2025 ISAKOS Biennial Congress ePoster
Utility of 3D biomodels in the surgical planning of femoral derotational osteotomies
Caterina Chiappe , MD, València, València SPAIN
Alejandro Roselló-Añón, PhD, València, València SPAIN
Vicente Sanchis-Alfonso, MD, PhD, Paterna - Valencia SPAIN
Joan Carles Monllau, MD, PhD, Prof., Esplugues de Llobregat, Barcelona SPAIN
Julio Domenech-Fernández, PhD, Navarra SPAIN
Hospital Arnau de Vilanova, València, Comunidad Valenciana, SPAIN
FDA Status Not Applicable
Summary
The resulting degrees of FAV measured do not always correspond to the degrees that had been planned after a derotational osteotomy. The hypothesis is that the femur rotation axis and the osteotomy rotation axis do not coincide. The objective is to demonstrate the reliability of the 3D technique for osteotomy adjustment through an intra and interobserver study.
ePosters will be available shortly before Congress
Abstract
Background
Increased femoral anteversion (FAV) is crucial in the genesis of anterior knee pain (AKP) and a femoral derotational osteotomy (FDO) has demonstrated good clinical results. It remains unclear at what level of the femur the osteotomy should be performed. Resulting degrees of FAV measured by Murphy's method do not always correspond to the degrees that had been planned after an FDO. The hypothesis of this study is that the femur rotation axis and the osteotomy rotation axis do not coincide. 3D technology is used to objectify the discrepancy between these two axes and to find solutions so that the two axes can coincide. The objective is to demonstrate the reliability and reproducibility of the 3D technique for osteotomy adjustment through an intraobserver and interobserver study.
Methods
Images of 8 CT scans of the femur corresponded to 7 patients with a diagnosis of AKP and increased FAV, were selected. Two surgeons performed the FAV measurement and simulation of FDO on 3D biomodels. The femoral osteotomies were defined at three levels, at 10ª,20ª,30ª. To determine interobserver agreement, measurements were performed independently by two surgeons. To evaluate intraobserver differences each surgeon repeated all measurements after 15 days.
Results
Interobserver and intraobserver agreement: ICC 0.930(95%CI 0.799-0.975) and 0.986 (95%CI 0.959-0.995). Osteotomies with and without adjustment (coinciding or not with the rotation axis of the fragments) gave the same correction value regardless of whether the osteotomy site was diaphyseal or supracondylar. Significant differences between the resulting values were observed when the osteotomy was performed at the intertrochanteric level. The misalignment of the proximal and distal fragment rotation axes tended to undercorrect by 34% when the intertrochanteric derotational osteotomy was 10° (3.4º IC95% 0.5-2.3), and undercorrect by 27% in osteotomies of 20° (5.4º IC95% 0.6-3.8) and 30º (8.2º IC95% 1-5.9).
Conclusion
The misalignment of the axes results in hypocorrection when the osteotomy is intertrochanteric. This phenomenon is not observed when the osteotomy is diaphyseal or supracondylar.