Distal femoral osteotomy planning: Reversed Miniaci's method is more accurate than Dugdale and Paley methods

Abstract

PurposesThe purpose of this study was to validate the reversed Miniaci method for distal femoral osteotomies and to compare the accuracy with Dugdale and Paley methods. MethodsBetween January 2019 and October 2021, 59 DFO were performed in a single center. Following application of the eligibility and exclusion criteria, radiographic measurements and analysis was performed for 24 patients by two independent observers, then repeated after one month. Medical planning software: PeekMed v2.3.7.6® was used. For all patients the following measurements were performed: Hip–Knee–Ankle (HKA), mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle (MPTA), joint line convergence angle (JLCA), joint line obliquity (JLO), width of the proximal tibia and the weight-bearing line (WBL). Each image was then analysed using the following planning methods for realignment surgery: Reversed Miniaci, Dugdale and Paley. Measurements were recorded post deformity correction. Difference between target and post-correction WBL was evaluated. This difference was adjusted by the objective in order to limit biases related to the different objectives according to the method. ResultsEighteen patients were managed for a varus osteotomy and 6 for a valgus osteotomy. Preoperative data was, HKA at 176.7±6.3, mLDFA at 90.6±5.4, MPTA 88.9±1.1, a WBL for valgus 80.9%±9.1 and for varus deformity 23.5%±11.7. Inter- and intra-rater reliability was>0.8 for every method. After normalizing reported precision on the amount of correction expected, reversed Miniaci method was the most accurate with a mean deviation from the target of 3%, compared to the Dugdale's method with 9% (p<0.001) and to Paley's method with 8.6% (p<0.001). ConclusionThe reversed Miniaci method is effective and reliable for planning distal femoral osteotomies. Compared to other planning methods, it is the most accurate approach for achieving a correction goal. Level of evidenceIV; retrospective cohort study.