MCP arthrodesis using an intramedullary interlocking device

BACKGROUND A variety of metacarpophalangeal joint (MCPJ) arthrodesis techniques have been described for the treatment of symptomatic arthritis and instability of the thumb MCPJ including K wire fixation, tension-band arthrodesis, plate fixation, intramedullary screw, and other intramedullary devices. This study presents a retrospective review of one surgeon's initial series of patients undergoing thumb MCP arthrodesis using an intramedullary compression device with a fixed angle of 25°. METHODS A retrospective chart and radiographic review of patients treated for thumb MCP arthrodesis using the intramedullary device was performed. Final radiographs were evaluated for arthrodesis angle, bony fusion, and implant fixation. Any complication found during surgery or the follow-up period was noted. RESULTS In this study, 17 patients were reviewed. Indications for surgery were osteoarthritis (five patients), rheumatoid arthritis (three patients), MCP instability alone (seven patients), and post-traumatic conditions (two patients). Of these, 12 patients had a simultaneous trapeziometacarpal (TMC) soft tissue arthroplasty. Mean follow-up was 4.9 months. All 17 patients had clinical and radiographic evidence of fusion at an average of 7.9 weeks, with an average fusion angle of 24.4°. There were no hardware complications, no infections, no revisions, and no indications for hardware removal. DISCUSSION Our study results indicate the technique promotes rapid union at a precise angle, provides strong fixation that does not require prolonged immobilization, does not cause hardware irritation, and can be used in conjunction with other procedures including TMC arthroplasty when MCP arthrodesis is indicated for joint instability.