title: The flexion-extension axis of the knee and its relationship to the rotational orientation of the tibial plateau.
abstract: We measured the optimal rotational alignment of the tibial component with respect to anatomic landmarks. Kinematic data were collected from functional maneuvers simulated in 20 cadaveric knees mounted in a joint simulator. The axis of knee motion was calculated for squatting and lunging activities over the interval of 30° to 90° of knee flexion. We then examined the accuracy and variability of 5 different anatomic axes in predicting the direction of knee motion. No one landmark guaranteed correct alignment of the tibial component and most predictors were highly variable (range, 6°-21°). The most accurate indicators were the medial third of the tibial tubercle (average error: squatting: 3.5° external rotation; lunging: 9.5°), and the medial-lateral axis of the resected tibial surface (6.7° and 1.1° internal rotation). The correct alignment of the tibial component can be best achieved by splitting the difference between these landmarks to eliminate placement of the component in excessive external and excessive internal rotation.
authors: Baylor College of Medicine, Houston, Texas, USA.
authors: Charles M
authors: CM
authors: Lawrie
authors: Philip C
authors: PC
authors: Noble
authors: Sabir K
authors: SK
authors: Ismaily
authors: Drew
authors: D
authors: Stal
authors: Steve J
authors: SJ
authors: Incavo
mesh_terms: D059925:Anatomic Landmarks; D001696:Biomechanical Phenomena; D002102:Cadaver; D005269:Femur / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000502:physiology; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging; D016059:Range of Motion, Articular; D013977:Tibia / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000502:physiology; D014057:Tomography, X-Ray Computed