CAJ | 학술논문

背景:胸腰椎骨折固定后相邻节段退变发生的一个重要因素是相邻运动节段出现过度活动,导致该节段应力集中,并且相邻节段的头侧较尾侧更容易发生退变,固定节段数量越多,相邻节段的应力越集中,退变概率越大.目的:通过对相邻双节段腰椎爆裂性骨折经皮椎弓根螺钉外固定进行生物力学测试,评价脊柱外固定器的即刻生物力学稳定性以及上位相邻椎体的运动范围退变情况.方法:选取6具新鲜成年猪脊柱标本(T14-S1,猪胸椎共有14个椎体).每具标本均按以下顺序进行生物力学测试:正常组、骨折组(L3,L4椎体制作成爆裂性骨折模型)、外固定组(L2,L5椎体行脊柱外固定器固定)、内固定组(取出脊柱外固定器后行 L2,L5椎体传统开放后路内固定).测试标本的固定节段(L2-L5)和上位相邻节段(L1)应用跨相邻2伤椎4钉外固定与内固定后的前屈、后伸、侧屈、轴向旋转角位移运动变化.结果与结论:骨折组各方位角位移运动范围均大于正常组,差异有显著性意义(P <0.05);两种固定状态下固定节段(L2-L5)各方位角位移运动范围均显著小于正常状态和骨折状态,差异有显著性意义(P <0.01),且两种固定状态下各方位的即刻稳定指数比较,差异均无显著性意义(P >0.05);与正常组比较,两种固定状态上位椎体(L1)的各方位角位移运动范围均增加;外固定组与正常组上位椎体(L1)三维运动范围比较:前屈、后伸时差异无显著性意义(P >0.05),侧屈、旋转时差异均有显著性意义(P <0.01);内固定组与正常组比较:前屈、后伸、侧屈、旋转时差异均有显著性意义(P <0.01).结果可见应用脊柱外固定器治疗相邻双节段腰椎爆裂性骨折,其即刻生物力学稳定性与传统开放后路内固定系统相当;两种固定方式均能引起上位正常相邻椎体侧屈、旋转的角位移增加,但脊柱外固定器较传统内固定在前屈、后伸时不会引起上位相邻椎体的运动范围显著增加. 揹景:胸腰椎骨摺固定後相鄰節段退變髮生的一箇重要因素是相鄰運動節段齣現過度活動,導緻該節段應力集中,併且相鄰節段的頭側較尾側更容易髮生退變,固定節段數量越多,相鄰節段的應力越集中,退變概率越大.目的:通過對相鄰雙節段腰椎爆裂性骨摺經皮椎弓根螺釘外固定進行生物力學測試,評價脊柱外固定器的即刻生物力學穩定性以及上位相鄰椎體的運動範圍退變情況.方法:選取6具新鮮成年豬脊柱標本(T14-S1,豬胸椎共有14箇椎體).每具標本均按以下順序進行生物力學測試:正常組、骨摺組(L3,L4椎體製作成爆裂性骨摺模型)、外固定組(L2,L5椎體行脊柱外固定器固定)、內固定組(取齣脊柱外固定器後行 L2,L5椎體傳統開放後路內固定).測試標本的固定節段(L2-L5)和上位相鄰節段(L1)應用跨相鄰2傷椎4釘外固定與內固定後的前屈、後伸、側屈、軸嚮鏇轉角位移運動變化.結果與結論:骨摺組各方位角位移運動範圍均大于正常組,差異有顯著性意義(P <0.05);兩種固定狀態下固定節段(L2-L5)各方位角位移運動範圍均顯著小于正常狀態和骨摺狀態,差異有顯著性意義(P <0.01),且兩種固定狀態下各方位的即刻穩定指數比較,差異均無顯著性意義(P >0.05);與正常組比較,兩種固定狀態上位椎體(L1)的各方位角位移運動範圍均增加;外固定組與正常組上位椎體(L1)三維運動範圍比較:前屈、後伸時差異無顯著性意義(P >0.05),側屈、鏇轉時差異均有顯著性意義(P <0.01);內固定組與正常組比較:前屈、後伸、側屈、鏇轉時差異均有顯著性意義(P <0.01).結果可見應用脊柱外固定器治療相鄰雙節段腰椎爆裂性骨摺,其即刻生物力學穩定性與傳統開放後路內固定繫統相噹;兩種固定方式均能引起上位正常相鄰椎體側屈、鏇轉的角位移增加,但脊柱外固定器較傳統內固定在前屈、後伸時不會引起上位相鄰椎體的運動範圍顯著增加.
