Hip Anatomy

Abstract

This chapter reviews the bony, capsular, ligamentous, muscular, and neurovascular anatomies of the hip joint with specific attention to structures of greatest clinical relevance. The hip is a ball-and-socket joint formed by the union of the femoral head and acetabulum. As such it possesses the potential for triplanar motion similar to the shoulder joint, but because the hip functions primarily in closed kinematic chain motions, e.g., gait, a need for stability tempers the mobility available at this articulation. The capsule of the hip joint provides stability to the joint and is reinforced by the presence of the intrinsic capsular ligaments. Intra-articular structures such as the labrum and ligamentum teres are also elements of the hip joint anatomy which impact its function. Musculature of the hip joint contributes to both the mobility and stability of the hip and can be compartmentalized regionally into the gluteal muscles and the muscles of the anterior, medial, and posterior thighs. Innervation to the hip joint is provided by the nerves crossing the joint. Classically the obturator nerve is considered the primary source of innervation to the hip; however, branches of the femoral and sciatic nerves also contribute to its sensory innervation. The primary source of blood supply to the hip joint is the medial femoral circumflex artery with additional contributions from the femoral and gluteal vessels. Knowledge of the anatomic relationships between the bony, ligamentous, muscular, and neurovascular structures is of great importance for surgical and nonsurgical treatments of hip joint pathology.