Innervation of vastus lateralis muscle.

Area of Science:

• Anatomy
• Surgical Anatomy
• Neuroanatomy

Background:

• The lateral surgical approach to the proximal femur poses a risk of nerve damage to the vastus lateralis (VL) muscle.
• Understanding the precise innervation pattern of the VL muscle is essential for orthopedic and trauma surgeons.

Purpose of the Study:

• To meticulously describe the detailed anatomical course and branching pattern of the nerve supply to the vastus lateralis (VL) muscle.
• To identify critical areas of innervation that may be vulnerable during lateral proximal femur surgery.

Main Methods:

• Dissection of ten (10) cadaveric lower limbs.
• Detailed anatomical mapping of the nerve trunk, its divisions, and branches supplying the vastus lateralis muscle.

Main Results:

• A single nerve trunk originating from the femoral nerve consistently innervates the VL muscle.
• This trunk divides into two main divisions, each further branching into two distinct rami.
• Reflecting the muscle anteriorly from the linea aspera preserved innervation, but splitting the muscle mid-femur denervated the posterior half.

Conclusions:

• The nerve supply to the vastus lateralis (VL) muscle follows a predictable anatomical course.
• Surgical techniques involving splitting the VL muscle in the mid-lateral line risk denervation of its posterior portion.
• Detailed anatomical awareness of VL innervation is vital for preventing iatrogenic injury during lateral proximal femur approaches.