What is Slipped Capital Femoral Epiphysis?
Slipped capital femoral epiphysis (SCFE), also known as slipped upper femoral epiphysis (SUFE), is a common hip condition in pre-teens and teenagers. This condition can be challenging to diagnose promptly because its symptoms may be unusual, such as pain in the thigh or knee, or appear slowly over time. When a young person has leg pain, there could be many different causes, so doctors always have to think about SCFE as a possible reason.
If the diagnosis of SCFE is delayed, there could be a higher risk of complications, including a condition called femoral head osteonecrosis, which is the death of bone tissue in the hip due to a lack of blood flow. Therefore, it’s important for healthcare providers to identify and consider SCFE in their diagnosis, especially when dealing with pre-adolescents and adolescents presenting with leg pain.
What Causes Slipped Capital Femoral Epiphysis?
In most instances, a condition known as Slipped Capital Femoral Epiphysis (SCFE) occurs for no apparent reason, and patients often do not have a history of injury or trauma before they start to experience symptoms. It’s been observed however, that some people who develop SCFE have pre-existing conditions like endocrine disorders such as hypothyroidism (low thyroid hormone levels), hyperthyroidism (high thyroid hormone levels), panhypopituitarism (a condition where the pituitary gland doesn’t produce certain essential hormones), and growth hormone deficiency.
This condition can also be associated with renal disorders (issues with the kidneys), and Down syndrome. Out of these, hypothyroidism is the most common cause of SCFE that isn’t idiopathic, meaning it doesn’t occur for no known reason. It is worth noting that if a child younger than ten years old or below the 50th percentile in weight shows signs of SCFE, it could indicate the need to investigate potential endocrine disorders.
Risk Factors and Frequency for Slipped Capital Femoral Epiphysis
SCFE, or Slipped Capital Femoral Epiphysis, affects the hip and is quite common among pre-teens and teenagers. It occurs roughly for every 10.8 out of 100,000 people. The largest risk factor for SCFE is obesity. Other things that could increase one’s risk include being male, rapid growth, previously receiving radiation therapy to the hip, and certain anatomical conditions, like the backwards tilting of the hip socket (acetabulum) or the ball of the femur (femoral head), which can cause more strain on the growth plate in the hip.
The average age that SCFE starts is around 11.2 years in girls and 12 years in boys. It typically affects the left hip more, but in around a quarter of cases, it affects both hips. Interestingly, recent studies are showing that SCFE is happening more frequently in younger children, and more often in both hips. This might be due to the increasing rates of childhood obesity.
- SCFE is a common hip problem in pre-teens and teenagers, affecting around 10.8 per 100,000 individuals.
- The leading risk factor for SCFE is obesity.
- Other risks include being male, experiencing quick growth, having had hip radiation therapy, and certain anatomical variations in the hip.
- SCFE often starts at about 11.2 years of age in girls and 12 years in boys.
- It usually affects the left hip, but in about 25% of cases, both hips are affected.
- Recent studies show an increase in SCFE incidence in younger children and in cases affecting both hips, possibly due to rising obesity rates in children.
Signs and Symptoms of Slipped Capital Femoral Epiphysis
Slipped Capital Femoral Epiphysis (SCFE) is a condition that should be considered in young people who have sudden, unexplained pain in their hip, thigh, or knee, especially if they’re limping or can’t put weight on the affected leg. The pain is most often felt in the hip, but can also occur in the groin, thigh, or knee. These symptoms can last anywhere from a few weeks up to 4-5 months before a diagnosis is made. It’s important to note that even if there’s no history of injury or trauma, SCFE could still be the cause of the pain. Patients with this condition often prefer to sit with the affected leg crossed over the other.
During a physical examination, the doctor may notice limited movement in the hip, pain when the hip is rotated, and a loss of hip flexibility. Patients may demonstrate a characteristic sign of SCFE called the Drehmann sign, which is an involuntary outward rotation of the hip when it’s bent to 90 degrees. There may also be signs of an abnormal gait, such as a shuffling walk or a limp, and in some cases, there may be muscle wasting in the thigh.
