What causes ulnar neuropathy at the elbow?

OBJECTIVE

To determine what causes ulnar neuropathy at the elbow (UNE) by analyzing patients' clinical, electrodiagnostic (EDx) and ultrasonographic (US) findings.

METHODS

In prospectively recruited patients with definite UNE, four blinded examiners took a history and performed neurologic, EDx and US examinations. A multivariate logistic regression model was used to investigate the association between UNE location and patient variables.

RESULTS

We included 117 patients; 73% with lesions in the retroepicondylar (RTC) groove and 27% under the humeroulnar aponeurotic arcade (HUA). In our multivariate model, hard manual labor (OR=152; 95% CI 12-1847; p<0.001), dominant arm involvement (OR=4.12; 95% CI 1.01-16.72; p=0.048), and age (OR=1.10; 95% CI 1.03-1.18; p=0.004) were predictive of ulnar neuropathy at HUA.

CONCLUSION

Our data suggest that UNE at HUA is related to years of hard labor affecting mainly dominant hands, and is caused by work-related changes in the HUA. By contrast, UNE in the RTC groove affects mainly the non-dominant arms of younger administrative workers and is caused by external compression of the ulnar nerve.

SIGNIFICANCE: We believe that our findings will help to improve the diagnosis and treatment of UNE patients, hopefully leading to improved clinical outcomes.