Multi-planar component alignment predicts functional outcomes after total knee arthroplasty: A prospective cohort study.

Abstract

Achieving optimal lower-limb alignment after total knee arthroplasty (TKA) is widely regarded as essential for implant longevity and functional success. While neutral mechanical alignment has traditionally been the target, the role of rotational alignment and its impact on clinical outcomes remains less well defined. This study aimed to evaluate the relationship between coronal, sagittal, and rotational postoperative component alignment and functional outcomes measured by the Oxford Knee Score (OKS) at 1-year post-TKA. A prospective cohort of patients undergoing primary TKA was assessed. Postoperative alignment in coronal and sagittal planes was measured using standard weight-bearing radiographs, while rotational alignment was evaluated using computed tomography (CT) scans. Functional outcomes were quantified using the OKS at 1-year follow up. Correlation analyses were performed to examine associations between multi-planar alignment and knee function. Significant positive correlations were observed between postoperative alignment in all three planes and OKS scores (P < 0.05). Patients with alignment closer to neutral mechanical axis and optimal femoral and tibial rotational positioning demonstrated superior functional outcomes. These findings reinforce the biomechanical and clinical importance of precise component positioning in TKA. Precise postoperative alignment in coronal, sagittal, and rotational planes is associated with improved knee function after TKA. Incorporating rotational alignment into routine postoperative evaluation may enhance understanding of patient outcomes. Future studies with larger cohorts and long-term follow up are warranted to further elucidate the impact of multi-planar alignment on implant durability and patient satisfaction.