Hip

ANATOMY OF THE HIP

The hip is a ball and socket joint that is found at the intersection of the pelvis and leg. The ball is formed by the round head of the thighbone (femur), and that is attached to the acetabulum. The ball and socket are connected by ligaments, which provide the joint with tremendous stability. All the different parts of the hip work together to move the joint. If any part of the hip is damaged, it will negatively affect the ability to bear weight and the range of motion of the joint.

BONES OF THE HIP

The femur is the thigh or upper leg bone and is the biggest bone in the body. There is a round protrusion at the top of the femur, which connects with the pelvis. This part is known as the femoral head or the head of the femur. The top of the femur has two more protrusions, which are called the lesser and greater trochanters. The muscles that facilitate hip motion are connected to the joint at the trochanters.

The femoral head fits into a concave area in the pelvis, which is known as the acetabulum. The pelvis is made up of different bones that join at the back with the lowest four fused vertebrae, and at the front with the cartilage pad. The point where the pelvis meets the sacrum is where you will find the sacroiliac joints. The bones of the acetabulum and the femoral head have a smooth layer of articular cartilage, which allows smooth movement and cushions the bones.

HIP JOINT SOCKET OR CAPSULE

When your hip surgeon is explaining the hip joint structure to you, they will also talk about the socket or capsule. The joint capsule is made of a thick ligamentous structure, which surrounds the joint. The synovial membrane is a thin tissue that covers the surfaces of the hip joint in the capsule.

LIGAMENTS OF THE HIP JOINT

We already mentioned that the stability of the hip joint is primarily due to its ligaments and muscles. The most important hip joint ligaments are:

• • Ischiofemoral ligament – It is connected to the lowest part of the pelvis, known as the ischium, and is found in the middle of the two trochanters of the femur.
  • Iliofemoral ligament – It stops the hip from hyperextension and helps connect the femur to the pelvis at the beginning of the joint.
  • Pubofemoral ligament – It joins the front part of the pelvis called the pubis with the femur.

THE LABRUM

The labrum is a round cartilage layer that surrounds the outside of the acetabulum to make the socket deep and ensure the joint has more stability.