Biomechanical Analysis of Cement-Screw Technique for Tibial Bone Defects in Total Knee Arthroplasty

The cement-screw technique stands out as an effective method for addressing tibial bone defects in total knee arthroplasty (TKA). However, the absence of consensus regarding the optimal angle for screw implantation poses a challenge. This study aimed to investigate the most suitable screw implantation angle for repairing tibial bone defects in TKA, with a focus on biomechanical considerations.

The angle of screw implantation was categorized into four groups: 0, 15, 30, and 45° relative to the tibial mechanical axis. Finite-element analysis was used to assess stress distribution and displacement in each group model. Static compression mechanical tests were conducted to evaluate the displacement generated by each group model. In addition, high-cycle fatigue compression tests were performed to assess the displacement and structural stiffness of each group model.

The finite-element analysis results indicated that at a screw implantation angle of 15°, the maximum stress on the screw, cement in the defect, prosthesis, and cement under prosthesis is minimized, with the least displacement of the screw. Biomechanical test results demonstrated that a 15° screw implantation angle led to minimum displacement and maximal structural stiffness in the model.

The screw implantation angle of 15° provides a biomechanical advantage in the cement-screw technique context for TKA tibial bone defects.