Anconeus Epitrochlearis Muscle as a Cause of Ulnar Nerve Compression at the Elbow

Abstract

Ulnar nerve entrapment is the second most common compressive neuropathy in the upper limb, after carpal tunnel syndrome (Dellon, 1986). One of the causes that must be considered is the accessory anconeus epitrochlearis muscle, which is present in 4% to 34% of the general population (Husarik et al, 2010; Vanderpool et al, 1968; Nellans et al, 2014). We describe a patient with symptoms of compression of the left ulnar nerve at the elbow and the result of the surgical treatment. The patient presented with hypoesthesia in the fourth and fifth fingers of the left hand, and reduction of strength in the fifth finger abduction. No alterations were found in the thumb adduction. Initially, the treatment was conservative (splint, physiotherapy, analgesics); surgical treatment was indicated due to the continuity of the symptoms. The ulnar nerve was surgically released and transposed, with complete recovery after 6 months of follow-up. Ulnar nerve entrapment at the elbow by the anconeus epitrochlearis muscle is not common, but it must not be ignored (Chalmers, 1978). Ultrasonography (Jung et al, 2013; Bargalló et al, 2010), elbow magnetic resonance imaging (MRI) (Jeon, 2005), and electromyography (Byun, 2011) can help establish the proper diagnosis.

Keywords

• ulnar nerve disease
• ulnar neuropathy