The prevalence of the anconeus epitrochlearis muscle in a Central European population.

Background: An anconeus epitrochlearis muscle (AE) is a common anatomical variant in the upper extremity, located at the medial aspect of the elbow. Its anatomical position contributes to the roof of the cubital tunnel. While it plays a role in protecting the ulnar nerve, it may also pose a risk for ulnar nerve compression. This study aimed to determine the true prevalence of AE in a Central European population.

Materials and methods: The presence of AE was evaluated in 115 cadaveric upper extremities from an undetermined number of subjects. The limbs for dissection were assumed to be healthy, and AE identification involved anatomical description and measurements. Data analysis aimed to determine the true prevalence, considering 95% confidence intervals.

Results: AE was present in 5 of the 115 cadaveric limbs (4.3%). Specimens lacking AE were observed, depicting normal cubital tunnel roof anatomy. When present, AE replaced the proximal part of the cubital tunnel roof, superficially coursing to the ulnar nerve. Morphological variations were noted.

Conclusions: The true prevalence of AE was 4.3% (95% CI = 0.2%-8.4%), consistent with recent studies. Historical reports indicate varying true prevalence up to 26%, possibly linked to manual labor changes. Contrary to prior assumptions, our study did not find a significantly higher true prevalence in the European population. AE's association with cubital tunnel syndrome is complex, with both protective and potentially compressive roles.