Deformities JOHN
of the Rheumatoid
L. SBARBARO,
JR., M.D.,
From Hand Service, Department of Orthopaedic Surgery, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania. FUNCTION is one of man’s greatest assets. In fact it has made his civilization possible. Sensation and proprioception are developed to the highest degree, and coordinated movement has its greatest expression in the human hand. It is no wonder that a hand ravaged by disease leaves the person severely disabled. In the rheumatoid hand, sensation and proprioception are usually preserved. However, there are occasions when rheumatoid nodules or reactive synovitis will produce sensory changes by compression. The vast majority of patients with rheumatoid hands present with synovitis or the secondary changes which occur as a result of synovitis. In the past, much time has been devoted to the study and treatment of the rheumatoid hand by corrective splinting and the various modalities of physical medicine. It has only been in recent years that the surgical approach to the problem has been applied to any signiticant degree. With an increasing experience in the rheumatoid hand, it is becoming more and more evident that the basic problem lies in the pathologic synovial membrane. Muscle spasm, tendon rupture, and joint deformity are all secondary manifestations of the disease. It is known that rheumatoid arthritis is a systemic disease with its principal manifestation at the joint level and that the rheumatoid process acts primarily on the connective tissue cells of the synovial tissue. Cartilage and bone are only secondarily involved by reactive and degenerative changes. The rheumatoid process provides the stimulus for synovial proliferation which is characterized by thickening of the
H
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Hand
Philadelphia, Pennsylvania
mesothelial layer and great enlargement of the subsynovial layer. The surface of the synovial membrane abounds with grape-like or nodular appendages produced by a proliferation of synovial cells and hypertrophy of the subsynovial layer. In the joint this pathologic tissue produces a pathologic fluid which impairs cartilage metabolism. In the tendon sheath this hypertrophic synovial tissue envelops the tendon and may devitalize the structure. It may also invade the substance of the tendon proper. This is indeed an aggressive synovial tissue which has its inception and development long before there is any evidence of cartilage and bone deterioration or tendon disruption. The future course of this disease process depends upon the activity of this membrane. This is a capricious disease whose activity waxes and wanes. In most instances the synovial reaction can be controlled by appropriate medication. There are, however, some patients whose disease cannot be controlled with current medical measures, and it is these patients who may benefit by an early surgical procedure. If medical measures have failed to produce a satisfactory remission in an appropriate period of time, serious consideration should be given to surgical extirpation of the diseased synovial membrane. It has been shown that once adequate synovectomy has been performed, the likelihood of recurrent disease in the synovectomized joint is rare. To perform synovectomy early in the course of the disease is a much simpler procedure than major reconstruction at a later date. Rheumatoid activity as such is no longer considered a contraindication to surgery. This is not intended to mean that surgery should be performed during an acute exacerbation for this is rarely, if ever, necessary. Rather, it is intended to mean that surgery may well be per-130
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Deformities of Rheumatoid Hand
formed during the subacute and chronic stages of the disease. The principal point to be emphasized is that the rheumatoid process at the joint level may well be an uncontrollable synovial reaction. If this abnormal synovial membrane is removed early in the course of the disease, many of the late sequelae can be averted and the joint can be maintained at a near normal status. If this invasive process is allowed to continue unabated, advanced destruction and grotesque deformity will develop. In the severely deformed hand only salvage procedures can be offered to improve hand function, and any small gain is greatly appreciated by the patient. The great challenge is in the hand with minimal involvement, for it is in this hand that the disease should be arrested before irreparable damage is done. With a clearer concept of functional anatomy, many of these hands are being restored to usefulness. Surgical removal of the pathologic synovial membrane has given encouraging results, for it has been demonstrated that the disease process can be arrested. The rheumatoid hand has characteristic deformities at the various sites of involvement, and it is the purpose of this paper to review the pathologic anatomy and to discuss the mechanisms of deformity. Classification is helpful in orienting our thinking, and it is for this reason that the deformities will be categorized according to anatomic areas. It is important to realize that the hand functions as a whole and what
