頸椎椎體螺釘失效后補(bǔ)救螺釘?shù)纳锪W(xué)性能研究要點(diǎn)_圖文

1、724史堡塞墮生型盤查!生!旦箜!鲞箜!塑堡!也墾翌!強(qiáng):叢!堡!Q!:!:!:盟!:j頸椎椎體螺釘失效后補(bǔ)救螺釘?shù)纳锪W(xué)性能研究胡勇孫肖陽(yáng)董偉鑫張蛟袁振山謝輝作者單位:315040寧波大學(xué)醫(yī)學(xué)院附屬寧波市第六醫(yī)院脊柱外科 通信作者:胡勇,Email:huyon9610163.COBDOI:10.3760/cma.j.issn.1001-9030.2016.03.051【摘要】 目的評(píng)估頸椎椎體螺釘(4.0mm失效后,常規(guī)頸椎椎體補(bǔ)救螺釘(4.5mm的生物力學(xué)性能。方法取4具新鮮尸體頸椎標(biāo)本(c3一c7,游離出20個(gè)完整頸椎椎骨。在椎體左右兩 側(cè)分別置入直徑4.0mm的頸椎椎體螺釘,測(cè)量螺釘

2、的最大旋入扭矩。在生物力學(xué)實(shí)驗(yàn)機(jī)上行最大 軸向拔出力實(shí)驗(yàn),記錄最大軸向拔出力。沿原進(jìn)釘點(diǎn)、原釘?shù)乐萌酥睆?.5mm的補(bǔ)救螺釘,測(cè)量補(bǔ)救螺釘置人時(shí)的最大扭矩,置入后在生物力學(xué)實(shí)驗(yàn)機(jī)上進(jìn)行最大軸向拔出力實(shí)驗(yàn)。比較頸椎椎體螺釘與補(bǔ)救螺釘?shù)淖畲笮伺ぞ匾约白畲筝S向拔出力,分析最大旋入扭矩與最大軸向拔出力的關(guān) 系。結(jié)果頸椎椎體螺釘組平均最大軸向拔出力為(380.01161.07N,補(bǔ)救螺釘組平均最大軸向 拔出力為(169.6377.20N,兩者差異有統(tǒng)計(jì)學(xué)意義(P0.01。頸椎椎體螺釘組置入的最大扭 矩平均值為(2.640.88kgf/cm,補(bǔ)救螺釘組置入的最大扭矩平均值為(1.500.36kgf/cm

3、,兩者 差異有統(tǒng)計(jì)學(xué)意義(P0.01。頸椎椎體螺釘組置入的最大扭矩與最大軸向拔出力顯著相關(guān)(r=0.768,P0.01,補(bǔ)救螺釘組置入的最大扭矩與最大軸向拔出力顯著相關(guān)(r=0.534,P0.01。 結(jié)論直徑4.0mm的頸椎椎體螺釘失效后,通過(guò)原釘?shù)乐萌胫睆?.5mm的補(bǔ)救螺釘并不能提供 足夠的生物力學(xué)穩(wěn)定性?！娟P(guān)鍵詞】椎體螺釘;頸椎;生物力學(xué)基金項(xiàng)目:浙江省衛(wèi)計(jì)委醫(yī)藥衛(wèi)生科學(xué)研究基金(2015KYA202A biomechanical evaluation of re、rision screw for failed cervical vertebrae screw fixation Hu Y

4、ong.Sun Xiaoyang,Dong Weixin,Zhang Jiao,Yuan Zhenshan,Xie Hui Departmentof卻inal Surgery,theAffiliated Ningbo No.6Hospitalof Ningbo Medwal College,Ningbo University.Ningbo3J 5040.China Correspondingauthor:肌yo粥,Emaif:huyon9610163.con【Abstract】ob1.iective.To evaluate thebiomechalnicalconlsequence of re

5、visionscrew for failedc e r -v i c a vertebrae screw fixation Methods Twenty cervica vertebra levels from four fresh frozen cadaveric cervical spine specimens(C3一C7were instrumented bilaterally with 4.0一am vertebrae screws.and in. sertional torque f ITwas measured with each revolution.Screws were te

