Slipped Upper Femoral Epiphysis (SUFE), also called Slipped Capital Femoral Epiphysis, is a condition involving the hip joint.
The hip joint is made up of a ball at the top of the thighbone (called the femoral head) which sits inside the socket (called the acetabulum) of the pelvis.
With SUFE, the growth plate which is located in the femoal head, slips downward and backward. A growth plate is where your bone grows and is an area of weakness.
The exact cause of SUFE is not yet known, but teenagers with increased weight or with certain hormone problems are at greater risk. Boys are more commonly affected than girls.
Symptoms
The symptoms of Slipped Upper Femoral Epiphysis (SUFE) include:
- Pain in the groin, thigh, or knee. Knee pain may be the only symptom present and can lead to a delayed diagnosis as there is no problem with the knee. The pain in the knee is a ‘referred pain’ from the hip joint.
- A limp or a turned out leg are usually present. The limp may be painless, but there is usually pain associated with the limp.
- Leg length discrepancy: The affected leg may also appear shorter than the unaffected side.
SUFE may be classified into two categories depending on whether the child is able to walk on the affected side. If they are unable to walk on the affected side, the SUFE is classified as unstable. If they can walk on the affected side then it is classified as stable. Most cases of SUFE are stable.
Causes
In many cases of Slipped Upper Femoral Epiphysis (SUFE), no cause can be found. There are however some factors that contribute to the formation of SUFE. These can be classified into two categories – mechanical (physical forces) or hormonal
Mechanical causes:
- Obesity: many children children with SUFE are overweight or obese. This increases the stress across the growth plate of the hip bone which is the site where the slip occurs.
- Trauma: Occasionally a child may have a fall at the at the time the problem started, however there may have been an underlying degree of SUFE that was aggravated by the fall.
Hormonal factors:
SUFE develops during puberty, a time of many hormonal changes. Rapid growth occurs in response to increased levels of growth hormone. This rapid growth is associated with an increased size in the growth plate of the hip bone and this may contribute to the decreased strength seen at puberty.
Other hormonal or endocrine disorders that are associated with SUFE include hypothyroidism, growth hormone deficiency, and hypogonadism.
Risk Factors
Slipped Upper Femoral Epiphysis (SUFE) occurs most commonly in early puberty with the average age of males being 13 and girls 12. It occurs more often in males than females, with 60% of cases being found in males.
Many children who suffer SUFE are overweight and this is seen as the greatest risk factor for developing the problem. There are also some ethnic backgrounds which have a higher risk associated with them. These include those of Pacific Island origin and those of African origin.
The presence of hormonal problems which affect the developing bone may also be risk factors for developing SUFE. These include hypothyroidism, growth hormone deficiency, and hypogonadism.
There does not seem to be a genetic predisposition to the condition.
Investigations
Diagnosis of Slipped Upper Femoral Epiphysis (SUFE) disease is often based on:
- Your child’s signs and symptoms: Pain in the hip area or knee, a limp on the affected side or a turned out and shortened leg.
- A physical exam: The child usually walks with a limp and the leg is turned out. Movement of the hip will be limited. Turning the hip inwards will be particularly restricted but other movements may also be affected. If the child is unable to put their weight on the affected hip then this may indicate the SUFE is unstable.
- Imaging studies: X-rays are usually taken and will provide a diagnosis in most cases. An MRI or CT scan is rarely required.
Complications
Initial complications
There are two main complications associated with Slipped Upper Femoral Epiphysis (SUFE). The bone (avascular necrosis) and the cartilage (chondrolysis) are the two areas affected:
- Avascular necrosis: this means that the blood supply to the hip bone (femur) has been interrupted due to the slip that has occurred. The more the bone has slipped, the more likely this complication can occur.
- Chondrolysis: this means the cartilage of the femur is damaged. Once cartilage has been damaged it usually does not recover and this can lead to an early wearing out (osteoarthritis) of the hip. There may be pain, stiffness and loss of muscle strength.
Long term complications
Most children with mild to moderate SUFE, who have not had avascular necrosis or chondrolysis do not develop any long term complications. Children with severe SUFE or those with avascular necrosis/ chondrolysis are more prone to developing early osteoarthritis (‘wear and tear’) of the hip.
Treatment
Treatment of Slipped Upper Femoral Epiphysis (SUFE) requires surgery to correct the problem. The aim of surgery is to stop the hip bone from slipping further and make sure any slip that has occurred is corrected. The earlier the treatment, the better the outcomes and for this reason a quick diagnosis is very important. The treatment for a stable SUFE (when the child can walk on the affected side) is slightly different to the treatment of unstable SUFE (when the child is unable to walk on the affected side).
Stable SUFE
The treatment for stable SUFE is usually to insert a single screw into the the thigh bone across the place where the bone is slipping. This holds the bone together and prevents any further slip. In some cases, the surgeon may decide to perform operations that include grafting bone or changing the angle of the bone but usually a single screw is all that is needed.
After the operation, crutches are recommended for several days. After this, the child is recovered to walk on the affected side to ensure the bone heals normally.
Unstable SUFE
Usually, unstable SUFE is considered a more urgent condition and operations will usually be carried out within a short time of the diagnosis. Before the operation, the joint may be drained of any fluid that may have accumulated due to the inflammation caused by the slip. The operation involves first lining the bones up by the use of traction and then placing one or two screws across the place where the bone has slipped.
Following the operation, crutches must be used for 6-8 weeks in order to prevent any further slip. Physiotherapy rehabilitation may be required to ensure the hip is moving well and that the surrounding muscles are strong.
Seeking Advice
Your Family Doctor (GP)
Your Family Doctor will be able to diagnose and help treat your problem. He or she will be able to
- tell you about your problem
- advise you of the best treatment methods
- prescribe you medications
- and if necessary, refer you to Specialists (Consultants) for further treatment
Talk to your child’s doctor if your child:
- Begins limping
- Complains of hip, groin or knee pain
Prevention
Many children who suffer Slipped Upper Femoral Epiphysis SUFE are overweight and this is seen as the greatest risk factor for developing the problem. In order to prevent SUFE, addressing any childhood obesity is the best step that can be taken.
Addressing any hormonal problems that affect the developing bone may also help decrease the risk of developing SUFE. These include hypothyroidism, growth hormone deficiency, and hypogonadism.
In a child who has had SUFE in one hip, there is a higher chance than in the general public that the other hip will develop the same problem. For this reason, the surgeon may discuss the possibility of an operation to prevent the unaffected hip from also developing SUFE.