*3.3.2.6 The lateral femorocutaneous nerve (LFCN)*

It emerges from underneath the inguinal ligament just medial to the ASIS and courses down along the surface of the sartorius muscle.

The proximal path of the nerve is relatively constant, but its branching is rather irregular, giving 0–5 branches when becoming more superficial; the most lateral of them are potentially on the course of AP (**Figures 8**, **9**).

Byrd [14] in an anatomic study of portal placement and relationship to the extraarticular structures in hip arthroscopy found that the LFCN had divided into three or more branches at the level of the AP and that this portal averaged only 0.3 cm from one of these branches.

Larson and Clohisy [16, 17] in a prospective multicenter trial including 1505 hip arthroscopies and in systematic review found that the most common complication was postoperative LFCN disturbance (16.5%), which persisted beyond 6 months in only 1.6%.

### *3.3.2.7 The femoral nerve*

The femoral nerve is the most lateral structure within the femoral triangle. It lies on the Psoas muscle belly at the approximate midpoint between the anterior superior iliac spine and pubic tubercle.

#### **Figure 8.**

*Origin and branches of the lateral femorocutaneous nerve. (1) Femoral nerve; (2) lateral femorocutaneous nerve with its branch; (3) psoas muscle; (4) sartorius muscle; (5) tensor fascia latae muscle.*

### **Figure 9.**

*A branch of the lateral femorocutaneous nerve accidentally cut in an anterior hip approach.*

The average minimum distance from the anterior portal to the femoral nerve was 3.2 cm [15].