may initially appear as an isolated lesion may have far reaching effects. WRIST
DEFORMITIES
Dorsal Tenosynovitis. One of the most common expressions of the disease is dorsal tenosynovitis. (Fig. 1.) This synovitis is initiated by an inflammatory reaction in the synovial membrane which surrounds the extensor tendons at the wrist. The presenting complaint is a slowly progressive swelling over the dorsurn of the wrist. It is at this stage that the lesion is cystic and contains fluid. Many of these early lesions can be adequately treated by aspiration and compression. With progression of the inflammatory process, the synovial tissue proliferates and hypertrophies into a shaggy fungating mass which converts the cyst into a solid mass. Further progression of this destructive process produces tendon destruction. (Fig. 2.) Opinion is divided as to whether this tendon destruction is produced by direct tendon invasion or secondary attritional change. The extensor tendons of the fourth and fifth fingers are the most frequently ruptured, although rupture of the extensor pollicus longus is by no means rare. Involvement of the distal radioulnar joint is frequently associated with dorsal tenosynovitis. Joint distention and capsular attenuation may result in dorsal dislocation of the distal ulna. If there is a persistence or progression of this synovial mass on the dorsum of the wrist, it should be removed surgically. Once tendon
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FIG. 3. Ulnar drift and subluxation of metacarpophalangeal joint. Dorsal hood is displaced into ulnar SUICUS.
rupture with dropping of one or more fingers has occurred, surgical reconstruction is necessary to restore function. If the distal ulna has dislocated and is prominent on the dorsum of the wrist, excision of the distal inch is indicated. Arthritis of the Wrist Joint. Synovitis of the radiocarpal joint results in a painful wrist with joint destruction and ultimate deformity. When the deformity produces significant impairment of hand function, arthrodesis of the wrist in the position of function will give a painless, stable, and useful hand. CarFal Tunnel Syndrome. On the volar aspect of the wrist, synovitis deep to the transverse carpal ligament will produce increasing tension in the unyielding fibro-osseous tunnel. The most common clinical manifestation of this condition is a median nerve neuritis or carpal tunnel syndrome. Decompression of the carpal tunnel is readily accomplished by division of the volar transverse carpal ligament and excision of a small segment of the ligament. Release of this ligament has not produced any weakness or functional impairment of the wrist. FINGER
JOINT DEFORMITIES
Early involvement of the Ulnar Dri$ metacarpophalangeal joint is characterized by and joint effusion, synovial hypertrophy, loosening of the capsular and ligamentous structures of the joint. The patient will complain of painful swollen joints during the acute phase. Gradually the symptoms subside as the chronic phase is entered. However, the synovial membrane continues to proliferate and invade
the local structures. With progressive distention of the capsule and attenuation of the ligaments, the joint becomes lax and disorganized. The dorsal hood displaces into the ulnar sulcus and the finger drifts into ulnar deviation. (Fig. 3.) The dorsal hood consistently goes to the ulnar side of the metacarpophalangeal joint because of the oblique pull of the long finger extensors when the wrist is in the functional position. When the long extensor tendon is displaced off the metacarpal head, it can no longer effectively extend the metacarpophalangeal joint. Intrinsic muscle spasm and/or flexor tendon over-pull will then maintain the finger in the flexed position. Continued rheumatoid activity of the metacarpophalangeal joint will ultimately result in complete dislocation of the finger. The skin over the metacarpal head may be so tightly drawn that ischemia and ulceration result. Usually all four metacarpophalangeal joints are involved simultaneously with the radial fingers presenting the greatest deformity. The treatment of this deformity is largely dependent on when the condition is first seen. If seen early, when there is merely synovial proliferation and joint distention, synovectomy and capsular plication will arrest the process and stabilize the joint. As ulnar drift and joint destruction