Validation of Catterall Classification in the Management of Legg-Calve- Perthes Disease

Introduction: Despite the advancement in the recent times, there is still no consensus about the ideal classification that could grade the patient with Perthes disease preoperatively and prognosticate its outcome on follow-up. Although principal dictum in the management of Perthes disease is to contain the femoral head in the acetabular socket to prevent deformation of the femoral head, method of containment and candidate selection for surgery depends on the stage of presentation of the disease where classification system plays a major role. The aim of our study to is validate the role of Catterall classification in grading the disease preoperatively and prognosticating its outcome and categorising the post op outcome by Catterall postoperative scale. Materials & methods: This is a prospective study done from 2014-2018 where 72 children with Perthes disease were categorised and managed based on the Catterall classification and outcome was analysed. Surgical containment by varus derotation osteotomy was done in
all patients presenting late and with severe disease and in atients with head at risk signs. Results: Mean age of presentation was 7.4 years and out of 72 children, 26 belonged to grade 2 and 32, 14 belonged to grade 3 and 4 respectively. Surgical containment was done in 68 patients and in all patients containment was maintained till last follow-up. At a mean follow up of 2.4 years, good results were obtained in 49, fair in 21 and poor in 3 children using Catterall’s postoperative classification. Radiological evaluation was done using Caput Index and Epiphyseal Quotient to assess the regenerative potential of the femoral head.
Statistical analysis revealed significant results on follow up, with earlier grades having significantly better outcome compared to the late stage of disease. Conclusion: We concluded from our study that Catterall classification was consistent in prognosticating better outcome in patients presenting with low grade at early age and ideally selecting patients for surgical containment for advanced disease. Our study suggests that
varus derotation osteotomy is an effective and easy surgical containment method for children with advanced disease that significantly altered the natural history of this self-limiting pathology