Measuring three-dimensional knee kinematics under torsional loading

Design, Repeatability, and Comparison to Literature Data of a New Noninvasive Device Called “Rotameter” to Measure Rotational Knee Laxity

“…Almquist et al [ 33 ] obtained 22 ± 6° and 25 ± 7° at ±6 Nm torque for a flexion of 60° and 90° of the knee. The same order of magnitude, 28° of total laxity, was obtained by Hemmerich et al [ 35 ] with MRI technique. Those last values, about 10° lower than P2, were reached by the use of RSA and MRI that allow measurements without any movements of soft tissues and adjacent joints.…”

“…With this very same device, Tsai et al [ 24 ] obtained noninvasively a total rotational laxity of 26 ± 6° at 30° of flexion with a 6 Nm torque by use of magnetic trackers mounted on the boot, tibia, and femur. Hemmerich et al [ 35 ] used Magnetic Resonance Imaging (MRI) to measure the rotation of the knee by combining this medical imaging apparatus and their prototype. The patient supine with the knee flexed at 30° provided a 28° total rotation for 5,8 Nm applied.…”

Knee Rotational Laxity in a Randomized Comparison of Single- Versus Double-Bundle Anterior Cruciate Ligament Reconstruction

“…Intraclass correlation coefficients of .99 and .93 were previously demonstrated for range of rotation in extended and flexed knee positions using this method. 11…”

Measurements of knee morphometrics using MRI and arthroscopy: a comparative study between ACL-injured and non-injured subjects

“…For example, the size of the femoral condyles and the ratio between medial and femoral condyle size. Differences in medial-to-lateral femoral condyle size ratio, change the amount of rotation of the knee, which could potentially cause differences in the demand for the ACL [8].…”