Thumb Carpometacarpal Instability: An International Survey on Terminology, Diagnostic Workup, and Treatment

BACKGROUND: Thumb carpometacarpal (CMC) instability is a controversial topic in hand surgery. This international survey examined the terminology, diagnostic approaches, and treatment strategies used by surgeons worldwide, and explored variations by geographic region and surgical specialty. METHODS: A cross-sectional survey was developed in collaboration with experienced hand surgeons and approved by the research committees of the Federation of European Societies for Surgery of the Hand and the American Association for Hand Surgery. The survey was distributed globally. Responses were analyzed by region and specialty. RESULTS: Responses were obtained from 208 surgeons across 38 countries. Most preferred the term 'Thumb CMC instability' (77%), whereas 16% used 'Stage I thumb CMC arthritis'. Encounter frequency varied widely, with responses ranging from daily (3%) to rarely (34%). Diagnosis was primarily based on clinical assessment of laxity, supported by radiographs (96%). Nonsurgical management was most commonly selected as first-line treatment (88%), with most surgeons proceeding to surgery only if symptoms persisted (76%). A wide range of surgical techniques was reported, with Eaton-Littler ligament reconstruction used most frequently (32%). U.S. surgeons reported encountering CMC instability more frequently than European surgeons. Choice of surgical technique differed by specialty, with plastic surgeons favoring ligament reconstruction and orthopedic surgeons more often selecting salvage procedures or arthroscopy. CONCLUSIONS: Thumb CMC instability is widely recognized but remains inconsistently defined, diagnosed, and managed. These findings highlight opportunities to improve and standardize care. We advise consistent use of the term 'thumb CMC instability' to improve communication in clinical practice and research.