A 30 year old male presented with history of pain in the left elbow radiating to forearm and in distal arm since many months. Examination findings revealed possibility of ulnar nerve entrapment.
- Thickening of the ulnar nerve was noted proximal to the medial epicondyle, measuring 0.5 cm in maximum thickness .It showed altered signal intensity appearing hyperintense on PDFS and T2WI and mildly hyperintense to muscle on T1WI, which was seen to extend for a length of 2.5cm. The ulnar nerve distal to the cubital tunnel was normal in caliber.
- Anconeus epitrochlearis (anomalous accessory muscle) visualized along the posterior part of the cubital tunnel causing compression of ulnar nerve against the medial epicondyle.
- No evidence of denervation edema noted in the muscles around the elbow.
Diagnosis: Compression of ulnar nerve in the cubital tunnel against medial epicondyle by anconeus epitrochlearis muscle.