Outcomes Following Interposition Arthroplasty of the First Metatarsophalangeal Joint for the Treatment of Hallux Rigidus: A Systematic Review

BACKGROUND: Interposition arthroplasty of the first MTP joint has recently experienced renewed interest as a treatment for hallux rigidus. The purpose of this study was to systematically review the rapidly expanding literature on PRO following interposition arthroplasty of the first MTP joint. METHODS: PubMed Central, Embase, and the Cochrane Central Register for Controlled Trials (CENTRAL) were searched. Inclusion criteria included length of time to follow-up, number of patients, outcome measure, and use of allogeneic or autogenous soft tissue or a synthetic matrix as interposition. RESULTS: 20 studies were included in the review, comprising 498 patients and 539 feet with mean time to follow-up of 4.5 years. The most common substance used for interposition in the included studies was autogenous first MTPJ capsular tissue, a technique reported on in 12 (60.0%) of the included articles. In studies reporting preoperative and postoperative outcomes by way of a standardized outcome scoring system, mean group improvements exceed minimal clinically important differences in the majority of studies. Eighty-five percent of the studies included in this review were of Level IV quality evidence, and of this subset of studies, 70.6% were of a retrospective nature. Progression to further surgery was observed in 3.8% of toes. The most common complication reported was transfer metatarsalgia of 1 or more lesser toes, observed in up to 57.9% of patients in one study. CONCLUSION: Interposition arthroplasty appears to be a viable option for the treatment of moderate to severe hallux rigidus in patients looking to salvage motion through the first metatarsophalangeal joint. A wide array of autogenous, allogeneic, and synthetic implant materials have surfaced in recent years, but long-term follow-up and prospective, comparative study designs with low risk of bias are limited. LEVEL OF EVIDENCE: Level IV, systematic review of Level III-IV studies