Slipped Capital Femoral Epiphysis

Slipped Capital Femoral Epiphysis (SCFE)
1. Hip Joint, posterior and inferior slippage of proximal femoral epiphysis on the femoral neck metaphysis

Age of onset: 8-15 years old
Boys account for two thirds of cases
Peak age of onset occurs during maximal pubertal growth spurt
1. Males: age 14 to 16 years (mean 13.5 years)
2. Females: age 11 to 13 years (mean 12 years)
Most common adolescent hip disorder
1. Prevalence: 10.8 per 100,000

Stability
1. Unstable SCFE (10% of cases) is defined as unable to ambulate without Crutches
Chronicity
1. Chronic SCFE is defined as being present for more than 3 weeks
2. May present acutely after Trauma exacerbates the already existing SCFE

Standard risks
1. Black, pacific islander, or hispanic children affected more often than white children
2. Overweight or obese (50 to 63% of cases)
Younger onset or atypical cases (e.g. underweight, Short Stature)
1. Arthritis
2. Endocrinopathy
  1. Hypothyroidism
  2. Growth Hormone supplementation
  3. Hypogonadism
  4. Panhypopituitarism
3. Renal Failure
4. Radiation Therapy
5. Chemotherapy

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)

SCFE is frequently misdiagnosed as benign diagnosis
1. Examples: Adductor Strain (uncommon in this age group), Osgood-Schlatter Disease
2. Correct diagnosis is often delayed as much as 3-4 months
Best prognosis with early diagnosis before significant displacement occurs
1. Have a high index of suspicion in a preadolescent or adolescent with Hip Pain

Pediatric Limp
Bilateral involvement in 35% of cases
Poorly localized hip and Leg Pain
1. Dull, aching pain in hip, groin, thigh or knee
2. Worse with activity and better with rest
Hip Pain with indolent course
1. Unilateral in up to 90% of cases
Pain may be referrred to knee
1. May present primarily as knee or distal thigh pain in 15-40% of cases

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
1. Patient externally rotates hip when the hip is actively flexed to 90 degrees
Markedly limited internal rotation (most predictive finding)
1. Hip abduction and hip flexion are also limited

Hip XRay AP with Frog-Leg Lateral View (Compare sides)
1. Widened Epiphyseal Plate (Growth Plate) compared with uninvolved side
2. Decreased epiphyseal height compared with uninvolved side
3. Displacement of femoral head (Wlison method of grading)
  1. Hip epiphysis displaced <33% of metaphysis width (mild)
  2. Hip epiphysis displaced 33-50% of metaphysis width (moderate)
  3. Hip epiphysis displaced >50% of metaphysis width (severe)
4. Draw line down the femoral neck on AP View (Klein's Line)
  1. Line does not transect lateral 25% of femoral head and neck in SCFE
  2. Frog-leg view is important, as AP Hip will miss SCFE in up to 60% of cases
5. Steel Sign
  1. Double density (double line) at the hip metaphysis
6. Lesser trochanter prominent
  1. Due to external rotation of hip
MRI Hip
1. Consider in high suspicion cases where XRay is non-diagnostic
2. May be indicated in early slippage and occult Fracture

Orthopedic Urgency!
Non-weight bearing status (Crutches or Wheel Chair)
Do not attempt to forcefully relocate SCFE
1. Risk of avascular necrosis
Hospitalization and operative fixation
1. Stable SCFE or Mild SCFE (displacement < 1/3 femoral neck width)
  1. In situ fixation with single screw is successful in 90% of mild cases (preferred method)
  2. Epiphysis is surgically pinned at current location at time of diagnosis
2. Unstable SCFE or Severe SCFE (displacement > 1/2 femoral neck width)
  1. High risk for longterm Disability from Hip Osteonecrosis or avascular necrosis (50% of cases), Femoroacetabular Impingement
  2. Repair timing and reduction method vary based on patient and surgeon preference
  3. Severe chronic SCFE may require osteotomies to realign and stabilize
Postoperative Rehabilitation
1. Multi-phased return to activity managed by physical therapy
2. Phase 1: Reduce inflammation, protect repair, Crutches, gait analysis
3. Phase 2: Crutches discontinued if normal pain free gait and painless Straight Leg Raise abduction
4. Phase 3/4: Improve strengthening, range of motion and aerobic fitness
5. Phase 5: Preparing for return to sport and other activity
Older methods
1. Spica hip Casting for 6 to 8 weeks
  1. Was used to reduce risk of Femoral Neck Fracture and protect epiphyses

Prophylactic pinning of unaffected hip
1. Not typically recommended
2. May be indicated in high risk for future SCFE (e.g. young patient, Obesity, endocrine cause)
Longterm follow-up with orthopedics after diagnosis
1. High risk of Hip Avascular Necrosis

Avascular Necrosis of the Femoral Head (20-50% of unstable SCFE patients)
1. 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)
1. May result from pin penetration of femoral head during single screw placement
2. Previously Incidence was as high as 7% following pinningm but now decreased to 1%
  1. Reduced risk attributed to improved pinning techniques
Femoroacetabular Impingement
1. Results from proximal femur anatomic changes with severe slip and malpositioning
2. May be prevented with subtrochanteric osteotomy
3. May be associated with labral tear

Stable SCFE
1. In situ fixation has a good longterm outcome, with advancing of athletic activity after epiphysis closes
Unstable SCFE
1. High risk for Hip Osteonecrosis (20-50% risk) and Femoroacetabular Impingement