ABSTRACT
This is a very common disease which is seen in ageing people, very
common in the Western world, while osteoarthritis of the knees is
commonly seen in the Asian countries.
Various theories have been postulated for this condition as
follows:
• Workload and forces acting on the hip joint during walking, which is nearly two to five times the body weight
• Changes in the articular geometry, such as a reduction in the surface area, symmetry, and stabuility of their articular
surfaces
• decrease in the resiliency of articular cartilage, along with death of the superficial chondrocytes and a decrease in the
chondroitin sulphate in the matrix
• A decrease in the viscosity of the synovial fluid, which affects joint lubrication
The lesion usually starts centrally with softening of the articular
surface, when it loses its smooth finish to become opaque when
these changes start in the centre and spread to the periphery.
The articular cartilage thus becomes eroded in the central weight-
bearing area and hence the subchondral bone is exposed and
eburnated. Hence there is an increase in the vascularity of the blood
vessels, resulting in an increase of the incongruity of the acetabulum,
which later affects the femoral head also.
