Occupant and crash characteristics in thoracic and lumbar spine injuries resulting from motor vehicle collisions

Background context

Motor vehicle collisions (MVC) are a leading cause of thoracic and lumbar (T and L) spine injuries. Mechanisms of injury in vehicular crashes that result in thoracic and lumbar fractures and the spectrum of injury in these occupants have not been extensively studied in the literature.

Purpose

The objective was to investigate the patterns of T and L spine injuries after MVC; correlate these patterns with restraint use, crash characteristics, and demographic variables; and study the associations of these injuries with general injury morbidity and fatality.

Study design/setting

The study design is a retrospective study of a prospectively gathered database.

Patient sample

Six hundred thirty-one occupants with T and L (T1–L5) spine injuries from 4,572 occupants included in the Crash Injury Research and Engineering Network (CIREN) database between 1996 and 2011 were included in this study.

Outcome measures

No clinical outcome measures were evaluated in this study.

Methods

The CIREN database includes moderate to severely injured occupants from MVC involving vehicles manufactured recently. Demographic, injury, and crash data from each patient were analyzed for correlations between patterns of T and L spine injuries, associated extraspinal injuries and overall injury severity score (ISS), type and use of seat belts, and other crash characteristics. T and L spine injuries patterns were categorized using a modified Denis' classification to include extension injuries as a separate entity.

Results

T and L spine injuries were identified in 631 of 4,572 vehicle occupants, of whom 299 sustained major injuries (including 21 extension injuries) and 332 sustained minor injuries. Flexion-distraction injuries were more prevalent in children and young adults and extension injuries in older adults (mean age, 65.7 years). Occupants with extension injuries had a mean body mass index of 36.0 and a fatality rate of 23.8%, much higher than the fatality rate for the entire cohort (10.9%). The most frequent extraspinal injuries (Abbreviated Injury Scale Grade 2 or more) associated with T and L spine injuries involved the chest (seen in 65.6% of 631 occupants). In contrast to occupants with major T and L spine injuries, those with minor T and L spine injuries showed a strikingly greater association with pelvic and abdominal injuries. Occupants with minor T and L spine injuries had a higher mean ISS (27.1) than those with major T and L spine injuries (25.6). Among occupants wearing a three-point seat belt, 35.3% sustained T and L spine injuries, whereas only 11.6% of the unbelted occupants sustained T and L spine injuries. Three-point belted individuals were more likely to sustain burst fractures, whereas two-point belted occupants sustained flexion-distraction injuries most often and unbelted occupants had a predilection for fracture-dislocations of the T and L spines. Three-point seat belts were protective against neurologic injury, higher ISS, and fatality.

Conclusions

T and L spine fracture patterns are influenced by the age of occupant and type and use of seat belts. Despite a reduction in overall injury severity and mortality, seat belt use is associated with an increased incidence of T and L spine fractures. Minor T and L spine fractures were associated with an increased likelihood of pelvic and abdominal injuries and higher ISSs, demonstrating their importance in predicting overall injury severity. Extension injuries occurred in older obese individuals and were associated with a high fatality rate. Future advancements in automobile safety engineering should address the need to reduce T and L spine injuries in belted occupants.     

Synthesis of [3α‐3H] 17α‐Hydroxy pregnenolone and [3α‐3H] Pregnenolone

For the first time, [3α‐³H] 17α‐hydroxy pregnenolone (1) was synthesized through a multiple step sequence. The presence of [3β‐³H] isomer in RP‐HPLC purified product was identified by tritium NMR. The [3β‐³H] isomer was then separated from [3α‐³H] 17α‐hydroxy pregnenolone with chiralPAK AD‐H column. [3α‐³H] pregnenolone (2) was synthesized from commercial available 5‐pregnen‐3,20‐dione in one step with an improved procedure.     

HPSEC法测定注射用头孢匹胺钠中聚合物的含量

目的建立HPSEC法对头孢匹胺钠中聚合物进行测定。方法采用TSKgelG2000SWXL色谱柱（7．8mmLD×30cm）;检测波长为254nm;以外标法测定聚合物的含量,并与头孢聚合物测定的文献方法进行比较。结果在该条件下头孢匹胺钠和聚合物峰分离良好;本法的定量限（S／N=9）为9ng;检测限（S／N=3）为3ng,本法测定的聚合物含量高于文献方法的结果。结论本方法简便、准确度高、灵敏度高,可有效的测定头孢匹胺钠中聚合物的含量。     

HPLC法测定右旋兰索拉唑控释胶囊中左旋异构体含量

目的：建立HPLC法对右旋兰索拉唑控释胶囊中左旋和右旋异构体进行拆分并测定其中左旋异构体含量。方法：采用Chiral-AGP手性柱（4.6 mm×150 mm,5μm）;流动相为乙腈-pH 6.0磷酸盐缓冲液（10∶90）;流速0.5 mL·min-1;柱温30℃;检测波长285 nm;进样量20μL。结果：兰索拉唑左旋和右旋异构体之间的分离度为3.0,左旋异构体的线性范围为0.51~5.10μg·mL-1（r=0.9996）,检测限为2.52 ng,平均回收率（n=9）为98.4%。结论：该方法操作简便,结果准确,可用于右旋兰索拉唑控释胶囊中左旋异构体的含量测定。     

