The anconeus epitrochlearis is a muscle variant sometimes present at the elbow. It is present in up to 34% of individuals and has been implicated in some cases of cubital tunnel syndrome. We report an unusual variant of this muscle with additional proximal attachments in the arm. We will review and discuss the background and the clinical relevance of such a muscle.
anconeus epitrochlearis; cubital tunnel syndrome; variant
Left elbow of the case presented herein.
Note the ulnar nerve (colored yellow) coursing from the medial arm into the cubital tunnel and deep to the anconeus epitrochlearis where it attaches (yellow arrows) the medial epicondyle of the humerus to the olecranon. Particular to this case is the proximal extension of this variant muscle onto the medial intermuscular septum (blue arrows) and superficial to the triceps brachii muscle (short white arrows to far left).