SCFE (http://www.chw.org/)

Definition: Slipped Capital Femoral Epiphysis (SCFE), also known as Slipped Upper Femoral Epiphysis (SUFE), is characterized by a displacement of the capital femoral epiphysis from the femoral neck through the physeal plate

Epidemiology

  • Incidence: 1/1000 and 1/10,000 (Kelsey 1970).
  • Mean age of presentation (Loder 1996)
    • Girls: 12 yrs
    • Boys: 13.5 yrs, respectively.
    • More common in males, with a M:F ratio of about 1.5:1.
  • Obesity is a significant risk factor
    • Up to 60% of patients measure at or above the 90th percentile for weight and age (Loder 1993).
    • SCFE can also be seen in tall, thin patients who have recently undergone a  growth spurt, which results in shearing stress on the weak epiphysis (Kim 2006)
  • Bilateral cases: 20 -40% of patients (Mick 2013).
    • In children who present with unilateral disease, the contralateral hip eventually slips in  30-  60%.
    • In patients with endocrine disorders, the contralateral hip slips in up to 100% of cases. (Loder 1993).

Mechanism

  • Anatomy: The proximal femoral physis contributes to metaphyseal growth of the femoral neck and to appositional growth of the femoral head
  • SCFE Development
    • Shearing forces applied to the femoral head exceed the strength of the capital femoral physis.
    • Results in anterior and superior displacement of the portion of the proximal femur that is distal to the growth plate. (Koop 1996)

Anterior and superior displacement of proximal femur (orthoinfo.aaos.org)

  • Factors that can contribute  to weakening the growth plate include (Weiner 1996)
    • Hormonal changes during puberty that lead to normal periosteal thinning/widening
    • Trauma
    • Obesity
    • Inflammation
    • Genetic predisposition
    • Endocrine disorders
    • Total body radiation

Clinical Presentation

  • Most common features on presentation are pain and altered gait (Koop 1996).
  • Assess for leg length discrepancy and any limitation in hip range of motion 
    • Hip may be held in external rotation
    • Pain elicited by experiences pain with range of motion, especially abduction, flexion, and internal rotation (Kim 2006)
  • Isolated thigh or knee pain (Matava 1999)
    • Seen in 15% of cases
    • Normal knee exam despite complaining of knee pain
  • Gait Assessment
    • May demonstrate Trendelenberg gait
    • A waddling gait is seen in patients with bilaterally SCFE
    • In severe cases, patient may be unable to bear weight and/or thigh and gluteal muscle atrophy may be present
  • Passive flexion of the hip from extension may cause abduction and external rotation (highly suggestive of SCFE) (Kim 2006)

Classification Systems

  • Three systems  to classify SCFE
  • Presentation patterns
    • Preslip
      • Pain without displacement
      • X-Rays show widening of the proximal femoral growth plate compared to contralateral side
    • Acute
      • Symptoms for less than 3 weeks
      • Effusion present
    • Acute on chronic
      • Symptoms for at least 3 weeks and present
      • Acute worsening of symptoms including pain and decreased range of motion
      • Joint effusion is present but unlike in acute cases, metaphyseal remodeling is present
    • Chronic
      • Intermittent symptoms for more than 3 weeks
      • Metaphyseal remodeling is present but without a joint effusion.
  • Stability
    • Stable – patients are able to walk (+/- crutches)
    • Unstable – patients are unable to bear weight, regardless of duration of symptoms.
  • Severity
    • Associated with prognosis
    • Mild – displacement is less than 1/3 the diameter of the femoral neck
    • Moderate – displacement is greater than 1/3 but less than ½ the diameter
    • Severe – displacement is greater than ½ the diameter of the femoral neck

Klein’s Line (openi.nlm.nih.gov)

X-Ray Findings

  • Required views
    • Anterior-posterior (AP) and lateral hips
    • Image both hips given incidence of bilateral  involvement 
  • AP View
    • Klein’s Line
      • A line drawn along the superior aspect of the femoral neck that intersects with the femoral head in normal hips
      • Suspect slippage (SCFE) if the line passes superiorly
    • SCFE findings
      • Widening of the femoral head physis
      • Irregularity of the growth plate
      • Slippage of the epiphysis “ice cream falling off of the cone”
  • Lateral View
    • Posterior displacement and step-off of the epiphysis on the femoral neck are better demonstrated on the lateral view
    • The cross-table view is recommended in patients who have acute onset of symptoms, to prevent further displacement in patients with unstable slips

