Background: Metacarpophalangeal (MCP) joint arthritis is common secondary to a variety of inflammatory, degenerative, and traumatic causes. Although MCP arthroplasty is more common for the second to fifth digits, primary arthrodesis can be used for high-demand patients with arthritis or unsalvageable fractures of the MCP joint. There has been limited recent studies on the outcomes of these patients.
Methods: A retrospective review of 38 fingers in 27 patients with primary arthrodesis from 1990 to 2020 was conducted. The major outcomes were complications, reoperations, radiographic union, and time to union. Patient-reported outcomes including the Michigan Hand Outcomes Questionnaire and a questionnaire specific to the operative MCP joint were collected.
Results: Rate of radiographic union was 84% including revisions. The average time to union was 3.6 months. Rates of complications, reoperation, and amputation were 26%, 16%, and 7%, respectively. Arthrodesis as part of emergent trauma reconstruction was significantly more likely to result in reoperation (50% vs 7%) and complication (63% vs 17%) than chronic arthritis. Patient-reported outcomes were fair to good with improvement in pain (79%), function (66%), and appearance (40%). Sixty-six percent (66%) of patients were satisfied with their surgery, and 73% would repeat the surgery.
Conclusion: Arthrodesis for unsalvageable MCP fractures was associated with higher rates of reoperation and complication than inflammatory or degenerative arthritis. Excluding emergent trauma, MCP fusion was reliable with a reoperation rate of 7% and a modest complication rate of 17%. Patients rated reasonable levels of satisfaction and willingness to repeat the procedure despite complications.
Keywords: anatomy; arthrodesis; hand; patient outcomes; primary arthrodesis; thumb metacarpophalangeal joints.