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The use of frozen-allograft radial head replacement for treatment of established symptomatic proximal translation of the radius: Preliminary experience in five cases
The Use of Frozen-AIIograft Radial Head Replacement for Treatment of Established Symptomatic Proximal Translation of the Radius: Preliminary Experience in Five Cases Robert M. Szabo, MD, MPH, Sacramento, CA, Robert N. Hotchkiss, MD, New York, NY, Robert R. Slater, Jr, MD, Sacramento, CA Five patients with disabling symptoms related to proximal translation (> 1 cm) of the radius following radial head excision (Essex-Lopresti lesion) were treated with implantation of a frozen-allograft radial head prosthesis. Following restoration of neutral ulnar variance at the wrist, a size-matched frozen radial head allograft was implanted and secured to the proximal radius with internal fixation. In three patients, this was a two-stage procedure; radial length was restored gradually using an Ilizarov external fixation device and the allograft was placed later. Patients were evaluated clinically and radiographically at a mean follow-up time of 3 years (range, 1-7 years). All patients had relief of wrist and elbow pain and were satisfied with the outcome of the operation. Forearm rotation improved by a mean of 37 ~ and wrist motion improved by a mean of 45 ~ Forearm reconstruction with frozen radial head allograft implantation may be a beneficial method of treatment for this difficult problem. (J Hand Surg 1997;22A:269-278.)
In 1930, B r o c k m a n first described two cases of symptomatic proximal migration of the radius after radial head resection.~ Since then, this problem has been recognized and reported by many other authors) -6 Owing to the combined effects of abnormalities at the radiocapitellar and distal radioulnar joints, dysfunction of the upper limb in this setting
From the Departments of Orthopaedic Surgery, University of California, Davis, Sacramento, CA, and the Hospital for Special Surgery, New York,NY. Received for publication Dec. 8, 1995; accepted in revised form Sept. 26, 1996. The author or one or more of the authors have received or will receive benefits for personal or professional use from a commercial party related directlyor indirectly to the subjectof this article. Reprint requests: RobertM. Szabo, MD, Departmentof Orthopaedic Surgery, University of California, Davis, 2230 Stockton Boulevard, Sacramento,CA 95817.
results from both pain and loss o f mobility at the wrist and elbow. The interosseous ligament of the forearm, also termed the central band of the interosseous m e m brane, is the principle stabilizer of the forearm in resistance to axial shear forces.7, 8 If this structure is disrupted, then acute or gradual proximal displacement of the radius may occur when loads are applied across the forearm either with muscle contraction or exogenous axial load. Force cannot be transmitted to the capitelhim in the absence of the radial head and cannot be shared with or transmitted to the ulna in the absence of an intact interosseous ligament.~,3-6, 8-~3 Treatment options for this difficult problem have varied widely and have been notably unsuccessful. In this report, we present 5 cases of established symptomatic proximal translation of the radius treated with implantation of a frozen radial head The Journal of Hand Surgery
269
270
Szabo et al. / Frozen-AIIograft Radial Head Replacement
allograft. In 3 of these, the treatment consisted of a two-stage procedure: Ilizarov graduated lengthening of the radius relative to the ulna followed by the implantation of a frozen-allograft radial head. The remaining 2 had failed previously inserted silicone prostheses, which were removed and replaced with a frozen-allograft radial head.
Materials and Methods There were 5 patients treated at our institutions between 1988 and 1995 with frozen radial head allografts for established symptomatic proximal radial translation secondary to prior trauma and radial head excision. Matched sets of standardized anteroposterior and lateral x-rays of each patient's normal elbow and forearms were used to obtain appropriately sized allografts. Treatment was tailored individually based on patient-specific problems as described below (Table 1). At surgery, a posterolateral approach to the elbow was used in each case. The annular ligament (which was present in each case) was resected off the ulna with a wafer of bone and reflected for later repair. Mirror-image step cuts were made in the native proximal radial shaft and harvested allograft. The bicipital
tuberosity was used as a landmark for orientation of both length and rotation. The allograft construct was secured to the radial shaft with an interfragmentary screw followed by a contoured small fragment plate and screws (Fig. 1). A T-plate, blade plate, or straight plate was chosen at the discretion of the surgeon. It has been shown in animal models that irrigating subchondral bone with a detergent can inhibit the immune response to transplanted osteoarticular allografts, probably by removing marrow cells and the histocompatibility glycoproteins on the surfaces of the allograft. 14 In addition, it has been suggested that the risk of viral transmission in musculoskeletal allografts can be reduced by removing blood and bone marrow from allografts. 15 In 3 of the 5 cases (those in which the surgery was performed by R.M.S.), all cancellous bone was removed from the allograft to decrease its antigenicity and replaced with harvested autogenous iliac crest bone graft; additional iliac crest cancellous bone graft was placed at the graft-recipient junction. The annular ligament was reattached to the ulna through drill holes or later using suture anchors. In 3 of the 5 cases, Ilizarov external fixator frames were attached to the forearm via proximal ulna and distal radius fixation pins, thus
Table 1. Summary of Age/Sex (y)
Dominant Hand/ Injured Side
1
22/M
R/R
2
24/M
L/L
3
46/M
R/L
4
33/M
R/L
Radial head and distal radius fractures
Radial head excision, pinning distal radius fracture (for 6 wk); Ilizarov frame used for 10 wk; gradual restoration of length over 2 wk
5
47/M
R/L
Radial head fracture; BBFF
Radial head excision, ORIF or BBFF
Case
Initial Injury Radial head fracture, Essex-Lopresti lesion, contralateral anterior shoulder dislocation, axillary nerve disruption Radial head fracture, Essex-Lopresti lesion, open ankle fracture dislocation Radial head fracture, open elbow dislocation
BBFF, both bone forearm fracture; ORIF, open reduction and internal fixation.
Initial Treatment Radial head excision, silicone prosthesis; axillary nerve graft
Radial head excision, silicone prosthesis
Radial head ORIF
The Journal of Hand Surgery / Vol. 22A No. 2 March 1997
F i g u r e 1. Intraoperative photograph of the radial head allograft (case 4) showing the step-cut osteotomy and internal fixation with a one,third tubular plate.
