[First results after implantation of a pyrocarbon-endoprosthesis in patients with degenerative arthritis].

Abstract

Aim: Evaluation of an unconstrained pyrocarbon prosthesis (Ascension) in the treatment of idiopathic degenerative arthritis of the proximal interphalangeal joint of the hand.

Methods: In this study 10 patients (13 implants), that were treated with this type of prosthesis between February 2002 and January 2005 were clinically and radiologically studied.

Results: All but one patient were satisfied with the postoperative situation and would agree to another operation. A significant pain reduction was observed. The average ROM was 58 degrees. Five patients demonstrated a free extension, two patients had a swan neck deformity, which could be actively compensated for, and the remaining six patients had an extension deficit of 30-45 degrees. The average flexion was 76 degrees (+/-12 degrees). X-ray examination was unremarkable in eight patients with a regular position of the endoprosthesis. However, in five patients significant radiolucent lines (>or=1 mm) were observed. So far, a luxation of the prosthesis has not occurred and all implants are still in-situ. However, a dorsal tenoarthrolysis had to be performed in 3 patients.

Conclusion: The results of this study show a high rate of patient satisfaction with a significant pain reduction. A missing osteointegration may be an explanation for the radiological results. The prosthesis has to be closely monitored in the future. Long-term results with a higher number of patients are necessary. A central registry for finger implants is recommended.