Testing for Slipped Capital Femoral Epiphysis
If your doctor thinks you might have slipped capital femoral epiphysis (SCFE), a condition where the ball at the head of the thigh bone slips off the neck of the bone, they will start by taking X-rays of both your hips. Having both hips in the picture lets the doctor compare the two sides. One sign your doctor will look for on the X-ray is called Klein’s line. To find this, they draw a line along the top of the thigh bone on the X-ray. Normally, this line will cross a specific part of the thigh bone. If it doesn’t, this could be a sign of SCFE.
There are other ways to spot SCFE on an X-ray. The Southwick slip angle measures the amount of slippage in the thigh bone, and the “S” sign involves drawing a line along the lower part of the thigh bone. If this line isn’t smooth or breaks unexpectedly, it could mean you have SCFE. Using these methods together can help improve the chances of detecting SCFE.
Other signs your doctor might look for on an X-ray are widening of the growth plate, which can be an early sign of SCFE, or the blurring of the upper part of the thigh bone due to it sliding over the ball part of the thigh bone.
If your X-rays don’t show any signs of SCFE, but your doctor still suspects you might have it, they might use an MRI scan. This can show other signs of SCFE, like swelling and growth plate widening. Some recent studies have suggested that ultrasound might be a better way to detect SCFE than X-rays, but more research is needed.
If you are under ten years old, haven’t reached puberty, shorter than most kids your age (more than two standard points below the average), or lighter than half the kids your age, your doctor might also run some blood tests. These could help identify other health conditions that might be causing your symptoms, like problems with your hormones or kidneys. If needed, the doctor can consult with a pediatric specialist for more specific tests.
Treatment Options for Slipped Capital Femoral Epiphysis
For both stable and unstable Slipped Capital Femoral Epiphysis (SCFE) – a condition where the ball at the head of the thigh bone (femur) slips off the neck of the bone in a backward direction, surgery is the main method that doctors use to manage the condition.
Surgery can be performed by using percutaneous screws to secure the head of the femur in place, preventing it from slipping further. It’s important to note that this method aims to fix the current position of the head of the femur, not to forcefully realign it, as this could increase the risk of bone death (osteonecrosis).
There is a debate over whether to use one or two screws for this procedure. A single screw can be sufficient, but two screws give more stability, although they can also result in a higher complication rate, including violation of the articular surface (the smooth area where bones meet).
The screw should be placed at the center of the bone head and should be perpendicular to the growth plate (physis). To achieve the right placement, the entry point should be toward the front of the thigh bone. However, doctors must be cautious not to position it too close to the line between the two bony protrusions (intertrochanteric line) to avoid interference during hip bending. The screws are secured about 5 millimeters from the subchondral bone (the layer of bone just under the cartilage) and at least five of the threads must engage in the bone to prevent further slipping.
This method is performed under x-ray guidance. The screw tip should not penetrate the part of the bone connecting to another bone in any view. After the surgery, patients can usually start putting weight on the affected leg right away if the SCFE is stable. If it’s unstable, they are advised to gradually start weight-bearing over six weeks.
There is also an option to use a procedure called Open Reduction and Internal Fixation (Modified Dunn Procedure), which aims to correct the deformity and stabilize the bone head while protecting the femur’s blood supply. This procedure involves side positioning of the patient, surgical dislocation of the hip, and securing the repositioned bone head with semi-flexible wires (K wires).
After this procedure, patients are typically advised to bear only partial weight on the affected leg for six weeks. It’s important to note that this procedure has sparked some debate and is recommended only for severe and unstable cases.
Another method of managing SCFE is through femoroacetabular impingement, a result of a bump on the thigh bone or when the slip angle is less than 30 degrees, which can be treated by removing the bump via osteochondroplasty.
In very severe SCFE cases with a slip of more than 30 to 45 degrees, or when the condition is painful or limiting movement, and there are no signs of hip joint arthritis (osteoarthritis) or bone necrosis, a surgery called a proximal femoral osteotomy can help.
For mild and moderate chronic SCFE cases with a metaphyseal bump that causes pain and restricted movement. Osteochondroplasty can be done arthroscopically (using a tiny camera to see inside the joint) or through a small incision over the hip joint, which is also known as a Smith-Peterson approach.
What else can Slipped Capital Femoral Epiphysis be?