271
placed at a subsequent procedure. In case 5, load cells were placed in series on the supports of the frame and calibrated to measure the stress in each vertical support. During correction, loads on each vertical column were measured at each position of correction. Rehabilitation was individualized by the treating surgeon, but all patients started elbow range of motion (ROM) exercises within the first 3 weeks after surgery. When grip strengths were measured, Jamar dynamometers (Asimov Engineering Comp., Los Angeles, CA) were set at position 3; reported values are means of three trials for each hand. The charts and radiographs were reviewed and each patient was recalled and examined personally by one of us for purposes of this report. Two patients' detailed case histories follow.
Case Presentations relieving stress across the graft and radiocapitellar joint. In one case, proximal radial translation was corrected acutely and the frame was attached at the same surgery when the allograft was placed; the frame was thus used to unload the allograft during healing. In 2 cases, the frames were used to gradually restore radioulnar alignment, the allografts being
Case 1 A 22-year-old right-handed man sustained multiple injuries in a motorcycle accident in 1986, including a left anterior shoulder dislocation and axillary nerve disruption, which required a subsequent nerve graft. He also sustained a radial head fracture with an
Individual Cases Injury-toAUografi Interval
Follow-up Period (y)
13 mo
7
No pain; working as auto mechanic
None
8y
2
None
None
6 mo
2
Wrist pain resolved; 50% elbow pain resolved; career change from farmer to teacher Little/no pain; working; playing golf
None
3 mo
4
Pain-free with activities of daily living, waterskiing; pain with hammering; working as electronics technician
None
4 mo
1
Little/no pain
Prior Procedures Prosthesis excision, elbow synovectomy
Prosthesis excision after 3 y; interposition arthroplasty after 7 y
Functional Outcome
Complications
Dislocated allograft requiring revision with temporary Ilizarov frame Ilizarov pin site inflammation delayed allograft 1 wk; allograft fixation plate removed and distal radioulnar joint hemiresection arthroplasty done at 6 mo llizarov pin track infection delayed allograft 1 mo
272
Szabo et al. / Frozen-AIIograft Radial Head Replacement
Figure 2. Lateral and anteroposterior x-ray films of the right elbow of a 22-year-old laborer (case 1) showing a silicone replacement arthroplasty used to treat an EssexLopresti lesion.
Figure 3. Anteroposterior and lateral x-ray films of the right elbow (case 1) after removal of the silicone prosthesis and synovectomy at l year after injury showing proximal translation of the radius with narrowing of the radiocapitellar joint. Note the cyst in the proximal radius that resulted from silicone synovitis.
Essex-Lopresti lesion of his right forearm. Initially, the treating surgeon removed the fractured radial head and inserted a silicone radial head replacement (Fig. 2). Within 1 year, the prosthesis fractured and silicone synovitis developed. One of us (R,M.S.) removed the prosthesis and did an elbow synovectomy. At the first postoperative visit, the radius was noted to have migrated proximally (Fig. 3). The patient complained of elbow and wrist pain associated with forearm weakness and a very prominent dislocated distal ulna. ROM is shown in Table 2. The patient's forearm was reconstructed using a frozen radial head allograft. The radius was readily distracted to restore neutral ulnar variance (Fig. 4). At last follow-up evaluation, nearly 7 years after the allograft was placed, the patient rated the overall result as excellent and considered his upper extrem-
ity normal in that he had no difficulties with daily activities. He had no pain, was working full time as an auto mechanic, and had returned to motorcycle riding. ROM and grip strength is shown in Table 2 and the difference in preoperative compared to postoperative ROM shown in Table 3. X-rays revealed that the allograft-host junction united and the internal fixation device position was unchanged. There was some subchondral collapse of the allograft and some narrowing of the radiocapitellar joint space, but it was not sufficient to cause symptomatic proximal migration (Fig. 5). Case 2 A 46-year-old fight-handed tree surgeon fell 35 feet from a cherry picker and sustained multiple injuries, including an open posterolateral fracture
Table 2. Individual Preoperative and Postoperative Ranges of Motion of the Elbow, Wrist, and Forearm and Grip Strength
Case
Elbow ROM (degrees) Preoperative Postoperative Flex Ext Flex Ext
1
125
0
2 3 4 5
125 115 135 135
15 30 40 40
125
Forearm ROM (degrees) Preoperative Postoperative Sup Pron Sup Pron
0
0
0
5
145 8 135 20 135 35 135 35
0 10 50 70
80 45 70 70
30 20 50 20
20 30 10 60 65
Wrist ROM (degrees) Preoperative Postoperative Flex Ext Flex Ext
80 85 90 60 80
70 50 0 15 0
Grip Strength (lb.) Dora Inj Inj N i
90
90
R
R
92
85 90 60 45
70 85 60 65
L R R R
L L L L
62 82 45 92 85 110 70 120
96
Dom, dominant hand; Ext, extension; Flex, flexion; Inj, injured extremity; Ni, noninjured extremity; Pron, pronation; Sup, supination.
The Journal of Hand Surgery / Vol. 22A No. 2 March 1997
273
Figure 4. Lateral x-ray film of the forearm (case 1) immediately after radial head allograft insertion. Note the restoration of neutral ulnar variance.
Table 3. Net Gain or Loss in Joint Range of Motion (degrees) Patient
A
Elbow
Forearm
Wrist
1
0
2 3 4 5
12 10 5 5
25 0 -25 100 85
30 35 85 45 30
B
Figure 5. (A) Anteroposterior and (B) lateral and radiocapitellar x-rays of the right elbow (case 1) 7 years after surgery. There is some subchondral collapse of the allograft and narrowing of the radiocapitellar joint space.
