Amandys(®) implant: novel pyrocarbon arthroplasty for the wrist.

Objectives: Post-traumatic, arthritic or degenerative destruction of the midcarpal and radiocarpal joints are difficult to treat. A new arthroplasty with a free interposition pyrocarbon implant, Amandys(®), is proposed for the treatment of extensive destruction of midcarpal and radiocarpal joints. Preliminary results are reported.

Methods: The prospective series included 25 patients, 15 males and 10 females with a mean age of 60. The indications were degenerative, post-traumatic or rheumatoid destruction of the wrist. Sixty percent of the patients had already had surgery on their wrist before the operation. The mean follow-up was 24months.

Results: Three patients had a reoperation: two for a repositioning of the implant and one for a styloidectomy. At the last follow-up, the mean grip strength was 16kg (51% of the contralateral side), the mean range of motion in flexion-extension was 68°. Mean strength and range of motion did not change significantly with the operation. Pain and function showed significant improvement. The mean pain score decreased from 6.7/10 to 3.7/10 postoperatively. The mean PRWE score decreased from 61/100 to 32/100.The mean QuickDash score decreased from 63/100 to 36/100. Ninety-six percent of the patients were satisfied or very satisfied. No dislocation or subsidence of the implant was noticed.

Conclusions: This minimally invasive pyrocarbon interposition increases the possibilities for the treatment of extensive articular destructions of the wrist. Indications must be limited to a well-aligned wrist with competent capsuloligamentous structure. This new arthroplasty is a reliable alternative to other surgical options, which are more radical or invasive such as total arthrodesis or total wrist prosthesis.