The current role of coronal plane alignment in Total Knee Arthroplasty in a preoperative varus aligned population: an evidence based review.

BACKGROUND Based on historical data, the current standard of care in Total Knee Arthroplasty (TKA) is to restore the overall alignment to a neutral mechanical axis of 0°±3° or even slight valgus. However, there is significant controversy in literature regarding intentionally placing the TKA in the patient's physiologic, rather than neutral (0±3°), mechanical alignment. QUESTIONS/PURPOSES The goal of this review is to provide a concise update on the present knowledge of coronal plane alignment TKA in a varus population. METHODS A systematic overview of the present literature was undertaken to determine basic science and clinical results in frontal plane alignment in primary TKA. RESULTS Results of studies based on laboratory research, retrieval analysis, cadaver research, finite models, survival scores, clinical outcome, gait analysis and radiographic outcome upon today are provided. CONCLUSIONS Currently placement of a TKA in neutral alignment of 0°±3° of frontal plane alignment is the standard of care. However, frontal plane alignment in neutral may not be as strongly correlated to survivorship as previously thought. Caution needs to be exercised before changing the standard of care, and more research needs to be performed.