Hurwitz D E, Sumner D R, Andriacchi T P, Sugar D A
Department of Orthopedic Surgery, Rush-Presbyterian-St. Luke's Medical Center, Chicago, IL 60612, USA.
J Biomech. 1998 May;31(5):423-30. doi: 10.1016/s0021-9290(98)00028-1.
This study tested the validity of the prediction of dynamic knee loads based on gait measurements. The relationship between the predicted loads at the knee and the distribution of bone between the medial and lateral sides of the tibia was examined. The motion and external forces and moments at the knee were measured during gait and a statically determinate muscle model was used to predict the corresponding forces on the medial and lateral tibial plateaus. In particular, the relationship between the knee adduction moment during gait and the ratio or distribution of medial to lateral tibial bone mineral content was studied. Bone mineral content was measured with dual energy X-ray absorptiometry in four regions, two proximal regions 20 mm in height, one medial and one lateral and two distal regions 20 mm in height, one medial and one lateral. The best single predictor of the medial lateral ratio of proximal bone mineral content (bone distribution) was the adduction moment (R2=0.31, p=0.003). Adding weight (negative coefficient. p=0.0004) and the ratio of the average predicted peak force on the medial plateau to the predicted peak force on the lateral plateau (positive coefficient, p=0.0033) to the regression model significantly increased the ability to predict the proximal medial lateral bone distribution (R2=0.72, p=0.0001). Distally neither the subject characteristics nor the gait moments and predicted forces were significant predictors of the bone distribution. The lack of a correlation distally may be reflective of the forces being more evenly distributed further from the tibial plateau. While it has long been suggested that the adduction moment is the primary determinate of the distribution of load between the medial and lateral plateaus, this is the first evidence of its relationship to the underlying bone distribution.
本研究检验了基于步态测量预测动态膝关节负荷的有效性。研究了膝关节预测负荷与胫骨内侧和外侧骨分布之间的关系。在步态过程中测量膝关节的运动、外力和力矩，并使用静定肌肉模型预测胫骨内侧和外侧平台上的相应力。特别地，研究了步态期间膝关节内收力矩与胫骨内侧和外侧骨矿物质含量的比例或分布之间的关系。使用双能X线吸收法在四个区域测量骨矿物质含量，两个近端区域高度为20mm，一个内侧和一个外侧，以及两个远端区域高度为20mm，一个内侧和一个外侧。近端骨矿物质含量（骨分布）的内侧与外侧比例的最佳单一预测指标是内收力矩（R2 = 0.31，p = 0.003）。将体重（负系数，p = 0.0004）以及内侧平台平均预测峰值力与外侧平台预测峰值力的比例（正系数，p = 0.0033）添加到回归模型中，显著提高了预测近端内侧与外侧骨分布的能力（R2 = 0.72，p = 0.0001）。在远端，受试者特征、步态力矩和预测力均不是骨分布的显著预测指标。远端缺乏相关性可能反映了离胫骨平台越远，力分布越均匀。虽然长期以来一直认为内收力矩是内侧和外侧平台之间负荷分布的主要决定因素，但这是其与潜在骨分布关系的首个证据。
