Anterior Elbow Pain Caused by Compression of the Lateral Antebrachial Cutaneous Nerve

The complex anatomy and biomechanics of the elbow joint can lead to diagnostic uncertainty when a clinician is determining the cause of a patient's anterior elbow pain. We present a case of anterior elbow pain with an uncommon and often overlooked etiology. Elbow pain due to compression of the lateral antebrachial nerve (LACN) has an unknown incidence or prevalence.

A 27-year-old left-hand dominant male presented to our orthopedic elbow clinic complaining of bilateral elbow clicking and discomfort which had been present for several years. His painful symptoms were localized to the anterior aspect of both elbows and had slowly become more painful despite simple analgesia and physiotherapy. Examination revealed the full range of movement of both elbows with no instability or weakness. Plain imaging and magnetic resonance imaging scans of both elbows did not reveal any pathology, and the decision was made to explore the right elbow, as this was the most symptomatic. Under general anesthesia with tourniquet an anterior curvilinear antecubital fossa incision was made. The lateral border of the distal biceps tendon showed evidence of compression of the LACN at the musculotendinous junction. The tendon was partially resected, and the nerve confirmed to move freely without further entrapment. At 4 weeks after surgery, he was completely asymptomatic. The patient was later listed to undergo a similar procedure to the left side; however, he could not go ahead with surgery so far due to work commitment.

Entrapment or compression of the LACN is an uncommon and often misdiagnosed differential diagnosis with patients presenting with anterior elbow pain, which can lead to permanent neurological damage if left untreated. A high index of suspicion is required to enable prompt diagnosis and investigation as surgical treatment has a high success rate, often with complete resolution of symptoms.