In-Service Exam
Hand - Rheumatoid - 2003





A 60-year-old woman with advanced rheumatoid arthritis has been unable to extend the ring and small fingers of the left hand for the past three months. The fingers can be passively extended, but the patient cannot maintain extension. A photograph is shown above.

Appropriate management of this patient would include which of the following procedures?

(A) Arthroplasties of the metacarpophalangeal joints
(B) Centralization of the extensor tendons
(C) Excision of the distal ulna
(D) Release of the radial tunnel
(E) Synovectomy of the radiohumeral joint

The correct response is Option C.

In this patient who has rheumatoid arthritis affecting the ulnocarpal joint, the carpus is supinated on the distal forearm, resulting in a relative prominence and dorsal subluxation of the distal ulna (caput ulna). Attrition ruptures of the common extensor tendons occur in this area and are typically caused by progressive erosion from rheumatoid synovitis. In severe cases, bone spurs and spicules can accelerate this process. Extensor tendon ruptures generally occur in a pattern beginning at the ulnarmost digits and extending to the radial digits (ie, Vaughn-Jackson progression). If left untreated, this patient is at increased risk for rupture of the common extensor tendons affecting the small finger first and then the ring finger.

Excision of the distal ulna, also known as the Darrach procedure, can be used to decrease the prominence of the distal ulna and to correct the supination of the carpus through reefing of the ulnar carpal ligaments. This procedure will
result in improved supination and pronation of the forearm. The distal ulna can be stabilized dynamically using several different techniques. Although the ruptured extensor tendons can be repaired directly or through grafting, they are more commonly transferred to the intact radial extensors. Complete synovectomy and transposition of the extensor tendon retinaculum can be performed adjuvantly to prevent further attrition ruptures.

Attrition ruptures at the level of the metacarpophalangeal (MP) joints are rare. Arthroplasty is indicated in patients with advanced rheumatoid arthritis who have severe degeneration and subluxation of the joints, but is not appropriate for correction of extensor tendon deficits.

Centralization of the extensor tendons is appropriate management of subluxation of the extensor tendons at the MP joints. Patients with this condition are able to maintain the digits in an extended position after they are passively placed in extension.

Release of the radial tunnel is indicated for management of posterior interosseous nerve palsy, and synovectomy of the radiohumeral joint is appropriate in patients with radial tunnel syndrome or compression neuropathy.

References
1. Bowers WH. The distal radioulnar joint. In: Green DP, Hotchkiss RN, Pederson WC, eds. Operative Hand Surgery. 4th ed. New York, NY: Churchill Livingstone, Inc; 1999;1:1019-1021.
2. Bowers WH, Zelouf DS. Treatment of chronic disorders of the distal radioulnar joint. In: Lichtman DM, ed. The Wrist and Its Disorders. 2nd ed. Philadelphia, Pa: WB Saunders Co; 1997:438.
3. Feldon P, Terrono AL, Nalebuff EA, et al. Rheumatoid arthritis and other connective tissue diseases. In: Green DP, Hotchkiss RN, Pederson WC, eds. Operative Hand Surgery. 4th ed. New York, NY: Churchill Livingstone, Inc; 1999;2:1670-1678.

In patients with rheumatoid arthritis, attritional rupture of which of the following tendons is most likely?

(A) Flexor digitorum profundus of the index finger
(B) Flexor digitorum profundus of the small finger
(C) Flexor digitorum superficialis of the index finger
(D) Flexor digitorum superficialis of the small finger
(E) Flexor pollicis longus

The correct response is Option E.

Patients with rheumatoid arthritis often experience attritional ruptures of the extensor and flexor tendons. Dorsal subluxation of the distal ulna typically results in ruptures of the extensor tendons in an ulnar-to-radial pattern. Ruptures of the flexor tendons occur most commonly in the carpal canal. Spurs have been shown to develop over a portion of the distal pole of the scaphoid, and the tendons often rupture over this region.

Ruptures of the flexor pollicis longus are most common, followed by the flexor digitorum profundus of the index finger. The flexor digitorum superficialis of the index finger and flexor digitorum profundus of the long finger are also frequently ruptured.

Reference
1. Feldon P, Terrono AL, Nalebuff EA, et al. Rheumatoid arthritis and other connective tissue diseases. In: Green DP, Hotchkiss RN, Pederson WC, eds. Operative Hand Surgery. 4th ed. New York, NY: Churchill Livingstone, Inc; 1999;2:1651.