The Adjustment of the Rotational Alignment of the Distal End of the Extramedullary Guide to the Anteroposterior Axis of the Proximal Tibia in Total Knee Arthroplasty

Author(s):  
Hideki Mizu-uchi ◽  
Hidehiko Kido ◽  
Tomonao Chikama ◽  
Kenta Kamo ◽  
Satoshi Kido ◽  
...  

AbstractThe optimal placement within 3 degrees in coronal alignment was reportedly achieved in only 60 to 80% of patients when using an extramedullary alignment guide for the tibial side in total knee arthroplasty (TKA). This probably occurs because the extramedullary alignment guide is easily affected by the position of the ankle joint which is difficult to define by tibial torsion. Rotational direction of distal end of the extramedullary guide should be aligned to the anteroposterior (AP) axis of the proximal tibia to acquire optimal coronal alignment in the computer simulation studies; however, its efficacy has not been proven in a clinical setting. The distal end of the guide can be overly displaced from the ideal position when using a conventional guide system despite the alignment of the AP axis to the proximal tibia. This study investigated the effect of displacement of the distal end of extramedullary guide relative to the tibial coronal alignment while adjusting the rotational alignment of the distal end to the AP axis of the proximal tibia in TKA. A total of 50 TKAs performed in 50 varus osteoarthritic knees using an image-free navigation system were included in this study. The rotational alignment of the proximal side of the guide was adjusted to the AP axis of the proximal tibia. The position of the distal end of the guide was aligned to the center of the ankle joint as viewed from the proximal AP axis (ideal position) and as determined by the navigation system. The tibial intraoperative coronal alignments were recorded as the distal end was moved from the ideal position at 3-mm intervals. The intraoperative alignments were 0.5, 0.9, and 1.4 degrees in valgus alignment with 3-, 6-, and 9-mm medial displacements, respectively. The intraoperative alignments were 0.7, 1.2, and 1.7 degrees in varus alignment with 3-, 6-, and 9-mm lateral displacements, respectively. In conclusion, the acceptable tibial coronal alignment (within 2 degrees from the optimal alignment) can be achieved, although some displacement of the distal end from the ideal position can occur after the rotational alignment of the distal end of the guide is adjusted to the AP axis of the proximal tibia.

2016 ◽  
Vol 136 (2) ◽  
pp. 271-276 ◽  
Author(s):  
Keizo Wada ◽  
Hiroshi Mikami ◽  
Daisuke Hamada ◽  
Hiroshi Yonezu ◽  
Koichi Oba ◽  
...  

Author(s):  
Kwang Won Choi ◽  
Farid Amirouche ◽  
Mark H. Gonzalez ◽  
Wayne Goldstein

Total knee arthroplasty (TKA) is known to be an excellent solution to patients experiencing considerable pain at the joint and difficulty flexing and extending their knee. Unfortunately, after surgery, cases of peri-prosthetic patellar fracture are possible. The prevalence of this fracture ranges from 0.11% to 21.4% for the over 400,000 TKAs that are conducted in the United States every year and therefore, patellar fracture can become a serious concern. The factors that lead to this are several and many researchers are still investigating this problem. This research shows that the position of the surgically inserted artificial patella, also referred to as the patellar button, influences occurrence of patellar fractures and attempts to derive the ideal position for the button to reduce the risk of patellar fracture.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
KwanSu Kang ◽  
Young Woong Jang ◽  
Oui Sik Yoo ◽  
Dukyoung Jung ◽  
Sung-Jae Lee ◽  
...  

