Radiographic Evaluation after Arthroscopic Partial Trapeziectomy with Suture-button Suspensionplasty for Thumb Carpometacarpal Arthritis

Background: Arthroscopic partial trapeziectomy with suture-button suspensionplasty was developed for the surgical treatment of thumb carpometacarpal arthritis. However, the relationship between clinical results and radiographic evidence is unclear. Methods: The authors retrospectively reviewed 33 consecutive patients who underwent arthroscopic partial trapeziectomy with suture-button suspensionplasty for thumb carpometacarpal arthritis between 2016 and 2021. Clinical and radiographic outcomes were recorded, and the correlations between them were evaluated. Results: The average patient age at surgery was 69 years. Patient radiologic evidence was Eaton stage Ⅱ in three thumbs, Ⅲ in 25 thumbs, and Ⅳ in five thumbs. The average trapezial space ratio (TSR) was 0.36 immediately after the operation but declined to 0.32 after 6 months. In contrast, the average joint subluxation was reduced to 0.005 immediately after the operation compared with 0.28 before, and was maintained at 0.04 at final follow-up. A statically significant correlation was detected between grip strength and TSR (P = 0.03), and between pinch strength and TSR (P = 0.02). A significant correlation was detected between TSR and trapezium height (P = 0.0215), which remained after partial trapeziectomy. No correlation was detected between rope position and other clinical or radiographic scores. Conclusions: Suture-button can have an effect on the medialization of the first metacarpal base. Excessive trapeziectomy can result in functional deficiency of the thumb through metacarpal subsidence, which potentially causes loss of grip and pinch strength.