274
Szabo et al. / Frozen-AIIograft Radial Head Replacement
dislocation of his left elbow. On the day of injury, the initial treating surgeon reduced the patient's elbow after irrigating and debriding the wound and treating the patient's other injuries. Four days later, the comminuted radial head was openly reduced and internally fixed to the shaft with 2 screws. Within 2 months, the repaired radial head fragments dislocated, the radius migrated 1 cm proximally, and the patient was referred to one of us (R.M.S.) for further treatment (Fig. 6). At that time, the patient had pain in his wrist and elbow. ROM and grip strength are shown in Table 2. The patient's radial head and neck were resected and replaced with a size-matched radial head allograft with some difficulty, owing to soft-tissue tension. Within 3 weeks, the replaced radial head dislocated in a long arm cast and bent the fixation plate (Fig. 7). The fixation was removed and the allograft double plated to the native radial shaft. In addition, an Ilizarov external fixator frame with proximal and distal rings was applied to the forearm to keep the radius distracted, unloading the radiocapitellar joint (Fig. 8). The patient started elbow and wrist ROM exercises 10 days after surgery. The Ilizarov frame was removed after 16 weeks when it was determined
A
Figure 6. Anteroposterior and lateral x-rays of the left elbow of a 46-year-old patient 2 months following open reduction and intemal fixation of a fractured radial head (case 2).
radiographically that union was certain. Pronationsupination exercises were immediately begun. At the time of his most recent follow-up examination, 2 years after surgery, the patient was very satisfied with the result. He was working, although no longer climbing ropes as a tree surgeon, and able to play
B
Figure 7. (A) Anteroposterior and (B) lateral x-rays of the left elbow (case 2) 3 weeks following placement of a radial head allograft. The radial head allograft is dislocated and the fixation plate is bent.
The Journal of Hand Surgery / Vol. 22A No. 2 March 1997
A
275
B
Figure 8. (A) Anteroposterior and (B) lateral x-rays of the left elbow (case 2) following relocation of radial head allograft, double-plating, and application of an Ilizarov external fixation frame.
A
B
Figure 9. (A) Anteroposterior and (B) radiocapitellar x-rays of the left elbow (case 2) 2 years after surgery. The allograft is healed and the radiocapitellar joint space is well preserved.
276 Szabo et al. / Frozen-AIIograft Radial Head Replacement golf again. He had little or no pain with most activities and even performed pushups without pain. Grip strength and ROMs are shown in Tables 2 and 3. X-rays showed that the allograft-host junction was united and that the position of the internal fixation device was unchanged. There was some subchondral collapse and a small quantity of mature bone in the interosseous space between the proximal radius and ulna, where the bone graft had been placed, but not complete synostosis (Fig. 9).
Results It may be difficult to interpret time to union of the host-donor interface radiographically with certainty. In our judgment, there was some obliteration of the interface and evidence of bridging trabeculae on plain x-ray films in our cases starting at 2 months after surgery. In all cases, the interfaces did unite. In case 5, static load was measured at a peak of 25 lb. (11.4 kgf) as the correction reached neutral. Equalization of length was achieved in 6 weeks, and the frame was left in place a total of 8 weeks. Static load decreased to 5 lb. (2.3 kgf) at 8 weeks, suggesting stress relaxation or mechanical creep of the softtissue linkage between the ulna and radius. In this group of 5 patients, wrist pain and wrist motion improved most, followed by forearm rotation. The mean gain in wrist motion was 45 ~ (SD, 23~ mean gain in forearm rotation was 37 ~ (SD, 54~ Elbow ROM improved by a mean of 6 ~ (SD, 5 ~ (Table 3). Patients were thoroughly counseled about the proposed risks and benefits of this procedure as well as about treatment alternatives. Therefore, although it is a subjective statement, we think it is meaningful that all patients said that they were very pleased with the results of their treatment and would choose this option again if faced with the same injury.
Discussion Proximal migration of the radius after radial head resection is unpredictable and is not always symptomatic or disabling. When this condition becomes symptomatic, the patient may have loss of forearm pronation and supination as well as wrist extension and disabling wrist pain. The ulna usually sits dorsal and distal to the radius, blocking forearm rotation. Coleman et al.16 and others 5,6,17 have reported patients with proximal radial translation without disabling pain or loss of mobility. The patients presented in this series all endured disabling pain, especially at the distal radioulnar joint. In a patient with
established proximal translation and dysfunction because of radioulnar inequality, ulnar shortening does not offer a predictable solution.10, lz If the ulna is shortened, the radius may continue to translate proximally because there is no radiocapitellar contact and the interosseous ligament remains incompetent. Silicone radial head replacement has failed to maintain length of the radius in the acute setting, 12 and material failure has also been reported. 17-21More recently, the use of a Vitallium radial head prosthesis (Howmedica, London, UK) was reported, 22 but this was placed in all patients acutely. No patient had established proximal radial translation with radioulnar inequality. Several authors have suggested that in order to salvage wrist function, the most reliable procedure is to create a one-bone forearm, shortening the ulna where necessary and creating a radioulnar synostosis, with the goal of preventing further proximal migration of the radius in exchange for eliminating forearm pronation and supination. 4,10,12 A recent study of patients reported by Peterson et al. indicated major complications in 10 of 19 patients, with the authors concluding that overall "results may be less predictable than previously reported. ''23 In all of our patients, acute shortening and creation of a single bone forearm was considered and offered as an alternative to allograft implantation. Forearm reconstruction using frozen radial head allograft may need to be performed in two stages. The amount of force required to restore radial length to achieve neutral ulnar variance is considerable. In the patient we monitored with load cells in each connecting rod (case 5), the static load reached a summed peak of approximately 25 lb. (11.4 kgf) of static load. Decay of this static tension decreased over a period of weeks. Case 3 illustrates what happens when acute lengthening and immediate allograft placement is attempted in the setting of wellestablished, long-standing deformity. Based on this load cell data and our experience, we would not recommend acute lengthening and immediate allograft implantation without cross-pinning the radius and ulna or external fixation. While we no longer use silicone radial head replacements, they may have afforded some stabilization in cases 1 and 2 by prolonged use, but not without the complications of fracture and synovitis. At final follow-up evaluation, the patients involved in cases 1-3 still had limited forearm pronation and supination. The patient in case 3 actually had a net loss of 25 ~ rotation. Bone graft was placed around
The Journal of Hand Surgery / Vol. 22A No. 2 March 1997
