Patellofemoral Joint Outcomes in Kinematically vs. Mechanically Aligned Total Knee Arthroplasty: A Systematic Review...

Background and Objectives: While multiple studies have compared mechanical alignment (MA) and kinematic alignment (KA) in total knee arthroplasty (TKA), the effect of alignment philosophy on the patellofemoral joint (PFJ) remains unclear. This systematic review evaluates PFJ-related outcomes following KA- versus MA-TKA indirectly through functional knee scores. Materials and Methods: A comprehensive search of Ovid MEDLINE, PubMed Central, and Embase was undertaken in October 2025 using search strategies developed by two independent librarians. Screening and data extraction were performed independently by two reviewers. All primary studies, including randomised and non-randomised studies, comparing KA- and MA-TKA that included functional Knee Society Score (KSS-F) or the Knee Injury and Osteoarthritis Outcome Score (KOOS) Sports subscale were included. Results: Of the 1570 identified studies, 13 met the inclusion criteria for the systematic review and meta-analysis. KA demonstrated a significant improvement in KSS-F at 1-year follow-up compared with MA (p < 0.05). At longer follow-up intervals, differences did not reach statistical significance (p = 0.07); however, outcomes consistently favoured KA, suggesting maintenance of the early functional advantage over time. Conclusions: KA-TKA is associated with superior PFJ-related functional outcomes at 1 year and shows a sustained trend towards improved performance in longer-term follow-up based on the surrogate scores. Further prospective studies incorporating PFJ-sensitive outcome measures are warranted to clarify long-term benefits.