II. Definitions
- Slipped Capital Femoral Epiphysis (SCFE)
- Hip Joint, posterior and inferior slippage of proximal femoral epiphysis on the femoral neck metaphysis
III. Epidemiology
- Age of onset: 8-15 years old
- Boys account for two thirds of cases
- Peak age of onset occurs during maximal pubertal growth spurt
- Males: age 14 to 16 years (mean 13.5 years)
- Females: age 11 to 13 years (mean 12 years)
- Most common adolescent hip disorder
- Prevalence: 10.8 per 100,000
IV. Classification
V. Risk Factors
- Standard risks
- Black, pacific islander, or hispanic children affected more often than white children
- Overweight or obese (50 to 63% of cases)
- Younger onset or atypical cases (e.g. underweight, Short Stature)
- Arthritis
- Endocrinopathy
- Hypothyroidism
- Growth Hormone supplementation
- Hypogonadism
- Panhypopituitarism
- Renal Failure
- Radiation Therapy
- Chemotherapy
VI. Pathophysiology
- Posterior and inferior slippage of proximal femoral epiphysis on the femoral neck metaphysis, at the Hip Joint
- Occurs before the Epiphyseal Plate closes (Growth Plate injury)
VII. Precautions
- SCFE is frequently misdiagnosed as benign diagnosis
- Examples: Adductor Strain (uncommon in this age group), Osgood-Schlatter Disease
- Correct diagnosis is often delayed as much as 3-4 months
- Best prognosis with early diagnosis before significant displacement occurs
- Have a high index of suspicion in a preadolescent or adolescent with Hip Pain
VIII. Symptoms
- Pediatric Limp
- Bilateral involvement in 35% of cases
- Poorly localized hip and Leg Pain
- Dull, aching pain in hip, groin, thigh or knee
- Worse with activity and better with rest
-
Hip Pain with indolent course
- Unilateral in up to 90% of cases
- Pain may be referrred to knee
- May present primarily as knee or distal thigh pain in 15-40% of cases
IX. Signs
- Antalgic Gait
- Compare exam to opposite side (except in bilateral SCFE)
- Hip held in abduction and external rotation
- Obligatory external rotation (Drehmann Sign) or Out-toeing of the effective leg
- Patient externally rotates hip when the hip is actively flexed to 90 degrees
- Markedly limited internal rotation (most predictive finding)
- Hip abduction and hip flexion are also limited
X. Imaging
-
Hip XRay AP with Frog-Leg Lateral View (Compare sides)
- Widened Epiphyseal Plate (Growth Plate) compared with uninvolved side
- Decreased epiphyseal height compared with uninvolved side
- Displacement of femoral head (Wlison method of grading)
- Hip epiphysis displaced <33% of metaphysis width (mild)
- Hip epiphysis displaced 33-50% of metaphysis width (moderate)
- Hip epiphysis displaced >50% of metaphysis width (severe)
- Draw line down the femoral neck on AP View (Klein's Line)
- Line does not transect lateral 25% of femoral head and neck in SCFE
- Frog-leg view is important, as AP Hip will miss SCFE in up to 60% of cases
- Steel Sign
- Double density (double line) at the hip metaphysis
- Lesser trochanter prominent
- Due to external rotation of hip
- MRI Hip
- Consider in high suspicion cases where XRay is non-diagnostic
- May be indicated in early slippage and occult Fracture
XI. Management
- Orthopedic Urgency!
- Non-weight bearing status (Crutches or Wheel Chair)
- Do not attempt to forcefully relocate SCFE
- Risk of avascular necrosis
- Hospitalization and operative fixation
- Stable SCFE or Mild SCFE (displacement < 1/3 femoral neck width)
- In situ fixation with single screw is successful in 90% of mild cases (preferred method)
- Epiphysis is surgically pinned at current location at time of diagnosis
- Unstable SCFE or Severe SCFE (displacement > 1/2 femoral neck width)
- High risk for longterm Disability from Hip Osteonecrosis or avascular necrosis (50% of cases), Femoroacetabular Impingement
- Repair timing and reduction method vary based on patient and surgeon preference
- Severe chronic SCFE may require osteotomies to realign and stabilize
- Stable SCFE or Mild SCFE (displacement < 1/3 femoral neck width)
- Postoperative Rehabilitation
- Multi-phased return to activity managed by physical therapy
- Phase 1: Reduce inflammation, protect repair, Crutches, gait analysis
- Phase 2: Crutches discontinued if normal pain free gait and painless Straight Leg Raise abduction
- Phase 3/4: Improve strengthening, range of motion and aerobic fitness
- Phase 5: Preparing for return to sport and other activity
- Older methods
- Spica hip Casting for 6 to 8 weeks
- Was used to reduce risk of Femoral Neck Fracture and protect epiphyses
- Spica hip Casting for 6 to 8 weeks
XII. Prevention
- Prophylactic pinning of unaffected hip
- Not typically recommended
- May be indicated in high risk for future SCFE (e.g. young patient, Obesity, endocrine cause)
- Longterm follow-up with orthopedics after diagnosis
- High risk of Hip Avascular Necrosis
XIII. Complications
-
Avascular Necrosis of the Femoral Head (20-50% of unstable SCFE patients)
- Premature degenerative Hip Arthritis (and need for hip reconstruction or total hip arthroplasty)
- Premature closure of the femoral head Growth Plate
- Chrondrolysis (articular cartilage acute loss)
- May result from pin penetration of femoral head during single screw placement
- Previously Incidence was as high as 7% following pinningm but now decreased to 1%
- Reduced risk attributed to improved pinning techniques
-
Femoroacetabular Impingement
- Results from proximal femur anatomic changes with severe slip and malpositioning
- May be prevented with subtrochanteric osteotomy
- May be associated with labral tear
XIV. Prognosis
- Stable SCFE
- In situ fixation has a good longterm outcome, with advancing of athletic activity after epiphysis closes
- Unstable SCFE
- High risk for Hip Osteonecrosis (20-50% risk) and Femoroacetabular Impingement
XV. References
- Broder (2022) Crit Dec Emerg Med 36(11): 18-9
- Gardiner (2018) Crit Dec Emerg Med 37(5): 3-14
- Jhun and Raam in Herbert (2016) EM:Rap 16(2):15-6
- Peck (2017) Am Fam Physician 95(12): 779-84 [PubMed]