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.

Resumo

A compressão do nervo ulnar é a segunda causa mais frequente de neuropatia compressiva no membro superior, após a síndrome do túnel do carpo (Dellon, 1986). Uma das causas que dever ser considerada é a presença do músculo anconeu epitroclear, que está presente em cerca de 4% a 34% da população (Husarik et al, 2010; Vanderpool et al, 1968; Nellans et al, 2014).

Descrevemos uma paciente com sintomas de compressão do nervo ulnar esquerdo no cotovelo, e o resultado do tratamento cirúrgico.

A paciente apresentava hipoestesia no IV e V dedos da mão esquerda, e diminuição de força na abdução do V dedo; não foram encontradas alterações na adução do polegar.

Inicialmente, o tratamento foi conservador (uso de splint, fisioterapia e analgésicos); a cirurgia foi indicada pela persistência dos sintomas.

O nervo ulnar foi cirurgicamente liberado e transposto, com melhora total dos sintomas após 6 meses de acompanhamento.

A compressão do nervo ulnar no cotovelo não é comum, mas não deve ser ignorada (Chalmers, 1978). Ultrassonografia (Jung et al, 2013; Bargalló et al, 2010), ressonância magnética do cotovelo (Jeon, 2005) e eletromiografia (Byun, 2011) auxiliam no diagnóstico.

Keywords

ulnar nerve disease - ulnar neuropathy

Palavras-chave

lesões do nervo ulnar - patologia do nervo ulnar

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