Farahmand Farzam, Naghi Tahmasbi Mohammad, Amis Andrew
Department of Mechanical Engineering, Sharif University of Technology, Azadi Avenue, Tehran, Iran.
Knee. 2004 Apr;11(2):89-94. doi: 10.1016/j.knee.2003.10.004.
Patellofemoral joint stability is a result of the restraining effects of the quadriceps muscles, the retinacular structures, and engagement of the bones. The role and significance of these mechanisms in restraining patellar lateral displacement was investigated in this study by measuring the force needed to cause 5 mm lateral displacement (i.e. the mechanical stability, or 'stabilising force') of the patella. Six cadaver knees had 175 N quadriceps load distributed among three muscle groups. With a force ratio matching the muscles physiological cross sectional areas, no significant change occurred in the patellar stabilising force between 0 and 60 degrees knee flexion, but a significant increase occurred between 60 and 90 degrees, presumably reflecting the contribution of the femoral groove. Variation of the quadriceps force distribution changed the stability significantly. Relaxing the vastus lateralis increased the patellar lateral stabilising force 52+/-8%, while relaxing vastus medialis reduced the stabilising force 47+/-9%. The minimum stabilising force was at 30 degrees knee flexion. Transection of the medial retinaculum reduced the lateral stabilising force 34% in the extended knee. This effect disappeared by 45 degrees knee flexion. It was concluded that the quadriceps muscles had a significant and consistent effect across the whole range of knee flexion, but the contribution of the medial retinaculum was restricted to extended knee postures.
髌股关节的稳定性是股四头肌、支持带结构以及骨骼相互作用产生约束作用的结果。本研究通过测量使髌骨产生5毫米外侧移位所需的力（即机械稳定性或“稳定力”），来探究这些机制在限制髌骨外侧移位中的作用和意义。六个尸体膝关节在三个肌肉群之间施加175牛的股四头肌负荷。当力的比例与肌肉的生理横截面积相匹配时，在膝关节从0度屈曲到60度的过程中，髌骨稳定力没有显著变化，但在60度到90度之间显著增加，这可能反映了股骨髁间沟的作用。股四头肌力量分布的变化显著改变了稳定性。放松股外侧肌会使髌骨外侧稳定力增加52±8%，而放松股内侧肌则会使稳定力降低47±9%。最小稳定力出现在膝关节屈曲30度时。切断内侧支持带会使伸直膝关节时的外侧稳定力降低34%。这种效应在膝关节屈曲45度时消失。研究得出结论，股四头肌在膝关节屈曲的整个范围内都有显著且持续的作用，但内侧支持带的作用仅限于伸直膝关节的姿势。
