Comparison of tibial rotation in fixed and mobile bearing total knee arthroplasty using computer navigation

Abstract

Tibial rotation is an important aspect of knee function and can be altered after total knee arthroplasty (TKA). These alterations include decreased internal rotation with knee flexion as compared to the normal state and paradoxical external rotation with flexion. Mobile bearing total knee prostheses may allow greater unconstrained tibial rotation. I compared tibial rotation after fixed bearing or mobile bearing total knee arthroplasty in 82 patients who underwent TKA with the tibia cut first technique to ascertain any differences. Using intraoperative imageless computer navigation, measurements included the determination of tibial rotation from extension to 90°flexion before and after prosthetic implantation with non-weight-bearing range of motion. I found that tibial rotation was significantly reduced after fixed bearing total knee replacement as compared to mobile bearing. In addition, the tibial position compared to the distal femur in extension was more external in fixed bearings compared to mobile bearings. Placing the fixed tibial tray with increased internal rotation could explain this difference.Résumé La rotation du tibia est un élément important sur le plan fonctionnel. Elle peut être altérée après une prothèse totale du genou. Ces altérations de la rotation portent sur une diminution de la rotation interne et paradoxalement une augmentation de la rotation externe en flexion. Une prothèse totale du genou à plateau mobile permet une libération plus importante de la rotation tibiale. Nous avons comparé cette rotation à partir de prothèses à la plateau fixe et à plateau mobile sur une série de 82 patients ayant bénéficie de cette arthroplastie avec une coupe première du tibia. Nous avons utilisé pour cela un système de navigation per opératoire. Nous avons trouvé à l'issue de cette étude que les rotations tibiales étaient significativement réduites après prothèse totale à plateau fixe versus prothèses à plateau mobile. Par ailleurs, la position du tibia en extension est en rotation externe par rapport au fémur distal. Cette rotation est plus importante dans les prothèses à plateau fixe que dans les prothèses à plateau mobile. Le positionnement du plateau tibial en rotation interne lors de l'intervention peut expliquer cette différence.

Tibiofemoral Rotation During Sit-to-Stand Activity After TKA

“…These results are similar to those reported in fluoroscopic studies in which a single leg lunge activity is performed. [6][7][8]12 The more demanding STS activity analyzed in this report seems to result in similar findings to an asymmetrically performed lunge maneuver.…”

“…10,11 Several studies have shown that the normal screw-home mechanism, external rotation of the tibia with knee extension, is altered after TKA. [6][7][8]12 However, these studies have been criticized as they do not apply to normal daily activity. For example, the movement reported was for non-weight-bearing activity or during a courtesy lunge type of maneuver.…”

Imageless computer assisted versus conventional total knee replacement. A Bayesian meta-analysis of 23 comparative studies

“…Computer assisted orthopaedic surgery (CAOS) was first introduced in 1999 by Krackow et al Its objective is to improve the accuracy of implant positioning and extremity alignment [11][12][13]. CAOS for total knee arthroplasty (TKA) is gaining popularity among orthopaedic surgeons.…”

Correlation between preoperative and postoperative knee kinematics in total knee arthroplasty using cruciate retaining designs

“…A few kinematic studies have been undertaken to investigate the kinematics of osteoarthritic knee preoperatively [2,3,11,15,20], but we are unaware of any kinematic studies that addressed the relationship between the kinematic variables of knees before and after TKA. Initially, navigation systems were used to improve implant alignment during TKA [10,13,14], but more recently a number of kinematic studies have used navigation systems to investigate passive knee kinematics in patients with osteoarthritis during TKA [3,5,11,20,21]. However, it still remains unclear how the preoperative knee kinematics affect the knee kinematics after TKA.…”