When a doctor is diagnosing a condition known as Slipped Capital Femoral Epiphysis (SCFE), they have to consider other conditions that the patient might have, particularly if the patient appears to be ill or has a fever. These could include:
- Infections like septic arthritis and osteomyelitis
If the patient mentions that their pain started after an incident like a sports injury, or other physical trauma, the doctor might also consider other conditions, such as:
- Avulsion fracture of the anterior iliac spine(s)
- Adductor muscle strain
- Ligamentous knee injury
- Femur or pelvic fractures
In addition, the doctor might also think about certain inflammatory processes that can cause symptoms similar to SCFE. These could include:
- Transient synovitis
- Legg-Calve-Perthes disease
- Osgood-Schlatter disease
With that being said, if the patient’s symptoms seem to be consistent with SCFE, even if they don’t fit the typical profile, the doctor should still consider getting plain radiographs (X-rays) of the hips.
What to expect with Slipped Capital Femoral Epiphysis
The Loder classification plays a big role in predicting the course of the disease. In a landmark study conducted in 1993, it was observed that patients with a condition called Slipped Capital Femoral Epiphysis (SCFE) deemed stable did not develop a condition known as osteonecrosis or bone death. However, almost half of the patients with SCFE considered unstable eventually developed osteonecrosis. This was also upheld in more recent research, including a systematic review.
Possible Complications When Diagnosed with Slipped Capital Femoral Epiphysis
: SCFE refers to a disorder in adolescents known as Slipped Capital Femoral Epiphysis. This disorder can cause a range of complications, including premature closure of the femur’s growth plate, degenerative bone disease in the hip, joint inflammation, friction between the thighbone and hip socket, tear in the hip socket’s rim, infection, consistent pain, and recurrence in the other hip. In the long run, it can even lead to early onset of hip arthritis.
Common Side Effects:
- Premature closure of the femur’s growth plate
- Degenerative bone disease in the hip
- Joint inflammation
- Friction between the thighbone and hip socket
- Tearing of the hip socket’s rim
- Infection
- Persistent pain
- SCFE in the other hip
- Early onset of hip arthritis
In cases of SCFE, the initial injury can sometimes lead to the collapse of the topmost part of the thighbone. Moreover, this risk increases if the condition is unstable. It is also possible for this to happen as a complication after surgery, when the insertion of metalwork in the upper back part of the thighbone could disrupt its blood supply.
Joint inflammation, another potential complication, is typically caused by an invasive procedure that affects the joint surface. Patients usually experience pain and a reduced ability to move their leg. X-rays show a smaller joint space, while a CT scan is more suited to assess whether the inserted metalwork may have invaded the joint space.
In the case of ‘femoroacetabular impingement’, it refers to a failure during the repair of the upper part of the thighbone which results in abnormal shape (“pistol grip deformity”). There are surgical methods for dealing with this, one of which does earlier.
Finally, it should be noted that in 1 to 2% of cases, the condition may continue to worsen even after fastening with a single screw.
Recovery from Slipped Capital Femoral Epiphysis
After surgery for SCFE (slipped capital femoral epiphysis), which is a hip disorder found mainly in teens, there isn’t much detailed guidance on patient rehabilitation. However, we do follow the rehabilitation plan that is used after surgeries aimed at preserving the hip, such as hip arthroscopy.
The recovery plan typically has five stages, each with their own goals and expected timelines.
The first stage involves using walking aids and analyzing the patient’s walking pattern from heel to toe. This stage is primarily focused on reducing joint swelling, protecting the repaired soft tissue, activating muscles that work together, and improving movement range.
The second stage is all about slowly stopping the use of crutches once the patient can walk normally without pain, and can also raise their straight leg and move it to the side without experiencing pain.
The third and fourth stages are dedicated to increasing the movement range and aerobic conditioning, along with strengthening patterns of functional movement.
The final stage is crucial in making sure the patient has enough power for daily activities or sports. The exact timeline for when the patient can return to sports will vary and be decided by the surgeon depending on the specific case.
Preventing Slipped Capital Femoral Epiphysis
Patients and their families need to understand that they must avoid putting any weight on the affected limb. It’s also necessary for them to know how to manage pain properly. If, following a consultation with a children’s bone specialist, they decide not to proceed with immediate surgery, they need to be aware of the details of slipped capital femoral epiphysis (SCFE, a condition where the hip joint slips out of place) and why seeing a bone specialist urgently for a follow-up is important. If there’s a chance that the family might not be able to, or might not want to, follow the bone specialist’s advice, it may be necessary to consider admitting the patient into the hospital for a consultation with a children’s bone specialist.
