Application of three-dimensional triangular external fixator in proximal femoral derotational osteotomy for excessive femoral anteversion

To evaluate the safety and efficacy of a novel three-dimensional triangular external fixator (3D-TEF) in combination with proximal femoral derotational osteotomy (PFDO) for the treatment of symptomatic excessive femoral anteversion (EFA). A retrospective analysis was conducted on data from 12 patients (23 limbs) who underwent PFDO with 3D-TEF from July 2018 to 2024. The preoperative and postoperative femoral neck anteversion angle (FNA) was measured using computed tomography scans, quality of life was assessed using the Pediatric Outcomes Data Collection Instrument (PODCI), and complications and bone healing time were recorded. Twelve patients underwent surgery on a total of 23 limbs, with a mean age of 10.4 years (7.00-17.00). The mean follow-up duration was 23.25 months (5.00-44.00). The preoperative FNA was 42.58 ± 7.57°, which significantly decreased to 17.99 ± 2.14° postoperatively ( t = 15.34, P < 0.001). The mean femoral neck-shaft angle measured 136 .25° ± 4. 26° preoperatively and 136.80° ± 4.24° postoperatively (t = -0.77, P > 0.05), indicating no statistically significant change. Postoperative PODCI scores approached normative levels. All patients showed improvement in symptoms of tripping and falling, as well as in the degree of FNA. Two complications were observed: one superficial pin tract infection and one knee flexion contracture, neither of which impacted final outcomes. All osteotomies achieved union without evidence of nonunion, malunion, delayed union, hardware loosening, or avascular necrosis. PFDO stabilized with the 3D-TEF yielded satisfactory outcomes in correcting EFA. The 3D-TEF may present itself as a viable alternative for treating EFA, offering positive clinical outcomes.