Incidence, epidemiology, and occupational outcomes of thoracolumbar fractures among U.S. Army aviators

The I-PREDICT 50th Percentile Male Warfighter Finite Element Model: Development and Validation of the Thoracolumbar Spine

Military personnel are commonly at risk of lower back pain and thoracolumbar spine injury. Human volunteers and postmortem human subjects have been used to understand the scenarios where injury can occur and the tolerance of the warfighter to these loading regimes. Finite element human body models (HBMs) can accurately simulate the mechanics of the human body and are a useful tool for understanding injury. In this study, a HBM thoracolumbar spine was developed and hierarchically validated as part of the Incapacitation Prediction for Readiness in Expeditionary Domains: an Integrated Computational Tool (I-PREDICT) program. Constitutive material models were sourced from literature and the vertebrae and intervertebral discs were hexahedrally meshed from a 50th percentile male CAD dataset. Ligaments were modeled through attaching beam elements at the appropriate anatomical insertion sites. 94 simulations were replicated from experimental PMHS tests at the vertebral body, functional spinal unit (FSU), and regional lumbar spine levels. The BioRank (BRS) biofidelity ranking system was used to assess the response of the I-PREDICT model. At the vertebral body level, the I-PREDICT model showed good agreement with experimental results. The I-PREDICT FSUs showed good agreement in tension and compression and had comparable stiffness values in flexion, extension, and axial rotation. The regional lumbar spine exhibited "good" biofidelity when tested in tension, compression, extension, flexion, posterior shear, and anterior shear (BRS regional average = 1.05). The validated thoracolumbar spine of the I-PREDICT model can be used to better understand and mitigate injury risk to the warfighter.

Functional Recovery Following Early Kyphoplasty Versus Conservative Management in Stable Thoracuolumbar Fractures in Parachute Jumpers: A Randomized Clinical Trial

STUDY DESIGN

A randomized clinical trial.

OBJECTIVE

To compare the functional recovery between early kyphoplasty and conservative care in paratroopers with stable thoracolumbar fractures.

SUMMARY OF BACKGROUND DATA

Treatment of traumatic stable thoracolumbar fractures in young individuals is still a debate. Conservative management and kyphoplasty are options of therapy. But enough data are not available for supporting each.

METHODS

We included 70 paratroopers with stable thoracolumbar fractures (A1 and A2 classification according to AOSpine thoracolumbar spine injury classification system) presenting <60 days after trauma and hyperintensity in T2-weighted magnetic resonance imaging. Old fractures and those requiring fixation were excluded. Patients were randomly assigned to 2 study groups to undergo percutaneous balloon kyphoplasty (n=34) or conservative care (n=36) by applying orthosis for 2 months. Patients were followed for 12 months and were evaluated clinically using visual analogue scale (VAS) and Oswestry disability index (ODI).

RESULTS

The baseline characteristics were comparable between 2 study groups. The VAS score and ODI decreased significantly in both study groups after 12 months of treatment. The VAS score was significantly lower in kyphoplasty group after the intervention (P<0.001), 1 month (P<0.001), 3 months (P<0.001), 6 months (P<0.001), and 12 months (P<0.001) after the intervention. In addition, the ODI was significantly lower after the intervention (P<0.001), 1 month (P<0.001), 3 months (P<0.001), 6 months (P<0.001), and 12 months (P<0.001) after the intervention. Kyphoplasty was associated with shorter duration of returning to parachuting (P<0.001) and shorter duration of absence from work (P<0.001).

CONCLUSIONS

Early kyphoplasty in stable thoracolumbar fractures after parachute jumping is associated with less pain, better functional recovery, less days of absence from work, and shorter duration of returning to parachuting.

