Reproducibility of an optical measurement system for the clinical evaluation of active knee rotation in weight-bearing, healthy subjects

• Published in: Orthopaedics & traumatology, surgery & research Vol. 98; no. 2; pp. 159 - 166
• Main Authors: Testa, R, Chouteau, J, Viste, A, Cheze, L, Fessy, M.-H, Moyen, B
• Format: Journal Article
• Language: English
• Published: France Elsevier Masson SAS 01.04.2012; Elsevier
• Subjects: Adult; Female; Follow-Up Studies; Gait - physiology; Gait analysis; Humans; Kinematics; Knee; Knee Joint - anatomy & histology; Knee Joint - physiology; Laxity; Male; Measurement system; Optical; Optical Devices; Orthopedics; Posture; Range of Motion, Articular - physiology; Reference Values; Reproducibility of Results; Rotation; Surgery; Weight-Bearing - physiology; Knee; Laxity; Measurement system; Optical; Kinematics; Rotation; Gait analysis; ROTATION; CINEMATIQUE; OPTIQUE; MESURE
• ISSN: 1877-0568; 1877-0568
• DOI: 10.1016/j.otsr.2011.08.017

Summary Introduction A knee is typically evaluated passively by a clinician during an office visit, without using dedicated measurement tools. When the knee is evaluated with the patient standing and actively participating in the movement, the results will differ than when the knee is passively moved through its range-of-motion by the surgeon. If a precise measurement system was available, it could provide additional information to the clinician during this evaluation. Hypothesis The goal of this study was to verify the reproducibility of a fast, flexible optical measurement system to measure rotational knee laxity during weight-bearing. Material and methods Two passive reflective targets were placed on the legs of 11 subjects to monitor femur and tibia displacements in three dimensions. Subjects performed internal and external rotation movements with the knee extended or flexed 30°. During each movement, seven variables were measured: internal rotation, external rotation and overall laxity in extension and 30° flexion, along with neutral rotation value in 30° flexion. Measurement accuracy was also assessed and the right and left knees were compared. Reproducibility was assessed over two measurements sessions. Results The calculated intra-class correlation coefficient (ICC) for reproducibility was above 0.9 for five of the seven variables measured. The calculated ICC for the right/left comparison was above 0.75 for five of the seven variables measured. Discussion These results confirmed that the proposed system provides reproducible measurements. Our right/left comparison results were consistent with the published literature. This system is fast, reproducible and flexible, which makes it suitable for assessing various weight-bearing movements during clinical evaluations. Level of evidence Level III, experimental study.