胫骨轴向旋转运动与膝关节屈伸运动耦合的研究

The coupling of tibial rotation and extension-flexion motion of knee joint

目的探讨膝关节置换前后,胫骨轴向旋转的方向、幅度与胫股关节屈伸运动的关系。方法将6具新鲜男性成人的左侧下肢标本安置于改良Oxford膝关节运动支架,对股内侧、股中间、股外侧肌群分别施以1.25∶1.5∶1的负荷。在被动屈伸膝关节的过程中,应用激光束发生器和反三角函数的方法,测量ΣPFC-PS膝关节假体置换前后胫骨轴向旋转的角度。结果膝关节置换术前,膝关节屈曲10°、20°、30°、60°、90°、120°、150°时胫骨平均内旋5.1°±2.3°、9.3°±3.3°、10.2°±4.8°、11.7°±3.5°、13.5°±8.4°、22.0°±8.6°、29.6°±9.3°;膝关节置换术后,平均内旋-2.2°±1.7°、-2.5°±1.5°、-2.0°±1.3°、1.7°±2.5°、3.9°±2.4°、13.5°±6.1°、18.6°±4.7°(膝关节伸直时胫骨旋转为0°,胫骨内旋为正值,外旋为负值)。结论(1)膝关节屈曲过程中,胫骨逐渐内旋。(2)胫骨的内旋运动是不等幅的:膝关节屈曲0°-30°过程中,胫骨发生大幅度内旋;30°-90°过程中,胫骨内旋运动进入平台期;超过90°时,胫骨再度发生大幅度内旋,可能与膝关节周围软组织在膝关节高屈曲时进一步松弛有关。(3)膝关节置换术后,膝关节屈曲0°-30°过程中胫骨小幅度反常外旋;30°-150°过程中胫骨内旋运动模式类似于正常膝关节,但幅?

Objective To investigate the coupling of tibial rotation and extension-flexion motion of knee joint both before and after total knee arthroplasty. Methods Six fresh-frozen left lower limbs from cadavers were tested using a modified Oxford motor rig for the knee joint. Anatomically based multiple loadings of the quadriceps mechanism were applied (Vastus medialis: 24.5 N, Vastus intermedius/rectus femoris: 29.4 N, Vastus lateralis: 19.6 N). The tibial rotation was tracked using a custom-made laser tracking device while the tibial-femoral flexion was measured with goniometer. Total knee arthroplasty (TKA) was performed using ΣPFC-PS posterior cruciate ligament substituting knee system. Results Before TKA, when the knee flexed 10°, 20°, 30°, 60°, 90°, 120° and 150°, tibia rotated 5.1°±2.3°, 9.3°±3.3°, 10.2°±4.8°,11.7°±3.5°, 13.5°±8.4°, 22.0°±8.6° and 29.6°±9.3° respectively. After TKA, tibia rotated -2.2°±1.7°, -2.5°±1.5°, -2.0°±1.3°, 1.7°±2.5°, 3.9°±2.4°, 13.5°±6.1° and 18.6°±4.7° respectively (Tibial rotation was defined as 0° in knee extension; internal rotation as positive and external rotation as negative). Conclusion The tibial internal rotation is coincident with tibial-femoral flexion, its magnitude of tibial rotation varies in different degrees of knee flexion. The tibial internal rotatation is significant in early knee flexion(0° to 30°), then enters into a platform stage on knee bending from 30° to 90°, Once the knee bends over 90°, the tibia rotates internally markedly again, maximum internal rotation is achieved in fully flexion, probably due to relaxation of soft tissue. After TKA, in early flexion (0° to 30°) the external rotation occurs abnormally, but later on 30° to 150°, it rotates again intenally as normal.