ObjectiveTo investigate the early effectiveness of surgical hip dislocation (SHD) combined with autologous iliac crest bone grafting in the treatment of femoral neck fracture nonunion in adolescents. Methods Between December 2020 and August 2024, 21 adolescent patients with femoral neck fracture nonunion were treated with SHD combined with autogenous iliac bone grafting. There were 16 males and 5 females, aged 15-25 years (mean, 19.1 years). According to the Pauwels classification, there were 8 cases of type Ⅱ fractures and 13 cases of type Ⅲ fractures. After the initial fracture, 18 patients had undergone reduction and internal fixation, while 3 had received conservative treatment. The interval from fracture to the operation was (12.0±9.3) months. Preoperatively, the Harris score was 52.0±4.2, the International Hip Outcome Tool-12 (iHOT-12) score was 45.6±3.2, and the visual analogue scale (VAS) score for pain was 5.1±0.8. Postoperative imaging was reviewed to assess femoral neck fracture healing and whether secondary collapse of the femoral head occurred. The Harris score, iHOT-12 score, VAS score, and complications were evaluated. Results All patients were followed up 12-55 months (mean, 27.7 months). During follow-up, no avascular necrosis of the femoral head, heterotopic ossification, infection, or other complications occurred. At last follow-up, the Harris score, iHOT-12 score, and VAS score were 88.1±4.4, 74.7±5.6, and 1.2±0.6, respectively, all of which significantly improved when compared with preoperative values (P<0.05). In all 21 cases, callus formation was observed at the fracture ends of the femoral neck, with good autogenous bone support and new bone formation in the femoral head and neck, and no collapse of the femoral head was observed. Internal fixator was removed in 5 patients at (25.8±7.1) months postoperatively. ConclusionSHD combined with autologous iliac crest bone grafting has a good early effectiveness in the treatment of femoral neck fracture nonunion in adolescents. The technique not only protects the blood supply of the femoral head, but also fully exposes the structure of the femoral neck fracture, allowing for sufficient freshness, bone grafting, and fixation treatment of the fracture end, thereby achieving good bone healing.