Evaluation of the screw position and angle using a post-contoured plate in the open wedge high tibial osteotomy according to the correction degree and surgical technique

• Anatomical plate is post-contoured to the surface geometry after the correction.
• Position and angle of the screw were evaluated in the anatomical plate.
• These were not different, regardless of the correction degree.
• These were not different, regardless of the surgical technique.

BackgroundThe purpose of the present study was to evaluate the screw insertion angle and orientation with an anatomical plate that is post-contoured to the surface geometry of the proximal tibia after open wedge high tibial osteotomy.MethodsFrom March 2012 to June 2014, 31 uni-planar and 38 bi-planar osteotomies were evaluated. Postoperative computed tomography data obtained after open wedge high tibial osteotomy using a locking plate were used for reconstruction of the 3 dimensional model with Mimics v.16.0 of the proximal tibia and locking plate. Measurement data were compared between 2 groups (gap lesser than or equal to 10 mm (Group 1) and gap greater than 10 mm(Group 2)). These data were also compared between the uniplanar (Group 3) and bi-planar (Group 4) osteotomy groups.FindingsDimensions of the medial proximal tibia of the sagittal plane, positions of the screw hole in the sagittal plane, and angles of screw insertion of all planes were not statistically different, regardless of the correction degree and operative technique. Additionally, angles of screw insertion were larger at the most anterior and posterior screw in the axial plane and most inferior screw showed smallest angle in the coronal plane.InterpretationUsing a post-contoured plate, the position and angle of the screw insertion were not different in the direction of the lateral hinge, regardless of the correction degree and operative technique. This could imply that it could be used universally in the open wedge high tibial osteotomy.