Slipped Capital Femoral Epiphysis (SCFE)

Description

Slipped capital femoral epiphysis (SCFE) is the most common hip disorder in adolescents. The “ball” at the top of the thighbone (the femoral head, or capital epiphysis) slips off the neck of the bone at the growth plate, usually backward and downward. It tends to occur during the growth spurt after puberty — roughly ages 12 to 16 in boys and 10 to 14 in girls — and is more common in children carrying extra weight.

How it happens (mechanism)

The growth plate at the top of the femur sits at an angle, and during the pubertal growth spurt two things happen at once: hormonal changes temporarily weaken the growth plate, and rising body weight increases the shearing force across it. When that force exceeds the strength of the weakened plate, the head slips off the neck through the growth plate — a bit like a scoop of ice cream sliding off a tilted cone. It is, in essence, a slip through the growth plate (a Salter-Harris type I separation). Most slips happen gradually over weeks to months; sometimes one occurs suddenly after a minor fall.

What matters

Two points are worth emphasizing. First, knee or thigh pain can be the only symptom. Pain from the hip is frequently felt in the thigh or knee, so a limping pre-teen or teen who complains of knee pain must have the hip examined and X-rayed — missing a SCFE because attention stayed on the knee is a classic, avoidable mistake.

Second, SCFE is time-sensitive. Left unaddressed, the head can slip further, and the more it slips — especially an unstable slip the child cannot walk on — the higher the risk of losing the blood supply to the femoral head (avascular necrosis), which is the main driver of a poor long-term outcome. For that reason the child is kept off the leg and the slip is fixed promptly. The other hip is also watched closely, because a meaningful share of children later slip the second side.

Symptoms

Common signs include:

• A limp, often with the foot and leg turned outward
• Pain in the groin, thigh, or knee
• Reduced hip motion, especially turning the hip inward
• In a more severe (unstable) slip, inability to bear weight on the leg

How it is diagnosed

X-rays of the pelvis, including a frog-leg lateral view, show the slip. An MRI can occasionally detect a very early (“pre-slip”) case before it is obvious on X-ray. If the child is young (under about 10), short, or underweight, blood tests are added to check for a hormonal or metabolic cause.

Treatment

SCFE is treated surgically, usually promptly. The most common procedure is in-situ fixation: a single screw is placed across the growth plate to stabilize the head and prevent any further slipping. The child stays off the leg until surgery. More severe or unstable slips may require a more involved operation. After fixation, the hip is followed, and the opposite hip is monitored — and sometimes pinned preventively, particularly when a hormonal condition is involved.

Recovery and long-term outlook

With timely in-situ fixation, most children do well and the slip is stopped from progressing. The main risks are loss of blood supply to the head (more likely with unstable slips), impingement from the changed shape of the hip, and arthritis later in life. Children are followed until the growth plate closes.

When to call the doctor

Have your child evaluated promptly for a limp with hip, thigh, or knee pain — especially if the foot turns outward. If your child cannot put weight on the leg, treat it as urgent and seek care right away.

Learn more

OrthoInfo (AAOS) — Slipped Capital Femoral Epiphysis (SCFE): orthoinfo.aaos.org

This information is for educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. For specific concerns about your child, consult a board-certified, fellowship-trained pediatric orthopaedic surgeon.