Evaluation of Dynamic Properties of Sodium-Alginate-Reinforced Soil Using A Resonant-Column Test

Ground reinforcement is a method used to reduce the damage caused by earthquakes. Usually, cement-based reinforcement methods are used because they are inexpensive and show excellent performance. Recently, however, reinforcement methods using eco-friendly materials have been proposed due to environmental issues. In this study, the cement reinforcement method and the biopolymer reinforcement method using sodium alginate were compared. The dynamic properties of the reinforced ground, including shear modulus and damping ratio, were measured through a resonant-column test. Also, the viscosity of sodium alginate solution, which is a non-Newtonian fluid, was also explored and found to increase with concentration. The maximum shear modulus and minimum damping ratio increased, and the linear range of the shear modulus curve decreased, when cement and sodium alginate solution were mixed. Addition of biopolymer showed similar reinforcing effect in a lesser amount of additive compared to the cement-reinforced ground, but the effect decreased above a certain viscosity because the biopolymer solution was not homogeneously distributed. This was examined through a shear-failure-mode test.     

Determining Adsorption Parameters of Potentially Contaminant-Releasing Materials Using Batch Tests with Differing Liquid-Solid Ratios

Adsorption parameters such as the distribution coefficient are required to predict the release behavior of contaminants using advection-dispersion models. However, for potentially contaminant-releasing materials (PCMs) such as dredged sludge and coal ash, these parameters cannot be obtained by conventional adsorption tests. This study developed a method to determine adsorption parameters for PCMs from a set of batch tests conducted in parallel as a function of the liquid-solid ratio (LS-parallel test). This LS-parallel test was performed on sandy soil derived from marine sediment using liquid-solid ratios from 1 to 300 L/kg. The water-contact time was also changed from 10 min to 28 d to elucidate the kinetics or equilibrium of contaminants released from the sample. Adsorption parameters were successfully obtained if the substance was under adsorption control. A column percolation test was performed to confirm the effectiveness of the obtained parameters. Good agreements were observed for SO₄²⁻ and B, but discrepancies remained for other substances such as F⁻ and As suggesting that improvements are necessary in both the LS-parallel test procedure and the advection-dispersion model.     

生姜中六六六、滴滴涕、三氯杀螨醇的CARB／NH2固相萃取柱-气相色谱测定法

目的建立CARR／NH2固相萃取柱前处理,气相色谱法测定生姜中六六六、滴滴涕、三氯杀螨醇的方法。方法样品切碎用乙腈提取、脱水、浓缩,CARB／NH：固相萃取柱净化,最后氮吹定容采用ECD检测器测定。结果该方法能很好地将4种六六六异构体、4种滴滴涕异构体和三氯杀螨醇分离开,各类同分异构体的加标回收率在85．7％-104．2％之间,相对测量不确定度小于10％,最低检出量为0．01ng。结论该方法能同时测定生姜中六六六、滴滴涕和三氯杀螨醇残留量,有较高的回收率。     

经后路全脊椎切除治疗结核治愈型胸腰椎角状后凸畸形

【摘要】 目的：探讨经后路全脊椎切除术治疗结核治愈型胸腰椎角状后凸畸形的有效性和安全性。方法：2008年１月~2012年１月,采用后路全脊椎切除手术治疗17例结核治愈型胸腰椎角状后凸畸形患者,男5例,女12例,年龄9～40岁,平均23.6岁。病程16～122个月,平均37.5个月,其中2例病例既往有经肋横突入路结核病灶清除手术史。病灶累及1～2个椎体8例,≥3个椎体9例。后凸畸形顶椎位于胸椎（T5～T10）5例,胸腰段（T11～L1）10例,腰椎2例。术前Cobb角60°～90°者13例,＞90°者4例,最大为102°,平均81.3°±12.8°。所有患者均可见驼背畸形,无低热、盗汗等结核中毒症状。术前、术后和末次随访时分别测量患者后凸Cobb角,并评估神经功能ASIA分级。结果：本组病例手术均顺利完成,手术时间330～450min,平均364min;术中出血量1600～2500ml,平均2218ml;术中输血1000～2000ml,平均1863ml。术中2例患者出现胸膜破裂,及时予以修补,经观察未发现气胸或血气胸。所有病例术后伤口均一期愈合,无窦道形成,内固定未见松动,未见神经功能加重者。术后Cobb角矫正至10°～28°,平均17.3°±3.6°,较术前明显改善（P<0.01）,后凸畸形矫正率平均为（68.7±6.5）%;术后随访13～34个月,平均18.7个月,末次随访时后凸Cobb角10°～32°,平均20.6°±3.9°,较术后平均丢失3.3°（P>0.05）,但与术前相比仍有明显改善（P<0.01）;植骨融合时间5～9个月,平均6.5个月;术前神经功能为D级的5例患者,4例恢复到E级,另1例仍为D级,但后凸畸形及局部疼痛已明显好转。结论：经后路全脊椎切除可安全有效地用于结核治愈型胸腰椎角状后凸畸形的矫形手术。