Interpositional Arthroplasty in the Treatment of Hallux Rigidus: A Systematic Review

Hallux rigidus is the most common arthritic condition of the foot. Interpositional arthroplasty (IPA) is indicated for advanced-stage hallux rigidus and attempts to maintain joint motion through insertion of a biologic spacer into the joint. However, the data evaluating the effectiveness of IPA are limited. The purpose of this study was to systematically review the outcomes of IPA in the treatment of hallux rigidus. MEDLINE, EMBASE, and Cochrane Library databases were systematically reviewed based on the preferred reporting items for systematic reviews and meta-analyses guidelines. Outcomes collected and analyzed included: American Orthopaedic Foot and Ankle Society (AOFAS) hallux metatarsophalangeal-interphalangeal (HMI) score, visual analogue scale score, short-form 36 score, range of motion (ROM), radiographic parameters, and postoperative complications. The level and quality of clinical evidence were recorded and assessed. Sixteen studies with a total of 428 patients met inclusion/exclusion criteria. The mean AOFAS-HMI score improved from 51.6 ± 10.1 (range 35.0-64.2) preoperatively to 86.0 ± 7.7 (range 71.6-95.4) postoperatively (p ≤ .001) at weighted mean follow-up of 58.0 ± 34.5 (range 16.5-135.6) months. The preoperative weighted mean total ROM was 39.3° ± 9.6° (range 24.2-49.9) and the postoperative weighted mean total ROM was 61.5° ± 4.8° (range 54.0-66.5) (p ≤ .001). The complication rate was 21.5% with metatarsalgia as the most commonly reported complication. One study was level 3 and 15 studies were level 4 clinical evidence. This systematic review demonstrates improvement in functional and ROM outcomes following IPA procedure at mid-term follow-up. The procedure however has a moderate complication rate. In addition, there is a low level and quality of evidence in the current literature with inconsistent reporting of data.