Metric study of Egyptian sacrum for lumbo-sacral fixation procedures

Lumbo-sacral fixation for the management of lumbo-sacral instability includes insertion of screws to the sacrum, most commonly into the posterior aspect of the pedicles of the first sacralvertebra. This study was carried out to determine the normal anatomical parameters of the Egyptian sacrum, particularly of the first sacral vertebra and its pedicles, to find the safest approach for sacral screw placement in lumbo-sacral fixation procedures, and to describe racial characteristics, if any. In this study, 45 adult Egyptian dry sacra of unknown sex were used. Eleven sacral parameters were measured using the Vernier sliding caliper which is accurate to 0.1 millimeter. In this study, the sacrum showed a mean height of 11.43 ± 0.88 centimeters a mean width of 10.39 ± 0.91 centimeters with a mean sacral index of 90.82 ± 1.80 %. The first sacral pedicle had a mean anterior height of 1.83 ± 0.49 centimeters, a mean depth of 2.99 ± 0.53 centimeters and a mean posterior height of 2.38 ± 0.50 centimeters. A medialtrajectory path (representing an anteromedially-oriented first sacral pedicle screw) starting from the infero-lateral border of the S1 facet to the sacral promontory in the middle line was 5.23 ± 0.52 cm. The findings of the present study could provide accurate and specific parameters of the sacrum among Egyptians that could enhance the safety of insertion of sacral screws during lumbo-sacral fixation procedures upon Egyptian patients.     

骶骨S2椎弓根外进钉固定的生物力学分析

背景：模拟骶骨骨折S2椎弓根钉外进钉固定拔出力与在拔出椎弓钉时的应变电测分析鲜有报道。 目的：测量S2椎弓根外进钉固定拔出力与骶骨应变分布,为临床提供生物力学参数。 方法：取正常国人新鲜尸体骶骨标本,以椎弓根钉外进钉方法固定于S2椎弓根,以小型力传感器与椎弓根钉固定装置连接测量椎弓根钉的拔出力,同时以动静态电阻应变仪,对预先粘贴在4个椎弓根螺栓固定边缘部位和骶骨不同部位的应变片进行应变电测量。1号进钉点位置为左侧第1骶后孔下缘最低点,2号进钉点位置为右侧第1骶后孔下缘最低点,3号进钉点为左侧第1骶后孔连线与骶外侧嵴的交点,4号进钉点为右侧第1骶后孔连线与骶外侧嵴的交点。测量椎弓根螺钉最大拔出力和骶骨各测点应变值。 结果与结论：外进钉1号螺钉拔出力为(399.0±7.2) N,2号螺钉拔出力为(281.0±5.2) N,3号螺钉拔出力为(196.0±4.3) N,4号螺钉拔出力为(220.1±4.6) N。应变电测量最小应变发生在2号螺钉8号测点,应变为(13.5±1.1) με;最大应变发生在1号螺钉1号测点,应变为(96.8±6.5) με。提示S2椎弓根钉外进钉固定方法符合生物力学原理。     

Anatomic considerations of the second sacral vertebra and dorsal screw placement

Summary Direct measurements and measurements from images of axial cross-sections on 20 cadaveric sacra that had been scanned on computer were used in this study. The measurements, including parameters from the vertebral body, lateral mass and spinal canal of the second sacral vertebra (S2) were performed. The length of the screw path and the optimal angulation of the screw placement for dorsal sacral internal fixation were also included. The mean values of height, anteroposterior diameter, width and breadth of the S2 were 25.0 mm, 13.5 mm, 29.4 mm and 83.0 mm, respectively. The mean values of the mid-sagittal diameter, maximum transverse diameter and area of the S2 spinal canal were 10.3 mm, 23.1 mm and 162.4 mm², respectively. The mean transpedicular screw length of the S2 and optimal medial angle were 25.2 mm and 30.0°, respectively. The mean lateral mass screw length of the S2 and optimal lateral angle were 32.8 mm and 22.0°, respectively. The present study provides quantitative anatomic data of the second sacral vertebra. All parameters indicate that, compared with our previous study, S2 is smaller than S1. When S2 lateral mass screw fixation is intended, anchoring the anterior cortex may violate the iliac vessels or lumbosacral trunk; therefore, understanding the unique anatomy of the S2 is imperative.

