Two-Year Clinical Outcomes of Patients Undergoing Synthetic Cartilage Arthroplasty for First Metatarsophalangeal Osteoarthritis.

Background Severe osteoarthritis (OA) of the first metatarsophalangeal joint (MTPJ) is usually treated by arthrodesis, which results in a loss of mobility in the joint. Cartiva (Stryker Corporation, Kalamazoo, USA) is a synthetic cartilage implant (SCI) designed to repair osteochondral defects in the treatment of the first MTP OA. Treatment using the Cartiva SCI should relieve symptoms of OA whilst sparing motion in the first MTPJ and may provide a superior alternative to arthrodesis. Objectives The objective of this article is to assess the clinical outcomes of a novel SCI, Cartiva, for arthroplasty in the management of the first MTPJ arthritis. Study design and methods We retrospectively reviewed 64 patients who had received a total of 67 Cartiva implants between May 2016 and June 2020. The average age of these patients at the time of surgery was 54.3 years with a range from 19 to 77 years. Forty-five of the 67 implants were used in females and 22 were used in males. Radiological Grade 2 OA was present in 46 cases with Grade 3 in 21 (Hattrup and Johnson classification). Validated patient-reported outcomes measures (PROMs) were used to assess the functional efficacy of the implants. All cases were performed by a single surgeon. The PROMs data was collected via follow-up phone calls with the patients who were asked questions from the American Academy of Orthopaedic Surgeons' Foot and Ankle Measure (AAOS-FAM), the EQ-5D-3L survey and the Manchester-Oxford Foot and Ankle Questionnaire (MOXFQ). All data collected was anonymised to preserve confidentiality and local hospital ethics committee approval was sought. All statistical analysis was done using Microsoft Excel (Microsoft® Corp., Redmond, WA) and Statistical Package for the Social Sciences (IBM SPSS Statistics for Windows, IBM Corp., Version 23.0, Armonk, NY). Results There was a significant improvement in all PROMs at three years, and one patient developed an implant-related infection. The average scores for the EQ-5D-3L survey significantly improved from 0.69 to 0.85 post-operative (post-op) (p<0.05). The mean MOXFQ scores improved from 42.5 to 15.4 post-op (p<0.05). The radiologic evaluation demonstrated satisfactory implant positioning in all cases at the last follow-up. Conclusions The data shows significant improvements between pre-op and post-op scores. The implication of this is that synthetic cartilage arthroplasty provides a viable alternative to arthrodesis in the treatment of OA affecting the first MTPJ. However, more studies may need to be done focusing on larger sample sizes and patients should be observed over a longer term, including a formal multi-centred clinical trial.