Understanding tibio-femoral motion

There has been little advance in understanding of tibio-femoral motion for a few decades. It has been held that during knee flexion the femur bodily rolls-back on the tibia, and furthermore that his phenomenon is produced by tension in the (`four-bar' linkage) cruciate ligaments. These concepts are flawed. Previous studies on joint motion have relied on techniques with various limitations causing inaccuracy and tendency to misinterpretation. Employing an `interventional' MRI scanner to image subjects standing and undertaking a squat the living knee can be image in three dimensions under weight-bearing conditions. This review article summarizes the findings of a number of studies from the unit employing this technique and other collaborators to define normal tibio-femoral kinematics. These findings represent a fundamental alteration in understanding in this field. (C) 2004 Elsevier B.V. All rights reserved.