the allograft-recipient junctions at the time of the initial surgery in these three cases and the final x-ray films showed small quantities of mature bone in the interosseous space between the proximal ulna and radius, which may have resulted from the bone grafting. In contrast, bone graft was not used in cases 4 and 5, and these patients had improved forearm rotation at final follow-up examination. Therefore, we no longer recommend the use of bone graft at the site of osteosynthesis. Radial head allograft longevity beyond 7 years has not been demonstrated. Undoubtedly, these grafts are experiencing load, but as of this report, they do not show worrisome collapse or severe degenerative change. The successful use of frozen allografts in other parts of the radius, 24 along with limited successful options for treatment of the Essex-Lopresti lesion where the radial head has been removed, prompted the trial of this new procedure. Because the biomechanical characteristics of an allograft could well approximate the native radial head, this alternative seemed attractive. The 5 patients reported in this series have tolerated the allograft well and have not shown progression of pain or progressive loss of motion. Wrist pain and extension improved most following restoration of neutral ulna variance. Despite the favorable results of the patients presented in this series, the use of allograft radial head replacement should still be considered cautiously. Because we did not have the original radial head, we could only estimate the proper size. At this time, we do not know the tolerances of fit required in this procedure. Equalization of radioulnar length at the distal radioulnar joint must be accomplished first, either during the same operation or as a separate procedure. Either ulnar shortening or a more graduated Ilizarov lengthening of the radius relative to the ulna is needed to correct the inequality at the level of the wrist. The force on the radial head allograft can be excessive if the soft-tissue equalization is not done gradually and maintained in the lengthened position prior to insertion of the allograft. The procedure for lengthening using external fixation and implantation of the allograft is technically demanding, but it addresses both the soft-tissue and osseous injuries that together cause forearm dysfunction and pain. If adequate realignment of the distal radioulnar joint is not achieved, ulnar impingement will persist despite restoration of radiocapitellar load sharing. In the case where an attempt was made to insert an allograft immediately after acute lengthening, excessive load on the allograft led to early failure,
277
requiring surgical revision. If the allograft is implanted without previous radial head replacement or the mechanical protection of prior ulnar shortening or the sustained use of external fixation, the allograft may sublux or the internal fixation may fail. Circular wire fixation using an Ilizarov apparatus is one method that allows fixation in the radius distally and the ulna proximally so that lengthening the distance (gradually or acutely) between the two points of fixation will result in distal translation of the radius. Other fixators can be constructed to yield the same effect. We do not believe that the interosseous membrane ever truly heals, perhaps because of the constant pull of the long finger flexors that originate from it. Undoubtedly, some scar formation occurs between radius and ulna after disruption of the interosseous membrane. If a temporary spacer is placed, such as a radial head prosthesis made of silicone, the membrane may be replaced by scar in a lengthened position. The prosthesis may ultimately fracture and fragment and allow proximal radial translation. However, in that setting it may be possible to place a radial head allograft to restore radioulnar length acutely because the scar tissue that has replaced the interosseous membrane formed in a lengthened position; an Ilizarov frame will be unnecessary. When the radial head is excised but no temporary spacer or prosthesis is used, the interosseous membrane may be replaced by scar tissue in a relatively contracted condition. Then it will be difficult or impossible to restore the correct radioulnar length relationship acutely at the time an allograft is implanted without placing excessive force on the allograft. This was demonstrated in one of our cases (case 3). In that setting, the Ilizarov technique is useful to gradually lengthen the scar tissue and allow restoration of the radioulnar length relationship or unload the allograft until healing of the host-donor bony interfaces occurs. Pin track infection, a potential problem with all external fixation techniques, is particularly important to avoid in the presence of an allograft. Frequent monitoring and patient education about the first signs of pin track inflammation can help avoid further complications. Despite the best efforts of tissue and bone banks to screen for diseases and infectious particles, there remains the inherent risk of transmitting diseases to graft recipients. A recent report showed that human cartilage may harbor human immunodeficiency vires (HIV) DNA in vivo in patients known to be HIV positive, although infectivity and disease transmission was
278
Szabo et al. / Frozen-AIIograft Radial Head Replacement
not studied. 25 The true risk of transmitting HIV or hepatitis viruses remains difficult to quantify, although the chance of obtaining donor tissue infected with HIV that has been properly screened is estimated to be about 1 in 4 million. 26 Nevertheless, these risks should be discussed with each patient. The salvage procedure of choice for this condition has been the creation of a radioulnar synostosis. Although forearm rotation is eliminated with creation of the synostosis, many patients can adapt and make positional accommodations. However, with more demands for keyboard skills, pronation is an increasing priority. With the recent report of 26% fair and 5% poor results with this approach, we may be justified in considering other alternatives. 23 Radial head allograft replacement is not presented here as the solution to this unsolved problem but rather as an option with some advantages. No other prosthetic replacement or interosseous membrane reconstruction has been successful to our knowledge. We remain cautiously optimistic about the usefulness of frozen radial head allografts to reconstruct forearms following radial head excision and subsequent symptomatic proximal migration of the radius. We are concerned that we have observed some subchondral collapse, which might result in further proximal radial migration if it continues to progress. Perhaps given enough time, however, the interosseous membrane stabilizes. A larger group of patients studied and a longer follow-up period is needed to confirm the value of this operation.
References 1. Brockman E. Two cases of disability at the wrist joint following excision of the head of the radius. Proc R Soc Med 1930;24:904-905. 2. Davidson P, JB Moseley J, Tullos H. Radial head fracture: a potentially complex injury. Clin Orthop 1993;297: 224-230. 3. Edwards G, Jupiter J. Radial head fracture with acute distal radioulnar dislocation: Essex-Lopresti revisited. Clin Orthop 1988;234:61-69. 4. Essex-Lopresti P. Fractures of the radial head with distal radial-ulnar dislocations. J Bone Joint Surg 1951;33B: 244-247. 5. Lewis R, Thibodeau A. Deformity of the wrist following resection of the radial head. Surg Gynecol Obstet 1937;64: 1079-1085. 6. McDougall A, White J. Subluxation of the inferior radioulnar joint complicating fracture of the radial head. J Bone J Surg 1957;39B:278-286. 7. Hotchkiss R, An K, Sowa D, Basta S, Weiland A. Pathomechanics of proximal migration of the radius: an
8.
9. t0. 11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23. 24.
