Newer Coronal Alignment Philosophies in Total Knee Arthroplasty: A Brief Review

Total Knee Arthroplasty (TKA) surgeries have been one of the most successful surgeries over the past half a decade. However a substantial proportion of patients undergoing TKA have the feeling of their replaced knee being an ‘unnatural one’. Also the conventional TKA requires the surgeon to maintain a coronal plane Hip Knee Angle (HKA) of 180 deg with the joint line being parallel to the horizontal and this requires a significant soft tissue release. Recently there are many different pre arthritic knee phenotypes been described with varying joint line obliquities and HKA angles. It is this difference of coronal HKA axis and joint line obliquity in the non replaced and the replaced knee that is believed to be the cause of dissatisfaction after TKA. Many coronal plane alignment philosophies have been reported to bridge this gap as mentioned earlier which replicate the pre arthritic knee anatomy with minimal soft tissue release. The only concern of the different philosophies is the long term implant survival when fixed in a non mechanically aligned position. However robotics have added a significant safety with calibrated execution to prevent outliers and improve implant survivorship. This is a brief review of the different coronal plane alignment philosophies in TKA.