What is the recommended monitoring and management for a child with stable Legg-Calve-Perthes (LCP) disease and possible developmental dysplasia of the hip (DDH) experiencing worsening left hip pain?

Monitoring and Management for Stable Legg-Calvé-Perthes Disease with Possible Developmental Dysplasia and Worsening Hip Pain

For a child with stable Legg-Calvé-Perthes disease (LCP) and possible developmental dysplasia of the hip (DDH) experiencing worsening left hip pain, immediate referral to a pediatric orthopedic specialist is necessary for comprehensive imaging and evaluation, as untreated conditions can lead to premature osteoarthritis and long-term mobility issues. 1

Immediate Assessment Recommendations

For a child with worsening hip pain and history of LCP and possible DDH:

• Obtain pelvic radiographs as the first-line imaging modality for children older than 4 months 1
• Assess for:
  • Limitation of hip abduction (most important clinical sign after 3 months) 1
  • Asymmetry of thigh or gluteal folds
  • Leg length discrepancy (Galeazzi sign)
  • Pain with hip movement

Imaging Protocol

The American College of Radiology recommends age-specific imaging approaches:

• For children older than 4 months: Pelvic radiography is the preferred modality 1
• If radiographs are inconclusive or to better evaluate femoral head involvement in LCP:
  • MRI may show proximal femoral abnormalities before they appear on radiography 2
  • MRI can assess for revascularization, healing, and complications in LCP 2

Management Algorithm

For DDH Component:

1. If hip is stable but shows radiographic abnormalities:

   • Serial physical examinations and periodic imaging assessments throughout treatment 3
   • Monitor acetabular index measurements on radiographs

2. If hip shows instability or worsening dysplasia:

   • For children under 6 months: Pavlik harness (success rate 70-95% when applied early) 1
   • For children 6-18 months: Consider closed reduction with hip spica cast 1
   • For older children: Surgical intervention may be necessary, including pelvic and/or femoral osteotomy 1

For Legg-Calvé-Perthes Component:

1. Monitoring for disease progression:

   • Regular radiographic follow-up to assess femoral head involvement
   • MRI to evaluate extent of avascular necrosis and revascularization 2

2. For worsening pain or limited range of motion:

   • Evaluate for femoroacetabular impingement, which can develop as a complication of LCP 4
   • Consider hip arthroscopy for treatment of mechanical symptoms if appropriate 5

Complications to Monitor

• Avascular necrosis: The most serious complication of DDH treatment and a predictor of poor prognosis 1
• Femoroacetabular impingement: Common in LCP due to femoral head deformity and acetabular remodeling 4
• Premature osteoarthritis: Untreated DDH can lead to early degenerative joint disease 3, 1
• Decreased mobility and strength: Long-term complications of both conditions 1

Follow-up Schedule

• Initial follow-up: 4-6 weeks after assessment
• Regular monitoring: Every 3-6 months depending on severity
• Continue monitoring through skeletal maturity, as complications can develop during growth spurts

Special Considerations

• The rare concurrent presentation of DDH with contralateral LCP requires careful evaluation of both hips 6
• Treatment approaches must address both conditions simultaneously when present
• The presence of worsening pain in a previously stable condition warrants urgent reassessment

Pitfalls to Avoid

• Focusing only on the known diagnosis while missing concurrent pathology
• Delaying referral to pediatric orthopedic specialist when pain is worsening
• Inadequate imaging follow-up during periods of rapid growth
• Failing to monitor for development of femoroacetabular impingement, which can occur as a complication of LCP 4

Remember that untreated DDH and LCP can lead to significant long-term morbidity including premature osteoarthritis, abnormal gait, and decreased quality of life, potentially requiring total hip arthroplasty at a young age 3, 1.