25. 26.
anatomic and mechanical study of the interosseous membrane of the forearm. J Hand Surg 1989; 14A:256-261. Rabinowitz R, Light T, Havey R, Gourineni P, Patwardhan A. The role of the interosseous membrane and triangular fibrocartilage complex in forearm stability. J Hand Surg 1994; 19A:385-393. Curr J, Coe W. Dislocation of the inferior radio-ulnar joint. Br J Surg 1946;34:74-77. Hotchkiss R. Injuries to the interosseous ligament of the forearm. Hand Clin 1994;10:391-398. Taylor T, O'Connor B. The effect upon the inferior radioulnar joint of excision of the head of the radius in adults. J Bone Joint Surg 1964;46B:83-88. Sowa D, Hotchkiss R, Weiland A. Symptomatic proximal translation of the radius following radial head resection. Clin Orthop 1995;317:106-113. Trousdale R, Amadio P, Cooney W, Morrey B. Radio-ulnar dissociation: a review of twenty cases. J Bone Joint Surg 1992;74A: 1486-1497. Rodrigo JJ, Heiden E, Hegyes M, Sharkey NA. Immune response inhibition by irrigating subchondral bone with cytotoxic agents. Clin Orthop 1996;326:96-106. Tomford WW. Transmission of disease through transplantation of musculoskeletal allografts. J Bone Joint Surg 1995;77A:1742-1754. Coleman D, Blair W, Shurr D. Resection of the radial head for fracture of the radial head. J Bone Joint Surg 1987;69A:385-392. Worsing R, Engber W, Lange T. Reactive synovitis from particulate silastic. J Bone Joint Surg 1982;64A: 581-584. Morrey B, Chao E, Hui E Biomechanical study of the elbow following excision of the radial head. J Bone J Surg 1979;61A:63-68. Bohl W, Brightman E. Fracture of a silastic radial-head prosthesis: diagnosis and localization of fragments by xerography. J Bone Joint Surg 1981 ;63A: 1482-1483. Gordon M, Bullough P. Synovial and osseous inflammation in failed silicone-rubber prosthesis. J Bone Joint Surg 1982;64A:574-580. Mayhall W, Tiley F, Paluska D. Fractures of Silastic radial-head prosthesis. J Bone Joint Surg 1981;63A: 459-460. Knight D, Rymaszewski L, Amis A, Miller J. Primary replacement of the fractured radial head with a metal prosthesis. J Bone Joint Surg 1993;75B:572-576. Peterson CA, Maki S, Wood MB. Clinical results of the one-bone forearm. J Hand Surg 1995;20A:609-618. Szabo RM, Thorson EP, Raskin JR. Allograft replacement with distal radioulnar joint fusion and ulnar osteotomy for treatment of giant cell tumors of the distal radius. J Hand Surg 1990;15A:929-933. Campbell DG, Oakeshott RD. HIV infection of human cartilage. J Bone Joint Surg 1996;78B:22-25. Buck B, Malinin T, Brown M. Bone transplantation and human immunodeficiency virus: an estimate of risk of acquired immunodeficiency syndrome (AIDS). Clin Orthop 1989;240:129-136.
In 1930, B r o c k m a n first described two cases of symptomatic proximal migration of the radius after radial head resection.~ Since then, this problem has been recognized and reported by many other authors) -6 Owing to the combined effects of abnormalities at the radiocapitellar and distal radioulnar joints, dysfunction of the upper limb in this setting
From the Departments of Orthopaedic Surgery, University of California, Davis, Sacramento, CA, and the Hospital for Special Surgery, New York,NY. Received for publication Dec. 8, 1995; accepted in revised form Sept. 26, 1996. The author or one or more of the authors have received or will receive benefits for personal or professional use from a commercial party related directlyor indirectly to the subjectof this article. Reprint requests: RobertM. Szabo, MD, Departmentof Orthopaedic Surgery, University of California, Davis, 2230 Stockton Boulevard, Sacramento,CA 95817.
results from both pain and loss o f mobility at the wrist and elbow. The interosseous ligament of the forearm, also termed the central band of the interosseous m e m brane, is the principle stabilizer of the forearm in resistance to axial shear forces.7, 8 If this structure is disrupted, then acute or gradual proximal displacement of the radius may occur when loads are applied across the forearm either with muscle contraction or exogenous axial load. Force cannot be transmitted to the capitelhim in the absence of the radial head and cannot be shared with or transmitted to the ulna in the absence of an intact interosseous ligament.~,3-6, 8-~3 Treatment options for this difficult problem have varied widely and have been notably unsuccessful. In this report, we present 5 cases of established symptomatic proximal translation of the radius treated with implantation of a frozen radial head The Journal of Hand Surgery
269
270
Szabo et al. / Frozen-AIIograft Radial Head Replacement
allograft. In 3 of these, the treatment consisted of a two-stage procedure: Ilizarov graduated lengthening of the radius relative to the ulna followed by the implantation of a frozen-allograft radial head. The remaining 2 had failed previously inserted silicone prostheses, which were removed and replaced with a frozen-allograft radial head.
Materials and Methods There were 5 patients treated at our institutions between 1988 and 1995 with frozen radial head allografts for established symptomatic proximal radial translation secondary to prior trauma and radial head excision. Matched sets of standardized anteroposterior and lateral x-rays of each patient's normal elbow and forearms were used to obtain appropriately sized allografts. Treatment was tailored individually based on patient-specific problems as described below (Table 1). At surgery, a posterolateral approach to the elbow was used in each case. The annular ligament (which was present in each case) was resected off the ulna with a wafer of bone and reflected for later repair. Mirror-image step cuts were made in the native proximal radial shaft and harvested allograft. The bicipital
tuberosity was used as a landmark for orientation of both length and rotation. The allograft construct was secured to the radial shaft with an interfragmentary screw followed by a contoured small fragment plate and screws (Fig. 1). A T-plate, blade plate, or straight plate was chosen at the discretion of the surgeon. It has been shown in animal models that irrigating subchondral bone with a detergent can inhibit the immune response to transplanted osteoarticular allografts, probably by removing marrow cells and the histocompatibility glycoproteins on the surfaces of the allograft. 14 In addition, it has been suggested that the risk of viral transmission in musculoskeletal allografts can be reduced by removing blood and bone marrow from allografts. 15 In 3 of the 5 cases (those in which the surgery was performed by R.M.S.), all cancellous bone was removed from the allograft to decrease its antigenicity and replaced with harvested autogenous iliac crest bone graft; additional iliac crest cancellous bone graft was placed at the graft-recipient junction. The annular ligament was reattached to the ulna through drill holes or later using suture anchors. In 3 of the 5 cases, Ilizarov external fixator frames were attached to the forearm via proximal ulna and distal radius fixation pins, thus
Table 1. Summary of Age/Sex (y)
Dominant Hand/ Injured Side
1
22/M
R/R
2
24/M
L/L
3
46/M
R/L
4
33/M
R/L
Radial head and distal radius fractures
Radial head excision, pinning distal radius fracture (for 6 wk); Ilizarov frame used for 10 wk; gradual restoration of length over 2 wk
5
47/M
R/L
Radial head fracture; BBFF
Radial head excision, ORIF or BBFF
Case
Initial Injury Radial head fracture, Essex-Lopresti lesion, contralateral anterior shoulder dislocation, axillary nerve disruption Radial head fracture, Essex-Lopresti lesion, open ankle fracture dislocation Radial head fracture, open elbow dislocation
BBFF, both bone forearm fracture; ORIF, open reduction and internal fixation.
