The Biomechanics Research On The Effects Of Femoral Neck By The Drilling Decompression Of The Femoral Head

Objective At present,the clinical treatment of femoral head necrosis collapse byintertrochanteric drilling decompression at an early stage is widely used, most drillingdecompression surgery in patients with pain symptoms significantly reduce or disappear, canmake the femoral head necrosis to get relief, to repair of area of bone necrosis, to obtain healingto some patients. However, drilling decompression after femoral neck inevitably produce bonetunnel, excessive residual bone tunnel or aperture metropolitan biological forces affecting thestrength of femoral neck, therefore, fresh femoral neck specimens at different aperture drillingdecompression of femoral head are prepared and their biomechanical characteristics are tested,explore avascular necrosis drilling decompression of the aperture’s influence on thebiomechanics of the femoral neck.Methods Fresh corpse of proximal femur specimens of30youths were collected, whichinclude18male and12female, aged from20to55, average age38. The cause of death issudden death, had no chronic protracted disease. All the specimens by dual energy X-ray bonedensity testing machine, selected24of BMD and femoral neck length is similar, randomlydivided into4groups (6in each group): Group1as the normal group, Group2as single-holedrilling decompression (D=10mm), Group3to2(D)=7mm hole drilling decompressiongroup, and Group4for3hole drilling (D=7mm).The sites in the tension side and pressureside of the femoral neck, together with the lesser trochanteric were chosen as the test points ofstrain, and the most medial femoral head placed highest point and location point displacementmeter, respectively, checking the horizontal displacement and vertical displacement of thefemoral head with2mm/mim linear loading step by step to1200n, read and record four groupsof specimens in the200N,400N,600N,800N,1000N,800N load under the strain anddisplacement of the corresponding value of specimens after30minutes rest linear load gradually at the same rate until the specimen to yield, yield load and the yield displacement.Results:of four groups of specimens, respectively, in200N,400N load,600N,800Nload,800N,1200N load under lateral femoral neck assertiveness strain values, the pressureside strain value, the horizontal displacement value and the vertical displacement of the femoralhead, femoral head hole drilling decompression single-hole drilling decompression group,2group and3hole drilling decompression group were greater than the normal group, normalgroup and3group drilling decompression group to compare strain values have significantdifference (P <0.05), two two compared between three groups of drilling decompression way,femoral neck primary tension side and pressure side strain values, horizontal displacement,vertical displacement value, minimum2hole drilling decompression group,2hole drilling andsingle-hole group,2holes drilled hole drilling decompression decompression group and3group,the femoral neck primary tension side and pressure side strain values, horizontal displacement,vertical displacement value difference have statistical significance (P<0.05), single-hole drillinghole drilling decompression decompression group and3group there was no statisticallysignificant difference (P>0.05); Yield load, the normal group (3724.35±321.34N), andcompared with two groups with3drilling decompression the difference was statisticallysignificant (P <0.05), two comparison between3drilling decompression group,2hole drillingdecompression group (3241.44±185.32N), compared with the single-hole drillingdecompression group or3hole drilling decompression group difference was statisticallysignificant (P <0.05), single-hole drilling decompression group compared with the3holedrilling decompression group there was no statistical significance difference(P>0.05), theyield displacement, the normal group (4.713±1.01mm), compared with3drillingdecompression group had statistically significant difference (P <0.05), compared two groupsbetween three groups of drilling way, there was no statistically significant difference (P>0.05).Conclusion: the intertrochanteric femoral head drilling decompression of postoperativeresidual bone tunnel, significantly affect the femoral neck biological mechanicsperformance;Single-hole (D=10mm), two holes (D=7mm),3holes (D=7mm) comparedthree different aperture drilling decompression,2holes (D=7mm) drilling decompression ofresidual bone tunnel way smaller effects on femoral neck biomechanical properties.