A slipped capital femoral epiphysis occurs when the upper end of the thighbone (femur) slips at the area where the bone is growing (growth plate or physis) and does not fit in the hip socket correctly. The condition is most common in teenagers.

Rapid growth and a hormone imbalance during adolescence may cause the femur to slip.

Symptoms usually begin between 8 and 16 years of age, and they may begin earlier in girls than in boys.

Symptoms may be triggered by growing or gaining weight quickly. Symptoms may include:

• Hip tenderness and decreased movement during the early stages of the condition.
• Increased pain when the toes are turned in toward midline (internal rotation of the hip).
• Mild discomfort in the groin, thigh, or knee while walking or running. Rest relieves this discomfort.
• Stiffness and a limp, especially when the person is tired.
• Knee pain.
• Muscle spasms.
• Mild to severe pain.

Treatment to prevent further slippage and reduce complications of the condition often involves surgery to secure the growth plate (physis) with a single screw or with pins. A slipped capital femoral epiphysis may lead to early degenerative arthritis of the hip if it is not detected early and treated properly.