In-vivo 6-DOF measurement of knee movement using an open MR system

Relative movement between the femur and tibia themselves has yet to be measured clinically, primarily due to the limitation of measurement methodology. To achieve such measurement, the authors developed a totally new method capable of measuring 6-DOF movement of the tibia relative to the femur, using an open MR system. Relative movement was computed in a manner as follows: (1) reconstruction of 3-D joint contours; (2) registration of the bone contours; (3) computation of the motion parameters. The authors actually measured knee movement of a subject during flexion and certified the validity and clinical applicability of their methodology