Sagittal Alignment

A slight flexion alignment is recommended for the femoral component, as both hyperextension and excessive flexion positioning are associated with pain, decreased clinical scores, and abnormal biomechanics. Additionally, the formation of an anterior cortical notch is linked to postoperative fractures and should be avoided as much as possible. The alignment angle of the tibial component varies depending on whether the posterior cruciate ligament (PCL) is preserved. In cruciate-retaining (CR) TKA, the preoperative posterior tibial slope should be maintained as much as possible; however, when the posterior slope is reduced, careful attention must be paid to PCL tension. In contrast, a posterior slope of approximately 3° to 5° is recommended in posterior-stabilized (PS) TKA. Although the posterior slope is generally reduced in PS TKA, excessive tightening of the flexion gap is less likely due to the resection of the PCL.