Possible implications of an accessory abductor digiti minimi muscle: a case report

Luis Ballesteros,Luis Ramirez

doi:10.1186/1749-7221-2-22

Abstract

BackgroundAccessory ADM was first reported in 1868 although muscular, vascular and nervous variations of the hypothenar eminence are rare, contrary to anomalous muscles in the wrist which are relatively common.Case presentationThis case report presents a bilateral variation of an accessory abductor digiti minimi muscle in a male specimen. Ulnar artery and ulnar nerves were taken into account regarding their position and trajectory related to this variation.ConclusionMuscle size may be an important factor in considering whether a variation is able to produce neurovascular compression and clinical implications.

Highlights

Accessory ADM was first reported in 1868 muscular, vascular and nervous variations of the hypothenar eminence are rare, contrary to anomalous muscles in the wrist which are relatively common.Case presentation: This case report presents a bilateral variation of an accessory abductor digiti minimi muscle in a male specimen
According to Sheppard, three cases of accessory ADM were first reported by Wood in 1868
Found an accessory ADM in 41% of 116 volunteers' asymptomatic ultrasound examinations, greater prevalence being found in male samples and bilateral presentation in 50% of cases for both genders

Summary

Background

This case report presents an abductor digiti minimi (ADM) muscle's bilateral accessory head, involving ulnar artery (UA) and ulnar nerve (UN) trajectories' sensorial and motor components. The deep UN motor branch may be compressed by this ADM accessory head and compromise palmar and dorsal interosseous muscles, hypothenar eminence muscles, lumbricals III and IV and hallux adductor, thereby producing a clinical "claw hand" appearance or resembling Guyon's canal syndrome. Having dealt with this variation's possible sensorial and motor effects, vascular effects must be considered. The morphological characteristics led to all the above explained symptomatic possibilities; lacking clinical judgment, further statements lose their functional value and become merely speculative

Conclusion

Findings

20. Basbaum AI