In Perthes disease (Legg-Calvé-Perthes), the lateral pillar classification (Herring classification) is the most widely used prognostic system. Which lateral pillar group is associated with the WORST prognosis for femoral head shape at skeletal maturity?

• A Group A — lateral pillar height maintained >50% of original
• B Group B — lateral pillar height 50-100% maintained
• C Group C — lateral pillar height <50% of original ✓
• D Group B/C border — 50% height maintained, narrow or calcified lateral column

Explanation

Herring's lateral pillar classification grades avascular necrosis extent: Group A = no lateral pillar involvement (excellent prognosis); Group B = >50% of lateral pillar height maintained (good prognosis, especially if age <8 at onset); Group B/C = exactly 50% height or narrow calcified pillar (intermediate); Group C = <50% lateral pillar height maintained (worst prognosis, high risk of femoral head deformity [coxa plana], acetabular incongruence, and early hip arthritis). Group C patients with age >8 years at onset have the worst outcome and are most likely to benefit from containment surgery (femoral/pelvic osteotomy).

Reference: Maheshwari Essential Orthopaedics, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.