Slipped Capital Femoral Epiphysis (SCFE)

Definition: Medial or posterior slippage of the femoral capital epiphysis relative to the metaphysis

Epidemiology:

  • Classic patient group: overweight adolescent boys
    • Over 80% of SCFE involves children with a BMI > 95th percentile (Manoff 2005).
    • Average age of onset: 12 years old
  • Bilateral SCFE is fairly common
    • 23% will have contralateral disease at the time of initial presentation, despite only complaining of unilateral pain (Hagglund 1988, Loder 1993).
    • Up to 60% of patients will go on to develop bilateral SCFE in their lifetime
    • 88% of subsequent slips occur within 18 months of diagnosing the first slip
  • Influenced by bone maturation, strength, and weight mismatch.
  • SCFE has also been associated with endocrine disorders such as hypothyroidism, hypogonadism, pan-hypopituitarism, but this is not as common.

Presentation:

  • Groin, hip and thigh pain most common (85%) – constant or intermittent
  • Isolated knee pain (15%)
  • Limited internal rotation
  • +/- Limp
  • Immobility or refusal to bear weight
  • Weakness
  • Abnormal gait alignment
  • May have no complaints of pain at time of presentation/examination

Differential Diagnoses:

  • Muscle strain
  • Pelvic fracture
  • Acute Rheumatic Fever
  • Developmental dysplasia of hip
  • Juvenile idiopathic arthritis
  • Legg-Calve-Perthes disease
  • Septic arthritis
  • Transient synovitis
  • Osteosarcoma

Complications:

  • Usually secondary to delays in diagnosis due to:
    • Vague, nonspecific symptoms as discussed above or delayed patient presentation
    • Failure to obtain appropriate imaging
      • SCFE can present as isolated knee or distal thigh pain in up to 15% of cases (Matava 1999).
    • Subtle diagnostic findings in mild cases missed by inexperienced radiologists or orthopedists
      • One retrospective study showed SCFE to be the second most commonly missed pediatric orthopedic diagnosis behind fracture (Skaggs 2002)
  • Numerous retrospective studies demonstrate that the average time of symptom onset to diagnosis is eight weeks
  • Subsequent complications
    • Avascular necrosis (AVN) of the femoral head
    • Femoroacetabular impingement (FAI)
    • Limb-length discrepancy
    • Decreased range of motion
    • Osteoarthritis

Diagnosis:

  • Plain Radiography (gold standard for diagnosis)
    • Views to obtain: XR Pelvis AP and Frog-Leg Lateral
      • Bilateral imaging should be obtained due to the high rate of bilateral disease on initial presentation
    • SCFE identified on XR has been traditionally described as ice cream slipping off the cone
      • Similar Salter Harris Type I Fracture due to disruption of physeal plate
    • Southwick Head Shaft Angle (SHSA) is used to classify the degree of slip
      • Mild: < 30o
      • Moderate: 31-50o
      • Severe: > 51o 
    • Klein’s Line/S-Sign
      • Klein’s Line
        • Line drawn along the femoral neck and passes through the epiphysis.
        • With SCFE, Klein’s Line does not include the epiphysis and instead will pass lateral to the epiphysis.
      • S-Sign
        • Smooth S-shaped line drawn along the femoral head-neck junction from lesser trochanter to the midpoint of the femoral head.
        • If the line is asymmetric, discontinuous, or has sharp turns the likelihood of SCFE is significantly increased.
        • The combination of Klein’s line and the S-Sign are 96.5% sensitive and 85% specific for all cases of SCFE (Rebich 2018)
          • Accurate and easily reproducible compared to SHSA making them more useful in early diagnosis and improving overall prognosis.

  • Ultrasound
    • 95% sensitivity (Magnano 1998)
    • Can show hip effusion or metaphyseal step-off when radiographs are negative
    • Operator dependent
  • MRI
    • Sensitivity as high as 88% (Magnano 1998).
    • Useful in detecting early SCFE in “pre-slip” phase by identifying physeal abnormalities of those at risk of slippage even without radiographic evidence (Khaladkar 2015)
  • CT
    • Generally not indicated given the other available imaging modalities
    • Avoid excessive and unnecessary radiation in children

Management:

  • All patients should be immobilized and made non-weight bearing
  • Obtain orthopedic consultation to determine need for early surgical intervention vs clinic referral for delayed repair
  • Simple (non-operative) closed reduction
    • Contraindicated in stable SCFE
    • Manipulation of an intact epiphyseal-metaphyseal interface without visualization can result in worsening instability and additional complications.
  • Identify avascular necrosis if present as this has been shown to be a complication of both delayed diagnosis as well as surgical repair of unstable SCFE
    • Preoperative
      • MRI with contrast
      • Bone scintigraphy
    • Intraoperative
      • Visual confirmation of bleeding by drilling into femoral head
      • Laser Doppler Flowmetry to measure pressure within the femoral head
  • Treatment options include open or closed surgical fixation via:
    • Percutaneous in situ fixation
    • Osteotomy
    • Capsulotomy

Take Home Points

  • Always consider SCFE in the differential diagnosis of a patient with non-traumatic hip, groin, thigh or knee pain
  • Early recognition and diagnosis are crucial to avoid complications
  • Immediate immobilization and urgent orthopedic consultation is crucial in management
  • Surgical repair is the only definitive treatment modality

Guest Post By

C. Blair Gaines, MD
Emergency Medicine, PGY-3
Jackson Memorial Hospital
Miami, FL

References

  1. Asad I et al. Point-of-Care Ultrasound Diagnosis of Slipped Capital Femoral Epiphysis. Clin Pract Cases Emerg Med 2019. PMID: 30775677
  2. Kim TY et al. Limping: Evaluation, Diagnosis, and Management in the Pediatric ED. Pediatric Emergency Medicine Practice 2006. [Link is HERE]
  3. Lien J et al. Pediatric Orthopedic Injuries: Evidence-Based Management in the Emergency Department. Pediatric Emergency Medicine Practice 2017. PMID: 28825959
  4. Millis MB. SCFE: Clinical Aspects, Diagnosis, and Classification.  Journal of Children’s Orthopaedics 2017. PMID: 28529655
  5. Otani T et al. Diagnosis and Treatment of Slipped Capital Femoral Epiphysis: Recent Trends to Note. Journal of Orthopedic Science 2018. PMID: 29361376
  6. Rahme D et al. Consequences of Diagnostic Delays in Slipped Capital Femoral Epiphysis. Journal of Pediatric Orthopaedics 2006. PMID: 16436942
  7. Rebich EJ et al. The S Sign: A New Radiographic Tool to Aid in the Diagnosis of Slipped Capital Femoral Epiphysis. JEM 2018. PMID: 29550284

Post Peer Reviewed By: Anand Swaminathan, MD (Twitter: @EMSwami) and Salim R. Rezaie, MD (Twitter: @srrezaie)

Cite this article as: C. Blair Gaines, MD, "Slipped Capital Femoral Epiphysis (SCFE)", REBEL EM blog, September 7, 2020. Available at: https://rebelem.com/slipped-capital-femoral-epiphysis-scfe/.
The following two tabs change content below.

C. Blair Gaines, MD

Emergency Medicine, PGY-3, Jackson Memorial Hospital, Miami, FL

Like this article?

Share on facebook
Share on Facebook
Share on twitter
Share on Twitter
Share on linkedin
Share on Linkdin
Share on email
Share via Email

Want to support rebelem?

Sponsored

0