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Bases anatomiques du vissage de la deuxième vertèbre sacrale

Résumé Les mesures ont été réalisées directement sur 20 sacrums de cadavres et à partir d'images scannérisées à partir de coupes transversales. Ces mesures intéressaient les paramètres du corps vertébral, de la partie latérale du sacrum, et du canal sacral à hauteur de la deuxième vertèbre sacrale (S2). Nous avons également mesuré la longueur du trajet de la vis et l'angle optimal de son insertion pour une fixation interne par voie postérieure. Les valeurs moyennes étaient les suivantes : hauteur 25,0 mm, diamètre sagittal 13,5 mm, épaisseur 29,4 mm, et largeur 83,0 mm. Les valeurs moyennes intéressant le canal sacral en S2 étaient les suivantes : diamètre sagittal médian 10,3 mm, diamètre transversal maximum 23,1 mm, surface 162,4 mm2. La longueur moyenne de la vis pédiculaire de S2 était de 25,2 mm et sa direction optimale était oblique en avant et médialement de 30,0° par rapport au plan sagittal. La longueur moyenne de la vis alaire insérée dans la partie latérale du sacrum en S2 était de 32,8 mm et sa direction optimale était oblique en avant et latéralement de 22,0°. La présente étude fournit des données anatomiques quantitatives concernant la deuxième vertèbre sacrale. En comparaison avec les données rapportées dans notre précédent travail, tous les paramètres montrent que S2 est plus petite que S1. Si l'on veut tenter la fixation de la vis dans la partie latérale de S2, la traversée de la corticale antérieure peut léser les vaisseaux iliaques ou le tronc lombo-sacral. C'est pourquoi la compréhension de l'anatomie particulière de S2 est indispensable.

     

合并腰骶移行椎时应用骶髂螺钉的临床解剖测量

目的　探讨合并腰骶移行椎时骶1、2椎弓根的形态学特点,为应用骶髂螺钉固定提供形态学基础。 方法　选取生前资料完整的标本共79例。对骶1、骶2椎体前后径、椎体高度、椎体横径、椎弓根前高、椎弓根后高、椎弓根宽度、进针深度、进针角度进行测量。 结果　正常骶1椎弓根前高(18.1± 　3.8)mm,后高(20.6±3.6)mm,宽度(27.7±3.1)mm;Ⅱ型骶1椎弓根前高(19.9±2.0)mm,后高(19.2±2.6)mm,宽度(29.9±2.2)mm;Ⅲ型骶1椎弓根前高(18.5±3.0)mm,后高(16.9±3.1)mm,宽度(27.8±2.2)mm。正常骶2椎弓根前高(12.4±2.3)mm,后高(14.34±2.9)mm,宽度(22.2±3.1)mm,Ⅱ型骶2椎弓根前高(10.4±1.5)mm,后高　(14.4±2.4)mm,宽度(19.5±2.7)mm;Ⅲ型骶2椎弓根前高(9.5±2.0)mm,后高(14.0±3.0)mm,宽度(18.6±3.4)　mm。Ⅱ型骶1椎弓根大于正常,Ⅲ型与正常接近。正常骶2椎弓根大于Ⅱ型和Ⅲ型。 结论　合并腰骶移行椎时可应用骶髂螺钉固定,骶1椎弓根可容纳1~2枚螺钉,骶2椎弓根可容纳1枚螺钉。     

