Disorders Which Might Occur With The Hip Joint
The hip is regarded as a ball and socket joint. The ball element is referred to as the femoral head, and is at the end of the thigh bone (femur). The socket is called the acetabulum and this is part of the pelvis. The joint surfaces that push towards each other are covered with a structure called cartilage that is lubricated with fluid; this permits the joint to move with no friction. Surrounding the hip joint are the capsule, ligaments, muscles, fascia, nerves and blood vessels. There’s a structure called the labrum which attaches to the boney rim of the acetabulum which serves to deepen the socket and have a operate as a vacuum seal.
Femoral Acetabular Impingement (FAI)
The shape, size and form of the hip joint can fluctuate from person to person. This may be from how we are genetically hard-wired, or how the hip joint develops as we go from childhood to adulthood, or other causes such as injury or pathology. Listed below, we have tried to simplify the distinct types of boney differences which often can cause impingement, but it is necessary to appreciate that there can be various degrees of these and variants.
1.PINCER – This is when the boney rim of the socket (acetabulum) is covering more of the ball (femoral head) than in the typical hip. A particular area of the socket is afflicted, and this triggers ‘pinching’ of the hip joint structures when the hip joint moves, thus termed impingement. In certain individuals, there is global overcoverage (involves the whole socket), and this is known as Coxa Profunda.
2.CAM – This phrase refers to a boney lump that is present at the top of the thigh bone (femoral neck). This lump can make the ball of the hip joint less spherical, and and once the hip joint moves, this lump can rub or catch against the hip joint structures.
3.CAM/PINCER MIXED IMPINGEMENT – Occasionally there might be overcoverage of the socket (pincer/coxa profunda) and additionally, the boney bump (CAM) on the femur.
Hip Dysplasia
This is a problem where the socket is not covering the ball (femoral head), sufficiently. There are various degrees of this. Measurements referred to as the ‘centre edge angle’ are taken from the xray to determine how much lack of coverage there is. Some patients are given a specific operation by specialist Surgeons referred to as a peri-acetabular osteotomy (PAO) to help repair this.
Hip Labral Tears
The fibrocartilagenous labrum which surrounds the socket can at times be torn or become degenerate. There are various classifications of this and it can be triggered by various factors including through injury or hip joint abnormalities such as FAI and dysplasia.
If you are affected by any of the injuries described in this article, you should consult your nearest hip physio.
By Louise Grant Physiotherapist in Leeds