CAJ | 학술논문

目的设计一种治疗股骨颈骨折的改良空心螺钉,并评价其力学性能. 方法对普通螺钉进行改良,通过有限元分析寻找最优侧孔直径、受力薄弱点,设计改良空心螺钉成品.采取成组设计,分为2组(n=40):改良组和常规组,每组按螺钉长度不同再分为4个亚组,分别为4.5、5.0、5.5、6.0 cm组,每个亚组10枚螺钉,通过三点折弯实验比较改良组与常规组4种不同长度螺钉的极限载荷. 结果改良空心螺钉侧孔开口与受力方向呈30°时,所承受的载荷最大,为960 N;当呈0°和60°时,所承受的载荷最低,约为500 N;侧孔开口直径与所能承受的最大载荷成反比.改良组与常规组4.5、5.0、5.5 cm长螺钉的极限载荷[(706.31±5.94) MPa vs.(710.63±7.17) MPa、(597.87±6.81)MPa vs.(603.34±6.28) MPa、(553.20±6.25) MPa vs.(546.90±7.67) MPa]、断裂载荷[(861.31±8.32) MPa vs.(867.23±5.82)MPa、(778.76±7.85) MPa vs.(783.54±5.36) MPa、(715.29±10.54)MPa vs.(719.87±8.12)MPa]比较差异均无统计学意义(P＞0.05).改良组与常规组6.0cm长螺钉的极限载荷[(436.40±6.54) MPa vs.(431.20±5.73) MPa]比较差异无统计学意义(P＞0.05),但断裂载荷[(535.86±10.53) MPa vs.(580.08±9.34) MPa)]比较差异有统计学意义(P＜0.05).结论本研究设计的改良空心螺钉极限载荷较常规螺钉无明显差异,可提供与常规螺钉相似的力学性能.
목적 설계일충치료고골경골절적개량공심라정,병평개기역학성능. 방법 대보통라정진행개량,통과유한원분석심조최우측공직경、수력박약점,설계개량공심라정성품.채취성조설계,분위2조(n=40):개량조화상규조,매조안라정장도불동재분위4개아조,분별위4.5、5.0、5.5、6.0 cm조,매개아조10매라정,통과삼점절만실험비교개량조여상규조4충불동장도라정적겁한재하. 결과 개량공심라정측공개구여수력방향정30°시,소승수적재하최대,위960 N;당정0°화60°시,소승수적재하최저,약위500 N;측공개구직경여소능승수적최대재하성반비.개량조여상규조4.5、5.0、5.5 cm장라정적겁한재하[(706.31±5.94) MPa vs.(710.63±7.17) MPa、(597.87±6.81)MPa vs.(603.34±6.28) MPa、(553.20±6.25) MPa vs.(546.90±7.67) MPa]、단렬재하[(861.31±8.32) MPa vs.(867.23±5.82)MPa、(778.76±7.85) MPa vs.(783.54±5.36) MPa、(715.29±10.54)MPa vs.(719.87±8.12)MPa]비교차이균무통계학의의(P＞0.05).개량조여상규조6.0cm장라정적겁한재하[(436.40±6.54) MPa vs.(431.20±5.73) MPa]비교차이무통계학의의(P＞0.05),단단렬재하[(535.86±10.53) MPa vs.(580.08±9.34) MPa)]비교차이유통계학의의(P＜0.05).결론 본연구설계적개량공심라정겁한재하교상규라정무명현차이,가제공여상규라정상사적역학성능.
Objective To evaluate the mechanical property of a kind of self-modified cannulate screws for the treatment of formal neck fracture.Methods We modified conventional cannulate screws to design a new kind with a side hole in the neck.Finite element analysis was used to identify the optimal diameter,orientation and weak strength point of the side hole in the new cannulate screws.Forty modified cannulate screws (MCS group) in 4 even subgroups of4 lengths (4.5 cm,5.0 cm,5.5 cm and 6.0 cm) were compared with 40 conventional cannulate screws (CCS group) in 4 corresponding even subgroups of 4 corresponding lengths.The ultimate load (MPa) and fracturing load (MPa) were compared between MCS group and CCS group by three-point bending mechanical tests.Results When the side hole was at the angle of 30°,MCS had the highest load,approximately 960 N; when the side hole was at the angles of 0° and 60°,MCS had the lowest load,about 500 N.There was a reverse proportion between the diameter of the side hole and the ultimate load of the screw.There were no significant differences between 4.5 cm,5.0 cm and 5.5 cm subgroups of MCS and CCS regarding ultimate load (706.31 ±5.94 MPa versus 710.63 ±7.17 MPa,597.87 ± 6.81 MPa versus 603.34 ± 6.28 MPa and 553.20 ± 6.25 MPa versus 546.90 ± 7.67 MPa,respectively) and fracturing load (861.31 ±8.32 MPa versus 867.23 ±5.82 MPa,778.76 ±7.85 MPa versus 783.54 ±5.36 MPaand715.29±10.54 MPa versus 719.87 ± 8.12 MPa,respectively) (P＞0.05).In the 6 cm subgroups,there was a significant difference between MCS and CCS regarding the fracturing load (535.86 ± 10.53 MPa versus 580.08 ± 9.34 MPa) (P ＜ 0.05),but no significant difference between MCS and CCS regarding the ultimate load (436.40 ± 6.54 MPa versus 431.20 ± 5.73 MPa) (P ＞ 0.05).Conclusion Since our self-modified cannulate screws and conventional ones have similar ultimate load,the former can provide similar mechanical performance as the latter do.