Anatomic Variations of Ligaments and Muscles Related with the Ulnar Nerve Entrapment Syndrome in the Upper Arm / 대한해부학회지

ABSTRACT

Compressive neuropathy of the ulnar nerve occurs commonly at the cubital tunnel, but it can also be occurred by the anatomic variations of the structures on the ulnar nerve passage. This study was thus performed to clarify the variations of the ligaments and muscles, which can cause the ulnar nerve entrapment syndrome in the upper arm. One hundred arms of 50 Korean adult cadavers were used. The arcade of Struthers, a musculo-tendinous band from the medial head of the triceps brachii to the medial intermuscular septum, was observed in 34% of the cases. This arcade was mostly in a narrow-band shape, but a broad-band shaped arcade was sometimes observed. The internal brachial ligament was observed in 17% of cases. The epitrochleoanconeus muscle between the medial epicondyle and the olecranon was observed in 3% of cases. The ulnar nerve was wrapped or covered by the medial head of triceps brachii in 5% of cases. This study is expected to further the current understanding of the anatomic variations of ligaments and muscles on the ulnar nerve passage, and to be helpful data for the diagnosis and treatment of the ulnar nerve entrapment syndrome in the upper arm.