Perioperative morbidity and mortality after lumbar trauma in the elderly

OBJECT Traumatic fractures of the thoracolumbar spine are common injuries, accounting for approximately 90% of all spinal trauma. Lumbar spine trauma in the elderly is a growing public health problem with relatively little evidence to guide clinical management. The authors sought to characterize the complications, morbidity, and mortality associated with surgical and nonsurgical management in elderly patients with traumatic fractures of the lumbar spine. METHODS Using the National Sample Program of the National Trauma Data Bank, the authors performed a retrospective analysis of patients ≥ 55 years of age who had traumatic fracture to the lumbar spine. This group was divided into middle-aged (55-69 years) and elderly (≥ 70 years) cohorts. Cohorts were subdivided into nonoperative, vertebroplasty or kyphoplasty, noninstrumented surgery, and instrumented surgery. Univariate and multivariable analyses were used to characterize and identify predictors of medical and surgical complications, mortality, hospital length of stay, ICU length of stay, number of days on ventilator, and hospital discharge in each subgroup. Adjusted odds ratios, mean differences, and associated 95% CIs were reported. Statistical significance was assessed at p < 0.05, and the Bonferroni correction for multiple comparisons was applied for each outcome analysis. RESULTS Between 2003 and 2012, 22,835 people met the inclusion criteria, which represents 94,103 incidents nationally. Analyses revealed a similar medical and surgical complication profile between age groups. The most prevalent medical complications were pneumonia (7.0%), acute respiratory distress syndrome (3.6%), and deep venous thrombosis (3%). Surgical site infections occurred in 6.3% of cases. Instrumented surgery was associated with the highest odds of each complication (p < 0.001). The inpatient mortality rate was 6.8% for all subjects. Multivariable analyses demonstrated that age ≥ 70 years was an independent predictor of mortality (OR 3.16, 95% CI 2.77-3.60), whereas instrumented surgery (multivariable OR 0.38, 95% CI 0.28-0.52) and vertebroplasty or kyphoplasty (OR 0.27, 95% CI 0.17-0.45) were associated with decreased odds of death. In surviving patients, both older age (OR 0.32, 95% CI 0.30-0.34) and instrumented fusion (OR 0.37, 95% CI 0.33-0.41) were associated with decreased odds of discharge to home. CONCLUSIONS The present study confirms that lumbar surgery in the elderly is associated with increased morbidity. In particular, instrumented fusion is associated with periprocedural complications, prolonged hospitalization, and a decreased likelihood of being discharged home. However, fusion surgery is also associated with reduced mortality. Age alone should not be an exclusionary factor in identifying surgical candidates for instrumented lumbar spinal fusion. Future studies are needed to confirm these findings.

Three Cases of Spine Fractures after an Airplane Crash

While injuries to the spine after an airplane crash are not rare, most crashes result in fatal injuries. As such, few studies exist that reported on spine fractures sustained during airplane accidents. In this report, we demonstrate three cases of spine fractures due to crash landing of a commercial airplane. Three passengers perished from injuries after the crash landing, yet most of the passengers and crew on board survived, with injuries ranging from minor to severe. Through evaluating our three spine fracture patients, it was determined that compression fracture of the spine was the primary injury related to the airplane accident. The first patient was a 20-year-old female who sustained a T6-8 compression fracture without neurologic deterioration. The second patient was a 33-year-old female with an L2 compression fracture, and the last patient was a 49-year-old male patient with a T8 compression fracture. All three patients were managed conservatively and required spinal orthotics. During the crash, each of these patients were subjected to direct, downward high gravity z-axis (Gz) force, which gave rise to load on the spine vertically, thereby causing compression fracture. Therefore, new safety methods should be developed to prevent excessive Gz force during airplane crash landings.

Does usage of a parachute in contrast to free fall prevent major trauma?: a prospective randomised-controlled trial in rag dolls

PURPOSE

It is undisputed for more than 200 years that the use of a parachute prevents major trauma when falling from a great height. Nevertheless up to date no prospective randomised controlled trial has proven the superiority in preventing trauma when falling from a great height instead of a free fall. The aim of this prospective randomised controlled trial was to prove the effectiveness of a parachute when falling from great height.

METHODS

In this prospective randomised-controlled trial a commercially acquirable rag doll was prepared for the purposes of the study design as in accordance to the Declaration of Helsinki, the participation of human beings in this trial was impossible. Twenty-five falls were performed with a parachute compatible to the height and weight of the doll. In the control group, another 25 falls were realised without a parachute. The main outcome measures were the rate of head injury; cervical, thoracic, lumbar, and pelvic fractures; and pneumothoraxes, hepatic, spleen, and bladder injuries in the control and parachute groups. An interdisciplinary team consisting of a specialised trauma surgeon, two neurosurgeons, and a coroner examined the rag doll for injuries. Additionally, whole-body computed tomography scans were performed to identify the injuries.

RESULTS

All 50 falls-25 with the use of a parachute, 25 without a parachute-were successfully performed. Head injuries (right hemisphere p = 0.008, left hemisphere p = 0.004), cervical trauma (p < 0.001), thoracic trauma (p < 0.001), lumbar trauma (p < 0.001), pelvic trauma (p < 0.001), and hepatic, spleen, and bladder injures (p < 0.001) occurred more often in the control group. Only the pneumothoraxes showed no statistically significant difference between the control and parachute groups.

CONCLUSIONS

A parachute is an effective tool to prevent major trauma when falling from a great height.

