In Perthes disease (Legg-Calvé-Perthes), the Herring lateral pillar classification is used to prognosticate outcomes. A child aged 9 years with Herring group C (lateral pillar height <50% of the contralateral side at the fragmentation stage) has the worst prognosis. The primary treatment principle for this group is:

• A Observation alone — outcomes are equivalent to conservative or surgical containment
• B Containment of the femoral head within the acetabulum during the healing phase (by femoral or innominate osteotomy) — biological moulding of the healing avascular head by the acetabular socket reduces femoral head deformity ✓
• C Early total hip replacement once avascular necrosis is confirmed
• D Valgus extension osteotomy to avoid hinge abduction

Explanation

The principle of treatment in Perthes disease is 'containment' — keeping the softened necrotic femoral head enclosed within the acetabulum during the fragmentation and early reossification stages so the acetabulum acts as a biological mould, encouraging re-ossification in a spherical shape. Herring group C patients (and group B/C borderline aged >8 years) have the worst natural history (flat femoral heads, early OA) and benefit most from containment procedures — either femoral varus osteotomy (improving coverage by redirecting the head into the acetabulum) or Salter innominate osteotomy (redirecting the acetabulum). Valgus extension osteotomy is reserved for the specific complication of hinge abduction (where the deformed head impinges on the acetabular rim in abduction), not primary treatment.

Reference: Maheshwari Essential Orthopaedics, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.