[Arthroscopic partial trapezectomy. A radio-anatomical study about 14 cases]

The aim of the study was to assess the accessibility of the trapezium surface to arthroscopic resection related to the degenerative stage, to define the surgical approach and to determine the efficacy of the X-rays for evaluating the amount of resected bone.

Fourteen trapezectomies were performed on seven cadaveric specimens using an arthroscopic procedure. Pre- and post-procedure X-rays were used to assess the initial trapeziometacarpal osteoarthritis and the resection performed. Each subject was randomized for using two posterior portals or two posterior portals and one anterior portal. At the end of the procedure, a dissection was performed for evaluating the quality of resection and the anatomical relationship of each surgical approach.

The stages of preprocedure osteoarthritis were comparable between the two sides of the same cadaveric specimen. On post-procedure X-rays, the resection appeared complete in only six out of 14 wrists. During dissection, no injury to neurovascular structures was observed, and the resection was visible macroscopically in 11/14 wrists. Three resections were incomplete, i.e., less than 20 % of total trapezial surface: two of them were seen in the most osteoarthritic cases of the study.

The arthroscopic approach presents an opportunity to access the entire trapezial surface, even if a high stage of osteoarthritis appears to be a risk for incomplete resection. The addition of a systematic anterior approach to the traditional dorsal approach does not increase the accessibility. Although radiography is not the most appropriate tool to assess the resected surface, it does help to locate the defects of resection and can guide the surgical procedure in situations where there is a risk of incomplete resection.