Initial Treatment Radial head excision, silicone prosthesis; axillary nerve graft
Radial head excision, silicone prosthesis
Radial head ORIF
The Journal of Hand Surgery / Vol. 22A No. 2 March 1997
F i g u r e 1. Intraoperative photograph of the radial head allograft (case 4) showing the step-cut osteotomy and internal fixation with a one,third tubular plate.
271
placed at a subsequent procedure. In case 5, load cells were placed in series on the supports of the frame and calibrated to measure the stress in each vertical support. During correction, loads on each vertical column were measured at each position of correction. Rehabilitation was individualized by the treating surgeon, but all patients started elbow range of motion (ROM) exercises within the first 3 weeks after surgery. When grip strengths were measured, Jamar dynamometers (Asimov Engineering Comp., Los Angeles, CA) were set at position 3; reported values are means of three trials for each hand. The charts and radiographs were reviewed and each patient was recalled and examined personally by one of us for purposes of this report. Two patients' detailed case histories follow.
Case Presentations relieving stress across the graft and radiocapitellar joint. In one case, proximal radial translation was corrected acutely and the frame was attached at the same surgery when the allograft was placed; the frame was thus used to unload the allograft during healing. In 2 cases, the frames were used to gradually restore radioulnar alignment, the allografts being
Case 1 A 22-year-old right-handed man sustained multiple injuries in a motorcycle accident in 1986, including a left anterior shoulder dislocation and axillary nerve disruption, which required a subsequent nerve graft. He also sustained a radial head fracture with an
Individual Cases Injury-toAUografi Interval
Follow-up Period (y)
13 mo
7
No pain; working as auto mechanic
None
8y
2
None
None
6 mo
2
Wrist pain resolved; 50% elbow pain resolved; career change from farmer to teacher Little/no pain; working; playing golf
None
3 mo
4
Pain-free with activities of daily living, waterskiing; pain with hammering; working as electronics technician
None
4 mo
1
Little/no pain
Prior Procedures Prosthesis excision, elbow synovectomy
Prosthesis excision after 3 y; interposition arthroplasty after 7 y
Functional Outcome
Complications
Dislocated allograft requiring revision with temporary Ilizarov frame Ilizarov pin site inflammation delayed allograft 1 wk; allograft fixation plate removed and distal radioulnar joint hemiresection arthroplasty done at 6 mo llizarov pin track infection delayed allograft 1 mo
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Figure 2. Lateral and anteroposterior x-ray films of the right elbow of a 22-year-old laborer (case 1) showing a silicone replacement arthroplasty used to treat an EssexLopresti lesion.
Figure 3. Anteroposterior and lateral x-ray films of the right elbow (case 1) after removal of the silicone prosthesis and synovectomy at l year after injury showing proximal translation of the radius with narrowing of the radiocapitellar joint. Note the cyst in the proximal radius that resulted from silicone synovitis.
Essex-Lopresti lesion of his right forearm. Initially, the treating surgeon removed the fractured radial head and inserted a silicone radial head replacement (Fig. 2). Within 1 year, the prosthesis fractured and silicone synovitis developed. One of us (R,M.S.) removed the prosthesis and did an elbow synovectomy. At the first postoperative visit, the radius was noted to have migrated proximally (Fig. 3). The patient complained of elbow and wrist pain associated with forearm weakness and a very prominent dislocated distal ulna. ROM is shown in Table 2. The patient's forearm was reconstructed using a frozen radial head allograft. The radius was readily distracted to restore neutral ulnar variance (Fig. 4). At last follow-up evaluation, nearly 7 years after the allograft was placed, the patient rated the overall result as excellent and considered his upper extrem-
ity normal in that he had no difficulties with daily activities. He had no pain, was working full time as an auto mechanic, and had returned to motorcycle riding. ROM and grip strength is shown in Table 2 and the difference in preoperative compared to postoperative ROM shown in Table 3. X-rays revealed that the allograft-host junction united and the internal fixation device position was unchanged. There was some subchondral collapse of the allograft and some narrowing of the radiocapitellar joint space, but it was not sufficient to cause symptomatic proximal migration (Fig. 5). Case 2 A 46-year-old fight-handed tree surgeon fell 35 feet from a cherry picker and sustained multiple injuries, including an open posterolateral fracture
Table 2. Individual Preoperative and Postoperative Ranges of Motion of the Elbow, Wrist, and Forearm and Grip Strength
Case
Elbow ROM (degrees) Preoperative Postoperative Flex Ext Flex Ext
1
125
0
2 3 4 5
125 115 135 135
15 30 40 40
125
Forearm ROM (degrees) Preoperative Postoperative Sup Pron Sup Pron
0
0
0
5
145 8 135 20 135 35 135 35
0 10 50 70
80 45 70 70
30 20 50 20
20 30 10 60 65
Wrist ROM (degrees) Preoperative Postoperative Flex Ext Flex Ext
80 85 90 60 80
70 50 0 15 0
Grip Strength (lb.) Dora Inj Inj N i
90
90
R
R
92
85 90 60 45
70 85 60 65
L R R R
L L L L
62 82 45 92 85 110 70 120
96
Dom, dominant hand; Ext, extension; Flex, flexion; Inj, injured extremity; Ni, noninjured extremity; Pron, pronation; Sup, supination.
