TY - JOUR
T1 - Q-angle influences tibiofemoral and patellofemoral kinematics
AU - Mizuno, Yasayuki
AU - Kumagai, Masaru
AU - Mattessich, Stephen M.
AU - Elias, John J.
AU - Ramrattan, Navin
AU - Cosgarea, Andrew J.
AU - Chao, Edmund Y.S.
N1 - Funding Information:
Funding for this work was provided by a research grant from the Whitaker Foundation and the Bristol-Myer/Squibb/Zimmer Center of Excellence Award. The authors would like to thank Prof. Nakamura at Kyoto University for advice regarding this research.
PY - 2001
Y1 - 2001
N2 - Numerous surgical procedures have been developed to correct patellar tracking and improve patellofemoral symptoms by altering the Q-angle (the angle between the quadriceps load vector and the patellar tendon load vector). The influence of the Q-angle on knee kinematics has yet to be specifically quantified, however. In vitro knee simulation was performed to relate the Q-angle to tibiofemoral and patellofemoral kinematics. Six cadaver knees were tested by applying simulated hamstrings, quadriceps and hip loads to induce knee flexion. The knees were tested with a normal alignment, after increasing the Q-angle and after decreasing the Q-angle. Increasing the Q-angle significantly shifted the patella laterally from 20° to 60° of knee flexion, tilted the patella medially from 20° to 80° of flexion, and rotated the patella medially from 20° to 50° of flexion. Decreasing the Q-angle significantly tilted the patella laterally at 20° and from 50° to 80° of flexion, rotated the tibia externally from 30° to 60° of flexion, and increased the tibiofemoral varus orientation from 40° to 90° of flexion. The results show that an increase in the Q-angle could lead to lateral patellar dislocation or increased lateral patellofemoral contact pressures. A Q-angle decrease may not shift the patella medially, but could increase the medial tibiofemoral contact pressure by increasing the varus orientation.
AB - Numerous surgical procedures have been developed to correct patellar tracking and improve patellofemoral symptoms by altering the Q-angle (the angle between the quadriceps load vector and the patellar tendon load vector). The influence of the Q-angle on knee kinematics has yet to be specifically quantified, however. In vitro knee simulation was performed to relate the Q-angle to tibiofemoral and patellofemoral kinematics. Six cadaver knees were tested by applying simulated hamstrings, quadriceps and hip loads to induce knee flexion. The knees were tested with a normal alignment, after increasing the Q-angle and after decreasing the Q-angle. Increasing the Q-angle significantly shifted the patella laterally from 20° to 60° of knee flexion, tilted the patella medially from 20° to 80° of flexion, and rotated the patella medially from 20° to 50° of flexion. Decreasing the Q-angle significantly tilted the patella laterally at 20° and from 50° to 80° of flexion, rotated the tibia externally from 30° to 60° of flexion, and increased the tibiofemoral varus orientation from 40° to 90° of flexion. The results show that an increase in the Q-angle could lead to lateral patellar dislocation or increased lateral patellofemoral contact pressures. A Q-angle decrease may not shift the patella medially, but could increase the medial tibiofemoral contact pressure by increasing the varus orientation.
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U2 - 10.1016/S0736-0266(01)00008-0
DO - 10.1016/S0736-0266(01)00008-0
M3 - Article
C2 - 11562129
AN - SCOPUS:0034865159
SN - 0736-0266
VL - 19
SP - 834
EP - 840
JO - Journal of Orthopaedic Research
JF - Journal of Orthopaedic Research
IS - 5
ER -