Radiologic analysis of the tibial intramedullary canal in Chinese varus knees: Implications in total knee arthroplasty

Seventy-two lower limb long radiographs were reviewed with respect to mechanical and anatomic axes. A template of an intramedullary tibial guide rod was employed to determine the accuracy of the intramedullary guide in producing ideal tibial cuts (ie, 90°) and acceptable tibial cuts (ie, 90° ± 2°). The mean difference of the angle formed by the 2 axes was 1.84° ± 1.42°. In our findings, 22.2% of patients would have unacceptable cuts if an intramedullary device were employed for the tibial cut during a total knee arthroplasty. A radiograph showing the whole tibia is required preoperatively to identify varus tibiae that are not suitable for the intramedullary method.