Objective: The primary aim of the present study is to comparison between using narrow and wide saw blade of proximal tibial bone cut in close slot cutting block guide verified by computer navigation system.
Material and Method: The authors evaluated 80 knees in 80 patients. After cutting the proximal tibia, the cutting surface was validated using the navigated cutting block adapter, and the angular difference between the cutting surface and that preoperatively planned in the sagittal and coronal planes was recorded.
Results: The average cutting error of all knees was 1.8° + 2.7° in use narrow blade and 1.2° + 2.2° in use wide blade. The authors did not find statistically significant difference between the first 40 patients and the next 40 patients. The average cutting error of sclerotic bone was 2.3° + 2.7° in use narrow blade and 1.1° + 2.1° in use wide blade. The authors find statistically significant. The average error in the coronal plane was 1.5° + 1.1° in valgus and 2 (2.5%) in varus of the 80 knees had a malalignment of more than 1° with respect to the targeted cutting plan.
Discussion: Alignment of cutting surface should be checked after cut proximal tibia and recut to reach target alignment and should be cut with wide saw blade especially in sclerotic bone.

Keywords: Total knee arthroplasty, Bone cutting, Malalignment, Distal femur, Navigation systems