Complications and Unplanned Reoperation After Thumb Metacarpophalangeal Arthrodesis

Purpose: Arthrodesis of the metacarpophalangeal (MCP) joint of the thumb is a common procedure to treat arthritis or instability. Studies reporting hardware complications and nonunion rates after thumb MCP joint arthrodesis report on small sample sizes. We aimed to describe the hardware complication rate, the nonunion rate, and the number of thumbs that achieve union among patients undergoing thumb MCP joint arthrodesis. Methods: A database spanning 5 urban hospitals in a single metropolitan region in the United States was searched for patients who underwent thumb MCP joint arthrodesis between January 1, 2004 and January 1, 2020. After reviewing patient records, we identified 122 thumbs that underwent MCP joint arthrodesis and had a minimum follow-up of 90 days. The primary outcome was unplanned reoperation after hardware complications and nonunion. Second, the number of thumbs that achieved radiographic union was reported for the tension band and screw fixation arthrodesis group. Results: Twenty-two (18%) out of 122 thumbs had hardware complications after thumb MCP joint arthrodesis, and 11 (9%) out of 122 thumbs developed a nonunion. Patients who underwent screw fixation arthrodesis had no events of hardware complications and subsequent hardware removal. The nonunion rate was 9/65 (14%) in the tension band arthrodesis group and 2 (4%) of 45 in the screw fixation arthrodesis group. Of the thumbs that had available radiographs to assess the healing of the arthrodesis, 34 (81%) of 42 were radiographically united in the tension band arthrodesis group and 29 (91%) of 32 in the screw fixation group. Conclusions: Our data suggest that screw fixation has fewer hardware complications and a lower reoperation rate than tension band arthrodesis. Type of study/level of evidence: Prognosis IV.