Synonyms
Coxarthrosis, hip joint arthrosis, hip arthrosis
Definition
Osteoarthritis of the hip is an irreversible, progressive destruction of the hip joint. It usually occurs as a result of an incorrectly positioned acetabulum or a femoral head that does not ideally fit the acetabulum.
Introduction
The bony hip joint is a large, central joint consisting of the joint head (femur) and the acetabulum. It is involved in every change of position (sitting, standing, lying), which means that osteoarthritis of the hip can lead to considerable restrictions in the everyday life of the affected patients. 14% of the population show signs of hip osteoarthritis on X-rays, of which only 5% suffer from symptoms. Osteoarthritis of the hip is one of the rare forms of arthritis. It occurs in 35% of cases on both sides.
Symptoms
The onset of the disease is usually insidious with little pain under stress. In the course of the disease there is radiating pain in the groin, thigh, buttocks or even up to the knee. Typically, the initial pain is felt mainly in the morning after getting up and after sitting for a long time.
These symptoms improve during the day, but increase again in the evening. Patients also complain of rapid fatigue and a feeling of stiffness as further symptoms. In the case of advanced arthrotic changes in the hip, inflammation of the synovial membrane (synovitis) occurs more frequently, which causes permanent pain independent of strain and masks typical symptoms such as starting pain.
Causes
A distinction must be made between primary and secondary arthrosis. While the cause remains unknown in primary osteoarthritis, secondary osteoarthritis is preceded by another disease of the hip. A congenital cause of secondary osteoarthritis of the hip is for example hip dysplasia, which has not been treated or has been treated unsuccessfully. Circulatory disorders of the femoral head (femoral head necrosis, Perthes disease) and solutions of the growth plate at the femoral head (epiphyseolysis capitis femoris) often lead to arthrosis of the hip. Malpositions of the leg axis, inflammation or injuries of the hip joint are further specific causes of coxarthrosis.
Diagnosis
Due to the variety of symptoms, the diagnosis is made by means of physical examinations and X-rays. Inhibition of abduction as well as internal rotation (i.e. turning inwards) of the femur in the hip can be signs of arthrosis in the hip joint in addition to an extension deficit. Typical signs of arthrosis such as a narrowing of the joint space or bony attachments (so-called osteophytes) are to be expected in the X-ray image. If the pain in the hip is unclear, arthrotic changes in the lumbar spine can also be the cause of the discomfort. By injecting a local anaesthetic into the joint space of the hip, it is possible in this case to determine where the pain comes from.
