This retrospective cohort reports 10-year outcomes of kinematically aligned TKA performed with patient-specific instrumentation. Patients were not restricted by degree of preoperative deformity. It asks whether coronal alignment in the varus or valgus outlier range, by mechanical alignment criteria, harms long-term survival and function.
The central teaching point: mechanical alignment outlier criteria do not predict failure after a kinematically aligned knee. KA deliberately restores the patient's native joint line, so most tibial components land in varus relative to the mechanical axis of the tibia. By MA logic that should fail. At 10 years it did not.
The mechanistic reason matters for boards. KA avoids ligament releases, keeps compartment forces near native, and lowers the knee adduction moment, which neutralizes the varus loosening mechanism that drives MA failures.
The failures here were sagittal, not coronal. Watch tibial slope and femoral component flexion. Set the tibial component parallel to the native medial slope and keep femoral flexion under 5 degrees to avoid patellofemoral instability.
Weigh the evidence carefully. This is a Level III, single designer-surgeon series, and designer surgeons report lower failure rates than independent surgeons. It is durability data, not a head-to-head trial.
This retrospective cohort reports 10-year outcomes of kinematically aligned TKA performed with patient-specific instrumentation. Patients were not restricted by degree of preoperative deformity. It asks whether coronal alignment in the varus or valgus outlier range, by mechanical alignment criteria, harms long-term survival and function.
The central teaching point: mechanical alignment outlier criteria do not predict failure after a kinematically aligned knee. KA deliberately restores the patient's native joint line, so most tibial components land in varus relative to the mechanical axis of the tibia. By MA logic that should fail. At 10 years it did not.
The mechanistic reason matters for boards. KA avoids ligament releases, keeps compartment forces near native, and lowers the knee adduction moment, which neutralizes the varus loosening mechanism that drives MA failures.
The failures here were sagittal, not coronal. Watch tibial slope and femoral component flexion. Set the tibial component parallel to the native medial slope and keep femoral flexion under 5 degrees to avoid patellofemoral instability.
Weigh the evidence carefully. This is a Level III, single designer-surgeon series, and designer surgeons report lower failure rates than independent surgeons. It is durability data, not a head-to-head trial.