Comparison of fixation techniques in Vancouver type AG periprosthetic femoral fracture: a biomechanical study

Abstract

Objective: The purpose of this study was to biomechanically compare cable, trochanteric grip plate, and locking plate techniques in Vancouver type AG fracture model in an in vitro test environment. Methods: Fifteen pieces of fourth-generation synthetic femora were separated into 3 groups of 5 models each. A greater trochanteric fracture model was created after femoral stem implantation. Group 1 was fixated with only cable, Group 2 with trochanteric grip plate, and Group 3 with locking plate. Horizontal stiffness, axial stiffness, and failure loads were compared between the groups. Results: In horizontal compression tests, Group 3 had the highest values, but the only statistically significant difference was between the locking plate group and cable group. Axial distraction test results showed that mean stiffness of Group 1 was 94.6 +/- 9.44 N/mm, that of Group 2 was 174.8 +/- 28.64 N/mm, and that of Group 3 was 185.6 +/- 71.64 N/mm. While locking plate versus cable fixation and grip plate fixation versus cable fixation showed statistically significant differences (p<0.05), comparison of locking plate versus grip plate fixation showed no statistically significant difference (p>0.05). In axial failure load test, Group 3 had the highest results. The only significant difference was between the locking plate and cable groups (p<0.05). Conclusion: In Vancouver type AG fractures stable fixation may be achieved with grip plate fixation and locking plates, with the former ensuring more stable osteosynthesis.