The Slipped Capital Femoral Epiphysis (SCFE)

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What is a SCFE?

The Slipped capital femoral epiphysis (SCFE, pronounced “skif-ee”) occurs when the femoral head slips off the neck of bone at the site of the growth plate. Often this gets described as the ice cream sliding off of the ice cream cone. A SCFE is a common hip condition that tends to occur more commonly in younger adolescent males (age 11-14 years), but the risk increases with an increased body mass index, such as childhood obesity. This condition usually develops gradually over time.  It is common in the setting of an identified SCFE for the history to reveal days to weeks of hip and/or knee pain prior to a relatively non-traumatic “injury,” such as stepping off of the school bus or curb and feeling a pop and increased pain. 

How does a SCFE occur?

Although the cause of a SCFE is not well understood, this condition is more commonly found in adolescents during periods of rapid growth. Many of the risk factors include excess weight, a family or personal history of SCFE, endocrine disorders such as metabolic syndrome or hyperthyroidism, or connective tissue disorder such as Marfan’s disorder.

What are the symptoms of a SCFE?

Symptoms of a SCFE may vary but in general a stable SCFE may have intermittent pain referred to the groin, knee, or hip that worsens with activity. Patients with unstable SCFEs may present with acute pain after an injury, the inability to walk, weight bear, or externally rotate leg, and the affected leg may appear shorter as well.

How often do SCFEs occur?

SCFEs may affect 1-10 patients per 100,000 patients, but the incidence seems to vary with location, season, gender and ethnicity. The incidence in the northeastern U.S. is 0.2 per 100,000 patients, but this incidence increases to 10 per 100,000 in Africans and Polynesians. Males are 2 times more likely to suffer from SCFEs than females. Obesity in general is connected with the occurrence of SCFE. 

How is a SCFE treated?

Treatment is aimed to reduce and prevent further slipping of the displaced femoral head. This is accomplished surgically by driving a screw across the fracture site. Often surgeons will “pin” or place a screw across the opposite leg’s growth plate because of the high risk of future slip. Once the growth plate has closed, the risk of a SCFE becomes negligible. Rarely an open reduction is performed with patients who have unstable fractures, where the surgeon will place two screws across the growth plate fracture to hold the femoral head in place until the growth plate naturally closes.

What are complications of having a SCFE?

The most common complication of a SCFE is avascular necrosis, where blood supplying the femoral head is compromised. This is a very painful complication that can lead to bone and soft tissue destruction, with the ball of the hip joint losing its natural smooth and round contour. Further surgical repair if often necessary in the setting of avascular necrosis. Another complication of SCFE is chondrolysis. This condition is characterized by degeneration of the articular cartilage over the ball that leads to permanent loss of hip movement, essentially arthritis and specifically osteoarthritis. Chondrolysis is a very painful and rapidly developing condition, which if present is treated with aggressive physical therapy and anti-inflammatory medication. An additional complication of SCFE is the development of hip impingement, with abnormal wearing of the cartilage in the socket, which also leads to premature osteoarthritis. 

By Luis Lozano and Jon Minor

References

Pan L. et al. “Trends in severe obesity among children aged 2 to 4 years enrolled in special supplemental nutrition program for women, infants, and children from 2000 to 2014”. JAMA Pediatrics. 2018;172(3):232–238pmid:29309485

Weber MD, Naujoks R, Smith B. “Slipped capital femoral epiphysis”. Orthopaedic Knowledge Online Journal 2008; 6(2). Accessed June 2016.

Woiczik MR, Pizzutillo PD, Gross RH, Carroll KL. “Musculoskeletal effects of Down Syndrome” Orthopaedic Knowledge Online Journal 2012; 10(10). Accessed June 2016.