10/09/2026
🔹 Hip anatomy 101 🔹
The hip joint enclosed by a capsule made up of an outer fibrous layer and an inner synovial membrane, together surrounding a fluid-filled cavity that keeps the joint lubricated.
Where the femur (thigh bone) and acetabulum (concave socket in the pelvis) actually meet, the surfaces are coated in hyaline cartilage, which is a smooth tissue designed to let the joint glide with minimal friction while absorbing the compressive load that comes with everyday movement and weight-bearing.
That range of motion isn't limitless, though. Two things work to keep the ball securely seated: the depth of the socket itself, and a ring of fibrocartilage called the labrum, which lines the rim of the acetabulum.
External to this, there are also a number of ligaments that provide stability and resist certain movements, helping to keep the hip secure while still allowing a large range of motion.
From a clinical perspective, understanding this normal anatomy matters because it's variations in the shape of this ball and socket that set the stage for femoroacetabular impingement syndrome, which we'll get into next.