The Epidemiology of Radial Tunnel Syndrome and Its Overlap With Lateral Epicondylitis.

PURPOSE: Radial tunnel syndrome (RTS) is characterized by nerve compression affecting the posterior interosseous nerve branch in the forearm, and its symptoms often overlap with those of lateral epicondylitis (LE). The purpose of this study was to examine the epidemiology of RTS, frequency of injections and surgical release, and overlap of RTS with LE. METHODS: We queried the PearlDiver database to identify RTS in patients older than 18 years. Demographic data, diagnostic or therapeutic injection within 30 days of diagnosis, surgical release within 1 year of diagnosis, and 90-day postoperative complication rates were evaluated. Using International Classification of Diseases, 10th Revision, laterality codes, we also determined the number of patients who had same-side RTS and LE and the proportion of patients who subsequently underwent simultaneous RT release and LE debridement. RESULTS: The prevalence of RTS in a representative United States insurance database was 0.091%, and the annual incidence was 0.0091%. There were 75,459 patients identified with an active RTS diagnosis. The mean age at the time of diagnosis was 52 years (range, 18-81 years), 55% were women, and 1,833 patients (2.4%) underwent RT release within 1 year. Fewer than 3% of the patients received an injection within 30 days of RTS diagnosis. The 90-day postoperative complication rates were low: 5% of the patients required hospital readmission and 2.1% underwent revision surgery. Approximately 5.7% of the patients with RTS also had a diagnosis of LE on the same side within 6 months of RTS diagnosis. In patients with ipsilateral RTS and LE who underwent surgery, 59.1% underwent simultaneous RT release and LE debridement, whereas 40.9% underwent isolated radial tunnel release. CONCLUSIONS: The analysis of a large insurance database showed that the diagnosis of RTS is rarely assigned, suggesting that the incidence of this nerve compression is low. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic III.