Eliminating impingement optimizes patellar biomechanics in high knee flexion  

作　　者：TANG Qi-heng ZHOU Yi-xin TANG Jing SHAO Hong-yi WANG Guang-zhi 

机构地区：[1]Department of Orthopaedic Surgery, Beijing Jishuitan Hospital,Fourth Clinical College of Peking University, Beijing 100035,China [2]Department of Biomedical Engineering, Tsinghua University,Beijing 100084, China

出　　处：《Chinese Medical Journal》2010年第16期2244-2248,共5页中华医学杂志（英文版）

基　　金：This research was supported by a grant from the National Natural Science Foundation of China （No.30772195）. We are very grateful to Dr. Alfred J. Tria from the Departments of Pathology and Laboratory Medicine and Surgery, Robert Wood Johnson Medical School, and the Orthopaedic Center of New Jersey, for his helpful comments and criticisms on an earlier version of this manuscript that have resulted in significant improvements. We thank Katharine O＇Moore-Klopf, ELS, for editorial assistance with the manuscript. We also thank XU Hai-jun, ZHANG Li-ang, DING Hui, ZHU Zhong-lin and DANG Xiao for technical assistance.

摘　　要：Background We investigated the impact of eliminating the impingement between extensor mechanism and tibial insert on patellar tracking and patellar ligament tension in high knee flexion.Methods Six cadaveric specimens were tested on an Oxford-type testing rig.The Genesis Ⅱ knee system was implanted into each specimen knee with the traditional tibial insert and high-flex insert successively.Compared to traditional insert, the high-flex insert was characterized with a chamfered anterior post and a chamfered anterior lip which eliminates patella-post and patellar ligament-anterior lip impingements.The patella was tracked with an NDI Optotrak Certus system.The patellar ligament tension was measured using a NKB S-type tension transducer.Results There was a decrease of resultant patellar translation relative to the femur with statistically significant （P 〈0.05）at 90° to 150° of knee flexion and a decrease of patellar ligament tension with statistical significance （P 〈0.05） at 100°,120°, 130°, and 140° of flexion using high-flex insert compared to traditional insert.Conclusions Eliminating the impingement between extensor mechanism and implant in high knee flexion altered patellar tracking and reduced patellar ligament tension, which would facilitate high knee flexion.Background We investigated the impact of eliminating the impingement between extensor mechanism and tibial insert on patellar tracking and patellar ligament tension in high knee flexion.Methods Six cadaveric specimens were tested on an Oxford-type testing rig.The Genesis Ⅱ knee system was implanted into each specimen knee with the traditional tibial insert and high-flex insert successively.Compared to traditional insert, the high-flex insert was characterized with a chamfered anterior post and a chamfered anterior lip which eliminates patella-post and patellar ligament-anterior lip impingements.The patella was tracked with an NDI Optotrak Certus system.The patellar ligament tension was measured using a NKB S-type tension transducer.Results There was a decrease of resultant patellar translation relative to the femur with statistically significant （P 〈0.05）at 90° to 150° of knee flexion and a decrease of patellar ligament tension with statistical significance （P 〈0.05） at 100°,120°, 130°, and 140° of flexion using high-flex insert compared to traditional insert.Conclusions Eliminating the impingement between extensor mechanism and implant in high knee flexion altered patellar tracking and reduced patellar ligament tension, which would facilitate high knee flexion.

关 键 词：extensor mechanism IMPINGEMENT patella BIOMECHANICS 

分 类 号：R686[医药卫生—骨科学]