Extensor Indicis Brevis Muscle: A Case Report

Area of Science:

• Anatomy
• Surgical Anatomy
• Medical Education

Background:

• Anatomical variations of hand muscles and tendons are frequently encountered.
• Most anomalous variations remain asymptomatic, often discovered incidentally during surgery or dissection.
• The index finger typically possesses two independent extensor tendons, with variations being less common than in other extensor tendons.

Observation:

• During a cadaver dissection for medical anatomy students, a muscular variant of the extensor indicis proprius (EIP) was identified.
• The dissection revealed the presence of the standard tendons to the index finger, alongside an anomalous muscle termed the extensor indicis brevis (EIB).
• This EIB muscle originated from the ulnar styloid process and inserted via a single tendon at the base of the proximal phalanx of the index finger.

Findings:

• A distinct extensor indicis brevis muscle variant was observed in the right hand of a male cadaver.
• The anomalous muscle's origin and insertion points were documented, differing from typical anatomical descriptions.
• This finding represents a less common anatomical variation of the extensor tendons of the index finger.

Implications:

• Awareness of the extensor indicis brevis anatomical variation is crucial for hand surgeons.
• This variation can potentially impact surgical procedures such as tendon reconstruction involving the index finger.
• Understanding such anomalies is vital for accurate diagnosis and successful surgical outcomes in hand surgery.