Supernumerary Muscles in the Hand and Wrist: Image and Clinical Presentation

Abstract

The current descriptive study presents an extensive clinical experience in treating aberrant muscles around the hand, illustrated through 23 clinical cases. These cases are particularly noteworthy due to the rarity of such conditions. Each case was meticulously documented, providing valuable insights into specific clinical manifestations. The following supernumerary muscles were identified: extensor digitorum brevis manus (EDBM), extensor digiti medii proprius, aberrant palmar muscles, flexor carpi radialis brevis (FCRB), and aberrant abductor digiti minimi (aADM).

The EDBM was observed in 7 cases, with a bilateral occurrence in 30% of the cases. In two instances, it was concomitant with a dorsal ganglion. Surgical excision yielded complete resolution of the symptoms. The extensor digiti medii proprius, which is an exceedingly rare presentation, required excision due to activity-aggravated discomfort. Two cases of supernumerary palmar muscles were identified, and one was an aberrant lumbrical requiring surgical intervention for nerve irritation.

The FCRB manifested in three cases in males with strenuous occupations, and it was clinically detected due to their prominent volume; surgical removal led to the disappearance of the discomfort. Five cases of accessory palmaris minor muscle (palmaris longus profundus, PLP) were found to be incidentalomas during carpal tunnel release surgery. Excision of the PLP, which was performed concurrently with surgery, markedly relieved symptoms. The aADM, which was detected in five cases, induced ulnar nerve compression. In severe cases, surgery combined with opening of the Guyon canal resulted in substantial improvement.

The present compilation ranks among the largest published studies on supernumerary muscles. Its findings highlight the importance of considering supernumerary muscles in the differential diagnosis of other more prevalent clinical syndromes.

Keywords

supernumerary muscles - musculotendinous abnormalities - extensor digitorum brevis manus

Publikationsverlauf

Eingereicht: 09. Oktober 2023

Angenommen: 01. April 2024

Artikel online veröffentlicht:
07. Juni 2024

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