Surgical Treatment Modalities in Pediatric Monostotic Fibrous Dysplasia of Proximal Femur - A Case Series.

Introduction: Monostotic fibrous dysplasia is a rare genetic non-inherited orthopedic condition presenting at any age with variable presentation. Proximal femur being the most common site, the mechanical factor predisposes it to increased chances of pathological fracture, which makes it challenging to choose an appropriate treatment modality and implant selection in children. Case Presentation: In this retrospective case series, six children aged 7-12 years with monostotic fibrous dysplasia with or without fracture were treated with different treatment modalities from 2015 to 2020. Extended curettage and bone grafting and stabilization were done with extramedullary implants such as locking plates and DHS. Autograft alone or combination with allograft was chosen according to size of lesion. Patients without fracture were treated with curettage and artificial bone graft substitute with hip spica. Patients were followed up to 12 months. Revised Musculoskeletal Tumor Society (MSTS) score at each follow-up and Toronto Extremity Salvage Score (TESS) at final follow-up. Results: Mean fracture healing time was 14.8 ± 2.28 weeks. in patients with fracture. Full weight-bearing was started at average 15.67 ± 2.94 weeks. One patient had shortening of 1 cm but none had any surgical site infection, loss of correction, or varus collapse more than 5°. Mean revised MSTS at 12 months was 24.2 ± 2.28 in patients with curettage, bone grafting, and internal fixation, while it was 27 in patients with curettage, grafting with hip spica. Mean TESS was found to be 90 ± 9.41 in internal fixation group, while it was 95 in patient with curettage, grafting with hip spica. Conclusion: Treatment modality should be chosen wisely after analyzing pre-operative radiograph, lesion size, presence of pathological fracture, and each patient profile. Extramedullary fixation devices can be an alternate choice of implant in children and adolescents for monostotic fibrous dysplasia. Long duration follow-up and patient counseling should be done for recurrence of lesion and deformities.