Hip arthroscopy: an anatomic study of portal placement and relationship to the extra-articular structures.

The purpose of this study is to accurately describe the relationship of the major neurovascular structures to standard portals used in hip arthroscopy. Placement of three standard arthroscopic portals was simulated in eight fresh paired cadaveric hip specimens by placing Steinmann pins into the joint under fluoroscopic control. The specimens were then dissected and the relationship of the portals to the following structures was recorded: lateral femoral cutaneous nerve, femoral nerve, ascending branch of the lateral circumflex femoral artery, superior gluteal nerve, and sciatic nerve. The lateral femoral cutaneous nerve had divided into three or more branches at the level of the anterior portal. The anterior portal averaged only 0.3 cm from one of these branches. The average minimum distance from the anterior portal to the femoral nerve was 3.2 cm. The ascending branch of the lateral circumflex femoral artery averaged 3.7 cm from the anterior portal. A terminal branch of this vessel was present in three specimens 0.3 cm from the portal. The superior gluteal nerve averaged 4.4 cm superior to the anterolateral and posterolateral portals. The sciatic nerve averaged 2.9 cm from the posterolateral portal. From this study, these portal placements appear to be safe. Proper positioning depends on careful attention to the topographical anatomy about the hip. Avoidance of the important structures depends on proper positioning and proper technique in portal placement.