6、nsile loaded to failure“inline” with the screw axis.and pullout strength(POStested.Then 4.5一mm revision screws were reinsertedalong the same trajectory.and IT was measured with each revolution,and puHout strength POS tested.ThePOS and IT results of the 4.0一mm vertebrae screws.and 4.5一mm revision scr

7、ews groups were eom pared.Results There was significant difference in screw POS between 4.0一mE titanium vertebrae screws group and 4.5一mm titanium revision screws group(380.01161.07N VS.(169.6377.20N,re spectively:P0.01I.There was significant difference in IT between 4.0一mm titanium vertebrae screws

8、group(INI(2.640.88kgf/cmand4.5mmrevision screwsgroup(1.500.36kgtYcm(P0.01.The 4.0一mmtitaniumvertebrae screws and 4.5一mm titanium revision screws in the cervi.cal spine had significant correlations between IT and POS(r=0.768,P0.01;r=0.534,P0.01. Conclusion 4.5一mill revision screw fixation cannot prov

9、ide enough biomechanical fixation for failed 4.0一mm eervical vertebrae screws fixation.【Key words】Vertebral screw;Cervical spine; BiomechanicsFund program:Medical and Health Technology Program in Zhejiang Province(2015KYA202實(shí)驗(yàn)研究臨床上頸椎前路鋼板內(nèi)固定技術(shù)的應(yīng)用已經(jīng)得到補(bǔ)救措施較多采用的是通過(guò)直徑4.5mm的頸椎椎體 普及m 2|,但與其他內(nèi)固定技術(shù)一樣,其也存在螺釘切

10、螺釘進(jìn)行補(bǔ)救,然而該補(bǔ)救措施能否提供足夠的生物割拔出而失效的可能。目前,對(duì)于此類螺釘失效的力學(xué)穩(wěn)定性相關(guān)文獻(xiàn)報(bào)道尚少。我們通過(guò)生物力學(xué)實(shí)萬(wàn)方數(shù)據(jù)生堡塞墅處型盤查!生!旦箜!鲞箜!塑垡塹!墾蘭巳!蠼:叢堂!Q!:!:翌:盟!:!驗(yàn),驗(yàn)證直徑4.5mm的補(bǔ)救螺釘是否能夠在直徑4.0ITlm的頸椎椎體螺釘因切割拔出而失效后提供足夠的生物力學(xué)穩(wěn)定性。材料與方法1.標(biāo)本制備:新鮮尸體下頸椎標(biāo)本4具,男性2具,女性2具;年齡3965歲,平均45.1歲。通過(guò)外觀檢查及x線攝片證實(shí)無(wú)明顯退變及骨性異常。每具標(biāo)本包括5個(gè)頸椎椎骨(C3、C4、C5、C6、C7,共游離出20個(gè)完整頸椎椎骨用于實(shí)驗(yàn)。在自然中立位狀態(tài)

11、下,用雙層塑料袋密封保存于一20下,實(shí)驗(yàn)前將標(biāo)本放在室溫下自然解凍,仔細(xì)剔除附著于頸椎椎骨上的肌肉、脂肪和結(jié)締組織等軟組織,完整保留骨性結(jié)構(gòu),制備出游離的頸椎椎骨模型。在下頸椎椎體左右兩側(cè)分別置人直徑4.0mm的頸椎椎體螺釘,用聚甲基丙烯酸甲酯(自凝型,上海齒科材料廠將頸椎棘突與椎板固定在包埋盒中。整個(gè)實(shí)驗(yàn)過(guò)程中,不斷用體積分?jǐn)?shù)為0.9%的等滲鹽水濕潤(rùn)標(biāo)本,防止標(biāo)本在實(shí)驗(yàn)期間由于水分蒸發(fā)引起組織形態(tài)和結(jié)構(gòu)穩(wěn)定性的改變。2.實(shí)驗(yàn)方法:頸椎椎骨后部用聚甲基丙烯酸甲酯(PMMA包埋時(shí),適當(dāng)調(diào)節(jié)椎體角度,保持頸椎椎體垂直向上,在椎體左右兩側(cè)分別置人直徑4.0mm的頸椎椎體螺釘(上海三友醫(yī)療器械有限公司

