A REPEATABLE ALIGNMENT METHOD AND LOCAL COORDINATE DESCRIPTION FOR KNEE-JOINT TESTING AND KINEMATIC MEASUREMENT

A method for aligning cadaver knee specimens to a mechanical testing r ig and determining local anatomical coordinate systems using landmarks identifiable on plane X-rays is introduced. Three sequential rotation al alignments are used to position the femur and tibia relative to the coordinate system of the testing mechanism. To validate this methodol ogy five independent observers aligned the same knee specimen. The max imum error in the alignment orientations of the tibia and femur was 2. 2 degrees from the mean. These small misalignments produced variations of up to 4.7 degrees in tibio-femoral rotations measured during knee flexion. Kinematic measurements of 15 specimens aligned using this pro cedure indicate that knee alignment is reproducible and physiologicall y relevant. (C) 1998 Published by Elsevier Science Ltd. All rights res erved.