The Study of Intramuscular Nerve Distribution Patterns and Relative Spindle Abundance of the Thenar and Hypothenar Muscles in Human Hand

Background

The intramuscular nerve distribution and relative spindle abundance of the human hand have not been well defined, although this is important in guiding hand surgery.

Methods

Forty human hands were dissected and subjected to modified Sihler’s stain and haematoxylin and eosin stain to investigate intramuscular nerve distribution and relative spindle abundance, respectively.

Results

The flexor pollicis brevis (FPB), adductor pollicis (AP), and abductor digiti minimi (ADM) contain separate nerve compartments. Neural anastomoses were observed in the thenar and hypothenar muscles, including the Y-like, O-like, H-like, and U-like appearance. We found that U-like neural anastomoses may be the characteristic of the opponens muscles. The relative spindle abundance was the greatest in the opponens muscles which may coordinate fine movements.

Conclusion

Except for the two opponens muscles, the rest of the thenar and hypothenar muscles could be used as whole muscle or half-muscle donors for muscle transplant. Our nerve map of the hand offers valuable guidance for hand reconstruction.