Arthroscopic interposition in thumb carpometacarpal osteoarthritis: A series of 26 cases.

In 2011, we reported good results after a mean follow-up of 14 months for a series of 25 patients who underwent thumb carpometacarpal osteoarthritis surgery in which a poly-L-lactic acid implant was interposed arthroscopically. The aim of this study was to evaluate the outcomes after a longer follow-up. The new series consisted of 26 patients, whose average age was 60 years, operated with arthroscopy for the interposition of an implant made of poly-L-lactic acid in 12 cases and tendon interposition in 14 cases. After an average follow-up of 20 months, the pain assessed with a visual analog scale was on average 6.61/10 before surgery and 6.03/10 after, the QuickDASH score was 56.36/100 before and 53.65/100 after, grip strength was 15.34kg before and 12.8kg after, pinch strength was 3.7kg before and 2.18kg after, Kapandji thumb opposition score was 8.96/10 before and 8.26/10 after. The radiological stage did not change. We noted one case of type 1 complex regional pain syndrome and 12 poor results, 11 of which were reoperated by trapeziectomy. Given our results and the lack of published studies with a high level of evidence, the value of isolated arthroscopy with interposition in the surgical treatment of thumb carpometacarpal osteoarthritis remains to be demonstrated.