Fluoroscopic validation of electrogoniometrically measured femorotibial translation in healthy and ACL deficient subjects

Abstract

Equipment which measure femorotibial motions indirectly by using a patellar pad are reported to have errors caused by deformation of soft tissues and slippage of the device. For the purpose of validation, the tibial translation in relation to the femur per degree of knee extension was estimated from the slope coefficients of the flexion-displacement curve, obtained by both fluoroscopic and electrogoniometric tests, in the knee of the dominant limb in healthy subjects and in both knees of patients with unilateral anterior cruciate ligament (ACL) deficiency. In addition, the anterior and posterior static knee laxity limits and the tibial resting position were evaluated. Within all knee groups, the tibia moved posteriorly in relation to the femur during extension. The measured movement was similar both with the electrogoniometer and with fluoroscopy thereby indicating that sagittal plane knee translation measurements with the CA-4000 electrogoniometer are reliable and in good agreement with the X-ray measurements, even though the measurements were made separately. The ACL injured knees showed approximately 20% smaller posterior movement of tibia in relation to femur per degree change of knee extension than the non-injured or control knees (p < 0.05) and a more anterior resting position of the tibia relative to femur as compared to the contralateral healthy knee during knee laxity testing (p = 0.002).

Quadriceps and hamstrings muscle control in athletic males and females

“…The validity and reliability of this device has been established in the literature and its accuracy was verified with onsite testing. 15,18 A calibration equation obtained during this onsite testing was used to convert the raw voltage data to millimeters of tibiofemoral translation.…”

Sagittal Plane Translation during Level Walking in Poor-Functioning and Well-Functioning Patients with Anterior Cruciate Ligament Deficiency

“…Sagittal plane translation (millimeters) and the knee flexion angle (degrees) were analyzed. The reproducibility 6,8 and validity 20 of the measurement system have been tested in our laboratory and shown to be satisfactory.…”

Rehabilitation after ACL Injury: A Fluoroscopic Study on the Effects of Type of Exercise on the Knee Sagittal Plane Arthrokinematics

“…The extent of ATT relative to the femur was determined for both the intact (considered as control) and ACL-deficient knees, at seven knee flexion angles, from 0° to 90°, with 15° intervals. The ATTs were obtained based on registration of anatomical landmarks in successive image frames (Figure 1(b)) [26]. …”