Kinematic alignment doesn't tell the whole story: It's time for kinetic alignment.

Abstract

Kinematic alignment is increasingly adopted in total knee arthroplasty (TKA) as a patient-specific strategy to restore native joint anatomy. However, its reliance on static radiographic measurements may not adequately reflect real-world functional biomechanics. This editorial underscores the importance of complementing static assessment with kinetic principles. This emerging concept, referred to as kinetic alignment, integrates dynamic parameters such as the dynamic hip-knee-ankle angle, knee adduction moment, ground reaction forces, and muscle forces to better characterise in vivo joint loading. These kinetic variables provide critical insight into joint loading during real-life activities and may offer greater predictive value for implant performance and patient satisfaction. Continued emphasis on static alignment targets may overlook key elements of in vivo knee function. Incorporating kinetic data into preoperative planning could support more tailored surgical decisions, helping to mitigate risks related to malalignment, overloading, and suboptimal outcomes. The editorial advocates for expanding the concept of alignment beyond static geometry, including both motion and load, and encouraging the orthopaedic and biomechanical communities to adopt a more functional and individualised perspective in TKA planning.