The diagnosis? Soofee.

What's 'soofee'? You might well ask. Some bizarre form of medical jargon? Well, actually, it's an acronym. It stands for SUFE: Slipped Upper Femoral Epiphysis (pronounced ee-piff-ee-sis). Now you probably understand why it's more commonly referred to as SUFE!¹. The condition is a fairly uncommon orthopaedic complaint that occurs mostly amongst teenage boys, particularly those that are overweight or obese. So what exactly is it?

A Little Anatomy Lesson

SUFE is indicated by a slow separation and slippage of the growth plate of the femur (the long bone of the leg) at the acetabulum (hip socket). In children, there are growth plates at the junction between the head and neck of the femur, which is referred to as the epiphysis. In later childhood and adolescence, the head of the femur may slip downwards and backwards out of the acetabulum, like ice cream partially sliding off a cone.

SUFE does not usually occur in adults, as once the growth plates are fused there is very little likelihood of the epiphysis slipping. In most occurrences of SUFE, the head of the femur usually slips backward and inward relative to the shaft of the bone. The consequent deformity of the hip joint causes a loss of motion and abnormal stresses, leading to pain (often in the hip or knee) and/or a limp on the affected side.

Who Has It?

SUFE is one of the common causes of acute hip pain in adolescence, with an incidence of approximately two per 100,000 people. While the exact reasons for SUFE happening is unknown, it is a disorder that typically affects teenage boys. The two main male body types that are most at risk of developing SUFE are:

• obese or overweight with underdeveloped genitalia

• tall, thin and athletic with normal sexual development

However, SUFE can also affect teenage girls and in fact any child between 10 and 18 years. There is evidence that suggests links between increased weight, the shape and position of the femur and the hormones of puberty can all contribute to the disorder. The condition can also occur in children who undertake high amounts of exercise; such as semi-professional sports players.

Symptoms

The presentation of SUFE is often subtle and clinicians need to bear the condition constantly in mind when assessing an older child or teenager with hip or knee pain, as a misdiagnosis can delay crucial treatment. Pain is usually the first symptom and it may occur in the groin, but more often it is in the thigh or knee. Pain increases with exercise and is often said by patients to feel 'like a sprain'.

A limp may occur early and an injury to the leg may highlight the problem, but is not necessarily the cause. The actual slipping of the femoral epiphysis may occur gradually or suddenly, unilaterally or bilaterally (one side or both sides), and may or may not follow minor or major trauma. If left untreated, the slippage tends to progress, with increasing risk of hip deformity and osteoarthritis.

Diagnosis

Diagnosis is usually often confirmed with a pelvic x-ray that shows the ball and socket joint of the hip and head of femur. If a slip is not obvious, an ultrasound scan or even MRI (Magnetic Resonance Imaging) scan of the hip may also be performed. However due to the expense of some of these investigations, an X-Ray is usually sufficient to confirm SUFE.

The disorder can be assessed as stable or unstable. It is often specified in grades as mild, moderate or acute dependent on the degree of the slip. A stable slip occurs when the head of the femur has only slipped a small amount; an unstable slip is where the head of the femur has slipped at least halfway out of the acetabulum, and will need repositioning. There are usually two courses of action in the realignment of a SUFE: the conservative method, or surgery.

The conservative method is to reposition SUFE in an affected hip by external manipulation of the area, sometimes called reduction. This will ensure the head of the femur is realigned into the hip socket. The child is then given crutches and a strict regime of physio to strengthen the muscles and hopefully prevent any recurrence. Unfortunately, conservative treatment is often not as effective as surgery as there is evidence that suggests that SUFE will continue to happen if the head of the femur is not fixed into position. There is also the likelihood that if SUFE has affected one hip, it will affect the other. Hence surgery is the preferred route to fixing the problem.

Surgery

The operation undertaken to repair SUFE is most commonly referred to as 'in situ percutaneous pinning'. The primary aim of the surgery is to prevent further slipping of the epiphysis. Fixation using the pin is considered to be the optimal and most commonly acceptable treatment. If the SUFE is unilateral (one-sided), prophylactic pinning to the other side will also be done, to reduce the risk of the unaffected side slipping in the future. The pins will remain in place and not be removed, unless they impinge on later growth and development, or are causing further problems.

While under a general anaesthetic, the child will have a small incision made to the lateral aspect of the upper thigh on the affected side. This is to allow the internal fixation of the single cannulated metal pin or screw, which is inserted so as to hold the femoral neck and head of the femur in place. X-Rays are performed during the operation to ensure correct placement.

There is a small possibility that a neck of femur osteotomy may have to take place in some acute occurrences of SUFE too. An osteotomy involves cutting into the neck of the femur to attempt to correct deformity to the hip. This will hopefully alter the line of weight bearing so as to relieve pressure on the hip, reducing the risk of further slips and giving the child greater mobility.

It Hurts

Having your leg cut open and a pin screwed into your bone is a pretty painful procedure for anyone, so post-operative pain management is very important. Many children will be administered morphine by a Patient Controlled Analgesia machine on return from the operating theatre.

A 'PCA' will infuse morphine into the body intravenously at a very low rate, but a 'bolus' or bulk amount of the drug can be administered by the patient themselves if they are in intense pain. The machine is programmed to only allow a preset dose to be given, as prescribed. Non Steroidal Anti-Inflammatory Drugs such as ibuprofen or diclofenac will also be prescribed alongside other analgesics such as paracetamol.

After the operation, strict bed rest follows for at least 24 hours. A wound dressing will cover the pin site(s), which needs to be checked for oozing and signs of infection post surgery for the following week. Once the wound has healed, physical activity can recommence and check X-Rays of the pelvis should then be done over the next 18-24 months to monitor for further slippage.

Exercise After Surgery

Physiotherapists will assess mobility needs post surgery. Most SUFE patients will use crutches for approximately six weeks, although a wheelchair may be suitable for extreme cases. Active and passive motion exercises will be explained by the physiotherapist too, with the aim of strengthening hip and leg muscles.

It is usual for the patient to return to normal routines (like school or work) approximately one week post-surgery as this allows time for good wound healing - although again in acute cases this period of time could be longer.

It is also very important that the child with SUFE, or in danger of developing SUFE, gets to grips with a proper diet and healthy lifestyle, due to the fact that being overweight is a risk factor. With a worldwide increase in childhood obesity, perhaps due to increasingly sedentary lifestyles, the chances of SUFE becoming more common are high.

Will It Get Better?

Full recovery is generally positive; any chances of the condition recurring in children who have had surgery and prophylactic pinning is minimal. There is greater likelihood the child with SUFE will experience hip motion difficulty, difference in leg length and further hip problems into adulthood. However, early detection and proper treatment is shown to decrease the possibility of later problems. In fact most affected children will lead full active lives after their hips have healed, as one h2g2 Researcher recalls:

Mine was cured...I went on to play rugby and earn a living running up and down ships engine rooms.

Please Note: h2g2 is not a definitive medical resource. If you have any health concerns you must always seek advice from your local GP. You can also visit NHS Direct or BBC Health.