February 22nd, 2012Disorders Which Might Occur With The Hip
The hip is known as a ball and socket joint. The ball element is referred to as the femoral head, it is at the end of the thigh bone (femur). The socket is termed the acetabulum which in turn is part of the pelvis. The joint surfaces that push against each other are protected with a structure called cartilage that is lubricated with fluid; this allows the joint to move without friction. Surrounding the hip joint are the capsule, ligaments, muscles, fascia, nerves and blood vessels. There’s a structure referred to as 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 individual to individual. This may be from how we are genetically programmed, or how the hip joint develops as we go from youth to adulthood, or other reasons such as injury or pathology. Underneath, we have attempted to simplify the various types of boney differences that may cause impingement, but it is important to understand that there can be different degrees of these and variations.
1.PINCER – This is when the boney rim of the socket (acetabulum) is covering up more of the ball (femoral head) than in the average hip. A particular area of the socket is affected, and this triggers ‘pinching’ of the hip joint structures when the hip joint moves, thus termed impingement. In a number of individuals, there is global overcoverage (involves the whole socket), and this is termed Coxa Profunda.
2.CAM – This term refers to a boney bump that is found towards the top of the thigh bone (femoral neck). This bump can make the ball of the hip joint less rounded, and so when the hip joint moves, this bump can rub or catch against the hip joint structures.
3.CAM/PINCER MIXED IMPINGEMENT – Sometimes there may be overcoverage of the socket (pincer/coxa profunda) and in addition to this, 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 different levels of this. Measurements called the ‘centre edge angle’ are obtained from the xray to determine how much lack of coverage there is. Some patients are given a specific operation by consultant Surgeons termed a peri-acetabular osteotomy (PAO) to help fix this.
Hip Labral Tears
The fibrocartilagenous labrum which encompasses the socket can at times be torn or become degenerate. There are different classifications of this and it can be brought on by various reasons including through injury or hip joint irregularities such as FAI and dysplasia.
If you are affected by any of the injuries described in this article, you should consult your nearest hip arthroscopy physio.
By Louise Grant Physiotherapists Leeds