This retrospective cohort asked whether restoring a patient's native coronal knee phenotype during TKA improves outcomes. Knees were classified by the CPAK system before and after surgery, then matched patients were compared to all others. The question: does keeping the native CPAK class predict better patient-reported outcomes?
Personalized alignment strategies like kinematic alignment aim to restore a patient's native coronal phenotype, on the theory that a more natural-feeling knee improves the roughly one-in-five dissatisfaction rate after TKA. This study tests that theory directly using CPAK, and finds it wanting: incidentally keeping the native coronal class did nothing for patient-reported outcomes at two years.
The practical lesson is that coronal alignment is only one plane of a three-dimensional problem. CPAK ignores sagittal slope, femoral flexion, and axial rotation, and it says nothing about soft-tissue balance. Don't over-index on hitting a native coronal target and assume the outcome follows. What actually predicted outcomes here were patient factors like BMI, depression, and lumbar spine disease.
Remember this is Level III retrospective data from a single surgeon using adjusted mechanical alignment, not a trial of kinematic alignment itself, so it argues against coronal matching as a sole driver rather than condemning personalized alignment outright.
This retrospective cohort asked whether restoring a patient's native coronal knee phenotype during TKA improves outcomes. Knees were classified by the CPAK system before and after surgery, then matched patients were compared to all others. The question: does keeping the native CPAK class predict better patient-reported outcomes?
Personalized alignment strategies like kinematic alignment aim to restore a patient's native coronal phenotype, on the theory that a more natural-feeling knee improves the roughly one-in-five dissatisfaction rate after TKA. This study tests that theory directly using CPAK, and finds it wanting: incidentally keeping the native coronal class did nothing for patient-reported outcomes at two years.
The practical lesson is that coronal alignment is only one plane of a three-dimensional problem. CPAK ignores sagittal slope, femoral flexion, and axial rotation, and it says nothing about soft-tissue balance. Don't over-index on hitting a native coronal target and assume the outcome follows. What actually predicted outcomes here were patient factors like BMI, depression, and lumbar spine disease.
Remember this is Level III retrospective data from a single surgeon using adjusted mechanical alignment, not a trial of kinematic alignment itself, so it argues against coronal matching as a sole driver rather than condemning personalized alignment outright.