Analysis of the effect of tibial torsion on tibial osteotomy in knee arthroplasty using a three-dimensional computed tomography-based modelling technique

Abstract

Background Extramedullary systems are commonly used in knee arthroplasty, with the rod location being determined from the tibial torsion line during surgery. The traditional method for tibial torsion measurement is not in accordance with clinical practice. This study aimed to evaluate proximal and distal tibial torsion using 3-dimensional (3D) computed technology to establish a new evaluation method, as well as to investigate the association between tibial torsion and postoperative alignment deviation. Methods Fifty-five osteoarthritis tibias with >10°varus preoperatively were divided into valgus, neutral, and varus groups based on their postoperative alignment deviation. A new method based on clinical practice was built using a 3D tibial model. Proximal and distal tibial torsions were measured by both the new and traditional methods. In addition, tibial osteotomy that followed the intramedullary osteotomy system was simulated on the 3D model in the varus and valgus groups to investigate the association between tibial torsion and alignment deviation. Results Proximal tibial torsion was smaller and distal torsion was greater in the valgus group than the other two groups, according to the new method ( p = 0.03 and p = 0.02, respectively). No significant difference was found when comparing these torsions by the traditional method ( p = 0.782 and p = 0.753, respectively). In the valgus group, the postoperative alignment deviation improved after simulated osteotomy guided by the intramedullary system, while no significant improvement was found in the varus group. Conclusion According to this new tibial-rotation evaluation method, valgus deviation in knee arthroplasty was identified as the main cause for knees in which the proximal tibial internal torsion is too small and the distal external torsion is too great. The use of an intramedullary system may help reduce this deviation. Trial registration Prospectively registered.

Tibial joint line orientation has no effect on joint awareness after mechanically aligned total knee arthroplasty

“…This optimizes load distribution during the mono‐ and bipedal phases of gait [10, 16] and is supposed to permit a more "natural feeling" [23]. Among the current alignment concepts, JL parallelism is most likely achieved with KA [9, 10, 15, 16]. Thus, it might be assumed that patients with KA TKA are more satisfied.…”

“…To “forget” about an artificial joint, because it feels natural can be considered the ultimate goal of arthroplasty. PRO assessed with the FJS‐12 seem to favor KA TKA compared to MA TKA [14–17] with an average of 46–80 points at mid‐term follow‐up. Compared with the literature [21–23], the mean FJS‐12 in our series was even slightly better, exceeding the mean normative values for FJS‐12 reported for the given age group (68 points in women and 79 points in men [12]).…”

Three‐dimensional analysis of mandibular morphology asymmetry and temporomandibular joint position in patients with unilateral Brodie bite

“…17 A most recent study indicated that the condylar volume and superficial area of the scissors-bite side were significantly greater than those on the non-scissors-bite side in patients with unilateral scissors-bite. 18 Nonetheless, these studies include individuals who have at least one posterior tooth with scissors-bite rather than patients with unilateral Brodie bite. Moreover, the condylar position is rarely investigated three-dimensionally in patients with unilateral Brodie bite.…”

“…Strikingly, it was found that the mandibular body and condylar process were remarkably asymmetrical in patients with unilateral scissors bite by the “surface‐to‐surface” mapping method 17 . A most recent study indicated that the condylar volume and superficial area of the scissors‐bite side were significantly greater than those on the non‐scissors‐bite side in patients with unilateral scissors‐bite 18 . Nonetheless, these studies include individuals who have at least one posterior tooth with scissors‐bite rather than patients with unilateral Brodie bite.…”