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

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.

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.

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.

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.