Outcome of Lesser Metatarsophalangeal Joint Interpositional Arthroplasty With Tendon Allograft

Background: Lesser toe metatarsal head degeneration and collapse can cause significant pain and disability. In the setting of global metatarsal head collapse, there are limited operative options. The purpose of our study was to evaluate clinical and radiographic outcomes after lesser toe metatarsophalangeal (MTP) joint interpositional arthroplasty with a tendon allograft and to describe the operative technique. Methods: We retrospectively reviewed a consecutive series of patients treated by 3 fellowship-trained foot and ankle surgeons at one institution. We created a phone survey to evaluate satisfaction, pain, and likelihood to repeat the surgery. Foot and Ankle Ability Measure (FAAM) scores were reviewed before and after surgery. Preoperative and postoperative radiographs were evaluated for preservation of metatarsal length. The procedure was performed through a dorsal midline approach. The metatarsal head was reamed to a concave shape. A tendon allograft was fashioned into a ball and secured to the metatarsal with an anchor. Fifteen feet in 14 patients underwent lesser MTP joint interposition arthroplasty, with the average age of 49 years (range, 24-69), and an average follow-up of 4.2 years. Results: Eighty percent (12/15) reported they would have the procedure again. Visual analog scale pain scores showed a decrease in pain from 7 to 1. FAAM sports subscale improved from 56% to 85%. Radiographically, the ratio of the affected metatarsal length to the adjacent metatarsal remained constant before and after surgery, suggesting preservation of the metatarsal cascade. Conclusion: Interpositional arthroplasty of the lesser MTP joints with a rolled tendon allograft provided a unique solution, as it allows the surgeon to fill a large void without harvesting an autograft. This study showed improved patient-reported outcomes, high patient satisfaction, and good radiographic outcomes. Lesser metatarsophalangeal joint allograft interposition arthroplasty was a viable solution as a salvage procedure in the setting of global metatarsal head collapse. Level of Evidence: Level IV, retrospective case series.