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Legg-Calve-Perthes

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Legg-Calve-Perthes, Aseptic Necrosis of the Femoral Head, Perthes Disease, Legg-Calve-Perthes Disease, Idiopathic Osteonecrosis of the Hip

  • See Also
  1. Pediatric Limp
  2. Osteochondrosis
  • Epidemiology
  1. Children age 4-9 years old typically affected (may affect ages 3-12 years old)
    1. Peak onset at ages 5 to 7 years old
  2. Boys affected 4-5 times more often than girls
  3. Familial in 20% of cases
  4. Incidence 1:1000 to 1:10,000
  5. Caucasian more often affected than african american
  6. Bilateral in 10-20% at time of diagnosis
  7. Typical body habitus
    1. Short to average height
    2. Average weight to Overweight (but not typically obese as seen in Slipped Capital Femoral Epiphysis)
  • Risk Factors
  1. Boys
  2. Low birth weight
  3. Short Stature
  4. Abnormal birth presentation (e.g. Breech Presentation)
  5. Family History
  6. Higher birth order
  7. Lower socioeconomic status
  8. Hyperactivity
  9. Obesity
  10. Passive Smoke Exposure
  • Pathophysiology
  1. Juvenile idiopathic, spontaneous onset, avascular necrosis of femoral head
  2. Results from a partial interruption of the blood supply to the femoral head
    1. Repeat episodes result in infarction and necrosis of the femoral head
  3. Subchondral Stress Fractures with remodeling over ensuing 2-4 years
    1. Femoral head flattens and subluxes
  • Etiology
  1. Idiopathic Osteochondrosis
  • Symptoms
  1. Insidious onset of Hip Pain or Pediatric Limp, worse with activity
  2. Anterior Hip Pain and Groin Pain
    1. May be referred as Knee Pain
  3. Unilateral Hip Pain in 84-90% of cases (bilateral Hip Pain in the remainder)
  • Signs
  1. Antalgic Gait
  2. Child walks with a limp on affected side
  3. Decreased Hip Range of Motion (pain may be absent)
    1. Limited hip abduction
    2. Limited hip internal rotation
  4. Leg Length Discrepancy (shortening on affected side)
  • Imaging
  1. Hip XRay
    1. Views
      1. Anteroposterior Pelvis
      2. Frog-leg lateral hip
    2. Findings
      1. XRay may appear normal early in condition
      2. Joint space widening
      3. Irregular physis widening
      4. Proximal femur growth center (capital epiphysis) with fragmentation, flattening, and sclerosis
        1. May demonstrate a subchondral Stress Fracture line
      5. Crescent sign
        1. Subcortical lucency represents bony destruction
  2. Hip MRI
    1. Indicated if non-diagnostic XRay results
    2. Bone Marrow changes may be present
    3. Hip Effusion
    4. Labrum and Articular Cartilage changes
  • Differential Diagnosis
  1. Septic Hip
  2. Transient Hip Synovitis
  3. Proximal femur Osteomyelitis
  • Management
  1. Orthopedic Consultation in all cases (within 1 week)
  2. Non-weight bearing initially
  3. NSAIDs may be used for pain
  4. Difficult management
    1. Long-term treatment
    2. Limited activity until resolution
  5. Bracing and Casting for up to 1-2 years
    1. Maintains femoral head within the acetabulum
  6. Surgical osteotomy to improve Hip Joint congruity
    1. Indicated in failed conservative management (esp. for over age 8 years old)
    2. Allows child back to activity in 4-6 months
  • Complications
  1. Severe degenerative hip disease (femoral head deformity)
    1. Requires hip replacement by middle age in 50% cases
  2. Proximal thigh atrophy and limb shortening
  3. Other complications
    1. Hip subluxation
    2. Premature physeal closure
    3. Hip Labral Tear
    4. Osteochondritis Dissecans
    5. Acetabular Dysplasia
    6. Femoral head deformity
  • Prognosis
  1. Fair at best to avoid longterm Arthritis (see complications above)
  2. Best prognosis for optimal range of motion is with early treatment at young age
    1. Age under 6 years old often fully recover without longterm deficit
  3. Predictors of worse prognosis
    1. Age over 6 years at onset of condition
    2. More severely affected femoral head deformity
    3. Hip Joint incongruity
    4. Decreased Hip Range of Motion
  • References
  1. Claudius and Behar in Majoewsky (2012) EM:RAP-C3 2(8): 1
  2. Gardiner (2018) Crit Dec Emerg Med 37(5): 3-14
  3. Jhun and Raam in Herbert (2016) EM:Rap 16(2):15-6
  4. Schleihauf (2019) Crit Dec Emerg Med 33(5): 19-28
  5. Achar (2019) Am Fam Physician 99(10): 610-8 [PubMed]
  6. Atanda (2011) Am Fam Physician 83(3): 285-91 [PubMed]
  7. Wiig (2008) J Bone Joint Surg Br 90(10): 1364-71 [PubMed]