腰椎经椎弓根动态固定椎弓根螺钉置钉的解剖学研究及临床意义

Anatomical study on the placement of pedicle screws in lumbar transpedicular dynamic stabilization and clinical significance

中文关键词:  腰椎动态固定  椎弓根螺钉  进钉点  外展角

英文关键词:Lumbar dynamic stabilization  Pedicle screws  Entry point  Transverse angle

中文摘要:

  【摘要】 目的：通过尸体解剖学及临床观察探讨腰椎经椎弓根动态固定椎弓根螺钉的进钉参数。方法：选取6具腰椎尸体标本（男性、女性各3具），观察副乳突出现情况拟定进钉点：对于副乳突可见的椎体，在L1~L3，其进钉点为副乳突与横突根部中上1/3水平线的交点（进钉点1）；在L4~L5进钉点为副乳突与横突根部中点水平线的交点（进钉点2）。对于副乳突不可见的椎体，L1~L3选择上关节突外缘与横突根部形成的凹槽与横突根部中上1/3水平线的交点为进钉点（进钉点3），L4~L5选择上关节突外缘与横突根部形成的凹槽与横突根部中点水平线的交点（进钉点4）。进钉点用金属针标记，在X线透视下观察金属针在椎弓根的位置；在CT横断面上观察钉道是否突破椎弓根内侧皮质或外侧皮质。椎弓根螺钉钉尾分别紧贴骨面（螺钉深度1）、沉入骨面2个螺纹（螺钉深度2）观察螺钉钉尾和腰椎骨性结构的解剖关系，观察横突根部是否断裂。螺钉深度1时，在侧位X线透视下观察螺钉钉尾和骨性结构的关系。回顾性研究在我院行腰椎经椎弓根动态固定手术共200例患者，男性91例、女性109例，年龄58.4±13.7岁，进钉点选择同前文解剖学研究。术后1周复查CT图像观测椎弓根螺钉突破椎弓根皮质的情况，螺纹边缘和椎弓根骨皮质重叠为突破椎弓根皮质。将未突破椎弓根皮质的螺钉即正常位置的椎弓根螺钉，测量螺钉外展角。结果：L3副乳突双侧6具标本均可见；L2、L4各5具双侧可见，另1具单侧可见；L5 4具双侧可见，1具单侧可见，出现率为75%。腰椎尸体标本进钉点标记后，X线透视下位于椎弓根形成的圆圈（“猫眼”）2~3点钟位置。通过CT均能设计螺钉钉道，螺钉路径（OP）均能通过椎弓根松质骨区、不和椎弓根内侧皮质或外侧皮质相切。置入椎弓根螺钉时，螺钉深度1不会造成横突断裂；螺钉深度2可见螺钉部分钉尾沉入上关节突外下方、横突根部的骨皮质内，L1左、右横突根部各有3、4例断裂，L2左、右横突根部各有3例断裂，L3左、右横突根部各有1、2例断裂，L4、L5横突根部未见断裂。螺钉深度1时，在侧位X透视下见螺钉钉尾刚好和椎板峡部的骨面平齐。术中在侧位透视时可以椎板峡部的骨面为参照依据，当钉尾刚好和椎板峡部的骨面平齐即是理想的螺钉深度。200例患者各腰椎固定情况：L1 14例，L2 31例，L3 50例，L4 136例，L5 184例，S1 70例，共485个椎体、置入970枚椎弓根螺钉。椎弓根螺钉突破椎弓根皮质：L1 10枚，L2 17枚，L3 18枚，L4 24枚，L5 24枚，S1 4枚，共97枚（97/970）。椎弓根螺钉外展角L1：19.79°±1.76°，L2：22.45°±1.75°，L3：25.08°±1.54°，L4：27.96°±2.14°，L5：25.18°±2.42°，S1：10.08°±2.62°。结论：L1~L3经椎弓根动态固定的螺钉进钉点推荐为副乳突与横突根部中上1/3水平线的交点，或上关节突外缘与横突根部形成的凹槽与横突根部中上1/3水平线的交点为进钉点；L4~L5，推荐为副乳突与横突根部中点水平线的交点，或上关节突外缘与横突根部形成的凹槽与横突根部中点水平线的交点；椎弓根螺钉的理想深度是钉尾紧邻骨面，侧位透视时钉尾紧邻椎板峡部的骨面。L1~S1动态固定椎弓根螺钉突破椎弓根皮质的比例为10.00%。L1~S1动态固定椎弓根螺钉理想的外展角分别为20°、23°、25°、28°、25°、10°。

英文摘要:

