Carpometacarpal Osteoarthritis Is Associated With an Increased Risk of Carpal Tunnel Syndrome.

Purpose: Carpometacarpal (CMC) osteoarthritis (OA) of the thumb finger is the most common joint OA in the upper extremity to require surgery. This study aims to assess the impact of CMC OA on the management of carpal tunnel syndrome (CTS) as well as outcomes following carpal tunnel release (CTR) surgery. Methods: This retrospective matched cohort study used data from the TriNetX Research Network. Patients without CTS and with an ambulatory visit between 2017 and 2018 were identified; using International Classification of Diseases (ICD)-10 codes, those with CMC OA were matched to a control cohort of those without it, and they were followed for 5 years to assess the development of CTS. Patients with CTS and CMC OA were then matched to a control cohort of patients with CTS and no diagnosis of CMC OA. Progression to therapy within three years was assessed; interventions were identified using Current Procedural Terminology (CPT) codes. Subanalysis of a secondarily matched cohort of patients undergoing CTR, with and without CMC OA, assessed 2-year postoperative outcomes. Results: A total of 31,075 patients were matched, and those with CMC OA were more likely to develop CTS. Of patients with CTS, those with CMC OA were more likely to receive corticosteroid injection and operative management than those without CMC OA. Secondary analysis of matched cohorts of 15,431 patients who underwent CTR demonstrated those with CMC OA had higher odds of postoperative opioid prescription, postoperative infection, postoperative EMG, and repeat CTR within one year than the cohort without CMC OA. Conclusions: Patients with CMC OA were more likely to develop CTS, receive corticosteroid injections, and undergo CTR. Among patients who underwent CTR, patients with CMC OA were more likely to have worse outcomes. Type of study/level of evidence: Prognostic, IIb.