What is the treatment for Legg-Perthes disease?

Treatment of Legg-Calvé-Perthes Disease

The treatment of Legg-Calvé-Perthes disease should be based primarily on the patient's age at disease onset and the extent of femoral head involvement, with surgical containment procedures recommended for children over 8 years of age with lateral pillar B or B/C border classification.

Disease Overview

Legg-Calvé-Perthes disease (LCPD) is an idiopathic hip disorder characterized by avascular necrosis of the growing femoral head. It typically affects children between 4-8 years of age but can occur between ages 2-15 1. The condition results from interrupted blood supply to the femoral head, leading to osteonecrosis and potential permanent femoral head deformity if not properly managed.

Prognostic Factors

Several key factors influence prognosis and guide treatment decisions:

1. Age at disease onset - Critical prognostic factor 2, 3
2. Extent of femoral head involvement - Assessed using lateral pillar classification 2
3. Femoral head deformity - Presence of "head-at-risk" signs 1
4. Lateral pillar collapse - Indicates severity 1
5. Gender - Females over 8 years at onset have worse outcomes 2

Treatment Algorithm

Children Under 6 Years of Age

• Recommended approach: Non-surgical management 1
• Rationale: Generally good prognosis regardless of treatment method 2
• Options:
  • Observation
  • Range-of-motion exercises
  • Non-weight bearing activities

Children 6-8 Years of Age

• Approach: Close observation with treatment based on lateral pillar classification
• Lateral Pillar Group A: Non-surgical management
• Lateral Pillar Group B:
  • Non-surgical management is typically sufficient 2
  • Consider surgical intervention if signs of femoral head deformity develop
• Lateral Pillar Group B/C or C: Consider surgical containment 2

Children Over 8 Years of Age

• Lateral Pillar Group A: Non-surgical management
• Lateral Pillar Group B or B/C border:
  • Recommended approach: Surgical containment 2
  • Evidence: Significantly better outcomes with surgical vs. non-surgical treatment (p≤0.05) 2
• Lateral Pillar Group C:
  • Poor outcomes regardless of treatment approach 2
  • Surgical intervention may be considered but with guarded prognosis

Surgical Treatment Options

1. Femoral Varus Osteotomy

   • Redirects the femoral head deeper into the acetabulum
   • Similar outcomes to innominate osteotomy 2

2. Innominate (Pelvic) Osteotomy

   • Improves acetabular coverage of the femoral head
   • Similar outcomes to femoral osteotomy 2

3. Surgical Hip Dislocation with Femoral Head Reshaping

   • For symptomatic residual deformity after healing
   • 10-year survival rate of 66% before requiring further intervention 4
   • Predictors of failure: severity of preoperative pain and deformity 4

Non-Surgical Treatment Options

1. Observation

   • Appropriate for younger children with minimal involvement
   • Regular follow-up to monitor disease progression

2. Range-of-Motion Exercises

   • Maintains hip mobility
   • No difference in outcomes compared to no treatment in controlled studies 2

3. Bracing

   • No proven benefit over observation in controlled studies 2
   • May be considered in specific cases to maintain containment

Monitoring and Follow-up

• Regular radiographic assessment to monitor femoral head involvement and deformity
• Assessment of hip range of motion
• Long-term follow-up into adulthood due to risk of secondary degenerative osteoarthritis 3

Treatment Efficacy

The number needed to treat with surgical intervention to achieve one spherical femoral head that would not have occurred otherwise is 6-7 patients 3. This modest treatment effect highlights the importance of careful patient selection for surgical intervention.

Conclusion

Age at disease onset and lateral pillar classification are the strongest prognostic factors in LCPD 2. While younger children (under 8 years) with lateral pillar group B classification generally do well regardless of treatment, older children (over 8 years) with lateral pillar group B or B/C border classification benefit significantly from surgical containment procedures 2. Treatment decisions should be guided by these evidence-based factors to optimize outcomes and minimize femoral head deformity.