Early Outcomes of a Synthetic Cartilage Implant for Treatment of Hallux Rigidus: A Series of 87 Patients

Abstract

Category:Midfoot/Forefoot; BunionIntroduction/Purpose:Arthritis of the first metatarsophalangeal joint (MTPJ), or hallux rigidus, is the most common arthritic condition of the foot, affecting 1 in 40 people over 50 years of age. One surgical option is the implantation of a synthetic polyvinyl alcohol hydrogel implant that has water content, tensile strength, and biomechanical properties similar to those of healthy human cartilage. This implant is supported by positive outcomes in a Level 1 clinical trial out to over 5 years follow-up. The objective of this case series was to determine if the positive results seen in the pivotal trial could be recreated in a ‘real world’ setting.Methods:All patients implanted with a synthetic cartilage implant by a single surgeon between September 2016 and December 2018 were retrospectively reviewed. Consecutive adult patients diagnosed with hallux rigidus that failed nonoperative treatment were included in the analysis. Patient demographics, complications, Foot and Ankle Ability Measures (FAAM), and a 10-point visual analog score (VAS) were collected from the chart review.Results:A total of 87 patients were available for review during the time interval of interest with a mean length of follow-up of 38.7 weeks (range, 2-125). The average patient age was 56.6 years (range, 21-80). Two (2.3%) patients were converted to fusion. The first at 71 weeks and the second at 73 weeks following the initial surgery. Six (6.9%) patients experienced some complications: 3 cases of synovitis treated with corticosteroid injection; 1 case of sesamoiditis; 1 case of neuritis; and 1 insufficiency fracture at the plantar aspect of the MTPJ with implant subsidence. Patients had mean FAAM ADL and VAS scores of 81.2 (range 21-100) and 0.6 (range, 0-3), respectively, at final follow-up.Conclusion:This retrospective review is one of the first presentations of outcomes for a synthetic cartilage implant in a ‘real world’ setting. Patients experienced excellent pain relief, good functional outcomes, and a satisfactory survival rate. This case series confirms the positive results seen in the original pivotal trial for this device.