배경:흉요추골절고정후상린절단퇴변발생적일개중요인소시상린운동절단출현과도활동,도치해절단응력집중,병차상린절단적두측교미측경용역발생퇴변,고정절단수량월다,상린절단적응력월집중,퇴변개솔월대.목적:통과대상린쌍절단요추폭렬성골절경피추궁근라정외고정진행생물역학측시,평개척주외고정기적즉각생물역학은정성이급상위상린추체적운동범위퇴변정황.방법:선취6구신선성년저척주표본(T14-S1,저흉추공유14개추체).매구표본균안이하순서진행생물역학측시:정상조、골절조(L3,L4추체제작성폭렬성골절모형)、외고정조(L2,L5추체행척주외고정기고정)、내고정조(취출척주외고정기후행 L2,L5추체전통개방후로내고정).측시표본적고정절단(L2-L5)화상위상린절단(L1)응용과상린2상추4정외고정여내고정후적전굴、후신、측굴、축향선전각위이운동변화.결과여결론:골절조각방위각위이운동범위균대우정상조,차이유현저성의의(P <0.05);량충고정상태하고정절단(L2-L5)각방위각위이운동범위균현저소우정상상태화골절상태,차이유현저성의의(P <0.01),차량충고정상태하각방위적즉각은정지수비교,차이균무현저성의의(P >0.05);여정상조비교,량충고정상태상위추체(L1)적각방위각위이운동범위균증가;외고정조여정상조상위추체(L1)삼유운동범위비교:전굴、후신시차이무현저성의의(P >0.05),측굴、선전시차이균유현저성의의(P <0.01);내고정조여정상조비교:전굴、후신、측굴、선전시차이균유현저성의의(P <0.01).결과가견응용척주외고정기치료상린쌍절단요추폭렬성골절,기즉각생물역학은정성여전통개방후로내고정계통상당;량충고정방식균능인기상위정상상린추체측굴、선전적각위이증가,단척주외고정기교전통내고정재전굴、후신시불회인기상위상린추체적운동범위현저증가.
BACKGROUND: Overactive adjacent motion segment is an important factor for adjacent segment degeneration after thoracolumbar fracture fixation, which can cause stress concentration on this segment, and the cephalad adjacent segment is more prone to degeneration than caudal adjacent segment. The more the fixed segments are, the higher the stress concentration of the adjacent segment, and the larger the degeneration rate. OBJECTIVE: To assess the biomechanical stability and range of motion degeneration of the upper adjacent vertebrae by the biomechanics testing of the pedicle screw external fixation for adjacent double segment lumbar burst fractures. METHODS: There were 14 vertebra samples (T14-S1) from six fresh adult pig spinal specimens. Each of them underwent a biomechanical test in the fol owing order to minimize the inter-group interference, including normal group, fracture group (L3 and L4 vertebral specimens were made into the burst fracture models), external fixation group (L2 and L5 vertebral specimens were fixed with spine external fixtor) and internal fixation group (the L2 and L5 vertebral specimens received the traditional open posterior fixation after the spine external fixtor removed). The range of motion of L2-5 and the upper adjacent segment L1 were measured under flexion, extension, lateral bending and axial rotation angles before and after internal fixation and external fixation. RESULTS AND CONCLUSION: Range of motion in the fracture group, internal fixation group and external fixation group was significantly larger than that of the normal group (P < 0.05). Range of motion of L2-5 in the internal fixation group and external fixation group was significantly less than that of normal and fracture groups (P < 0.01). There was no significant difference in immediate stability index between the internal fixation group and external fixation group (P > 0.05). Compared with normal group, the range of motion of the upper vertebra L1 after internal and external fixation was increased; there was no significant difference in range of motion of upper vertebrae L1 under flexion and extension between external fixation group and normal group (P > 0.05), but there was significant difference under lateral bending and axial rotation (P < 0.01). There was significant difference in range of motion of the upper vertebra L1 under flexion, extension, lateral bending and axial rotation between internal fixation group and the normal group (P < 0.01). Compared with traditional internal fixation, the immediate stability index of the spinal external fixation in treating adjacent double segment burst fractures was equal. Both two fixation methods could increase the range of motion of the adjacent upper vertebra under lateral bending and rotation. But the spinal external fixation could not increase the range of motion of adjacent upper vertebrae under flexion and extension.