S2横形螺钉固定变异骶骨Ⅲ区骨折的影像解剖学研究

目的　探讨S1椎不能横形置入骶髂螺钉固定骶骨Ⅲ区骨折时,置入S2横形螺钉的安全参数。 方法　用Mimics软件对96例骨盆CT数据进行三维重建,模拟横形置入S1、S2螺钉,根据能否横形置入S1螺钉将骶骨病例分为正常组与变异组。重建骨盆周围软组织,确定S2横形螺钉进钉点B、髂前上棘顶点M、髂嵴上点N的体表投影点B1、M1、N1,并测量各点间的长度。 结果　正常组男、女B1M1长度分别为(140.94±16.64) mm、(143.95±16.27) mm,均明显大于变异组男、女B1M1的长度(129.37±14.93) mm、(132.07±16.84) mm (P男＜0.05,P女＜0.05)。正常组与变异组B1N1的长度男性分别为(69.92±6.73) mm、(72.64±7.46) mm,女性分别为(60.80±7.05)mm、(58.85±7.81) mm,其差异均无统计学意义(P男＞0.05,P女＞0.05)。正常组与变异组M1N1的长度男性分别为(157.58±16.83) mm、(150.48±13.21) mm,女性分别为(156.79±15.84)mm、(151.49±16.58)mm,其差异均无统计学意义(P男＞0.05,P女＞0.05)。 结论　当S1椎为腰骶移行椎、高位骶骨或骶骨翼斜坡陡峭变异时不能横形置入骶髂螺钉,可经S2横形置入直径7.0 mm螺钉固定骶骨Ⅲ区骨折,术者在透视监视下可通过触摸髂前上棘及髂嵴来确定S2螺钉的体表进钉点。     

骶骨纵形骨折后路钢板固定置钉的应用解剖

目的 通过对骶骨的解剖学测量,为骶骨纵形骨折后路钢板固定的临床应用提供钉道基础数据。方法 选取20例成人骶骨标本,按骶骨后路钢板固定置钉的钉道要求,设定进针点：骶（S1）关节突外侧a点,S1关节突下侧b点,S2、S3、S4的入点c、d、e位于a点与S4骶骨后孔假想连线上,且各位于上下骶骨后孔间连线的中点处;两侧进针点间的距离分别为af、bg、ch、ci、dj、ek;内侧钉道长度分别为A1、A2、B、C、D、E;外侧钉道长度分别为F、G、H、I、J、K和外侧钉道角度分别为Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ、Ⅵ。结果A1、A2、B值分别为(31.70±3.54)mm、(35.59±4.50)mm和(27.83±3.80)mm; F、G、H、I、J值分别为(43.68±5.11)mm、(30.10±4.00)mm、(27.66±3.33)mm、(23.51±3.26)mm和(18.72±4.18)mm;Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ值分别为(5.75±4.14)°、(12.65±5.22)°、(10.05±6.78)°、(8.75±5.87)°和(16.33±8.46)°。结论 内外侧置钉进针点间距离适合钢板的使用;置钉钉道长度内侧相对固定,外侧多变;外侧置钉角度变化较大。     

Trabecular Bone Structural Variation in the Proximal Sacrum Among Primates

The sacrum occupies a functionally important anatomical position as part of the pelvic girdle and vertebral column. Sacral orientation and external morphology in modern humans are distinct from those in other primates and compatible with the demands of habitual bipedal locomotion. Among nonhuman primates, however, how sacral anatomy relates to positional behaviors is less clear. As an alternative to evaluation of the sacrum's external morphology, this study assesses if the sacrum's internal morphology (i.e., trabecular bone) differs among extant primates. The primary hypothesis tested is that trabecular bone parameters with established functional relevance will differ in the first sacral vertebra (S1) among extant primates that vary in positional behaviors. Results for analyses of individual variables demonstrate that bone volume fraction, degree of anisotropy, trabecular number, and size-corrected trabecular thickness differ among primates grouped by positional behaviors to some extent, but not always in ways consistent with functional expectations. When examined as a suite, these trabecular parameters distinguish obligate bipeds from other positional behavior groups; and, the latter three trabecular bone variables further distinguish knuckle-walking terrestrial quadrupeds from manual suspensor-brachiators, vertical clingers and leapers, and arboreal quadrupeds, as well as between arboreal and terrestrial quadrupeds. As in other regions of the skeleton in modern humans, trabecular bone in S1 exhibits distinctively low bone volume fraction. Results from this study of extant primate S1 trabecular bone structural variation provide a functional context for interpretations concerning the positional behaviors of extinct primates based on internal sacral morphology. Anat Rec, 302:1354–1371, 2019. © 2018 Wiley Periodicals, Inc.     

A quantitative study on the sacrum of the dog.

