is noted, demonstrating phenomenon of poor tolerance of endosteal bone to this move ment pattern.
Table II. Radiographic position of implant in 150 thumbs classified according to implant style, capsuloligamentous reinforcement method, and implant fixation technique Implant model
APL
Procedure No. thumbs Displacement Mild Moderate Radial articulation Dislocation Revision of dislocation*
Concave silicone No. 372
Convex
32 8 7
2 3 2*
31 8 6 2 4 0 0
I
FCR
18 2
l
FCR and intermetacarpal wire
Intermetacarpal wire fixation
21 3
18
2
1
2 2*
Concave high-peiformance silicone
0
0 0 0 1
2 1*
l
Implant transjixation with wire 30 1
0 0 0 0
APL = Adductor pollicis long slip; FCR = flexor carpi radialis slip. *Indicates number that has been surgically revised. For example, under the column heading Convex, 2 of the 3 dislocations were surgically revised.
trapezium implant, which acts as a replacement for the removed pathologic bone, must have certain features if it is to be tolerated by the host tissue and be stable and durable. It must not be permanently fixed, because this will result in eventual breakdown of the fixation and the
tissue involved. The spacer must be accurately placed and be completely and securely encapsulated. The flexible material should be tear resistant, chemically inert, and biologically unaffected by the host. Implant resection arthroplasty of the trapezium, with
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careful correction of other associated deformities, has resulted in long-term, excellent functional and cosmetic results in this group of cases. A mobile, stable, pain free, durable arthroplasty resulted in 147 of 150 thumbs. Patients have been able to return to normal activities, including physically stressful work and sports. If certain technical considerations in the treat ment program are carefully adhered to, predictably good and reproducible results will be easily obtained.
REFERENCES 1. Swanson AB: Silicone rubber implants for replacement of arthritic or destroyed joints in the hand. Surg Clin North Am 48:1113-27, 1968 2. Burton R: Basal joint arthrosis of the thumb. Orthop Clin North Am 4:331-47, 1973 3. Eiken 0: Prosthetic replacement of the trapezium in sur gery of the hand. Scand J Plast Reconstr Surg 5:131, 1971 4. Haffajee D: One hundred cases of trapeziometacarpal joint arthrosis treated by silicone arthroplasty. (Mono graph) Lund, Sweden, Feb 1976 5. Lister GO, Kleinert HE, Kutz JE, Atasoy E: Arthritis of the trapezial articulations treated by prosthetic replace ment. Hand 9:117-29, 1977 6. Bennett EH: Fracture of the metacarpal bone of the thumb. Br Med J 12:2, 1886 7. Boyes JH: Bunnell's surgery of the hand, ed 5. Philadel phia, 1970, JB Lippincott Co 8. Nalebuff EA: Diagnosis, classification, and management of rheumatoid thumb deformities. Bull Hosp Joint Dis 29:119-37, 1968 9. Swanson, AB: Disabling arthritis of the base of the thumb. Treatment by resection of the trapezium and flexible (silicone) implant arthroplasty. J Bone Joint Surg [Am] 54:456-71, 1972 10. Cars tam N, Eiken 0, Andren L: Osteoarthritis in the trapezioscaphoid joint. Acta Orthop Scand 39:354-8, 1968
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11. Swanson AB: Flexible implant resection arthroplasty of the hand and extremities. St. Louis, 1973, The CV Mosby Co 12. Swanson AB: Disabilities of the thumb joints and their surgical treatment including flexible implant arthro plasty. Instructional Course Lectures, AAOS, St. Louis, The CV Mosby Co 12:89-104, 1973 13. Swanson AB: Flexible implant arthroplasty in the hand. Clin Plast Surg 3:141-57, 1976 14. Swanson AB, deGroot Swanson G: Thumb disabilities in rheumatoid arthritis: Classification and treatment. In Symposium on tendon surgery of the hand, AAOS, St. Louis, 1975, The CV Mosby Co, pp 233-54 15. Swanson AB, deGroot Swanson G: Disabling osteoar thritis in the hand and its treatment. In Symposium on osteoarthritis, St. Louis, 1976, The CV Mosby Co, pp 196-232 16. Swanson AB, deGroot Swanson G: Flexible implant re section arthroplasty: A method for reconstruction of small joints in the extremities. Instructional Course Lec tures, AAOS, St. Louis, The CV Mosby Co, 27:27-60, 1978 17. Swanson AB, Meester WD, deGroot Swanson G, Ran gaswamy L, Schut GED: Durability of silicone im plants-An in vivo study. Orthop Clin North Am 4: 1097-112, 1973 18. Swanson AB: Finger joint replacement by silicone rubber implants and the concept of implant fixation by encapsu lation. Ann Rheum Dis [Br] 28:47-55, 1969 19. Eaton RG, Littler JW: A study of the basal joint of the thumb, treatment of its disabilities by fusion. J Bone Joint Surg [Am] 51:661-8, 1969 20. Matev IB: Surgical treatment of the spastic "thumb-in palm" deformity. J Bone Joint Surg [Br] 45:703, 1963 21. Swanson AB: Surgery of the hand in cerebral palsy and muscle origin release procedures. Surg Clin North Am 48:1129-38, 1968 22. Swanson AB, Mays J, Yamauchi Y: A rheumatoid ar thritis evaluation record for the upper extremity. Surg Clin North Am 48:1003-13, 1968