Lumbrical Muscles Neural Branching Patterns: A Cadaveric Study With Potential Clinical Implications

Area of Science:

• Anatomy
• Neuroscience
• Hand Surgery

Background:

• Lumbrical muscles are intrinsic hand muscles originating from flexor digitorum profundus tendons.
• Typical innervation involves the median nerve for the first two and the ulnar nerve for the last two lumbricals.
• Anatomical variations in lumbrical muscles and their nerve supply are well-documented.

Purpose of the Study:

• To investigate the typical and variable neural supply of lumbrical muscles in cadaveric hands.
• To document the branching patterns of the median and ulnar nerves to the lumbrical muscles.

Main Methods:

• Dissection of eight fresh frozen cadaveric hands.
• Tracing the median and ulnar nerves to their terminal branches supplying the lumbrical muscles.
• Noting lumbrical muscle innervation patterns and nerve branching.

Main Results:

• Typical lumbrical muscle innervation patterns were confirmed.
• The second lumbrical nerve received dual innervation from both median and ulnar nerves in 12.5% of hands.
• Lumbrical nerve bifurcation was observed in 54.5% of cases, with specific branch thicknesses noted for the third and fourth lumbricals.

Conclusions:

• The complex innervation patterns of lumbrical muscles highlight unique anatomical branching.
• These findings are vital for managing deep palmar injuries and transmetacarpal amputations.