Changes in the Functional Range of Motion of the Thumb Metacarpophalangeal Joint After Trapeziometacarpal Arthrodesis for Patients With Advanced Trapeziometacarpal Osteoarthritis.

PURPOSE: Advanced-stage trapeziometacarpal (TMC) osteoarthritis of the thumb often presents with concomitant hyperextension deformity of the metacarpophalangeal (MCP) joint. Although several studies have reported simultaneous procedures to correct this deformity, the indication for these procedures remains controversial. The purpose of this study was to evaluate changes in the range of motion (ROM) of the thumb MCP joint before and after TMC arthrodesis.

METHODS

We evaluated the functional flexion and extension and functional ROM of the MCP joints during the performance of 10 activities of daily living tasks before and after TMC arthrodesis in 10 thumbs of 9 patients with Eaton stage III TMC osteoarthritis and hyperextension deformity of the MCP joint.

RESULTS

The mean functional flexion of the MCP joint increased from 26° to 38°, and the mean functional extension of the MCP joint decreased from 16° to 5° of hyperextension. There was no change in the mean total arc of functional ROM of the MCP joint.

CONCLUSIONS

The MCP joint motion shifted from extension to flexion after TMC arthrodesis, and the total arc of functional ROM of the MCP joint was similar before and after arthrodesis.

TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.