Proximal femoral varus osteotomy for Legg–Calvé–Perthes disease: do age and lateral pillar classifications influence short-to-mid-term clinical and radiological outcomes?

Introduction: Proximal femoral varus osteotomy (FVO) is one of the most used treatment methods with acceptable outcomes for Legg–Calvé–Perthes disease (LCPD). We aimed to investigate the influence of age at disease onset and the Lateral Pillar classification on clinical and radiological outcomes of FVO surgery LCPD patients between 6-12 years of age.Hypothesis: Proximal FVO surgery in the early fragmentation phase of LCPD patients led to acceptable clinical and radiographic outcomes in a 3-year follow-up, regardless of preoperative age and Herring type.Material and methods: 50 patients with LCPD (Herring groups B, B/C, and C) who underwent FVO were retrospectively reviewed. We evaluated radiological (center-edge angle, extrusion index, epiphyseal index, acetabular index, articulo-trochanteric distance (ATD)) and clinical (hip abduction range of motion (ROM), Trendelenburg sign, pain, and Harris hip score (HHS)) outcomes with a follow-up of 37.3 ± 10.5 months (range: 24 - 180 months). Finally, the overall treatment outcome was assessed using the Stulberg classification.Results: The ROC Curve analysis did not reveal any significant relationship between age and clinical or radiological outcomes, and there was no predictable age cut-off for surgical outcomes (P=0.13). No significant difference was found in Stulberg classification at the follow-up between patients with type B, B/C, and C of the lateral pillar (P>0.05).Discussion: Our results demonstrated that open-wedge proximal FVO surgery in the early fragmentation phase of LCPD patients led to acceptable clinical and radiographic outcomes in a 3-year follow-up. Each sample of our study was very small and a lot of variables were measured, making this result not adequately strong enough to draw a robust conclusion. However, FVO surgery remains a possible suggestion for patients in the early fragmentation phase, and age and lateral pillar type may not be limiting factors.Level of Evidence: IV; Therapeutic Retrospective cohort.