Patient-specific proximal femoral plate combined with a modular 3D-printed osteotomy guide system in children with developmental dysplasia of the hip: a retrospective comparative study.

BACKGROUND: To evaluate the clinical value of a patient-specific proximal femoral plate combined with a modular 3D-printed osteotomy guide system in children with developmental dysplasia of the hip (DDH) undergoing proximal femoral osteotomy. MATERIALS AND METHODS: This retrospective study included children with DDH who underwent proximal femoral osteotomy assisted by a modular 3D-printed osteotomy guide system. Patients were divided into a customized plate group and a conventional locking compression pediatric hip plate (LCP-PHP) group. Perioperative outcomes, including blood loss, operative time for the femoral procedure, and fluoroscopy frequency, were compared. Radiographic parameters, including neck-shaft angle (NSA), femoral anteversion angle (FAA), acetabular index (AI), and center-edge (CE) angle, were assessed postoperatively and at final follow-up. Functional outcomes, complications, and measurement reliability were also evaluated. RESULTS: A total of 40 patients were included. The mean follow-up duration was 32.32 ± 4.18 months in the customized plate group and 31.39 ± 3.88 months in the conventional LCP-PHP group. No major complications were observed in either group. Compared with the conventional LCP-PHP group, the customized plate group showed a significantly smaller loss of planned NSA correction, whereas FAA correction loss was similar between groups. No significant between-group differences were found in blood loss, operative time, fluoroscopy frequency, postoperative radiographic parameters, final follow-up outcomes, or functional results. Reliability analysis demonstrated excellent reproducibility of radiographic measurements, supporting the validity of the difference in NSA correction loss. CONCLUSIONS: A patient-specific proximal femoral plate combined with a modular 3D-printed osteotomy guide system appears to be a feasible and safe option for proximal femoral osteotomy in children with DDH. Compared with the conventional LCP-PHP, the customized plate more accurately maintained the planned NSA correction and may help improve correction accuracy in pediatric hip reconstruction.