Slip of the Femoral Head Epiphysis
What Is Slip of the Femoral Head Epiphysis (SCFE)?
Slipped capital femoral epiphysis (SCFE) is a hip condition seen in growing adolescents and pre-adolescent children. The ball-shaped epiphysis at the head of the femur slips backwards and downwards from the neck of the bone along the growth plate, which is still open. This slip causes pain, stiffness and a limp in the affected hip and usually develops gradually.
SCFE is the most common hip disorder in adolescents, and early diagnosis is very important. Treatment aims to stop the femoral head slipping any further; early and appropriate treatment reduces the risk of complications and preserves long-term hip function. For general information about hip problems you can review the hip page.
Hip Anatomy and the Growth Plate
The hip is a ball-and-socket joint formed by the femoral head (the ball) and the acetabulum (the socket). Like other long bones, the femur grows from its ends rather than its centre; the growth plate (physis) lies between the shaft of the bone (metaphysis) and the end of the bone (epiphysis).
In SCFE the problem is precisely at this growth plate. During the rapid growth of adolescence the plate is relatively weak, and the femoral epiphysis can slip along it over the neck. Once the growth plate closes (when the skeleton matures) the risk of slipping disappears.
Who Is Affected? Risk Factors
The exact cause of SCFE is not fully known, but a combination of mechanical load on the growth plate and hormonal factors is thought to play a role. Certain conditions raise the risk.
- Age: usually 12-16 years in boys and 10-14 years in girls; it is linked to the rapid growth of early adolescence.
- Excess weight, because it increases the load on the growth plate.
- A family history of SCFE.
- Hormonal and metabolic disorders (thyroid disease, growth hormone treatment, kidney-related bone disease); these are looked for especially in cases outside the typical age range.
Symptoms
Symptoms usually begin insidiously over weeks to months. An important warning: SCFE pain is sometimes felt only in the knee or the thigh, so in an adolescent presenting with knee pain the hip must always be assessed.
- Pain in the hip, groin, thigh or knee.
- A limp or an abnormal gait that increases with activity.
- The affected leg turning outwards and restriction of internal rotation of the hip.
- In unstable cases, an inability to bear weight and a difference in leg length.
Stable and Unstable SCFE
SCFE is divided into two groups according to whether the patient can bear weight on the affected leg; this distinction determines the urgency of treatment and the risk of complications.
- Stable SCFE: the patient can bear weight on the hip with or without crutches. Most cases are of this type and the risk of complications is lower.
- Unstable SCFE: the patient cannot bear weight even with crutches. It is a more serious condition, requires urgent assessment and carries a higher risk of the blood supply to the femoral head being disrupted (avascular necrosis).
SCFE is usually one-sided, but in a proportion of patients the other hip can also be affected, most often within the months following the first episode.
Diagnosis: Examination and Imaging
Diagnosis begins with the history and physical examination. On examination, restriction of internal rotation of the hip and a tendency of the leg to turn outwards are typical; the gait is assessed.
- X-ray: anteroposterior and lateral (frog-leg) views of both hips are the basic study; the slip is seen and its degree is assessed.
- Both hips are imaged together, because an early slip on the other side may be silent.
- In selected cases MRI is used to show an early slip, and blood tests are used to look for an underlying hormonal or metabolic cause at ages outside the typical range.
Surgical Treatment
SCFE is a surgical problem; the aim is to stop the femoral head slipping any further. Timely surgery is decisive in preserving hip function.
- In situ fixation with a screw: the most commonly used method for stable and mild-to-moderate slips. A screw placed across the growth plate stops the slip and allows the plate to close.
- More extensive surgery for unstable and severe slips: repositioning of the femoral head and fixation with screws may be needed, and these cases require closer follow-up.
- Preventive fixation of the other hip: a preventive screw may be considered in selected patients who are at high risk of a slip on the other side.
Complications and the Long Term
The two main serious complications of SCFE are disruption of the blood supply to the femoral head (avascular necrosis) and damage to the joint cartilage (chondrolysis); these are seen more often in unstable and severe slips in particular.
A femoral head that heals but is left misshapen can set the stage for hip impingement and early hip arthritis in later years. For this reason patients who have had SCFE are followed regularly until the skeleton matures and for some time afterwards.
When Should You See a Doctor?
In SCFE, early diagnosis is critical in preventing the slip from progressing and avoiding lasting problems. Knee or hip pain in an adolescent should not be ignored.
- Your child or adolescent has persistent pain in the hip, groin, thigh or knee together with a limp.
- The leg turns outwards or there is difficulty rotating the hip inwards.
- The leg cannot bear any weight; this is an emergency and needs assessment without delay.
To have hip symptoms assessed you can contact Assoc. Prof. Serkan Sürücü, and you can also review the other conditions covered within hip surgery.