gms | German Medical Science

Objectives/Interrogation: The Pyrocardan® trapezometacarpal interposition implant is a free intra-articular spacer composed of pyrocarbon. It is a biconcave resurfacing implant that is both ligament and bone-stock sparing. A primary indication for use is early- to moderate-stage trapezometacarpal osteoarthritis. This study examined survivorship, clinical and patient-reported outcomes with the Pyrocardan® implant. It was hypothesized that the postoperative outcome measures of the Pyrocardan implant would be comparable to those seen with LRTI surgeries and Bellemère's original series [1].

Methods: In this prospective case series, 33 patients (21 female) received a total of 39 Pyrocardan® implants from 2012 to 2017. Patients were assessed pre-operatively and at 6 weeks, 3 months, 6 months, 1 year, 2 years and beyond (long term) wherever possible. The post-operative pain and function outcome measures were analysed alongside a matched cohort of LRTI patients from our own institution. These results will be discussed in relation to Bellemère's published results [1].

Results and Conclusions: There have been no complications or revision surgeries for the series. One patient has had a subsequent MCPJ fusion. All 39 joints were followed up post-operatively at an average of 17 months (range 6 weeks - 5yrs). Average age at operation was 57 years (range 46 - 71). Thirty-four of the 39 joints were assessed greater than or equal to 6 months post index surgery. Outcome measure scores improved from pre-operative assessment to the most recent follow up equal or greater than 2 years. Median PRWHE score decreased from 65.7 to 17.5, median QuickDASH from 50.0 to 17.5 and on visual analogue scales median pain decreased from 63.5 to 13.0 and satisfaction increased from 8.5 to 90.0. Average grip strength at a minimum of two years was 28.7 kg, as compared to LRTI (19.6 kg) and Bellemere's series (25 kg). In an age matched cohort assessed at a minimum of 2 years, average grip strength increased from 17 kg pre-op to 28.9 kg post-op in the Pyrocardan patients and from 17 kg to 20 kg in patients who underwent an LRTI procedure.

Pyrocardan provides a safe, effective treatment for pain relief and improved functional use of the hand for trapeziometacarpal arthritis. Patient-reported clinical outcomes were at least equivalent to LRTI and are comparable to Bellemère's original series [1]. Grip and pinch strength were better in the Pyrocardan series.