A Biomechanical Research Of Hollow Screws And Static Locking Plate With Hollow Screws For Femoral Neck Fracture

Objective To explore the biomechanical differences between hollow screws and static locking plate with hollow lag screws for femoral neck fracture. It provides reference for making appropriate surgery plan.Methods After obtaining the agreement of the Ethics Committee of The Fifth Hospital of Wuhan, Sixteen sets of femurs provided by the anatomy teaching and research section of Wuhan university, and the research of biomechanical studies of femoral neck facture is obtained the permission of Wuhan university and Wuhan university of anatomy teaching and research section.Those models all are healthy adult tibial, naked eye view have no abnormalities, fracture, loose performance.And all the models have a X-ray radiography to exclude injury and pathological bone. then eliminate adhesion muscle and ligament.There are 8 males and 8 females above them, aged 45~60 years, with an average age of 51 years.The neck of the femur was sawn with an electric saw to form femoral neck facture models. After anatomic reduction, the fracture samples were fixed with hollow screws(n = 8) and static locking plate with hollow lag screws(n = 8). The models were placed in the Zwick Z100 electronic universal material test machine and torsional testing machine(RNJ-500) and were given cyclic linear load 800 N, cyclic torisional load 3000 cycles. Then to observe two groups of ultimate load.Results The average displacement of two groups in linear testing is(0.94 ± 0.11) mm,(1.26 ± 0.18) mm(P < 0.01) respectively, the difference was statistically significant. The limited axial load is(24.78 ± 4.13) Nm,(16.44 ± 5.29) Nm(P < 0.01) respectively, the difference was statistically significant. The average displacement of two groups in torsional testing is(4.01 ± 0.11) °,(6.44 ± 0.13) °(P < 0.01) respectively, the difference was statistically significant.Conclusion Static locking plate with hollow lag screws is significantly higher than the hollow nails both in anti- linear load and torsional load. Static locking plate with hollow lag screws is beneficial to cure femoral neck fracture and can be applied in the clinical practice.