Prognostic Significance of Metaphyseal Changes in Legg-Calvé-Perthes Disease.

Abstract

Previous studies have established the relationship between changes in the femoral head epiphysis and prognosis of Legg-Calvé-Perthes disease (LCPD), whereas the clinical significance of metaphyseal changes remains to be elucidated. This study aims to investigate the correlation between the type of metaphyseal changes and disease severity, as well as determine whether it is associated with the prognosis of LCPD based on radiographic outcomes after undergoing containment therapy. A retrospective analysis was conducted on the records of 105 patients with unilateral LCPD who underwent containment treatment. Three common types of metaphyseal changes were assessed using anteroposterior and frog-leg lateral radiographs, and the correlation between these change types and other clinical prognostic indicators was further analyzed. Univariate and multivariate logistic regression models were used to analyze potential risk factors affecting femoral head shape in children over 6 years of age, based on the Sphericity Deviation Score (SDS) was measured after epiphyseal healing, including age, stage at diagnosis, lateral pillar classification, Catterall classification, type of metaphyseal changes, and treatment method. A total of 105 patients (mean age at diagnosis 6.8 y) were included. Among them, 6 showed no metaphyseal reaction, 45 had localized osteopenia, 29 exhibited cystic changes, and 25 presented with diffuse reactions. Of these patients, 40 received conservative treatment and 65 underwent surgeries. Surgical intervention significantly improved femoral head containment (extrusion index: 29.5±7.9 to 7.6±5.6, P <0.001). The frequency of spherical femoral heads after healing differed significantly among metaphyseal groups ( P <0.001), with the diffuse reaction group showing a higher rate of nonspherical femoral heads and significantly greater metaphyseal widening. Patients under 6 years had better outcomes than older children (88.9% vs. 56.5%, P =0.001). In patients over 6 years, multivariate analysis identified lateral pillar collapse (OR: 4.63, P =0.023) and diffuse metaphyseal reactions (OR: 7.31, P =0.009) as risk factors of poor femoral head sphericity. Cystic changes were not significantly associated with poor outcomes. Diffuse metaphyseal reaction is indicative of more severe condition in patients with LCPD, as well as its serve as a strong predictor of poor prognosis in patients over 6 years old, whereas metaphyseal cysts are less significant in predicting femoral head shape. Level III-prognostic study.