ED Management

  • Provide analgesia
  • Definitive treatment is operative and involves the stabilization of the diseased physis via percutaneous pinning
  • All patients diagnosed with SCFE should be strictly non-weightbearing
  • Disposition
    • Refer to orthopedic surgeon for planned surgical correction, usually within 24-48hrs
    • Consider admission to hospital, especially in acute or bilateral cases (Mick 2013)
  • Atypical Presentations
    • Should be considered in
      • Children < 10 years of age or  > 16 years of age
      • Weight < 50th percentile for age
      • Height < 10th percentile for age
    • Diagnostic consideration: renal failure, history of radiation therapy, endocrine/metabolic disorders (Loder 2001)
    • Workup: BMP, TSH, Urine studies (Wells 1993)

Prognosis

  • Complications of SCFE include avascular necrosis of the femoral head, which is more common in acute and unstable slips
  • Patients are also at slight risk for gait disturbances and leg-length discrepancies
  • In patients without complications, osteoarthritis of the hip usually develops over a course of decades
  • In instances of unilateral SCFE most contralateral cases occur within the first 2 years after the initial slip (Mick 2013)
  • Prophylactic pinning is controversial and if this is not performed, patients with unilateral SCFE should be followed closely by an orthopedic surgeon

Take Home Points

  • Image bilaterally as SCFE is often bilateral even in the absence of bilateral symptoms 
  • Patients may present with isolated knee or thigh pain without any hip pain, which can lead to delayed diagnosis and worse outcomes
  • More than 50% of SCFEs can be missed when the chief complaint is knee pain. Always range the hip and note the presence or absence of pain in patients presenting with knee pain
  • SCFE is usually seen in adolescent, obese patients. However, it can also be seen in tall, thin patients who have recently undergone a recent growth spurt

Read More

Radiopaedia: Slipped Upper Femoral Epiphysis

Davenport M et al. An Evidence –Based Approach to Pediatric Orthopedic Emergencies. Pediatric Emergency Medicine Practice. 2009;6(5). EB Medicine

References

Kelsey JL et al. The incidence and distrubition of slipped capital femoral epiphysis in Connecticut and Southwestern United States. J Bone Joint Surg Am. 1970;52(6):1203. PMID 5460281

Loder RT. The demographics of slipped capital femoral epiphysis. An international multicenter study. Clin Orthop Relat Res 1996; 322: 8-27. PMID 8542716

Kim TY et al. Limping: Evaluation, Diagnosis, and Management in the Pediatric ED. Pediatric Emergency Medicine Practice. 2006;3(8). EB Medicine

Mick NW, Valasek AE. Pediatric orthopedic emergencies. in Orthopedic Emergencies: Expert Management for the Emergency Physician. Cambridge University Press 2013: 165-177. DOI: 10.1017/CBO9781139199001.008

Loder RT et al. The epidemiology of bilateral slipped capital femoral epiphysis. A study of children in Michigan. J Bone Joint Surg Am. 1993; 75(8): 1141-7. PMID 8354672

Egol KA et al. Handbook of Fractures 5th edition. Philadelphia, PA. Wolters Kluwer. 2015. pp. 662-669. ISBN-13: 978-1451193626

Koop S et al. Three common causes of childhood hip pain. Pediatr Clin North Am. 1996;43(5):1053. PMID 8858073

Weiner D. Pathogenesis of slipped capital femoral epiphysis: current concepts. J Pediatr Orthop B. 1996;5(2):67. PMID 8811532

Matava MJ et al. Knee pain as the initial symptom of slipped capital femoral epiphysis: an analysis of initial presentation and treatment. J Pediatr Orthop. 1999;19(4):455. PMID 10412993

Loder RT et al. Clinical characteristics of children with atypical and idiopathic slipped capital femoral epiphysis: description of the age-weight test and implications for further diagnostic investigation. J Pediatr Orthop. 2001;21(4):481. PMID 11433161

Wells D et al. Review of slipped capital femoral epiphysis associated with endocrine disease. J Pediatr Orthop. 1993;13(5):610. PMID 8376562