SLIPPED UPPER FEMORAL EPIPHYSIS

Slipped epiphysis is an important cause of limp, thigh and knee pain in late childhood and adolescence.

During the adolescent growth spurt and under the influence of growth hormones the cartilage growth plate at the top of the femur (thigh bone) near the hip joint widens and becomes softer.

The forces on the growth plate can exceed its strength and in this situation the shaft of the femur can slip on the head of the femur.

Pain is frequently felt in the groin, thigh and particularly the knee and is associated with a limp which persists.

The condition is more common in the overweight patient because the forces on the growth plate are higher. There is thus an increasing incidence with the increase in the number of overweight adolescents.

The general incidence is approx 1/5000.

Both hips will be affected in approx 30% of patients but not necessarily simultaneously.

Most patients present with a chronic slip which has been present for a few weeks but occasionally the presentation can be acute after an injury or fall. This is like a fracture of the hip, the child can’t weight bear and it can be complicated by loss of blood supply to the head of the femur.

Treatment of slipped epiphysis involves putting a screw up the neck of the femur, across the growth plate and into the head to prevent further slipping and encourage the growth plate to close.


 
                  Lateral Hip X-ray                                              AP Pelvis X-ray
 

 
              Frog Leg Lateral X-ray

All images above show a screw preventing further slippage.

If there is a severe deformity after the growth plate has been stabilized it may be necessary to change the shape of the upper femur to improve the mechanics of the hip joint and decrease or delay the onset of premature osteoarthritis. This is an osteotomy.

Osteoarthritis in adult life is a complication of slipped epiphysis because of the altered mechanics of the hip joint secondary to deformity of the bone after the slip.

Any adolescent with knee or thigh pain and a limp should have a frog leg lateral hip x-ray to look for a slipped epiphysis.