Slipped Capital Femoral Epiphysis (SCFE)
You should immediately suspect slipped capital femoral epiphysis (SCFE) in this 12-year-old severely obese female presenting with acute hip pain, medial thigh and knee pain, limp, and decreased hip range of motion.
Clinical Reasoning
This presentation is classic for SCFE, which represents an orthopedic emergency requiring urgent evaluation and treatment. The key diagnostic features align perfectly:
Age and obesity: SCFE is the most common hip pathology in children aged 8-15 years 1, and severely obese children are significantly more likely to develop SCFE 2. Her BMI >99th percentile places her at substantially elevated risk.
Pain pattern: The combination of hip pain with referred pain to the medial thigh and knee is pathognomonic for hip pathology 3, 4. This referred pain pattern frequently causes diagnostic delays when providers focus on the knee rather than the hip 1.
Acute presentation with limp and decreased range of motion: These are cardinal features of SCFE 3. The inability to bear weight without severe limping over several days indicates this is likely an unstable SCFE, which carries higher risk of complications.
Critical Action Points
Obtain immediate AP and frog-leg lateral radiographs of both hips (bilateral views are essential as SCFE can be bilateral) 2. Do not delay imaging - SCFE requires urgent orthopedic consultation and surgical stabilization to prevent:
- Avascular necrosis of the femoral head
- Progressive slip
- Chondrolysis
- Permanent hip dysfunction 5
Important Clinical Pitfalls
Do not be misled by knee pain alone - hip pathology commonly presents as knee or thigh pain in children 3, 4, 6. The referred pain pattern causes significant diagnostic delays when non-orthopedic providers evaluate these patients 1.
Do not assume normal BMI excludes SCFE - while severe obesity is a major risk factor 2, SCFE can occur in normal-weight children, particularly after trauma 5.
Bilateral involvement occurs more frequently in severely obese children 2, so always image both hips even if symptoms are unilateral.
Differential Considerations
While SCFE is the primary concern, also consider:
- Septic arthritis - would typically present with fever, inability to bear weight, and more acute onset 7, 4
- Transient synovitis - usually follows viral illness, less severe symptoms
- Osteomyelitis - would show systemic signs of infection 7
The several-day progression without fever and the specific pain pattern strongly favor SCFE over infectious etiologies in this case.