The aim of this study was to record sacral bone morphometry that may help in selection of the implant type and proper size in sacroiliac separation. For this reason, sacral lengths and width, the length of each sacral vertebrae, distances between cranial and caudal articular processes, vertical and transversal diameters of the cranial endplate, sacral tuberositas and articular surface areas were obtained from 11 dogs. Additionally, the transverse and vertical diameters of the bony structure and sacral canal were measured from six cross-sections. The data of the study were determined to be representative of the sacral values for average-sized dogs, which was confirmed statistically. The highest value was the sacral width among the linear measurements. The ventral sacral length was longer than the dorsal sacral length. The total lateral area of the sacral wing was measured as 677.46 (142.1)mm2. The transverse diameters of the first sacral vertebra important for screw implantation were 46.02 (4.33)mm and 44.18 (5.29)mm in the first and second cross-sections, respectively.     

Surgical anatomy of the presacral area

Objective  L5–S1 instabilities can be fixated using minimally invasive presacral approach. The close relationship between the sacrum and neurovascular as well as intestinal structures may complicate the procedure during this approach. This requires knowledge regarding the normal anatomy of the presacral area to avoid the iatrogenic injuries. The aim of this study was to measure the distance between the sacrum and the structures anterior to it. Materials and methods  The measurements were performed on ten cadavers fixed with formaldehyde and ten MR imaging studies on individuals without any pathology in the presacral area. The distances between the sacrum and the presacral structures (i.e., middle and lateral sacral arteries, sympathetic trunks, internal iliac arteries and veins, and colon/rectum) were measured. Results  Cadaver study showed that the middle sacral artery was located on the right side in 55.0%, on the left side in 31.7%, and on the midline in the 13.3% of cases. The distance between the sacral midline and middle sacral artery was found to be 8.0 ± 5.4, 9.0 ± 4.9, 8.7 ± 6.0, 8.6 ± 6.4, and 4.7 ± 5.0 mm at the levels of S1–2, S2–3, S3–4, S4–5, and S5–coccyx, respectively. The distance between the sacral midline and the sympathetic trunk ranged between 22.4 ± 5.8 and 9.5 ± 3.2 mm in different levels between S1 and coccygeal level. The study also showed that the distance between the posterior wall of the intestine (colon/rectum) and the ventral surface of the sacrum can be as close as 11.44 ± 7.69 mm on MR images. Conclusion  This study showed that there was close distance between the sacral midline and the structures anterior to it. The close relationships, as well as the potential for anatomical variations, require the use of sacral and presacral imaging before presacral approach.     

Radiographic method to assess the prevalence of sacral spina bifida occulta

Spina bifida occulta of the sacrum is the most common type of spinal deformity. Many authors have published data on the frequency of spina bifida occulta, with varying results. Some possible reasons for this variability could include the differing methods used to gather data and differing ways of classifying the condition. This study attempts to develop an X-ray method to study sacral spina bifida occulta in a standardized fashion, using an angulated antero-posterior technique. This technique is then used to estimate the frequency of sacral spina bifida occulta in an Australian sample. The sacra of 53 cadavers were X-rayed and the level of closure of the sacral spinal canal recorded. The X-ray technique was validated by open dissection of six of the cadavers studied and was shown to be accurate to half a sacral segment. No sacra with a completely open sacral canal were found, two sacra (4%) were open from S2 down to S5 and ten sacra (19%) were open from S3 down to S5. The most common condition (43%) recorded was where S4 and S5 only were open. Eighteen cadavers (34%) showed only S5 open, and interestingly, no sacra were recorded as having the dorsal sacral arch completely closed. A study of a larger sample will follow using the validated X-ray technique.     

骶管的应用解剖学研究

目的为骶管阻滞麻醉提供解剖学依据。方法对180个成人干燥骶骨和30具成人尸体标本的骶管及骶骨背面邻近区域的有关结构进行形态学观察,并测量骶管裂孔及有关结构的径线。结果在干燥标本上,骶管后壁完整的有106例,占58.89%,骶管后壁有裂或孔约为39.44%,骶管裂孔形态以三角形多见,为41.11%,其次是长方形。不规则形或马蹄形;骶管裂孔高为(24.52±2.74)mm,底宽为(14.91±1.07)mm,孔尖矢径为(5.71±1.01)mm,孔尖至S2下缘距离为(32.41±0.59)mm;在成人尸体标本上,尾骨尖至两骶角连线中点的距离为(44.38±0.95)mm,裂孔尖至两髂后上棘连线中点的距离为(48.58±1.25)mm。结论根据解剖特点,骶管裂孔穿刺法明显优于骶管上端穿刺法和骶管后壁裂孔穿刺法。由于年龄。性别和个体差异等因素不相同,故临床上综合各种因素灵活运用麻醉方法。     