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273
Figure 4. Lateral x-ray film of the forearm (case 1) immediately after radial head allograft insertion. Note the restoration of neutral ulnar variance.
Table 3. Net Gain or Loss in Joint Range of Motion (degrees) Patient
A
Elbow
Forearm
Wrist
1
0
2 3 4 5
12 10 5 5
25 0 -25 100 85
30 35 85 45 30
B
Figure 5. (A) Anteroposterior and (B) lateral and radiocapitellar x-rays of the right elbow (case 1) 7 years after surgery. There is some subchondral collapse of the allograft and narrowing of the radiocapitellar joint space.
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Szabo et al. / Frozen-AIIograft Radial Head Replacement
dislocation of his left elbow. On the day of injury, the initial treating surgeon reduced the patient's elbow after irrigating and debriding the wound and treating the patient's other injuries. Four days later, the comminuted radial head was openly reduced and internally fixed to the shaft with 2 screws. Within 2 months, the repaired radial head fragments dislocated, the radius migrated 1 cm proximally, and the patient was referred to one of us (R.M.S.) for further treatment (Fig. 6). At that time, the patient had pain in his wrist and elbow. ROM and grip strength are shown in Table 2. The patient's radial head and neck were resected and replaced with a size-matched radial head allograft with some difficulty, owing to soft-tissue tension. Within 3 weeks, the replaced radial head dislocated in a long arm cast and bent the fixation plate (Fig. 7). The fixation was removed and the allograft double plated to the native radial shaft. In addition, an Ilizarov external fixator frame with proximal and distal rings was applied to the forearm to keep the radius distracted, unloading the radiocapitellar joint (Fig. 8). The patient started elbow and wrist ROM exercises 10 days after surgery. The Ilizarov frame was removed after 16 weeks when it was determined
A
Figure 6. Anteroposterior and lateral x-rays of the left elbow of a 46-year-old patient 2 months following open reduction and intemal fixation of a fractured radial head (case 2).
radiographically that union was certain. Pronationsupination exercises were immediately begun. At the time of his most recent follow-up examination, 2 years after surgery, the patient was very satisfied with the result. He was working, although no longer climbing ropes as a tree surgeon, and able to play
B
Figure 7. (A) Anteroposterior and (B) lateral x-rays of the left elbow (case 2) 3 weeks following placement of a radial head allograft. The radial head allograft is dislocated and the fixation plate is bent.
The Journal of Hand Surgery / Vol. 22A No. 2 March 1997
A
275
B
Figure 8. (A) Anteroposterior and (B) lateral x-rays of the left elbow (case 2) following relocation of radial head allograft, double-plating, and application of an Ilizarov external fixation frame.
A
B
Figure 9. (A) Anteroposterior and (B) radiocapitellar x-rays of the left elbow (case 2) 2 years after surgery. The allograft is healed and the radiocapitellar joint space is well preserved.
276 Szabo et al. / Frozen-AIIograft Radial Head Replacement golf again. He had little or no pain with most activities and even performed pushups without pain. Grip strength and ROMs are shown in Tables 2 and 3. X-rays showed that the allograft-host junction was united and that the position of the internal fixation device was unchanged. There was some subchondral collapse and a small quantity of mature bone in the interosseous space between the proximal radius and ulna, where the bone graft had been placed, but not complete synostosis (Fig. 9).
Results It may be difficult to interpret time to union of the host-donor interface radiographically with certainty. In our judgment, there was some obliteration of the interface and evidence of bridging trabeculae on plain x-ray films in our cases starting at 2 months after surgery. In all cases, the interfaces did unite. In case 5, static load was measured at a peak of 25 lb. (11.4 kgf) as the correction reached neutral. Equalization of length was achieved in 6 weeks, and the frame was left in place a total of 8 weeks. Static load decreased to 5 lb. (2.3 kgf) at 8 weeks, suggesting stress relaxation or mechanical creep of the softtissue linkage between the ulna and radius. In this group of 5 patients, wrist pain and wrist motion improved most, followed by forearm rotation. The mean gain in wrist motion was 45 ~ (SD, 23~ mean gain in forearm rotation was 37 ~ (SD, 54~ Elbow ROM improved by a mean of 6 ~ (SD, 5 ~ (Table 3). Patients were thoroughly counseled about the proposed risks and benefits of this procedure as well as about treatment alternatives. Therefore, although it is a subjective statement, we think it is meaningful that all patients said that they were very pleased with the results of their treatment and would choose this option again if faced with the same injury.
