Mizuno Y, Kumagai M, Mattessich S M, Elias J J, Ramrattan N, Cosgarea A J, Chao E Y
Johns Hopkins Orthopaedic Biomechanics Laboratory, Baltimore, MD 21205, USA.
J Orthop Res. 2001 Sep;19(5):834-40. doi: 10.1016/S0736-0266(01)00008-0.
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 degrees to 60 degrees of knee flexion, tilted the patella medially from 20 degrees to 80 degrees of flexion, and rotated the patella medially from 20 degrees to 50 degrees of flexion. Decreasing the Q-angle significantly tilted the patella laterally at 20 degrees and from 50 degrees to 80 degrees of flexion, rotated the tibia externally from 30 degrees to 60 degrees of flexion, and increased the tibiofemoral varus orientation from 40 degrees to 90 degrees 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.
已经开发出许多外科手术来通过改变Q角（股四头肌负荷向量与髌腱负荷向量之间的角度）来纠正髌骨轨迹并改善髌股关节症状。然而，Q角对膝关节运动学的影响尚未得到具体量化。进行了体外膝关节模拟，以将Q角与胫股关节和髌股关节运动学联系起来。通过施加模拟的腘绳肌、股四头肌和髋关节负荷来诱导膝关节屈曲，对六个尸体膝关节进行了测试。在膝关节正常对线、增加Q角和减小Q角后对膝关节进行了测试。增加Q角会使髌骨在膝关节屈曲20度至60度时显著向外移位，在屈曲20度至80度时使髌骨向内倾斜，在屈曲20度至50度时使髌骨向内旋转。减小Q角会使髌骨在20度以及屈曲50度至80度时显著向外倾斜，使胫骨在屈曲30度至60度时向外旋转，并使胫股关节内翻方向在屈曲40度至90度时增加。结果表明，Q角增加可能导致髌骨外侧脱位或髌股关节外侧接触压力增加。Q角减小可能不会使髌骨向内移位，但可能通过增加内翻方向来增加胫股关节内侧接触压力。
