Displacement of the upper epiphysis (growing end) of the femur (thigh bone). Such displacement is rare; it usually affects children between 11 and 13, and occurs more often in boys and obese children. The condition may also run in families. During normal growth, the epiphysis is separated from the shaft of the bone by a plate of cartilage. This is an area of relative weakness, so that a fall or other injury can cause the epiphysis to slip out of position. A limp develops, and pain is felt in the knee or groin. The leg tends to turn outwards and hip movements are restricted.
Surgery is needed to fix the epiphysis into its correct position and is usually completely successful.
In some cases, the other hip may also need to be stabilized.
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