The Hip Joint
The hip is a large weight-bearing joint concerned mostly with standing, moving about, walking and running. One of the biggest joints in the body, it is a synovial joint with synovial membrane lining the joint capsule which secretes a lubricating fluid and a nutritional food for the cartilage lining the joint.
The hip is a ball and socket joint, allowing a large range of movement in many directions. The socket is a deep depression in the side of the pelvis which faces sideways and downwards. The ball is the spherical head of the thigh bone or femur. The ball and socket fit together to give a strong, stable joint with good movements. Strong ligaments and a ligamentous bag called the joint capsule hold the joint together, with the synovial membrane lining inside.
The joint surfaces are covered with articular cartilage, a smooth, shiny and slippery material which allows us to move our body weight about without feeling any friction or stiffness in our joints. The largest muscles in the body, the buttock muscles, are placed near the hip and are used to propel us forward by pulling on the pelvis and the thigh bone.
The hip does not even need its muscle strength to provide stability when weight-bearing as the head is locked into the socket by a fibrocartilage lip called the labrum. This makes the hip very stable in virtually all conditions and dislocation is rare without signficant force involved. The angle between the shaft of the femur and the neck which holds the head is usually in the range 120-140 degrees, and if this varies greatly there may be an abnormality of hip structure.
We are large, heavy animals and normal hips are important if we are to function well in daily life. If someone starts to get hip arthritis they will notice some pain or stiffness after more vigorous activity, which will settle quickly when they stop. This can progress until the pain comes on quickly even on smaller movements and persists even when resting for a while. Once pain is constant and disturbing sleep, with strong limitation of walking, consideration will be given to a total hip replacement.
Abnormalities of the socket, head or both are common, either at birth or during development, and may make it more likely that people will get hip arthritis. Hip dysplasia, an abnormal development of the hip usually apparent soon after birth on routine assessment, is conservatively managed in the vast majority of cases but hip surgery is required in some. Adults with dysplastic hips may have to have hip replacement early in their life.
Hip Replacement Abroad
Many people have hip replacement surgery in the UK every year, about 50,000 new hips going in to arthritic joints. Hip replacement risks and hip replacement complications are important matters, especially when considering hip replacement abroad due to the lower level of hip replacement costs in foreign countries such as India and Thailand. Hip replacement cost comparisons show very large savings by having hip surgery and many other types of surgery abroad.