Mid-term Results of the MOJE Hallux MP Joint Replacement

Abstract

Background: There are reports of good early results in small numbers of patients implanted with the ‘Moje’ ceramic prosthesis. Published evidence thus far involves only small groups of patients with short-term followup. The purpose of this prospective study was to evaluate the emerging mid-term clinical and radiographic results from our center. Materials and Methods: We describe our single-surgeon experience of 63 components in 48 patients at a mean followup of 44 months. Patient satisfaction was assessed by questionnaire and radiographic assessment performed immediately post operatively and at the latest followup. Results: Mean American Orthopaedic Foot and Ankle Society (AOFAS) Hallux score increased from 56 to 72 ( p >0.01) and mean satisfaction score was 7.6 (scale 1–10). Sixty-seven percent reported minimal or no pain. Five implants have been removed (8%), four because of pain associated with implant loosening and subsidence, and one because of deep infection. Fifty-seven percent of metatarsal and 56% of phalangeal components had subsided and we found radiographic evidence of loosening in 58% of X-rays analyzed at latest followup. Prosthetic subsidence was associated with greater margin of uncovered bone under the prosthesis ( p = 0.05 for metatarsal, p = 0.03 for proximal phalanx component) and longer followup ( p >0.001). Conclusion: In spite of the good clinical outcome at the mid-term stage with 91% implant survival, given the widespread loosening and subsidence encountered in our study, the long-term outcome following this procedure is uncertain. Level of Evidence: III, Prospective, Case Control Study