Fusion of the thumb metacarpophalangeal joint to treat posttraumatic arthritis.

Thumb metacarpophalangeal (MCP) fusion to treat posttraumatic arthritis is retrospectively reviewed in 18 patients, 16 of whom were examined and functionally tested, with an average follow-up of 18 months. All patients were satisfied. There was 100% fusion in an average of 59.9 days. Preoperative disabling MCP pain was present in all patients, and mild postoperative pain and difficulty in picking up small objects were present in 78%. Results did not depend on position of fusion or preoperative arc of MCP motion. Key pinch strength was significantly increased by fusion. Complications included four pin tract infections without sequelae and three cases of prominent tension band hardware, which were removed in two.