Comparative digital study of two cranial rotation methods of the proximal fragment on the center of rotation of angulation-based leveling osteotomy planning with different tibial distal anatomical axes

The center of rotation of angulation (CORA)-based leveling osteotomy (CBLO) technique was developed for cranial cruciate ligament (CrCL) rupture treatment, aiming to modify the mechanical-anatomical angle (AMA), which is described as a predictive risk factor for the disease and is recommended to be taken into consideration when one is choosing a surgical procedure for tibial plateau slope alteration. Identifying a tibial distal anatomical axis (DAA) is essential in CBLO surgical planning and measuring AMA amplitude. The aim of this study was: to evaluate two methods of cranial rotation of the proximal fragment using four different tibial distal anatomical axes for digital planning on the CBLO technique, comparing its effectiveness in achieving the desired tibial plateau angle (TPAd) and closing the AMA angle. Tibial measurements were made with the vPOP pro software using 30 mediolateral radiographs of canine stifles. The DAA described by four authors was used based on the amount of Rotation completed (Rc) for each. The rotation methods evaluated were: 1) commercial CBLO table (RT) and 2) overlapping the tip of the intercondylar eminence with the corresponding DAA line (RE). The TPAd to be obtained was fixed at 10°, and the final AMA to be achieved at 0°. The mean values and standard deviations of the final TPA and final AMA with the rotation method were TPA(RT)f(%TPAd), TPA(RE)f(%TPAd), AMA(RT)f(%AMAzero), AMA(RE)f(%AMAzero). The results of each author were Hulse 10.0 ± 0.3(46.6%), 9.9 ± 0.1(60%), 0.3 ± 0.3(33.3%), 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. The initially described RT obtained a higher percentage of AMA at zero degrees. Therefore, the RE method is discarded for use as an alternative to CBLO planning.