Vancouver C-type Periprosthetic Fracture With Medial And Lateral Locking Compression Plate-biomechanical Study

Objectives: At present,most orthopedic surgeons will choose the lateral locking compression plate for treatment of VancouverC Peri-prosthesis.However,with a fractured or comminuted Vancouver C type periprosthetic fracture on the medial side of the femur,the use of a lateral locking compression plate alone may cause instability of the medial femoral line,leading to a series of complications such as malunion,nonunion,or delay Healing,dysfunction,etc.So we designed an internal femoral anatomical medial locking compression plate to compensate for medial fixation instability and reduce or avoid complications.The biomechanical study properties of Vancouver C-type periprosthetic fractures were compared by vertical ballast test,torsion test,anterior and posterior,medial and lateral four-point bending test,and the optimal fixation was selected to clinically treat Vancouver C-type prosthesis provide a new method.Methods: Twenty pairs of fresh intact femur specimens were selected to create a Vancouver C-type fracture model.At the fracture end,the lateral locking compression plate A Group(distance between the proximal end of the plate and the tip of the prosthesis 2 bone diameters)and the media locking compression plate were used-Group B(distance between the proximal end of the plate and the tip of the prosthesis 2 bone diameters)was subjected to axial ballast test,torsion test,medial and lateral four-point bending test,and four-point bend test anterior and posterior,and two internal fixation methods were tested.Result: In the axial ballast test,the average stiffness of the M-LCP and L-LCP was not significantly different from the average platen stiffness(1000.65 vs 998.31 N/mm;P=0.957).In the torsion test,the average torsion stiffness of the M-LCP was less than L-LCP(6.2551 vs 8.1573 Nm/degree;P<0.05).In the anterior and posterior four-point bending test,the average stiffness of the M-LCP was greater than L-LCP(905.87vs797.44N/mm;P<0.05).In the medial and lateral four-point bending test,the average stiffness of the M-LCP was less than L-LCP(953.71 vs.919.35 N/mm P < 0.05).Conclusion: The strength of the overall structure of the distal femoral M-LCP and the distal femoral L-LCP at least consistent with the pressure-displacement curve of the axial ballast,especially when the axial pressure is greater than 400N-500 N.The overall strength of the M-LCP is superior to that of the L-LCP,which is useful for the correction of force lines,the reduction of fracture malunion,and knee varus when treating relatively crushed Vancouver C type femoral component fractures.The occurrence of the disease has obvious clinical value,and it has good clinical significance for postoperative functional exercise and daily life after fracture healing.