Treatment of osteonecrosis of the femoral head in Ficat stage III after femoral neck fracture in children and adolescents by basicervical femoral neck rotational osteotomy

Aims: Osteonecrosis of the femoral head (ONFH) after femoral neck fracture poses challenges in children, particularly at Ficat stage III. Limited effective treatments are available. This study explores basicervical femoral neck rotational osteotomy (BFNRO) for ONFH following fracture of the femoral neck in children and adolescents, and evaluates its outcomes. Methods: Children and adolescents with ONFH (Fiat stage III) following fracture who underwent BFNRO at our centre from June 2017 to September 2022 were included. Follow-up exceeded one year, with data on modified Harris Hip Score (mHHS), range of motion (ROM), patient satisfaction, femoral head collapse, necrotic area repair, leg length, and osteoarthritis (OA) progression recorded. Results: This study included 15 patients (15 hips; eight male and seven female) with a mean age of 12.9 years (10 to 17). Nine patients had BFNRO alone, and six had combined periacetabular osteotomy. Rotation angles varied from 70° to 90° for anterior rotation and 110° to 135° for posterior rotation. Nine patients had femoral neck fixation in a varus position (10° to 30°). The postoperative contour of the weightbearing area of the femoral head has significantly improved in all patients. At a mean follow-up of 28.6 months (12.2 to 72.7), mean mHHS significantly improved (65.2 (SD 8.6) to 90.2 (SD 5.8); p < 0.001). Only one patient showed femoral head further collapse. Patients experienced no/mild hip pain (visual analogue scale 0 to 3), slight restriction in ROM, and mild limb shortening. Two patients had OA progression. No infections or nerve injuries were observed, and no arthoplasies undertaken. Conclusion: Even with late stage ONFH after fracture, BFNRO in children and adolescents can provide positive early to mid-term results by relocating the necrotic area and restoring the integrity of the anterior-lateral column of the femoral head, thereby preventing femoral head collapse and delaying the onset of severe OA.