Slipped capital femoral epiphysis (SCFE) affects the hip joint in some children and teens. The growth plate separates from the main bone at the top of the femur (thigh bone). The round head of the femur stays in the acetabulum (hip socket) while the neck and shaft of the femur slip up and away from the head.
SCFE may affect both hips. In fact, 20 to 40 percent of the time the condition is bilateral. Bilateral means it affects both hips. Only one hip may be painful, so it is common for doctors to carefully watch the other hip to recognize the disease as early as possible. The earlier the diagnosis is made, the more effective the treatment.
A recent study of the biomechanics of SCFE has shed some new light on the bilateral development of SCFE. It seems the angle and geometry of the hip that slips is very similar to the hip that doesn’t slip. The shear stress on the joint combined with the inclined angle of the epiphyseal growth plate may be risk factors for SCFE.
Many of the children with SCFE are overweight or even medically obese. The added weight increases the shear stress even more. When the stresses on the hips of children with normal hips are compared to children with SCFE, there is a higher average shear stress among the children with SCFE. This is true even when the body weight is factored into the analysis.
What we don’t know yet is how to predict who might develop SCFE on the second side. More studies are needed to find those predictive risk factors.