Slipped capital femoral epiphysis (SCFE) is a condition of the hip that occurs during adolescence and affects the ball part of the hip (the femoral head). In a normal hip, the round femoral head located at the top of the thigh bone (femur) moves within a round socket (acetabulum), located in the pelvis. In a growing child, the femoral head is divided by the growth plate into the epiphysis (the area that moves within the acetabulum) and the metaphysis (connects the hip to the rest of the thigh bone). In SCFE, the growth plate weakens during the adolescent growth spurt resulting in the epiphysis moving, or “slipping,” off the metaphysis.
There are two types of SCFE: a slow slipping of the epiphysis (stable SCFE) and a sudden slipping resulting in severe pain and inability to walk (unstable SCFE).
This condition primarily affects adolescent children – boys from the ages of 13-15 and girls from the ages of 11-13. These are the most common ages; however, any child over the age of 10 who is still growing is susceptible to this condition. SCFE is associated with overweight children.
The cause of SCFE is currently unknown, although it is associated with a weakened growth plate and anatomical changes in the patient. Several factors seem to contribute:
- Excessive weight.
- Weak bone and growth plate due to hormone abnormalities, such as low thyroid hormone or growth hormone.
- Anatomy of the hip where the motion of the hip allows for more external rotation than internal rotation (retroversion).
SCFE is fairly uncommon and occurs in approximately five out of 100,000 adolescents. It is known to have a higher incidence in Polynesian and African-American ethnic groups.
The most common symptoms of a child with SCFE are pain in the groin, thigh or knee in addition to a limp. The pain may be non-specific in the thigh or knee, and it is crucial that an adolescent with knee pain be evaluated for a SCFE as well. More subtle symptoms are a decrease in activity, a foot beginning to turn out while walking and difficulty with bending the knee and hip straight up toward the chest without rotating the leg.
In a stable SCFE, the child may have pain and a limp for a while before the diagnosis is made. With an unstable SCFE, the pain will be sudden and severe, preventing the child from walking on the hip.
This is a chronic slipping of the epiphysis of the hip resulting in groin, thigh or knee pain. The longer symptoms have been present, the worse the change in the shape of the femoral head. After the SCFE has healed, the abnormal shape of the femoral head may cause decreased motion in the hip with occasional pain. Also, greater deformity of the hip is associated with the hip wearing out earlier in life and leading to arthritis.
This is an acute slipping of the epiphysis of the hip resulting in immediate groin/hip pain and inability to walk. Commonly, the child will have had mild pain for weeks to months leading up to the sudden event. The concern with unstable SCFE – and the main difference between it and stable SCFE – is the possibility of the blood supply to the hip being disrupted. Termed avascular necrosis (AVN), the lack of blood flow causes the femoral head to die resulting in long-term pain, limping and the possibility of a hip replacement in early adulthood. Because of the concern for AVN, unstable SCFEs should be treated as soon as possible.