MOJE Ceramic Metatarsophalangeal Arthroplasty: Disappointing Clinical Results at Two to Eight Years

Abstract

Among the surgical treatment options for osteoarthritis of the first metatarsophalangeal joint (MTPJ) are a number of different designs of total arthroplasty, including the MOJE, a ceramic press fit arthroplasty. We present a 2- to 8-year followup of 31 procedures. Thirty-two MOJE arthroplasties were undertaken for painful hallux rigidus in 30 patients (nine male, 21 female) over 6 years (mean age 61.9; range, 37 to 76). At followup patients' symptoms, levels of function and radiographs were scored using SF-36, modified Kitaoka and AOFAS systems. Followup rate was 97%, with mean followup time 58 months (range, 28 to 97). Mean scores were: Kitaoka 53.8 (15 to 75), AOFAS 61.3/100 (range, 18 to 100), SF-36 physical combined 48.6 (27.6 to 58.7) SF-36 mental score 52.2 (19.5 to 62.2). Sixteen showed radiological evidence of component loosening (either lucency, subsidence or both) and one radiograph revealed component fracture. Eight implants have been revised. In patients who had not undergone subsequent fusion, 15 had less than 36 degrees of movement, nine had 36 to 45 degrees, four were in the 46 to 60 range, and only one had more than 60 degrees. There were no infections. Although previous studies have suggested favorable initial outcomes with the MOJE prosthesis, all have focused only on the early results. In our series, the reoperation rate of 26% at up to 8 years is worryingly high, especially given that 16 (52%) showed loosening. Although there appears to be a cohort of patients who have satisfactory outcomes with the MOJE, we would suggest the continued use of this implant.