MatOrtho proximal interphalangeal joint arthroplasty: minimum 2-year follow-up.

The MatOrtho proximal interphalangeal replacement is a cementless cobalt-chromium metal-on-polyethylene mobile-bearing surface replacement arthroplasty. The aim of this study is to report the outcome and complications of this implant at a minimum of 2 years follow-up from a single institution. A retrospective case review was performed on all MatOrtho proximal interphalangeal joint replacements performed with a minimum of 2 years follow-up. Patient demographics, diagnosis, implant revision and other surgical interventions were recorded. Subjective and objective outcomes were evaluated at latest follow-up, including pain scores, range of motion, function and radiographic assessment. A total of 109 implants were inserted in 56 patients. Nine implants (six patients) were lost to follow-up. Of the remaining 100 implants, 75 had been undertaken in females. The mean age at time of surgery was 64 years and the principal diagnosis was osteoarthritis in 74%. The mean follow-up was 47 months (range 24-77). Within the group there was a statistically significant diminution in pain. There was also an improvement in functional scores post-operatively. Improvement in range of motion was seen in those joints with a pre-operative range of motion greater than 20°. Radiologically there was no evidence of loosening or of implant subsidence at final follow-up. The revision rate was 13%. Nine joints were revised to the NeuFlex (silicone rubber) prosthesis, three were converted to an arthrodesis and one had exchange of the MatOrtho prosthesis. The survival of the MatOrtho proximal interphalangeal joint arthroplasty was 85% at a minimum of 2-years follow-up. Patients can be advised that the procedure achieves good pain relief, improvement in functional scores and may improve range of motion. We would, however, caution against this implant's use in joints that are either stiff or have significant deformity and/or instability pre-operatively.