12、,測(cè)量并記錄最大旋人力矩,然后進(jìn)行拔出力實(shí)驗(yàn),拔出螺釘后,在同一釘?shù)乐萌胫睆綖?.5mm的頸椎椎體補(bǔ)救螺釘,測(cè)量并記錄補(bǔ)救螺釘置入時(shí)的最大扭矩,然后在生物力學(xué)實(shí)驗(yàn)機(jī)上進(jìn)行最大軸向拔出力實(shí)驗(yàn)。頸椎椎體螺釘組與補(bǔ)救螺釘組螺釘旋人深度相同,每枚螺釘旋人時(shí)均使用力矩扳手(N10DPSK,艾固公司,最大軸向拔出力實(shí)驗(yàn)在Instron 8874型生物力學(xué)實(shí)驗(yàn)機(jī)(Instron公司上進(jìn)行,將用PMMA包埋的單個(gè)椎體安放于臺(tái)鉗上固定,該臺(tái)鉗可進(jìn)行前后、左右2個(gè)軸向的平移及旋轉(zhuǎn),可調(diào)節(jié)固定椎體的角度,使頸椎椎體螺釘?shù)妮S線與實(shí)驗(yàn)機(jī)的拉伸方向一致,沿頸椎椎體螺釘方向以2mm/min的加載速率進(jìn)行拔出實(shí)驗(yàn)。最大軸向拔

13、出力是載荷一變形曲線的最高點(diǎn),螺釘拔出力記錄的頻率為50Hz。3.統(tǒng)計(jì)學(xué)方法:應(yīng)用SPSS 18.0統(tǒng)計(jì)軟件分析,計(jì)算最大軸向拔出力和最大旋入扭矩的值以均數(shù)標(biāo)準(zhǔn)差(元s表示。通過(guò)配對(duì)樣本t檢驗(yàn),比較頸椎椎體螺釘組與補(bǔ)救螺釘組的最大拔出力以及最大旋人扭矩值,觀察差異是否有統(tǒng)計(jì)學(xué)意義。頸椎椎體螺釘組最大旋人扭矩與最大拔出力之間相互的關(guān)系采用PearsonS相關(guān)分析,以P0.05為差異有統(tǒng)計(jì)學(xué)意義。725 結(jié) 果1.頸椎椎體螺釘最大軸向拔出力與最大旋人扭矩 的測(cè)量結(jié)果:見(jiàn)表1。表1兩組頸椎椎體螺釘最大拔出力與最大扭矩比較(豆s2.頸椎椎體螺釘最大軸向拔出力與最大旋人扭矩 的關(guān)系:頸椎椎體螺釘組的最大

14、扭矩與最大軸向拔出 力間呈正相關(guān)(r=0.768,P0.01,補(bǔ)救螺釘組的最 大扭矩與最大軸向拔出力間呈正相關(guān)(r=0.534,P4mm,當(dāng)置入直徑 4.5mm的補(bǔ)救螺釘后并不能產(chǎn)生足夠的摩擦阻力和 擠壓力。螺釘最大拔出力作為頸椎椎體螺釘穩(wěn)定性的 重要指標(biāo),被用于反映螺釘?shù)姆€(wěn)定性。有研究表明對(duì) 螺釘軸向拔出力產(chǎn)生影響的因素主要有以下幾點(diǎn):螺 釘外徑、進(jìn)釘深度、骨礦物質(zhì)密度(BMD、螺紋間距和 螺釘形狀等【lO-15。本實(shí)驗(yàn)結(jié)果顯示,頸椎椎體螺釘組 平均最大軸向拔出力為(380.01161.07N,補(bǔ)救螺 釘組平均最大軸向拔出力為(169.6377.20N,兩者 差異有統(tǒng)計(jì)學(xué)意義,說(shuō)明直徑4.0

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