Estudo clínico epidemiológico das fraturas da coluna vertebral

OBJETIVO: Realizar um levantamento epidemiológico das fraturas da coluna vertebral. MÉTODOS: Estudo de revisão de prontuário, retrospectivo analisando dados clínicos e epidemiológicos no período de 1991 a 2010. Foram avaliados dados como: idade, sexo, procedência, escala de Frankel admissional, mecanismo de trauma, tipo de fratura, tratamento e complicações, nos prontuários de 1.917 pacientes submetidos a tratamento de fraturas da coluna vertebral. O teste do qui-quadrado foi utilizado para comparação entre as variáveis discretas e o teste t Student foi utilizado no caso de variáveis contínuas, adotando níveis de significância de p < 0,05. RESULTADOS: A maioria dos pacientes era do gênero masculino (85,2%), média de idade de 34 anos, procedência urbana (69,2%), sendo o mecanismo de trauma a queda de altura (40,4%). Quando a causa for mergulho em águas rasas, está associada a lesões na região cervical, pacientes mais jovens e tende a produzir déficit neurológico. As fraturas isoladas aconteceram em 75,6% dos casos, afetando mais o nível L1 (11,4%), sendo que o tratamento cirúrgico foi indicado em 88,2%, sem complicações pós-operatórias na maioria dos casos (61,7%). CONCLUSÃO: Os autores sugerem mudanças principalmente na área habitacional, com campanhas educacionais preventivas e orientações para jovens que gostam de fazer atividades recreativas como mergulho em água rasa.

The effect of vehicle protection on spine injuries in military conflict

BACKGROUND CONTEXT

To evaluate the effect of critical time periods in vehicle protection on spine injuries in the Global War on Terror.

PURPOSE

To characterize the effect of method of movement on and around the battlefield during Operation Enduring Freedom and Operation Iraqi Freedom from 2001 to 2009 in terms of its impact on the incidence and severity of spinal fractures sustained in combat.

STUDY DESIGN/SETTING

Retrospective study.

PATIENT SAMPLE

Mounted and dismounted American servicemembers who were injured during combat.

METHODS

Extracted medical records of servicemembers identified in the Joint Theater Trauma Registry from October 2001 to December 2009. Methods of movement were defined as mounted or dismounted. Two time periods were compared. Cohorts were created for 2×2 analysis based on method of movement and the time period in which the injury occurred. Time period 1 and 2 were separated by April 1, 2007, which correlates with the initial fielding of the modern class of uparmored fighting vehicles with thickened underbelly armor and a V-shaped hull. Our four comparison groups were Dismounted in Time Period 1 (D1), Dismounted in Time Period 2 (D2), Mounted in Time Period 1 (M1), and Mounted in Time Period 2 (M2).

RESULTS

In total, 1,819 spine fractures occurred over the entire study period. Four hundred seventy-two fractures (26%) were sustained in 145 servicemembers who were mounted at the time of injury, and 1,347 (74%) were sustained by 404 servicemembers who were dismounted (p<.0005). The incidence of fractures in the dismounted cohort (D1+D2) was significantly higher than in the mounted cohort (M1+M2) in both time periods (D1 vs. M1, 13.75 vs. 3.95/10,000 warrior-years [p<.001] and D2 vs. M2, 11.15 vs. 4.89/10,000 warrior-years [p<.0001]). In both the mounted and dismounted groups, the thoracolumbar (TL) junction was the most common site of injury (36.1%). Fractures to the TL junction (T10-L3) increased significantly from Time Period 1 to 2 (34% vs. 40% of all fractures, respectively, p=.03). Thoracolumbar fractures were significantly more severe in that there were more Arbeitsgemeinschaft fur Osteosynthesefragen/Magerl Type A injuries versus all TL fractures, 1.75 versus 2.68/10,000 or 27% of all spine fractures in Time Period 1 versus 40% in Time Period 2 (p=.007). Furthermore, there were significantly fewer minor fractures (spinous process and transverse process fractures) (p<.0001). In Time Period 2, significantly more TL spine fractures were classified as major fractures, according to the Denis classification system, in both the mounted and dismounted groups; M1 group, 61 of 226 (27%) versus the M2 group, 86 of 246 (34%) (p<.0005) and 173 of 786 (22%) in the D1 group versus 193 of 561 (34%) in the D2 group. The spinal cord injury (SCI) incidence did not change in the mounted groups in Time Period 1 (7 of 71, 9.9%) versus Time Period 2 (7 of 74, 9.5%) (p=.935). In the dismounted groups, SCI actually decreased from D1 (55 of 228, 24%) to D2 (28 of 176, 16%) (p=.0428).

