Estudo digital sobre as influências no planejamento da Osteotomia de Nivelamento baseada no Centro de Rotação de Angulação da utilização de diferentes eixos anatômicos tibiais distais e métodos de rotação do fragmento proximal

Abstract

The Center of Rotation of Angulation (CORA) - Based Leveling Osteotomy (CBLO) technique was developed for the treatment of cranial cruciate ligament rupture (CrCLR), with the aim of modifying the mechanical-anatomic angle (MAA), which is described as a predictive risk factor for the disease and is recommended to be taken into account when choosing the surgical procedure for tibial plateau disruption. One of the main complications of this technique is the mislocalization of the CORA related to the delineation of the distal anatomic axis (EAD) of the tibia. The aim of this study was: 1) to evaluate the accuracy of four distal anatomic axes for planning the CBLO technique; 2) to determine if there is superiority among any of them in relation to their positioning at the tibial tuberosity width (TTW) level to obtain the desired tibial plateau angle (TPAd) and reduce the AMA; 3) to evaluate two methods of proximal fragment rotation in CBLO, comparing their efficacy in reducing the TPA and closing the AMA. In addition, the initial AMA amplitude (AMAi) was measured using the four distal anatomical axes, comparing the results with each other and with those described in the literature, to find out if there are significant differences in patients with RLCCr. Tibial measurements were performed in vPOP pro software using 30 mediolateral radiographs of canine knees. The EAD described by four different authors was used, from which two rotation groups were obtained: concluded (Rc) and not concluded (Rn), determining superiority (Hulse 50%, Osmond 40%, Miles 40% and Tudury 53.3%) based on the amount of Rc in relation to the authors' EAD. The location of EAD relative to TTW was determined in a percentage range that guaranteed success as a result of one's superiority in perfecting digital planning (%EadTTW). The rotation methods evaluated were 1) the commercial CBLO table (RT) and 2) overlapping the tip of the intercondylar eminence with the corresponding EAD line (RE). The TPAd to be obtained was set at 10° and the final AMA to be achieved at 0°. The mean and standard deviation of the final TPA and final AMA corresponding to the rotation method: TPA(RT)f(%TPAd), TPA(RE)f(%TPAd), AMA(RT)f(%AMAzero), AMA(RE)f(%AMAzero) and the result of each author were Hulse 10.0±0.3(46.6%), 9.9±0.1(60%), 0.3±0.3(33 0.3%), 0.3±0.3(13.3%), Osmond 10.1±0.2(75%), 10, 1±0.2(83.3%), 0.4±0.4(33.3%), 0.4±0.3(8.3%), Miles 10.0±0.1(66.6%), 10.0±0.1(75%), 0.2± 0.1(16.6%), 0.2±0.1(8.3%), Tudury 9.6±0.6(31.2%), 9.5±0.2(31.2%), 1.0±0.7(18.7%), 1.0±0.6(12.5%) respectively. Mean AMAi was 5.4±1.1 for Hulse, 3.0±1.3 for Osmond, 3.2±1.5 for Miles and 5.9±1.4 for Tudury, with significant differences between all authors (P<0.05) except between Osmond and Miles. Hulse's EAD was more accurate and related to a %EadTTW of 37.6±4.3 for rotations to complete. The RT initially described obtained a higher percentage of AMA at grade zero, thus discarding the RE method for use as an alternative in CBLO planning. It was not possible to determine a value of AMAi that was shown to be superior due to the nature of the study, so future comparisons with these EADs between healthy and affected patients are recommended to know if there would be accuracy as a predictive factor for the appearance of RLCCr.