gms | German Medical Science

Objectives/Interrogation: The aim of the study was to report outcomes after around 10 years following pyrocarbon interposition (PyroDisk) trapeziometacarpal joint implant with partial trapeziectomy for carpometacarpal osteoarthritis of the thumb in a single center.

Methods: We retrospectively reviewed the longterm clinical and radiological outcomes of 16 patients who had a pyrocarbon interposition implant (PyroDisk; Integra Life Sciences, Plainsboro, NJ) arthroplasty, with partial trapeziectomy. The rate and causes of repeat surgeries, and complications were examined.

Results and Conclusions: The mean follow-up period was 115 months. Patient satisfaction was high. The mobility of the operated thumb was restored to a range of motion comparable to the contralateral thumb. Grip strength was improved. Overall function, according to the Quick DASH and PWRE scores, showed a good improvement. Pain decreased in all cases according to the numerical rating scale. Radiological evaluation revealed no progression of the periprosthetic lucency of the implant after 2 years in 11 of 16 patients. Progression of lucency did not predict implant loosening or failure at 10 years. Scaphotrapeziotrapezoid joint was preserved in all cases. No patient had symptomatic instability that required revision. No dislocations occurred. The 10-year survival of the prosthesis was 100%, but only 8 patients (50%) have forgotten their thumb.

The PyroDisk implant for treating advanced trapeziometacarpal arthritis did not demonstrate superiority over published outcome data of other prosthesis or total trapeziectomy with or without ligament reconstruction and tendon interposition. Indeed, the perceived expectation of these procedures is to be able to achieve the "forgotten thumb". However, in several particular cases, like nickel allergy for example, Pyrodisk can be still proposed.