Introduction. Several ongoing studies aim to improve the survival rate following total knee arthroplasty (TKA), which is an effective orthopedic surgical approach for patients with severely painful knee joint diseases. Among the studied strategies, baseplate rotational arrangement techniques for TKA components have been suggested but have been the subject of only simple reliability evaluations. Therefore, this study sought to evaluate comparatively three different baseplate rotational arrangement techniques that are commonly used in a clinical context. Materials and Methods. Three-dimensional (3D) finite element (FE) models of the proximal tibia with TKA were developed and analyzed considering three baseplate rotational arrangement techniques (anterior cortex line, tibial tuberosity one-third line, and tibial tuberosity end line) for six activities of daily life (ADLs) among patients undergoing TKA. Mechanical tests based on the ASTM F1800 standard to validate the FE models were then performed using a universal testing machine. To evaluate differences in biomechanical characteristics according to baseplate rotational arrangement technique, the strain and peak von Mises stresses (PVMSs) were assessed. Results. The accuracy of the FE models used in this study was high (94.7 ± 5.6%). For the tibial tuberosity one-third line rotational arrangement technique, strains ≤ 50 µstrain (the critical bone damage strain, which may affect bone remodeling) accounted for approximately 2.2%–11.3% and PVMSs within the bone cement ranged from 19.4 to 29.2 MPa, in ADLs with high loading conditions. For the tibial tuberosity end line rotational arrangement, strains ≤ 50 µstrain accounted for approximately 2.3%–13.3% and PVMSs within the bone cement ranged from 13.5 to 26.7 MPa. For anterior cortex line rotational arrangement techniques, strains ≤50 µstrain accounted for approximately 10.6%–16.6% and PVMSs within the bone cement ranged from 11.6 to 21.7 MPa. Conclusion. The results show that the most recently developed frontal cortex line rotational alignment technique is the same or better than the other two rotational alignment techniques in terms of biomechanics. This finding can be, however, dependent on the contact characteristics between the baseplate and the proximal tibia. That is, it is indicated that the optimum baseplate rotational arrangement technique in terms of reducing the incidence of TKA mechanical failure can be achieved by adjusting the characteristics of contact between the baseplate and the proximal tibia.


Author(s):  
Masanori Tsubosaka ◽  
Tomoyuki Kamenaga ◽  
Yuichi Kuroda ◽  
Koji Takayama ◽  
Shingo Hashimoto ◽  
...  

AbstractSeveral studies have reported better clinical outcomes following kinematically aligned total knee arthroplasty (KA-TKA) than mechanically aligned TKA. Consistent reproduction of a KA-TKA is aided by accurate tibial bone resections using computer navigation systems. This study compares an accelerometer-based portable navigation system with a conventional navigation system on tibial bone resection and clinical outcomes in KA-TKA. This study included 60 knees of patients who underwent primary KA-TKA between May 2015 and September 2017. They were randomly assigned to the OrthoPilot and iASSIST groups. A tibial bone cut was performed with 3 degree varus and 7 degree posterior slope in relation to the mechanical axis in all cases. The tibial component angle (TCA) and posterior slope angle (PSA) were evaluated by postoperative radiography, and those that deviated more than 2 degree were set as outliers. The clinical outcomes were the knee range of motion (ROM) and 2011 Knee Society Score (KSS) evaluated at 1 year postoperation. The groups were compared in terms of the TCA, PSA, number of outliers, ROM, and 2011 KSS (p < 0.05). No significant difference was observed between the groups in terms of the mean TCA, PSA, number of outliers, ROM, and categories of the 2011 KSS (objective knee indicators, symptoms, satisfaction, expectations, and functional activities). Although tibial bone cuts were performed with 3 degree varus and 7 degree posterior slope, no significant difference was observed between the OrthoPilot and iASSIST groups in terms of the accuracy of cuts or postoperative clinical result. The iASSIST was found to be a simple and useful navigation system for KA-TKA.


2011 ◽  
Vol 26 (2) ◽  
pp. 268-273 ◽  
Author(s):  
Hiroki Watanabe ◽  
Ryuichi Gejo ◽  
Yoshikazu Matsuda ◽  
Ichiro Tatsumi ◽  
Kazuo Hirakawa ◽  
...  

The Knee ◽  
2021 ◽  
Vol 31 ◽  
pp. 64-76
Author(s):  
Takao Kaneko ◽  
Tadashi Igarashi ◽  
Kazutaka Takada ◽  
Shu Yoshizawa ◽  
Hiroyasu Ikegami ◽  
...  

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