CONCLUSIONS

The incidence of spine fractures and SCI is significantly higher in dismounted operations. The data suggest that current uparmored vehicles convey greater protection against spinal fracture compared with dismounted operations in which servicemembers are engaged on foot, outside their vehicles. The TL junction is at greatest risk for spine fractures sustained in mounted and dismounted combat operations. Recently, the incidence of TL fractures, especially severe fractures, has significantly increased in mounted operations. Although there has been an increased incidence of TL spine fractures, in context of the number of servicemembers deployed in support of Operation Enduring Freedom/Operation Iraqi Freedom, these severe fractures still represent a relatively rare event.

Gene-modified adult stem cells regenerate vertebral bone defect in a rat model

Vertebral compression fractures (VCFs), the most common fragility fractures, account for approximately 700,000 injuries per year. Since open surgery involves morbidity and implant failure in the osteoporotic patient population, a new minimally invasive biological solution to vertebral bone repair is needed. Previously, we showed that adipose-derived stem cells (ASCs) overexpressing a BMP gene are capable of inducing spinal fusion in vivo. We hypothesized that a direct injection of ASCs, designed to transiently overexpress rhBMP6, into a vertebral bone void defect would accelerate bone regeneration. Porcine ASCs were isolated and labeled with lentiviral vectors that encode for the reporter gene luciferase (Luc) under constitutive (ubiquitin) or inductive (osteocalcin) promoters. The ASCs were first labeled with reporter genes and then nucleofected with an rhBMP6-encoding plasmid. Twenty-four hours later, bone void defects were created in the coccygeal vertebrae of nude rats. The ASC-BMP6 cells were suspended in fibrin gel (FG) and injected into the bone void. A control group was injected with FG alone. The regenerative process was monitored in vivo using microCT, and cell survival and differentiation were monitored using tissue specific reporter genes and bioluminescence imaging (BLI). The surgically treated vertebrae were harvested after 12 weeks and subjected to histological and immunohistochemical (against porcine vimentin) analyses. In vivo BLI detected Luc-expressing cells at the implantation site over a 12-week period. Beginning 2 weeks postoperatively, considerable defect repair was observed in the group treated with ASC-BMP6 cells. The rate of bone formation in the stem cell-treated group was two times faster than that in the FG-treated group, and bone volume at the end point was 2-fold compared to the control group. Twelve weeks after cell injection the bone volume within the void reached the volume measured in native vertebrae. Immunostaining against porcine vimentin indicated that the ASC-BMP6 cells contributed to new bone formation. Here we show the potential of injections of BMP-modified ASCs to repair vertebral bone defects in a rat model. Our results could pave the way to a novel approach for the biological treatment of traumatic and osteoporosis-related vertebral bone injuries.

Thoracolumbar vertebral fractures in Sweden: an analysis of 13,496 patients admitted to hospital

National Longitudinal data of thoracolumbar fracture incidence, trends or mortality rates are lacking. The correlation between admissions and operations of thoracolumbar vertebral fractures has not been investigated. The aim of our nationwide population-based epidemiological study was to analyse the incidence, admissions, operations, and case fatality rate among patients with thoracolumbar vertebral fractures admitted to hospital in Sweden. The Swedish Hospital Discharge Register (SHDR) and the Cause of Death Register (CDR) were linked to determine the incidence of surgical interventions, trends, characteristics of the patients, and case fatality rate for thoracolumbar vertebral fractures based on comprehensive national data. The annual incidence of thoracolumbar fractures was on average 30 per 100,000 inhabitants and did not change considerably during the study period. Among patients younger than 60 years of age the annual incidence was 13 per 100,000 and was twice as high in men compared to women. The proportion operated on was 15%. In the age-group 60 years and older the majority were women. In this group two percent were operated on. However, males were operated on twice as often as women. The 90-day case-fatality rate after surgery was 1.4%. This information may assist health care providers in health care planning. Moreover, these data can also be used for power calculations when planning future clinical studies.

The reliability of nonreconstructed computerized tomographic scans of the abdomen and pelvis in detecting thoracolumbar spine injuries in blunt trauma patients with altered mental status

BACKGROUND

Computerized tomography, traditionally utilized to evaluate and detect visceral abdominal and pelvic injuries in multiply injured patients with altered mental status, also has been useful for detecting thoracolumbar spine fractures and dislocations. The purpose of the present study was to test the reliability of nonreconstructed computerized tomography of the abdomen and pelvis as a screening tool for thoracolumbar spine injuries in blunt trauma patients with altered mental status.