Discussion Proximal migration of the radius after radial head resection is unpredictable and is not always symptomatic or disabling. When this condition becomes symptomatic, the patient may have loss of forearm pronation and supination as well as wrist extension and disabling wrist pain. The ulna usually sits dorsal and distal to the radius, blocking forearm rotation. Coleman et al.16 and others 5,6,17 have reported patients with proximal radial translation without disabling pain or loss of mobility. The patients presented in this series all endured disabling pain, especially at the distal radioulnar joint. In a patient with
established proximal translation and dysfunction because of radioulnar inequality, ulnar shortening does not offer a predictable solution.10, lz If the ulna is shortened, the radius may continue to translate proximally because there is no radiocapitellar contact and the interosseous ligament remains incompetent. Silicone radial head replacement has failed to maintain length of the radius in the acute setting, 12 and material failure has also been reported. 17-21More recently, the use of a Vitallium radial head prosthesis (Howmedica, London, UK) was reported, 22 but this was placed in all patients acutely. No patient had established proximal radial translation with radioulnar inequality. Several authors have suggested that in order to salvage wrist function, the most reliable procedure is to create a one-bone forearm, shortening the ulna where necessary and creating a radioulnar synostosis, with the goal of preventing further proximal migration of the radius in exchange for eliminating forearm pronation and supination. 4,10,12 A recent study of patients reported by Peterson et al. indicated major complications in 10 of 19 patients, with the authors concluding that overall "results may be less predictable than previously reported. ''23 In all of our patients, acute shortening and creation of a single bone forearm was considered and offered as an alternative to allograft implantation. Forearm reconstruction using frozen radial head allograft may need to be performed in two stages. The amount of force required to restore radial length to achieve neutral ulnar variance is considerable. In the patient we monitored with load cells in each connecting rod (case 5), the static load reached a summed peak of approximately 25 lb. (11.4 kgf) of static load. Decay of this static tension decreased over a period of weeks. Case 3 illustrates what happens when acute lengthening and immediate allograft placement is attempted in the setting of wellestablished, long-standing deformity. Based on this load cell data and our experience, we would not recommend acute lengthening and immediate allograft implantation without cross-pinning the radius and ulna or external fixation. While we no longer use silicone radial head replacements, they may have afforded some stabilization in cases 1 and 2 by prolonged use, but not without the complications of fracture and synovitis. At final follow-up evaluation, the patients involved in cases 1-3 still had limited forearm pronation and supination. The patient in case 3 actually had a net loss of 25 ~ rotation. Bone graft was placed around
The Journal of Hand Surgery / Vol. 22A No. 2 March 1997
the allograft-recipient junctions at the time of the initial surgery in these three cases and the final x-ray films showed small quantities of mature bone in the interosseous space between the proximal ulna and radius, which may have resulted from the bone grafting. In contrast, bone graft was not used in cases 4 and 5, and these patients had improved forearm rotation at final follow-up examination. Therefore, we no longer recommend the use of bone graft at the site of osteosynthesis. Radial head allograft longevity beyond 7 years has not been demonstrated. Undoubtedly, these grafts are experiencing load, but as of this report, they do not show worrisome collapse or severe degenerative change. The successful use of frozen allografts in other parts of the radius, 24 along with limited successful options for treatment of the Essex-Lopresti lesion where the radial head has been removed, prompted the trial of this new procedure. Because the biomechanical characteristics of an allograft could well approximate the native radial head, this alternative seemed attractive. The 5 patients reported in this series have tolerated the allograft well and have not shown progression of pain or progressive loss of motion. Wrist pain and extension improved most following restoration of neutral ulna variance. Despite the favorable results of the patients presented in this series, the use of allograft radial head replacement should still be considered cautiously. Because we did not have the original radial head, we could only estimate the proper size. At this time, we do not know the tolerances of fit required in this procedure. Equalization of radioulnar length at the distal radioulnar joint must be accomplished first, either during the same operation or as a separate procedure. Either ulnar shortening or a more graduated Ilizarov lengthening of the radius relative to the ulna is needed to correct the inequality at the level of the wrist. The force on the radial head allograft can be excessive if the soft-tissue equalization is not done gradually and maintained in the lengthened position prior to insertion of the allograft. The procedure for lengthening using external fixation and implantation of the allograft is technically demanding, but it addresses both the soft-tissue and osseous injuries that together cause forearm dysfunction and pain. If adequate realignment of the distal radioulnar joint is not achieved, ulnar impingement will persist despite restoration of radiocapitellar load sharing. In the case where an attempt was made to insert an allograft immediately after acute lengthening, excessive load on the allograft led to early failure,
277
requiring surgical revision. If the allograft is implanted without previous radial head replacement or the mechanical protection of prior ulnar shortening or the sustained use of external fixation, the allograft may sublux or the internal fixation may fail. Circular wire fixation using an Ilizarov apparatus is one method that allows fixation in the radius distally and the ulna proximally so that lengthening the distance (gradually or acutely) between the two points of fixation will result in distal translation of the radius. Other fixators can be constructed to yield the same effect. We do not believe that the interosseous membrane ever truly heals, perhaps because of the constant pull of the long finger flexors that originate from it. Undoubtedly, some scar formation occurs between radius and ulna after disruption of the interosseous membrane. If a temporary spacer is placed, such as a radial head prosthesis made of silicone, the membrane may be replaced by scar in a lengthened position. The prosthesis may ultimately fracture and fragment and allow proximal radial translation. However, in that setting it may be possible to place a radial head allograft to restore radioulnar length acutely because the scar tissue that has replaced the interosseous membrane formed in a lengthened position; an Ilizarov frame will be unnecessary. When the radial head is excised but no temporary spacer or prosthesis is used, the interosseous membrane may be replaced by scar tissue in a relatively contracted condition. Then it will be difficult or impossible to restore the correct radioulnar length relationship acutely at the time an allograft is implanted without placing excessive force on the allograft. This was demonstrated in one of our cases (case 3). In that setting, the Ilizarov technique is useful to gradually lengthen the scar tissue and allow restoration of the radioulnar length relationship or unload the allograft until healing of the host-donor bony interfaces occurs. Pin track infection, a potential problem with all external fixation techniques, is particularly important to avoid in the presence of an allograft. Frequent monitoring and patient education about the first signs of pin track inflammation can help avoid further complications. Despite the best efforts of tissue and bone banks to screen for diseases and infectious particles, there remains the inherent risk of transmitting diseases to graft recipients. A recent report showed that human cartilage may harbor human immunodeficiency vires (HIV) DNA in vivo in patients known to be HIV positive, although infectivity and disease transmission was
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Szabo et al. / Frozen-AIIograft Radial Head Replacement
not studied. 25 The true risk of transmitting HIV or hepatitis viruses remains difficult to quantify, although the chance of obtaining donor tissue infected with HIV that has been properly screened is estimated to be about 1 in 4 million. 26 Nevertheless, these risks should be discussed with each patient. The salvage procedure of choice for this condition has been the creation of a radioulnar synostosis. Although forearm rotation is eliminated with creation of the synostosis, many patients can adapt and make positional accommodations. However, with more demands for keyboard skills, pronation is an increasing priority. With the recent report of 26% fair and 5% poor results with this approach, we may be justified in considering other alternatives. 23 Radial head allograft replacement is not presented here as the solution to this unsolved problem but rather as an option with some advantages. No other prosthetic replacement or interosseous membrane reconstruction has been successful to our knowledge. We remain cautiously optimistic about the usefulness of frozen radial head allografts to reconstruct forearms following radial head excision and subsequent symptomatic proximal migration of the radius. We are concerned that we have observed some subchondral collapse, which might result in further proximal radial migration if it continues to progress. Perhaps given enough time, however, the interosseous membrane stabilizes. A larger group of patients studied and a longer follow-up period is needed to confirm the value of this operation.
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