How are the common problems of the wrist in Rheumatoid Arthritis managed surgically?
RA has a predilection for the small joints of the hand and wrist. The wrist is almost universally involved and usually presents predictable patterns of involvement and resultant deformities. The goal of medical management lies in control of the inflammatory synovitis to prevent destruction of bony and soft-tissue structures. When this fails, surgery can be used to remove inflammatory synovium or correct deformity.
The dorsal wrist capsule and dorsal tendon sheath are commonly involved with synovitis and tenosynovitis that can lead to extensor tendon rupture. Prevention of tendon rupture is far better than tendon transfer and, therefore, if medical control is inadequate, early surgical synovectomy and tenosynovectomy are warranted. The term Vaughn-Jackson syndrome is applied when the extensor tendons of the ring and small finger have ruptured. Primary tendon repair is usually not possible, especially if the rupture occurred longer than a few days previously. Tendon transfer surgery is then required to restore function.
On the volar aspect of the wrist, tenosynovitis of the flexor tendons can cause compression of the median nerve in the carpal canal, leading to carpal tunnel syndrome. It can also lead to rupture of the flexor pollicis longus tendon, leading to inadequate thumb flexion and resting hyperextension at the interphalangeal joint. This is the Mannerfelt syndrome and requires tendon transfer or arthrodesis of the interphalangeal joint of the thumb.
The distal radioulnar joint is commonly involved by synovitis, which leads to laxity of this joint, osseous destruction of the ulnar head, and pain with forearm rotation. The ulnar head becomes dorsally prominent and adds to stress on the ulnar extensor tendons. This constellation of findings is called the caput ulna syndrome. Its surgical management entails aggressive synovectomy, ulnar head excision, capsulorrhaphy, and lateral tenodesis using a portion of the extensor carpal ulnaris tendon.
When the radiocarpal joint is involved with advanced changes, total wrist arthroplasty (TWA) or wrist arthrodesis can be used to control pain and improve function in over 90% of patients. However, over 20% of patients receiving a TWA will need a revision.