Biomechanical evaluation of compression buttress screw and medial plate fixation for the treatment of vertical femoral neck fractures

•A novel fixation strategy, compression buttress screw (CBS) fixation, was proposed for femoral neck fractures. Two differently-designed screws (PTCS and FTHCS) combined to construct a regular triangle configuration play distinct roles in biomechanics. One PTCS in the proximal neck functions as a sliding implant to provide dynamic compression during surgery, while two FTHCSs in the distal neck play the role of asymptotical sliding and as an “interosseous buttress” in the medial quadrant of the femoral neck postoperatively.•Biomechanical testing revealed that the CBS fixation was comparable to the anteromedial plate fixation (AMP) and medial buttress plate fixation (MBP), and demonstrated superior biomechanical performance than medial buttress plate fixation without proximal screw (MBPw) to some extent.•Compared with the plate fixations, the CBS fixation could not only achieve similar biomechanical strength but also possesses the surgical advantages of pure screw fixation. Thus, it is advisable to promote the application of CBS fixation for vertical femoral neck fracture. To compare the biomechanical properties of compression buttress screw (CBS) fixation with three plate fixation methods for the treatment of vertical femoral neck fractures (FNFs). A total of forty synthetic femoral models with simulated Pauwels type III fractures (angle of 70°) were equally assigned to one of four fixation groups: CBS fixation, anteromedial plate fixation (AMP), medial buttress plate fixation (MBP) and medial buttress plate fixation without proximal screw (MBPw). Within each group, half of the specimens were randomly assigned to two loading settings, an axial compression loading test and a hip-flexion torsion test. There were no significant differences in axial load to failure, axial stiffness, torsional strength, or torsional stiffness when comparing CBS with MBP (p>0.05). In the axial compression loading test, both CBS and MBP showed higher load to failure and axial stiffness than MBPw (p