Hip

    Alternate Meaning: Hip(Slang)

In anatomy, the hip is the bony projection of the femur, known as the greater trochanter, and the overlying muscle and fat constitute the hip. The hip joint is the articulation between the femur and the acetabulum of the pelvis.

Hip replacement is the most successful, cheapest and safest form of replacement surgery. The first artificial hips were inserted in the 1930s, made of steel or chrome they were better than arthritis but had a number of drawbacks. The main problem being that the articulating surfaces could not be lubricated by the body, leading to wear and loosening and hence the need to replace the joint again, revision operations. Attempts to use teflon prodcued joints that caused osteolysis and wore out within two years.

The modern artificial joint owes much to the work of John Charnley at the Manchester Royal Infirmary, his work in the field of tribology resulted in a design that completely replaced the other designs by the 1970s. Charnley's design was a polyethylene design that could be lubricated with synovial fluid, joined to the femoral bone with bone cement. Wear issues only made it suitable for sedentary patients, but the improvements in friction led to the Charnley design being chosen over the other options (the designs of McKee and Ring)