A Biomechanical Study Of Application AO Tension Band For Different Level Patellar Fractures

Objective:The aim of this study was to evaluate the stability of AO tension band for the fixation of different level patellar fractures.Method:8cadaver joints were used. We used fretsaw to create middle level transverse patellar fractures, upper and lower1/3, upper and lower1/4transverse patellar fractures models. Then AO tension bands were used to fix them to create biomechanical models. We loaded forces to quadriceps femoris until the fractures sites displacement with1mm.Results:When fracture sites displace with lmm, in the middle level transverse fractures the largest loading was452.2±15.1N; in upper1/3transverse fractures the largest loading was361.2±12.3N; in lower1/3transverse fractures the largest loading was351.0±5.6N; in upper1/4transverse fractures the largest loading was226.7±5.8N; in lower1/4transverse fractures the largest loading was215.3±13.1N. Conclusion:As a normal single knee physiological loading350N-400N, AO tension bands could provide sufficient stability for middle and upper or lower1/3transverse patellar fractures, but it’s insufficient stability for upper or lower1/4transverse patellar fractures.