Slipped capital femoral epiphysis (SCFE aka SUFE)

–

= physeal disruption & slippage of femoral neck in relation to the femoral head, which remains enlocated in acetabulum

• They can be classified according to:
  • ability to weight bear
    • Stable – the patient is able to weight bear on the affected leg
    • Unstable – the patient is unable to weight bear on the affected leg, even with crutches
  • duration of symptoms
    • Acute – sudden onset of severe symptoms and inability to weight bear
    • Chronic – gradual onset and progression of symptoms for more than 3 weeks, without sudden exacerbation. This is the most common presentation (85% of patients with SUFE)
    • Acute on chronic – sudden exacerbation of symptoms due to acute displacement of a chronically slipped epiphysis

Aetiology

• usually develops during periods of rapid growth, shortly after the onset of puberty
  • most commonly occurs between the ages of 12 and 16 in boys, and the ages of 10 and 14 in girls.
• more common in boys (60%) than girls
• Bilateral slippage is common
• Sometimes SCFE occurs suddenly after a minor fall or trauma. More often, however, the condition develops gradually over several weeks or months, with no previous injury
• unknown, but biomechanical and biochemical factors play an important role.
  • Most often idiopathic
  • Acute trauma
  • Obesity – 50% of adolescents with SUFE are above the 95th percentile for weight
  • Endocrine disorders eg. Hypothyroidism, GH deficiency, pan hypopituitarism
  • Renal failure osteodystrophy
  • Other: XRT, Down syndrome
• Risk Factors
  • Obesity
  • Males
  • Ethnicity – African americans, Pacific islanders, Latinos
  • Period of rapid growth (10-16yrs age)

Symptoms

• SUFE commonly presents with knee pain as the only presenting complaint
• pain
  • may complain of vague pain in the groin, thigh or knee. 
  • Pain is aggravated by activity
• Limp
  • walk with an antalgic gait
  • If the slip is acute and unstable, these children cannot walk.
• out-toeing and some shortening of the affected limbs
• patients prefer to sit in a chair with affected leg crossed over the other, pain usually present for weeks to several months before dx made 

Signs

• Relative shortening & external rotation of affected leg
• Antalgic / Trendelenburg gait
• Waddling patterned gait if bilateral disease
• Restricted flexion, abduction & internal rotation of hip
• thigh atrophy
• Drehmann Sign
  • A very reliable sign of a chronic SUFE, even when mild, is detection of obligatory external rotation during flexion of the hip.
  • As the hip is flexed on the affected side, the thigh will automatically externally rotate and abduct.

1. 

Investigation

1. XR – determine stability & confirm diagnosis. AP & Frog lateral pelvis views of both hips
   • Widening & irregularity of physis
   • Degree of slip of eiphysis

Management

1. WC or non-weight bearing until ortho review (urgent, refer to ED)
2. Surgical fixation to stabilize, protect vascular supply to femoral head & prevent further deformity

Complications

1. Osteonecrosis – the risk is up to 50% in an unstable SUFE, even with treatment
2. Chondrolysis – this can result from the process of the SUFE itself, but more commonly it is from unrecognised screw/pin penetration from surgical stabilisation. The overall incidence of this is approximately 7%
3. Osteoarthritis – patients with a moderate or severe SUFE have higher risk of early degenerative joint disease
4. Impingement – patients with a severe SUFE have a risk of deformity through the femoral neck when the SUFE is stabilised and healed. This can cause femoral acetabular impingement, and may require further surgical treatment to correct this
5. Early degenerative OA
6. Contralateral hip SCFE 
7. residual proximal femoral deformity & limb length discrepancy