become manifest, arthroplasty and reconstruction are necessary. Swan Neck. Deformities of the proximal and distal interphalangeal joints are seen in combination. The swan neck deformity, as it is frequently called, is characterized by hyperextension of the proximal interphalangeal joint and flexion of the distal interphalangeal joint. (Fig. 4.) It is the most frequently encountered deformity of the interphalangeal joints and is commonly seen in association with a flexion deformity of the metacarpophalangeal joint. This combination of flexion of the metacarpophalangeal joint and hyperextension of the proximal interphalangeal joint is known as the intrinsic plus or intrinsic positive position. It is produced by muscle spasm or contracture of the intrinsic mechanism. The basic problem is again an aggressive synovial membrane. AS in the metacarpophalangeal joint the capsule is distended and the ligaments are attenuated by the proliferative and invasive synovial tissue. The lateral bands which are intimately associated with joint function are displaced dorsally and become adherent to the central slip of the
Deformities of Rheumatoid
43;;
Hand
FIG. 4. Swan neck cu grasslioppcr defurmity. This is a 11ypcrextenGon deformity of the proknal intcr],hulallg~~~l joint and flexion deformity of the distal interpl~alangcal joiut. Patkilt ;1150II:IS nswciated ulnar tlrift :tt thr met:tcarpophalangenl joints. FIG. 5. BoutonniZre deformity. This is a fised fle?tion deformity :rt the proximal illterl)halangeal joint and hyp
formity of the proximal interphalangeal joint with consequent hyperextension of the distal interphalangeal joint. Surgical experience with this lesion is limited. Soft tissue procedures have been largely unsuccessful. However, arthrodesis of the prosima1 interphalangeal joint in the position of function will rid the pahn of the flexed digit. The flexor tendon sheath Snapping h’inger. is lined with a synovial membrane which may be involved in the rheumatoid process. The fibro-osseous tunnel is a semirigid structure, and the synovial proliferation leads to encroachment on the gliding tendon. Clinically, the patient complains of a snapping finger. and on examination a mass may be palpated in the palm in the region of the metacarpal head. These lesions usually respond to conservative measures. However, there are occasions when release and excision of the sheath are necessary. There are a few instances in which rupture c,f-a flexor tendon has occurred. TIIUMB
DEFORMITIRS
The joints of the thumb are frequently involved in the destructive process of rheumatoid activity. The interphalangeal joint is the most common site. The patient will complain of pain, instability, and inability to pinch. Clinically the joint is either subluxated or completely dislocated. Since the thumb represents 50 per cent of hand function, significant impairment
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is a severe disability. The treatment of choice is stabilization by arthrodesis of the joint. This is a relatively small procedure, and the results have been very gratifying. The interphalangeal joint is usually fused in full extension. It is uncommon for more than one joint in the same thumb to require fusion. NODULES
Rheumatoid nodules may occur anywhere in the soft tissues of the hand. They are frequently asymptomatic and require no specific therapy. Pain may occur when a nodule is located on an opposing surface or adjacent to a digital nerve. Grossly, the nodule is firm and has a fibrous consistency. Microscopically, the nodule demonstrates the nonspecific inflammatory changes of rheumatoid disease. For symptomatic nodules, local excision of the lesion is the treatment of choice.
Dorsal tenosynovitis, tendon rupture, and deformity of the wrist may be satisfactorily managed by the surgical approach. Ulnar drift, swan neck, and boutonniere deformities are difficult to treat. There are several procedures available. However, there is no completely satisfactory answer at the present time. Stabilization of the thumb gives good results because its functional demand is that of a stable opposable post. Each hand must be individually evaluated so that a carefully planned approach may be formulated. The functional demand required of the hand will usually influence the treatment. It is not necessary to wait for the burned-out or arrested stage before definitive treatment is instituted. Early synovectomy is indicated before irreversible damage has been produced. REFERENCES
SUMMARY
The deformities of the rhuematoid hand are produced by an inflammatory process which has its main expression in the synovial tissue.
1.
L. R. The rheumatoid hand. Cl&. Orthop., 15: 127, 1959. 2. STRAUB, L. R. Surgery of the arthritic hand. West. J. Surg., 68: 5, 1960. STRAUB,
American
Journal of Surgery