Factors Associated With Surgical Intervention for Osteoarthritis of the Thumb Carpometacarpal Joint.

Purpose This retrospective study aimed to analyze the initial clinical factors associated with surgical intervention for osteoarthritis of the thumb carpometacarpal (CMC) joint. Methods The study included patients who first visited our hand surgery clinic, were given the diagnosis of osteoarthritis of the thumb CMC joint between May 2012 and January 2015, and were observed for more than 3 years. Patients were classified into 2 groups according to whether they had undergone surgery during the follow-up period. The following variables were extracted and included in a bivariate analysis : sex, age, age at onset, disease duration, dominant hand, pain visual analog scale (VAS) scores at rest and during use, night pain, Eaton classification, use of an orthosis, number of injections, tender area, range of motion, grip strength, pinch strength, Kapandji abduction index, palmar abduction distance, grind test results, CMC joint shape on radiographs, dorsal subluxation ratio, volar tilt of the metacarpal, presence or absence of ossicles, and the surgeon who recommended the surgery. Variables with P values less than .05 in the bivariate analysis were included in a logistic regression model. Results The study included 80 thumbs of 48 patients. Pain scores at rest and during use, and the dorsal subluxation ratio were identified as factors significantly associated with surgical intervention in the bivariate analysis. The subsequent logistic regression analysis including these factors as explanatory variables also identified the VAS score at rest and dorsal subluxation ratio as significantly associated with surgical intervention. Conclusions The VAS score at rest and the dorsal subluxation ratio at the first clinical visit were associated with the likelihood of future surgical intervention within 3 years in patients with osteoarthritis of the thumb CMC joint. Type of study/level of evidence Prognostic IV.