Incidence of Cubital Tunnel Syndrome in the U.S. Military Population.

PURPOSE: Cubital tunnel syndrome (CuTS) is the second most common peripheral nerve entrapment syndrome. However, existing epidemiological evidence regarding the estimated incidence of the CuTS disease burden in specific populations is sparse, especially among the U.S. military. The purpose of this study was to describe the demographics and determine the incidence of CuTS among active duty U.S. military service members.

METHODS: All first-time occurrences for CuTS among military members were identified using International Classification of Diseases, Ninth Revision, clinical modification code 354.2 for ulnar nerve lesions in the U.S. Defense Medical Epidemiology Database. A multivariable Poisson regression analysis was used to estimate the incidence rate ratio (IRR) per 1,000 person-years and 95% confidence intervals (95% CI), while controlling for sex, race, age, rank, and service. Rate-ratios were calculated using different referent factors based on differences in sex, race, age, rank, and service branch.

RESULTS: During the 10-year study period, the total number of incident cases of CuTS was 31,568, and a total of 13,745,456 person-years were documented. The overall unadjusted IRR of CuTS during the study period was 2.3 per 1,000 person-years (95% CI, 2.27-2.33). The 35- to 39-year age group had the highest adjusted IRR of CuTS. In addition, females, Caucasians, and junior enlisted service members showed significantly higher IRRs.

CONCLUSIONS: Our study was able to provide baseline epidemiological data on IRRs and influential risk factors in CuTS. We demonstrated an incidence of CuTS that is comparable with previously reported IRRs, which have varied from 0.08 to 8.0 cases per 1,000 person-years. This study also found significantly higher risk for the development of CuTS with increased age and among U.S. Army service members.

TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.