Function Assessment for Rheumatoid Thumb Deformity

Abstract

Objective: Nalebuff's type I deformity of the rheumatoid thumb, which is the most common thumb deformity with rheumatoid arthritis, can be classified into three stages according to the range of motion of the thumb. However, a functional assessment for each stage has never been undertaken. Methods: The ranges of motion of the thumb metacarpophalangeal and interphalangeal joints were evaluated to determine Nalebuff's clinical stage, and both the Modified Kapandji Index (MKI) and the simple test for evaluating hand function (STEF) were used to evaluate hand function in 32 rheumatoid arthritis patients with type I deformity. We assessed hand function in each stage, and examined the relationship between the three clinical stages and dysfunction of the hand. Results: The scores for both MKI and STEF were significantly reduced in parallel with advancing stage of thumb deformity. Conclusion: Nalebuff's staging system is also useful for reflecting the level of thumb function.

A New Approach for the Correction of Type I Thumb Deformity Owing to Rheumatoid Arthritis

“…Type I thumb deformity, also known as a boutonniere deformity, causes flexion and palmar dislocation of the MCP joint as a result of synovitis; these symptoms subsequently progress toward hyperextension of the IP joint. 1 Rerouting of the EPL attempts to correct flexion of the MCP joint and hyperextension of the IP joint by tenodesis of the EPL on the proximodorsal aspect of the proximal phalanx. 3 , 10 Terrono and Millender 10 reported a high recurrence rate of 60%, and deformity progression could not be prevented even when adapted for early-stage patients.…”

“…It occurs frequently and causes cosmetic and functional disorders in hand grip, pinching, and activities of daily living. 1 Among the joints affected, the distal thumb is commonly involved and prone to functional disorders. Treatment of distal thumb deformities is a significant subject in the approach to rheumatoid hands, because the thumb has such an important role in hand function.…”