骶二椎弓根钉外进钉固定拧紧力与骶骨应变分布规律的研究

研究骶二椎弓根钉固定拧紧力与骶骨应变分布,为临床骶二椎弓根钉固定术提供生物力学参数。取正常国人新鲜尸体骶骨标本,以椎弓根钉内进钉法固定于骶二椎弓根,以小型力传感器与椎弓根钉固定装置连接,测量椎弓根钉的拧紧力,同时以动静态电阻应变仪对预先粘贴在四个椎弓根螺栓固定边缘部位和骶骨不同部位的应变片进行应变电测量。得出了椎弓根钉的最大拧紧力和S1,椎体、S2椎体、S3椎体正中线左侧和右侧应变值,还得出了s,左侧、S,右侧上关节突关节面部位及S1、2左侧,S1、2右侧骶后孔连线与骶中间嵴交点处应变值。说明骶二椎弓根钉术式符合生物力学原理。     

青少年骶骨骶髂螺钉钉道增龄变化的数字化评估

目的 通过数字化分析、测量青少年骶骨安全骨性螺钉钉道并观察钉道增龄变化的规律。 方法 收集160名10~17岁健康青少年志愿者骨盆CT扫描数据,三维重建测量S1、S2横向骶髂螺钉最优置钉通道的轴向狭窄处的宽度,测量S1、S2最优钉道经“骶骨经髂骨”（trans-sacral trans-iliac,TSTI）螺钉通道长度,测量S1、S2 TSTI通道投影长短轴长度并观察通道随年龄增长的变化规律。 结果 S1骶髂螺钉安全通道宽度,男性：左（8.96±2.02）mm,右（9.03±2.24）mm;女性：左（8.26±1.96）mm,右（8.37±2.11）mm。S1处TSTI螺钉长度,男性（141.25±5.92）mm,女性（134.37±5.68）mm。S2骶髂螺钉安全通道宽度,男性：左（6.49±1.98）mm,右（6.38±1.88）mm;女性：左（6.21±1.76）mm,右（6.14±1.55）mm。S2处TSTI螺钉长度,男性（126.28±4.94）mm,女性（122.31±5.13）mm。 结论 青少年在S1、S2均存在影像学上安全的骨性髂骶螺钉通道,随着年龄的增长,通道投影长短轴比例逐渐加大,高度的增长速度快于宽度的增长速度。     

骶二椎弓根钉内进钉固定拔出力与骶骨应变分布规律的实验研究

目的研究骶二椎弓根钉固定拔出力与骶骨应变分布规律,为临床骶二椎弓根钉固定术提供生物力学参数。方法取正常人新鲜尸体骶骨标本,以椎弓根钉内进钉方法固定于骶二椎弓根,于电子万能试验机上进行相应力学测试,并利用动静态电阻应变仪对预先粘贴在四个椎弓根螺栓固定边缘部位和骶骨不同部位的应变片进行测量。结果得出了椎弓根钉的最大拔出力为（514．5±9．4）N,发生在2号钉位置;最大应变发生在1号钉,其最大应变为（168．5±5．8）X10一。结论骶二椎弓根钉内进钉固定应变分布合理,有利于平衡和稳定。     

骶骨骨折后路横置钢板固定的影像解剖学研究

目的研究后路横置钢板固定骶骨骨折的可行性。方法临床采集60例成人正常骨盆CT数据(男30例,女30例),导入Mimics14.1行三维重建,用MedCAD模拟置钉,观测螺钉位置及毗邻,确定S1～4进钉点。测量钉道长度及其与水平面、冠状面及矢状面的夹角。解剖30侧成人尸体标本,观察进钉点毗邻。2具成人骨盆标本模拟置钉,经X线验证试验结果。结果男性内侧钉道长度S1为(32.78±2.10)mm、S2为(28.54±2.67)mm、S3为(18.54±1.86)mm、S4为(12.58±1.18)mm;女性内侧钉道长度S1为(31.18±2.52)mm、S2为(26.00±2.49)mm、S3为(16.79±2.09)mm、S4为(11.19±1.53)mm;男性外侧钉道长度S1为(35.78±1.88)mm、S2为(29.99±2.48)mm、S3为(22.53±2.21)mm、S4为(13.62±1.58)mm;女性外侧钉道长度S1为(33.03±2.23)mm、S2为(29.34±3.87)mm、S3为(21.00±2.12)mm、S4为(12.72±1.83)mm;验证结果满意。结论后路横置钢板可固定骶骨纵形或斜行骨折,从形态学上具有可行性。     

