Comparison of Postoperative Alignment of Total Knee Replacement Using Computer-Assisted Navigation with Conventional Guiding System in Chinese Population with Significant Coronal Femoral Bowing

Background/Purpose: Coronal femoral bowing is common in Chinese population. This might affect the restoration of mechanical alignment in conventional total knee replacement (TKR). The aim of the study was to compare the postoperative alignment of conventional TKR with computer-assisted navigation TKR (CAN-TKR), to investigate the effect of femoral bowing on postoperative alignment in conventional TKR and to understand the role of CAN-TKR in limbs with significant femoral bowing. Methods: This is a retrospective study of 331 knees that underwent TKR (either conventional or CAN-TKR) in our centre from January 2010 to June 2012. The incidence of coronal femoral bowing was measured. The postoperative alignments were compared between the two groups. Results: The incidence of excessive coronal femoral bowing was 41.4%. For patients with or without significant coronal femoral bowing, the CAN-TKR group was significantly better in restoring postoperative mechanical axis and the coronal femoral angle (p < 0.05). Proportions of outliers were also much less in the CAN-TKR group. Conclusion: CAN-TKR reduces outliers in all patients, and is especially superior in restoring mechanical alignments in patients with significant coronal femoral bowing.