Slipped upper femoral epiphysis

Slipped Upper Femoral Epiphysis is a common cause of hip and knee pain in children aged 10-17. It is the most common hip disorder in adolescence. It is the displacement of the upper femoral epiphysis. Slippage occurs through the growth plate (epiphysis between the head and neck of the bone). The femoral epiphysis remains in the acetabulum (hip socket), while the metaphysis (end of the femur) move in an anterior direction.

It is abbreviated SUFE and is also known as Slipped Capital Femoral Epiphysis (SCFE).

Epidemiology
SUFE affects approximately 1-3 per 100,000 people. It should be suspected in adolescents and more frequently occurs in boys (male 2:1 female). It is strongly linked to obesity. Other risk factors include: Family history, Endocrine disorders, Radiation / chemotherapy, African heritage or Mild trauma.

Pathology
The displacement of the upper femoral epiphysis. Slippage occurs through the growth plate (epiphysis between the head and neck of the bone). The femoral epiphysis remains in the acetabulum (hip socket), while the metaphysis (end of the femur) move in an anterior direction.

Signs, symptoms and risk factors
Symptoms are waddling gait, loss of motion in the hip joint, externally rotated foot, pain in the knee / groin / hip and shortening of the hip. In up to 20% of cases slippage is bilateral.

The diagnosis is a combination of clinical suspicion plus radiological investigation. It should be noted that 20-50% of SCFE are missed or misdiagnosed on their first presentation to a medical facility. This is because the common symptom is knee pain. This is referred pain from the hip. The knee is investigated and found to be normal.

Treatment
Once SUFE is suspected, the patient should be non weight-bearing and remain on strict bed rest. It should be regarded as an orthopaedic emergency as further slippage may result in occlusion of the blood supply and avascular necrosis. Almost all treatment requires surgery. Surgery involves the placement of one or two pins into the femoral head to prevent further slippage. The chances of a slippage occurring in the other hip are 20% within 18 months of diagnosis of the first slippage and consequently the opposite unaffected femur may also require pining.

It has been shown in the past that attempts to correct the slippage by moving the head back into it's correct position can cause the bone to die. Therefore the head of the femur is usually pinned 'as is'. A small incision is made in the outer side of the upper thigh and metal pins are placed through the femoral neck and into the head of the femur. A dressing covers the wound and the pins are removed after approximately 12 months.

Complications
Failure to treat the condition may lead to: Avascular necrosis (death of the femoral head), Degenerative hip disease, Gait abnormalities and Chronic pain.