A lateral approach has been described for use in patients lying supine [56] with the leg slightly medially rotated. There is only one landmark which is the greater trochanter of the femur. The needle is inserted horizontally 1 to 2 cm below the lateral skin projection of the greater trochanter in order to pass just below the lower border of the femur (Figure 7). If bone contact is made, the needle is withdrawn and re-inserted slightly more posteriorly until twitches are elicited in the foot. In recent years, this technique has elicited several publications in adult patients. It is suitable for catheter placement [57], but requires excellent immobilization of the lower extremity during the postoperative period in order to avoid inadvertent catheter removal.

All these proximal approaches require the same amount of local anesthetic (rather large) as indica-ted in Table 1. Infusion regimens for continuous blockade are displayed in Table 3. They result in the same distribution of anesthesia which includes the territory of the sciatic nerve but also, in virtually all pediatric patients, that supplied by the posterior femoral nerve block (i.e., the dorsal part of the thigh).




                                     Figure 7. Proximal lateral approach to the sciatic nerve
                                     1. Greater trochanter of the femur
                                     2. Femur
                                     3. Sciatic nerve