Comparing Alignment of Proximal Tibia first cut between Narrow and Wide saw Blade in CAS TKA
Pawaris Sungkhun MD*, Viroj Larbpaiboonpong MD*, Thana Turajane MD*, Ukrit Chaweewannakorn MD*
Affiliation : * Department of Orthopaedic Surgery, Police General Hospital, Bangkok, Thailand
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 preopera-
tively 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
