What is slipped capital femoral epiphysis?
A slipped capital femoral epiphysis, also known as slipped upper femoral epiphysis, is the medical term for the separation of the top of the femoral bone (thigh bone) called the femoral head, from the rest of the femoral bone. The break happens along the growth plate, which is the growing section of the bone in young adolescents, allowing the two ends to slip away from each other out of their normal position.
The top of the femoral bone (the femoral head) is formed into a smooth ball shape that fits perfectly into the hip socket on the pelvis called the acetabulum, which is why it is known as a ball-in-socket joint. The femoral head and acetabulum are surrounded by and protected by a tough capsule, strong ligaments and muscles that keep the joint flexible and durable. During adolescence up until the age of 20, bones are growing, this is made possible by the area of bone at the end of the long bones in your body called the epiphysis. The epiphysis is separated from the rest of the bone, known as the shaft or diaphysis, by the epiphyseal plate, referred to as the growth plate in the hip. The epiphysis is known as the capital femoral epiphysis. A slipped capital femoral epiphysis happens along this growth plate and allows the epiphysis to slip away from the shaft of the bone.
Why & when does slipped capital femoral epiphysis happen?
A slipped capital femoral epiphysis can affect both femurs at the same time and most commonly occurs in boys aged 11 -15. In particular it most commonly occurs in children who are obese or very tall and thin going through sudden and rapid growth spurts. During growth spurts the epiphysis is put under an increasing pressure, at this stage the epiphysis can’t hold the added weight from obesity which further increases the downward force causing it to break and slip. It is estimated that the condition affects 2 out of every 100,000 children, making it one of the most common hip complaints in children. There have been some cases reported linking the condition to certain hormone disorders, kidney failure.
What does hip slipped capital femoral epiphysis feel like?
The symptoms of a slipped capital femoral epiphysis vary depending on whether the slip occurs suddenly with trauma, for example due to a fall or gradually overtime due to obesity. In cases related to trauma, the child will feel a very intense, immediate sharp pain around the hip and groin. The child will not be able to weight bear, making walking excruciating and you may notice that one leg is slightly shorter than the other. In the cases where the onset is gradual the child may have been complaining of pain and stiffness around the hip for weeks or months. They might be limping ever so slightly with the limp worsening as the pain worsens. In some cases pain is only felt around the knee and lower thigh misleadingly referred from the hip. Similar to sudden cases you may notice that one leg is slightly shorted and is turned outward compared to the other leg. The child will also complain of increased pain when playing, jumping and skipping. In some gradual cases any trauma might cause it to slip suddenly.
How will hip slipped capital femoral epiphysis be diagnosed?
Your GP or A&E doctor will be able to diagnose you by listening to your symptom history, fully examining your hip and knee as well as identifying any risk factors. Your doctor will order an X-ray of both hips to confirm the diagnosis and identify the extent of the slip. Occasionally the slip isn’t fully visible on X-rays and in these cases an MRI or a CT scan will be ordered as this will give a more detailed view of the hip. The occurrence of a slipped capital femoral epiphysis with no evident risk factor i.e. obesity or recent growth spurt may prompt doctors to investigate for any underlying conditions.
What treatment options are available for slipped capital femoral epiphysis?
Whether the slip happens suddenly or gradually, it is important that the slip is diagnosed and treated promptly. The main treatment is surgery to stabilise the slip, generally pins and screws are used to secure the capital femoral epiphysis to the shaft of the femur, preventing any further slippage. In some cases, more complex surgery is required and occasionally, if it is felt a slip of the other hip is probable, then the surgeon may choose to operate on both hips simultaneously.
Surgery is normally very effective with a high success rate, however there are cases where complications like chondrolysis (damage to the joint cartilage) and avascular necrosis (damage to the joints blood supply) occur leading to further surgery being needed.
If obesity is a concern then it is advisable to consult a dietician or nutritionist who can examine your child’s daily diet and suggest where and what improvements could be made. Some massage therapy for tightened thigh and buttock muscle may be helpful, however a physical trainer or exercises prescribed by your physiotherapist or GP will help to strengthen your child’s leg improving their recovery and prognosis.