Tibial Rotation in TKA: Mechanical vs Kinematic Alignment and Akagi’s Line (16 June 2026)

Date: June 16, 2026 In this educational lecture, Dr. Takafumi Hiranaka discusses tibial rotational alignment in total knee arthroplasty (TKA), with particular emphasis on the tibial anteroposterior axis, mechanical alignment, kinematic alignment, and anatomical reference landmarks. Determining the appropriate rotational position of the tibial component is an important but sometimes challenging step in TKA. The lecture compares the principles of mechanical alignment and kinematic alignment and explains how each approach defines the direction of the tibial component. In mechanical alignment, the component is generally positioned according to predefined anatomical and mechanical reference axes. In kinematic alignment, rotational positioning is considered in relation to the patient’s native joint anatomy and the functional relationship between the femur and tibia. The video also reviews Akagi’s line, an established anatomical landmark extending from the posterior cruciate ligament insertion to the medial edge of the patellar tendon insertion. The advantages and limitations of using this landmark are discussed, particularly in knees with anatomical variation, osteoarthritis, deformity, or altered soft-tissue balance. Using simple visual analogies, the lecture highlights the difference between imposing a fixed mechanical direction and allowing component positioning to follow the patient’s individual knee anatomy and motion. This video is intended for orthopedic surgeons, arthroplasty fellows, residents, and healthcare professionals interested in TKA alignment, rotational positioning, knee biomechanics, and personalized knee replacement. Key Topics Tibial component rotational alignment Tibial anteroposterior axis Mechanical alignment Kinematic alignment Akagi’s line PCL insertion Patellar tendon insertion Anatomical landmarks in TKA Femoral–tibial rotational relationship Personalized alignment Knee biomechanics and kinematics Hashtags #TotalKneeArthroplasty #TKA #TibialRotation #TibialComponent #AkagisLine #MechanicalAlignment #KinematicAlignment #PersonalizedAlignment #KneeReplacement #KneeSurgery #OrthopaedicSurgery #KneeBiomechanics #KneeKinematics #Arthroplasty #OrthopedicEducation #TakafumiHiranaka