Review Question - QID 217923

The medial antebrachial cutaneous nerve (C in Figure A) is at risk with cubital tunnel release. It is located approximately 3cm distal to the medial epicondyle.

Cubital tunnel syndrome is a compressive neuropathy of the ulnar nerve caused by anatomic compression in the medial elbow. Diagnosis is made clinically with presence of sensory changes to the ring and little finger, intrinsic muscle weakness and a positive Tinel's sign over the cubital tunnel. Treatment may be nonoperative modalities such as bracing or surgical decompression depending on the severity and duration of symptoms, and success of nonoperative treatment. The medial antebrachial cutaneous nerve crosses the surgical field at an average of 3.1cm distal to the medial epicondyle

Chowdhry et al. reported on the location of the medial brachial cutaneous nerve on the basis of anatomical landmarks. They reported that at about 7cm proximal to the medial epicondyle, there is an arborization of 2 to 3 cutaneous branches. They concluded that knowledge of the anatomy of the course of the medial brachial cutaneous nerve can help the surgeon better plan his or her operative approach to maximize aesthetic benefit and limit nerve injury.

Lowe et al. reviewed the posterior branch of the medial antebrachial cutaneous nerve and its course in proximity to the cubital tunnel. They reported that the medial antebrachial cutaneous nerve branches were noted to cross distal to the medial humeral epicondyle 100% of the time at an average distal distance of 3.1cm. They concluded that an understanding of the general position of the medial antebrachial cutaneous nerve branches during ulnar nerve release at the elbow may help to prevent iatrogenic injury to this cutaneous nerve.

Figure A is an unlabeled brachial plexus. Illustration A is the corresponding labeled brachial plexus

Incorrect Answers:
Answer 1: The medial pectoral nerve arises from the medial cord of the brachial plexus to supply the pectoral muscles. It usually pierces the pectoralis minor, then continues to supply mainly the sternocostal portion of pectoralis major
Answer 2: The medial brachial cutaneous nerve crosses the field 7 cm proximal to the medial epicondyle and arborizes into two to three terminal branches
Answer 4: The ulnar nerve is a terminal branch of the medial cord of the brachial plexus. It contains mainly fibers from the anterior rami of spinal nerves C8 and T1, but may sometimes carry C7 fibers as well.
Answer 5: The median nerve is a branch of the brachial plexus with contributions for the lateral and medial cords and supplies most of the superficial and deep flexors in the forearm, thenar and lumbrical muscles. It also gives sensation to certain areas of the skin of the hand.