A novel technique for sacropelvic fixation using image-guided sacroiliac screws: a case series and biomechanical study

In this study, we sought to assess the safety and accuracy of sacropelvic fixation performed with image-guided sacroiliac screw placement using postoperative computed tomography and X-rays. The sacroiliac screws were placed with navigation in five patients. Intact specimens were mounted onto a six-degrees-of-freedom spine motion simulator. Long lumbosacral constructs using bilateral sacroiliac screws and bilateral S1 pedicle and iliac screws were tested in seven cadaveric spines. Nine sacroiliac screws were well-placed under an image guidance system (IGS); one was placed poorly without IGS with no symptoms. Both fixation techniques significantly reduced range of motion (P < 0.05) at L5–S1. The research concluded that rigid lumbosacral fixation can be achieved with sacroiliac screws, and image guidance improves its safety and accuracy. This new technique of image-guided sacroiliac screw insertion should prove useful in many types of fusion to the sacrum, particularly for patients with poor bone quality, complicated anatomy, infection, previous failed fusion and iliac harvesting.     

脊柱矫形后发生近端交界性后凸危险因素的荟萃分析

文题释义： 近端交界性后凸：是脊柱矫形术后出现的并发症之一,通常因手术近端内固定交界区的应力改变引起,是一种与脊柱融合相关的邻近节段疾病。 近端交界区后凸角：采用 Cobb 角测量法测量,它被定义为最上端固定椎体的下终板和上2个相邻椎体的上终板之间的后凸角,若该后凸角大于10°,且同术前相比增加10°以上,则认为发生了近端交界性后凸。 背景：对于实施脊柱畸形矫形的患者,近端交界性后凸是术后常见的并发症,可导致成年人和青少年脊柱畸形患者多种不良临床预后。因此,有必要对可能导致矫形术后患者发生近端交界性后凸的危险因素进行分析,以扩大对近端交界性后凸的认识并为预防其发生提供指导。 目的：通过荟萃分析评价影响脊柱畸形矫形术后发生近端交界性后凸畸形的危险因素。 方法：在PubMed、EMbase、Cochrane、中国知网和万方医学检索截止至2019年5月发表的公开文献,严格评价文献质量,根据纳入标准和排除标准选择文献,收集相关数据,使用RevMan 5.3软件统计分析相关数据,评估荟萃分析结果。 结果与结论：①共纳入26篇文献,总计4 498例患者,其中921例患者术后发生近端交界性后凸,经分析后显示脊柱矫形术后近端交界性后凸发生率为25%;②年龄,体质量指数,骨质疏松,手术椎体数量,最上端固定椎体至胸腰段(T₁₀-L₁),最下端固定椎体固定至骶骨/骨盆/髂骨,术后近端交界区后凸角、腰椎前凸角和矢状面垂直偏移,术前术后近端交界区后凸角变化、腰椎前凸角变化和矢状面垂直偏移变化,以上指标在近端交界性后凸患者和非近端交界性后凸患者之间差异有显著性意义(P < 0.05);③而性别、截骨、前后联合手术、术前近端交界区后凸角、术前腰椎前凸角在近端交界性后凸患者和非近端交界性后凸患者之间差异无显著性意义(P > 0.05);④该荟萃分析显示,非手术因素中高龄、体质量指数、骨质疏松;手术因素中固定节段> 5个椎体,最上端固定内固定至胸腰段,最下端固定至骶骨/骨盆/髂骨,术后近端交界区后凸角、腰椎前凸角、矢状面垂直偏移,术前术后近端交界区后凸角、腰椎前凸角、矢状面垂直偏移变化较大是近端交界性后凸发生的主要危险因素。可通过干预高危人群及手术方案的制定,降低近端交界性后凸的发生率。由于多种非手术因素和手术因素共同作用产生近端交界性后凸,仍需进行更严谨的流行病学研究为减少近端交界性后凸的发生提供可靠证据。 ORCID: 0000-0002-1890-0731(张健) 中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程     

