Background： Joint line （JL） is a very important factor for total knee arthroplasty （TKA） to restore. The objective of this study was to evaluate the early clinical and kinematic results of TKAs with posterior-sta...Background： Joint line （JL） is a very important factor for total knee arthroplasty （TKA） to restore. The objective of this study was to evaluate the early clinical and kinematic results of TKAs with posterior-stabilized （PS） or cruciate retaining （CR） implants in which the JL was elevated postoperatively. Methods： Data were collected from patients who underwent TKA in our department between April 2011 and April 2014. The patients were divided into two groups based on the prosthesis they received （PS or CR）. At 1-year postoperatively, clinical outcomes were evaluated by the American Knee Society （AKS） knee score, AKS function score, and patella score. In vivo kinematic analysis after TKA was performed on all patients and a previously validated three-dimensional to two-dimensional image registration technique was used to obtain the kinematic data. Anteroposterior （AP） translation of the medial and lateral femoral condyles, and axial rotation relative to the tibial plateau, were analyzed. The data were assessed using the Mann-Whitney test. Results： At time of follow-up, there were differences in the AKS knee scores （P = 0.005）, AKS function scores （P = 0.025）, patella scores （P = 0.015）, and postoperative range of motions （P = 0.004） between the PS group and the CR group. In the PS group, the magnitude of AP translation for the medial and lateral condyle was 4.9 ± 3.0 mm and 12.8 ± 3.3 mm, respectively. Axial rotation of the tibial component relative to the femoral component was 12.9 ± 4.5°. In the CR group, the magnitude of AP translation for the medial and lateral condyle was 4.3 ±3.5 mm and 7.9 ± 4.2 mm, respectively. The axial rotation was 6.7 ± 5.9°. There were statistically different between PS group and CR group in kinematics postoperatively. Conclusion： Our results demonstrate that postoperative JL elevation had more adverse effects on the clinical and kinematic outcomes ofCR TKAs than PS TKAs.展开更多
Background：The goal of total knee arthroplasty （TKA） is to restore knee kinematics.Knee prosthesis design plays a very important role in successful restoration.Here,kinematics models of normal and prosthetic knees ...Background：The goal of total knee arthroplasty （TKA） is to restore knee kinematics.Knee prosthesis design plays a very important role in successful restoration.Here,kinematics models of normal and prosthetic knees were created and validated using previously published data.Methods：Computed tomography and magnetic resonance imaging scans of a healthy,anticorrosive female cadaver were used to establish a model of the entire lower limbs,including the femur,tibia,patella,fibula,distal femur cartilage,and medial and lateral menisci,as well as the anterior cruciate,posterior cruciate,medial collateral,and lateral collateral ligaments.The data from the three-dimensional models of the normal knee joint and a posterior-stabilized （PS） knee prosthesis were imported into finite element analysis software to create the final kinematic model of the TKA prosthesis,which was then validated by comparison with a previous study.The displacement of the medial/lateral femur and the internal rotation angle of the tibia were analyzed during 0-135° flexion.Results：Both the output data trends and the measured values derived from the normal knee＇s kinematics model were very close to the results reported in a previous in vivo study,suggesting that this model can be used for further analyses.The PS knee prosthesis underwent an abnormal forward displacement compared with the normal knee and has insufficient,or insufficiently aggressive,＂rollback＂ compared with the lateral femur of the normal knee.In addition,a certain degree of reverse rotation occurs during flexion of the PS knee prosthesis.Conclusions：There were still several differences between the kinematics of the PS knee prosthesis and a normal knee,suggesting room for improving the design of the PS knee prosthesis.The abnormal kinematics during early flexion shows that the design of the articular surface played a vital role in improving the kinematics of the PS knee prosthesis.展开更多
基金Acknowledgments We would like to thank the subjects for their time and enthusiasm. We also thank our fluoroscopy technologist Qing-Hua Liu.This work was supported by a grant from the National Natural Science Foundation of China （No. 81472139）.
文摘Background： Joint line （JL） is a very important factor for total knee arthroplasty （TKA） to restore. The objective of this study was to evaluate the early clinical and kinematic results of TKAs with posterior-stabilized （PS） or cruciate retaining （CR） implants in which the JL was elevated postoperatively. Methods： Data were collected from patients who underwent TKA in our department between April 2011 and April 2014. The patients were divided into two groups based on the prosthesis they received （PS or CR）. At 1-year postoperatively, clinical outcomes were evaluated by the American Knee Society （AKS） knee score, AKS function score, and patella score. In vivo kinematic analysis after TKA was performed on all patients and a previously validated three-dimensional to two-dimensional image registration technique was used to obtain the kinematic data. Anteroposterior （AP） translation of the medial and lateral femoral condyles, and axial rotation relative to the tibial plateau, were analyzed. The data were assessed using the Mann-Whitney test. Results： At time of follow-up, there were differences in the AKS knee scores （P = 0.005）, AKS function scores （P = 0.025）, patella scores （P = 0.015）, and postoperative range of motions （P = 0.004） between the PS group and the CR group. In the PS group, the magnitude of AP translation for the medial and lateral condyle was 4.9 ± 3.0 mm and 12.8 ± 3.3 mm, respectively. Axial rotation of the tibial component relative to the femoral component was 12.9 ± 4.5°. In the CR group, the magnitude of AP translation for the medial and lateral condyle was 4.3 ±3.5 mm and 7.9 ± 4.2 mm, respectively. The axial rotation was 6.7 ± 5.9°. There were statistically different between PS group and CR group in kinematics postoperatively. Conclusion： Our results demonstrate that postoperative JL elevation had more adverse effects on the clinical and kinematic outcomes ofCR TKAs than PS TKAs.
文摘Background：The goal of total knee arthroplasty （TKA） is to restore knee kinematics.Knee prosthesis design plays a very important role in successful restoration.Here,kinematics models of normal and prosthetic knees were created and validated using previously published data.Methods：Computed tomography and magnetic resonance imaging scans of a healthy,anticorrosive female cadaver were used to establish a model of the entire lower limbs,including the femur,tibia,patella,fibula,distal femur cartilage,and medial and lateral menisci,as well as the anterior cruciate,posterior cruciate,medial collateral,and lateral collateral ligaments.The data from the three-dimensional models of the normal knee joint and a posterior-stabilized （PS） knee prosthesis were imported into finite element analysis software to create the final kinematic model of the TKA prosthesis,which was then validated by comparison with a previous study.The displacement of the medial/lateral femur and the internal rotation angle of the tibia were analyzed during 0-135° flexion.Results：Both the output data trends and the measured values derived from the normal knee＇s kinematics model were very close to the results reported in a previous in vivo study,suggesting that this model can be used for further analyses.The PS knee prosthesis underwent an abnormal forward displacement compared with the normal knee and has insufficient,or insufficiently aggressive,＂rollback＂ compared with the lateral femur of the normal knee.In addition,a certain degree of reverse rotation occurs during flexion of the PS knee prosthesis.Conclusions：There were still several differences between the kinematics of the PS knee prosthesis and a normal knee,suggesting room for improving the design of the PS knee prosthesis.The abnormal kinematics during early flexion shows that the design of the articular surface played a vital role in improving the kinematics of the PS knee prosthesis.
