Hip joint arthrosis
Detailed view of a hip joint that has been damaged by arthrosis with destruction of the cartilage layers
Hip joint arthrosis is a disease that destroys the surface of the joint – the cartilage. In many people, a pathological wearing of the joints occurs with increasing age. Excessive weight, excessive strains or the slightest injury to the joint (e.g. those caused by certain sports) support the development of an arthrosis. The term “primary arthrosis” refers to an arthrosis that occurs as part of the normal aging process. A “secondary arthrosis” is one where the cause is due to previous damage, e.g. following articular fractures, in rheumatism or defective positions or malformation of the hip joint. Over a number of decades, the smooth layer of cartilage tissue becomes increasingly worn down and rough. It develops furrows and cracks, decreasing the femoral head’s ability to move freely in the hip socket. Small parts of the cartilage that have become detached can also irritate the inner joint membrane. Joint injuries caused by accidents, excessive or defective strain or pathologically positioned hip joints can also lead to damage to the cartilage surface. This wearing process takes it course as a fully-grown adult is no longer able to recreate any joint cartilage. The joint mucosa starts to become inflamed and swollen. As things develop, the cartilage surface and the point where bone and cartilage meet are destroyed. The bone that is adjacent to the joint also changes. It becomes harder (sclerosis) and deforms. A bead-like bone projection (osteophytes) results. The chronic inflammation also leads to a thickening of the capsule. These factors increasingly restrict a joint’s ability to move, which also leads to a shortening of the muscles and tendons that move the joint. In the last stage of the arthrosis the joint cartilage can become completely worn down and an extensive stiffening of the joint occurs. The consequences of the arthrosis are pains that initially occur during strain but then increasing manifests even when at rest. A typical feature of arthrosis is the “start-up pains” in the morning or after a long time spent sitting. The range of movement becomes increasingly shorter – the mobility of the joint decreases. As the joint is used less, the musculature also becomes weaker, leading to a constant reduction in the resilience of the entire organism and therefore to the individual becoming increasingly invalid. The pathological changes to the arthrosis joint can be seen in the X-ray. The narrowing of the joint space, the thickening of the bone and the deformation are visible. Fig. 3.