Principles of treating the sequelae of Perthes disease.

Despite early treatment efforts, many patients with Perthes disease are left with residual femoral head deformity, which can be symptomatic with a residual limp and poor hip motion. Many such patients can be treated using an extra-articular femoral osteotomy. Selecting treatment methods for patients with symptomatic Perthes disease with healed but deformed femoral heads has always been difficult but is now even more complex because of the new possibilities of femoral head-neck recontouring and femoral head reduction surgery. Occasionally, patients develop osteochondritis dissecans when there is little femoral head deformity. The primary objective of management is to establish the exact cause of pain and address that cause specifically. This article outlines an approach to these patients.