骶髂关节前路钢板螺钉固定手术安全区的应用解剖学研究

目的　通过对骶髂关节周围解剖和CT重建进行研究,明确骶髂关节前路钢板螺钉固定的安全区。 方法　选15具成人尸体骨盆,做以下测量：L4、L5神经前支到骶髂关节线的水平距离及到骶骨翼的垂直距离;L4、L5神经根从椎间孔到真骨盆缘的长度及其中点直径;在CT冠状位二维重建中测量：骶髂关节切线与矢状面的夹角;骶髂关节骶骨侧宽度。 结果 L4、L5神经根从上到下距离骶髂关节线的距离逐渐减小,最宽处分别为（2.1±0.2）cm和（2.6±0.2）cm,最窄处分别为（1.2±0.2）cm和（1.5±0.2）cm;L4神经根距离骶骨面的垂直距离从上到下也是逐渐减少,最高处约10 mm,最低处则紧贴骨膜,L5神经根前支则全长紧贴于骨膜;从出椎间孔到真骨盆边缘L4神经根的长度为（7.4±0.8）cm,其中点直径为（2.7±0.8）　mm;L5神经根的长度为（3.9±0.5）cm,其中点直径为（7.3±1.4）mm;CT重建中观察结果：骶髂关节面与矢状面的角度约为30度;骶髂关节线到椎管外侧缘的距离从上到下逐渐减少,最宽处3.3 cm,最窄处2.3 cm;到椎间孔外侧缘的距离较为恒定,约2 cm;　结论　骶髂关节前路钢板螺钉的安全区：钢板应置于骶髂关节的中、上部,上钢板向骶骨侧剥离不超过2.5 cm,下钢板向骶骨剥离不超过1.5 cm,螺钉内倾30°植入。     

Cross-sectional study of the neural ossification centers of vertebrae C1–S5 in the human fetus

Purpose

An understanding of the normal evolution of the spine is of great relevance in the prenatal detection of spinal abnormalities. This study was carried out to estimate the length, width, cross-sectional area and volume of the neural ossification centers of vertebrae C1–S5 in the human fetus.

Materials and methods

Using the methods of CT (Biograph mCT), digital-image analysis (Osirix 3.9) and statistics (the one-way ANOVA test for paired data, the Kolmogorov–Smirnov test, Levene’s test, Student’s t test, the one-way ANOVA test for unpaired data with post hoc RIR Tukey comparisons) the size for the neural ossification centers throughout the spine in 55 spontaneously aborted human fetuses (27 males, 28 females) at ages of 17–30 weeks was studied.

Results

The neural ossification centers were visualized in the whole pre-sacral spine, in 74.5 % for S1, in 61.8 % for S2, in 52.7 % for S3, and in 12.7 % for S4. Neither male–female nor right–left significant differences in the size of neural ossification centers were found. The neural ossification centers were the longest within the cervical spine. The maximum values referred to the axis on the right, and to C5 vertebra on the left. There was a gradual decrease in length for the neural ossification centers of T1–S4 vertebrae. The neural ossification centers were the widest within the proximal thoracic spine and narrowed bi-directionally. The growth dynamics for CSA of neural ossification centers were found to parallel that of volume. The largest CSAs and volumes of neural ossification centers were found in the C3 vertebra, and decreased in the distal direction.

Conclusions

The neural ossification centers show neither male–female nor right–left differences. The neural ossification centers are characterized by the maximum length for C2–C6 vertebrae, the maximum width for the proximal thoracic spine, and both the maximum cross-sectional area and volume for C3 vertebra. There is a sharp decrease in size of the neural ossification centers along the sacral spine. A decreasing sequence of values for neural ossification centers along the spine from cervical to sacral appears to parallel the same direction of the timing of ossification. The quantitative growth of the neural ossification centers is of potential relevance in the prenatal diagnosis and monitoring of achondrogenesis, caudal regression syndrome, diastematomyelia and spina bifida.