Which nerve is at risk of injury during an anterior approach to the hip joint?

Explanation

## Anterior Hip Approach and Nerve Injury **Key Point:** The femoral nerve lies medial to the femoral artery and is at significant risk during anterior hip approaches (Smith-Petersen approach) if retraction is excessive or misdirected. ### Anatomical Relationships in Anterior Hip Approach ```mermaid flowchart TD A[Anterior Hip Approach]:::action --> B[Incision between Sartorius and TFL]:::outcome B --> C[Identify Femoral Artery]:::action C --> D{Nerve Position?}:::decision D -->|Medial to artery| E[Femoral Nerve]:::urgent D -->|Lateral to artery| F[Femoral Vein]:::outcome E --> G[Risk of injury with medial retraction]:::urgent G --> H[Quad weakness, sensory loss anteromedial thigh]:::urgent ``` **High-Yield:** In the anterior approach (Smith-Petersen), the femoral nerve enters the thigh medial to the femoral artery. Excessive medial retraction of soft tissues can stretch or directly injure the femoral nerve, leading to quadriceps weakness and loss of sensation over the anteromedial thigh. **Clinical Pearl:** The femoral nerve injury during hip surgery results in quadriceps weakness and difficulty with knee extension — a functionally disabling complication. Careful lateral retraction (away from the femoral vessels) is essential. **Mnemonic:** **LAV** = Lateral (safe retraction), Artery, Vein (medial to these is femoral Nerve — avoid medial retraction).