METHODS

The study consisted of fifty-nine consecutive patients with altered mental status who were admitted to a Level-II trauma center. Each patient had a nonreconstructed computerized tomographic scan of the abdomen and pelvis (5-mm slices), and of the chest when indicated, as well as anteroposterior and lateral radiographs of the thoracolumbar spine. Reconstructed computerized tomographic scans dedicated to the spine (< or =2-mm slices) were completed. With use of the reconstructions as the gold standard, sensitivity and specificity with 95% confidence intervals were calculated to assess the diagnostic accuracy of using the nonreconstructed computerized tomographic scans and the radiographs.

RESULTS

Reconstructions of the spine detected seventy-two thoracolumbar spine fractures, whereas nonreconstructed computerized tomographic scans of the abdomen and pelvis detected fifty-eight and those of the chest detected sixteen. With use of the reconstructions as the standard, computerized tomography of the chest, abdomen, and pelvis had a sensitivity of 89% (95% confidence interval, 65% to 96%) and a specificity of 85% (95% confidence interval, 65% to 96%) for the detection of all fractures, compared with 37% and 76% for plain radiographs, respectively. Computerized tomography of the chest, abdomen, and pelvis was 100% sensitive and specific for the detection of whether a patient had any fracture at all, whereas radiographs were 54% sensitive and 86% specific. No fractures that were missed on nonreconstructed computerized tomography required surgery or other interventions.

CONCLUSIONS

Nonreconstructed computerized tomography detected fractures of the thoracolumbar spine more accurately than plain radiographs did and is recommended for the diagnosis of thoracolumbar spine fractures in acute trauma patients with altered mental status. Reconstructions do not need to be ordered unless an abnormality that is found on the nonreconstructed computerized tomographic scan needs additional elucidation.

Surgical treatment of traumatic fractures of the thoracic and lumbar spine: a systematic review of the literature on techniques, complications, and outcome

STUDY DESIGN

A systematic review of the literature, pertaining surgical treatment of traumatic thoracic and lumbar spine fractures, was performed.

OBJECTIVES

To provide information on surgical techniques for traumatic spine fracture management, their respective performance and complication rates, based on previously published information.

SUMMARY OF BACKGROUND DATA

The treatment of traumatic fractures of the thoracic and lumbar spine remains controversial. There is insufficient evidence in the literature to choose between the various surgical options. In absence of conclusive studies, a systematic review can be an alternative to obtain more convincing information.

METHODS

Full-text papers from 1970 until 2001 were included if strict inclusion criteria were met. Five surgical subgroups were recognized: posterior short-segment (PS), posterior long-segment (PL), reports on both posterior short- and long-segment (PSL), anterior (A), and anterior combined with posterior (AP) techniques. Clearly defined and generally accepted parameters were scored and subsequently analyzed. The preoperative injury severity of the surgical groups was compared. The neurologic, radiologic, and functional outcome and complications of all groups were assessed.

RESULTS

A total of 132 papers, the majority being retrospective case-series, were included representing 5,748 patients. The preoperative injury severity revealed an inequality between the subgroups. Partial neurologic deficits had the potential to resolve irrespective of treatment choice. None of the five techniques used was able to maintain the corrected kyphosis angle. The functional outcome after surgery seems to be better than generally believed. Complications are relatively rare.

CONCLUSIONS

In general, surgical treatment of traumatic spine fractures is safe and effective. Surgical techniques can only be compared using randomized controlled trials.

Parachute use to prevent death and major trauma related to gravitational challenge: systematic review of randomised controlled trials

OBJECTIVES

To determine whether parachutes are effective in preventing major trauma related to gravitational challenge.

DESIGN

Systematic review of randomised controlled trials.

DATA SOURCES

Medline, Web of Science, Embase, and the Cochrane Library databases; appropriate internet sites and citation lists.

STUDY SELECTION

Studies showing the effects of using a parachute during free fall.

MAIN OUTCOME MEASURE

Death or major trauma, defined as an injury severity score > 15.

RESULTS

We were unable to identify any randomised controlled trials of parachute intervention.

CONCLUSIONS

As with many interventions intended to prevent ill health, the effectiveness of parachutes has not been subjected to rigorous evaluation by using randomised controlled trials. Advocates of evidence based medicine have criticised the adoption of interventions evaluated by using only observational data. We think that everyone might benefit if the most radical protagonists of evidence based medicine organised and participated in a double blind, randomised, placebo controlled, crossover trial of the parachute.