Slipped capital femoral epiphysis

Slipped capital femoral epiphysis
Classification and external resources
DiseasesDB	12185
eMedicine	article/413810

Slipped capital femoral epiphysis (also known as "Slipped upper femoral epiphysis") is a medical term referring to a fracture through the physis (the growth plate), which results in slippage of the overlying epiphysis.

The capital (head of the femur) should sit squarely on the femoral neck. Abnormal movement along the growth plate results in the slip.

Often this condition will present in obese prepubescent males, especially young black males, and sometimes females with an insidious onset of thigh or knee pain with a painful limp. Hip motion will be limited, particularly internal rotation.

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.

Classification

• Atypical
• Typical

• Stable
• Unstable

• Acute
• Chronic

Signs and symptoms

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 knee starts to get sore about 2-4 months before the actual hip goes. the pain in the knee can come and go.

Cause

SCFE is often associated with obesity. The Centers for Disease Control offers a body mass index (BMI) calculator to help determine a person's risk for obesity. [1]

The disorder can sometimes be associated with endocrinopathies such as thyroid problems.

Diagnosis

The diagnosis is a combination of clinical suspicion plus radiological investigation. 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.

File:SCFE FROG B&W.jpg

This disease warrants x-rays of the pelvis (AP and frog lateral). The appearance of the head of the femur in relation to the shaft likens that of a "melting ice cream cone". The severity of the disease can be measured using the Southwick angle.

Consultation with an orthopaedic surgeon is necessary to repair this problem. Untreated cases can result in serious growth abnormalities and permanent disability.

The disease can be treated with external in-situ pinning or open reduction and pinning. The risk of reducing this fracture is disruption of the blood supply. Some also advocate pinning the unaffected side prophylactically.

Treatment

Once SCFE 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 (risk 25%). 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 pinning.

It has been shown in the past that attempts to correct the slippage by moving the head back into its 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.

Complications

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

Epidemiology

SCFE is a Salter-Harris type 1 Fracture through the proximal femoral physis. Stress around the hip causes a shear force to be applied at the growth plate. Certainly, trauma has a role in the manifestation of the fracture, but an intrinsic weakness in the physeal cartilage also is present. The almost exclusive incidence of SCFE during the adolescent growth spurt indicates a hormonal role. Obesity is another key predisposing factor in the development of SCFE.3

The fracture occurs at the hypertrophic zone of the physeal cartilage. Stress on the hip causes the epiphysis to move posteriorly and medially. By convention, position and alignment in SCFE is described by referring to the relationship of the proximal fragment (capital femoral epiphysis) to the normal distal fragment (femoral neck). Because the physis has yet to close, the blood supply to the epiphysis still should be derived from the femoral neck; however, this late in childhood, the supply is tenuous and frequently lost after the fracture occurs. Manipulation of the fracture frequently results in osteonecrosis and chondrolysis because of the tenuous nature of the blood supply.4,5,6

SCFE 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. Author: Brent Adler, MD, Chief of Musculoskeletal Imaging, Department of Radiology, Children's Hospital

See also

• Legg–Calvé–Perthes syndrome - another cause of avascular necrosis of the femoral head, seen in younger children than SCFE.

References

• Loder, R. Slipped Capital Femoral Epiphysis. American Family Physician 1998 57: 2135.
• Harrison's internal medicine ( used in UUCM)de:Jugendliche Hüftkopflösung