Anatomical Variations in Muscles Taking Attachment at Medial Carpal Region

Area of Science:

• Anatomy
• Orthopedics
• Surgical Anatomy

Background:

• Anatomical variations in hypothenar muscles (Abductor Digiti Minimi, Flexor Digiti Minimi, Opponens Digiti Minimi) and Flexor Carpi Ulnaris can lead to ulnar nerve compression in Guyon's canal.
• These variations may affect neurovascular pathways in the wrist.

Purpose of the Study:

• To investigate the prevalence and types of anatomical variations in the hypothenar muscles and Flexor Carpi Ulnaris.
• To assess the clinical significance of these variations in relation to ulnar nerve entrapment and vascular compression syndromes.

Main Methods:

• Analysis of fifty cadaveric upper limbs.
• Detailed examination of origin, insertion, nerve supply, and accessory structures of hypothenar muscles and Flexor Carpi Ulnaris.
• Statistical assessment of the prevalence of observed variations.

Main Results:

• Abductor Digiti Minimi variations: single belly (80%), two bellies (20%), additional slips (10%), nerve supply variations (30%).
• Flexor Digiti Minimi variations: origin from hamate hook (74%), fibromuscular arch (26%) enclosing nerve/artery (22%).
• Opponens Digiti Minimi variations: present in 98%, with nerve/artery piercing (32%). Flexor Carpi Ulnaris variations: normal insertion (98%), additional tendinous slip (2%).

Conclusions:

• Observed anatomical variations in hypothenar muscles and Flexor Carpi Ulnaris are clinically significant.
• Recognition of these variations is essential for accurate diagnosis and effective surgical management of ulnar nerve entrapment and vascular compression syndromes.