Outcomes After Interpositional Arthroplasty of the First Metatarsophalangeal Joint

Background: For patients with hallux rigidus seeking a motion-sparing procedure, interposition arthroplasty is an alternative to fusion. The purpose of this study was to report patient outcomes after interpositional arthroplasty for hallux rigidus. Methods: All patients undergoing interpositional arthroplasty at our institution from 2001 to 2014 were identified and a retrospective chart review was performed. Follow-up was conducted through a telephone survey to obtain survivorship, satisfaction, and functional scores. Survivorship of the interpositional arthroplasty procedure was defined as no subsequent surgery on the hallux after the index procedure. Patients were excluded for incomplete records. Complications were recorded. From 2001 to 2014, 183 patients were identified. Of these, 14 were excluded for incomplete data, leaving 169 patients. Of these, 133 had an average follow-up of 62.2 months (range, 24.3 months to 151.2 months). Results: The overall failure rate was 3.8% (5/133). Patient-reported outcome was rated as excellent in 65.4% (87/133) or good in 24.1% (32/133) of patients and fair or poor in 10.5% (14/133) of patients. Of 133 patients, 101 (76%) were able to return to fashionable or regular footwear. The infection rate was 1.5% (2/133). Patient-reported cock-up deformity of the first metatarsophalangeal joint (MTPJ) occurred in 4.5% (6/133) of patients. In addition, 17.3% (23/133) of patients reported metatarsalgia of the second or third MTPJ at the time of final follow-up, and there was no significant difference between interposition types (P = .441). Conclusion: Interpositional arthroplasty for hallux rigidus was found to have excellent or good results in most patients at a mean follow-up of 62.2 months. Level of Evidence: Level IV, retrospective case series.