  【Abstract】 Objectives: To explore the implant parameters of pedicle screws in lumbar transpedicular dynamic stabilization through autopsy and clinical observations. Methods: 6 lumbar spine cadaver specimens were selected, including 3 males and 3 females. Determining the screw entry point by observing accessory process: for the vertebra where the accessory process was visible, in L1-L3, the entry point was the intersection point of accessory process and the middle-upper 1/3 horizontal line of the transverse process root(Entry point 1), and in L4-L5, the entry point was the intersection point of accessory process and the mid-point horizontal line of the transverse process root(Entry point 2); For the vertebra where the accessory process was not visible, in L1-L3, the entry point was the intersection point of the groove formed by the outer edge of the superior articular process and the transverse process and the middle-upper 1/3 horizontal line of the transverse process root(Entry point 3), and in L4-L5, the intersection point of the groove formed by the outer edge of the superior articular process and the transverse process and the mid-point horizontal line of the transverse process root(Entry point 4). The entry points were marked with metal needles, and the position of metal needle at the pedicle was observed under X-ray fluoroscopy. On CT cross-section, screws were simulated and observed to see whether the screw path broke through the medial or lateral cortex of the pedicle. The tail of the pedicle screw was respectively closely attached to the bone surface(screw depth 1) and sank into two threads of the bone surface(screw depth 2) to observe the anatomical relationship between the tail of the pedicle screw and the bony structure of the lumbar vertebrae, and at the same time, to observe whether the root of the transverse process was fractured. At screw depth 1, the relationship between the screw tail and the bony structure was observed under lateral X-ray fluoroscopy. A retrospective study was conducted on a total of 200 patients who underwent lumbar transpedicular dynamic stabilization in our hospital, including 91 males and 109 females, with an age of 58.4±13.7 years. The selection of the screw entry point was mentioned above. One week after operation, CT images were reexamined to observe the situation of the pedicle screw breaking through the pedicle cortex. The overlap of the thread edge and the pedicle cortical bone indicated the breakthrough of pedicle cortex. The transverse angle of the screws that did not penetrate the cortical layer of the pedicle was measured. Results: The bilateral accessory processes of L3 were visible in all 6 specimens; The accessory processes was visible on bilateral sides of L2 and L4 in 5 specimens, and on unilateral side in the other specimen; At L5, the accessory process was visible on both sides in 4 specimens, and on unilateral side in 1 specimen, with a visible rate of 75%. The entry points were marked on the lumbar autopsy specimens, which were located at 2 to 3 o′clock position on the circle formed by the pedicle ("cat′s eye") under X-ray fluoroscopy. All screw pathways could be designed through CT, and the screw paths(OP) could pass through the cancellous bone area of the pedicle without being tangent to the medial or lateral cortex of the pedicle. When the pedicle screw was inserted, at screw depth 1, it did not cause transverse process fracture, while at screw depth 2, it could be seen that the t獡?潬映?瑦栠整?汥愠浳楣湲慥?搠異牡楲湴朠?污慮瑫攠物慮汴?映汴畨潥爠潬獯捷潥灲礠??呤栠敯?灴牥潲瀠潰牡瑲楴漠湯?漠晴??ㄠ?印??灲攠摡楲捴汩散?獬捡牲攠睰獲?扣牥敳慳欬椠湷杩?瑨桩牮漠畴杨桥?瑣桯敲?灩散摡楬挠汢敯?捥漠牡瑴攠硴?楥猠??は??楯湦?摴票湥愠浴楲捡?獳瑶慥扲汳楥稠慰瑲楯潣湥??听栠攳?楡摮敤愠水?瑦牲慡湣獴癵敲牥獳攠?慴渠杴汨敥猠?晡潳牥????却??搠祬湥慦浴椠捡?晤椠硲慩瑧楨潴渠?灲敡摮楳捶汥敲?獥挠牰敲睯獣?慳牳敥?㈠は???㈱????????????????????愠湢摡??????牴敨獥瀠敬捥瑦楴瘠敡汮祤?right transverse processes of L2, and 1 and 2 fractures at the base of the left and right transverse processes of L3, and no fractures were observed at the base of the transverse processes of L4 and L5. When the screw was at depth 1, the tail of the screw was exactly flush with the bone surface of the isthmus of the lamina on the lateral X-ray. Fixation conditions in 200 patients were L1 in 14 cases, L2 in 31 cases, L3 in 50 cases, L4 in 136 cases, L5 in 184 cases, and S1 in 70 cases, altogether 485 verterbrae and 970 pedicle screws were involved. The number of pedicle screws broken through the pedicle cortex in L1-S1 was as follows: 10 for L1, 17 for L2, 18 for L3, 24 for L4, 24 for L5, and 4 for S1, totaling 97(97/970). The transverse angle of the pedicle screws in L1 to S1 were 19.79°±1.76°，22.45°±1.75°, 25.08°±1.54°, 27.96°±2.14°, 25.18°±2.42°, and 10.08°±2.62° respectively. Conclusions: The recommended screw entry point for lumbar transpedicular dynamic stabilization in L1-L3 is the intersection point of accessory process and the middle-upper 1/3 horizontal line of the transverse process root, or the intersection point of the groove formed by the outer edge of the superior articular process and the transverse process and the middle-upper 1/3 horizontal line of the transverse process root; And in L4-L5, it is recommended to insert at the intersection point of accessory process and the mid-point horizontal line of the transverse process root, or the intersection point of the groove formed by the outer edge of the superior articular process and the transverse process and the mid-point horizontal line of the transverse process root. The ideal screw depth is that the screw tail adjacent to the bone surface, and adjacent to the bone surface of the isthmu