Pneumorrhachis (PR) is defined as presence of free air in the spinal canal. Traumatic PR is very rare, and its exact incidence and pathogenesis is unknown. A comprehensive literature search was performed using the PubMed, Cochrane Library, Google Scholar and Scopus databases to identify articles relevant to traumatic PR published till January 2023. A total of 34 resources were selected for inclusion in this narrative review. Traumatic PR can be classified anatomically into epidural and intradural types. In the epidural type, air is present peripherally in the spinal canal and the patients are usually asymptomatic. In contrast, in intradural PR, air is seen centrally in the spinal canal and patients present with neurological symptoms, and it is a marker of severe trauma. It is frequently associated with traumatic pneumocephalus, skull fractures or thoracic spine fracture. Computed tomography (CT) is considered to be the diagnostic modality of choice. Epidural PR is self-limited and patients are generally managed conservatively. Patients with neurological symptoms or persistent air in spinal canal require further evaluation for a potential source of air leak, with a need for surgical intervention. Differentiation between epidural and intradural PR is important, because the latter is an indication of severe underlying injury. CT imaging of the entire spine must be performed to look for extension of air, as well as to identify concomitant skull, torso or spinal injuries Most patients are asymptomatic and are managed conservatively, but a few may develop neurological symptoms that need further evaluation and management.

Pneumorrhachis (PR) refers to free air in the spinal canal. We aim to describe a case report and conduct a systematic review focused on the clinical presentation, diagnosis, and management of traumatic PR. We conducted a language-restricted PubMed, SciELO, Scopus, and Ovid database search for traumatic PR cases published till June 2019. Categorical variables were assessed by Fisher's exact test. In addition to our reported index case, there were 82 articles (96 individual cases) eligible for meta-analysis according to our inclusion/exclusion criteria. Eighty per cent of patients had blunt trauma, while 17% had penetrating injuries. Thirty-four per cent of cases were extradural PR, 21% intradural PR, and unreported PR type in 43%. Nine per cent of patients presented with symptoms directly attributed to PR: sensory radiculopathy (2%), motor radiculopathy (1%), and myelopathy (6%). CT had a 100% sensitivity for diagnosing PR, MRI 60%, and plain radiograph 48%. Concurrent injuries reported include pneumocephalus (42%), pneumothorax (36%), spine fracture (27%), skull fracture (27%), pneumomediastinum (24%), and cerebrospinal fluid leak (14%). PR was managed conservatively in every case, with spontaneous resolution in 96% on follow-up (median = 10 days). Prophylactic antibiotics for meningitis were given in 13% PR cases, but there was no association with the incidence of meningitis (overall incidence: 3%; prophylaxis group (0%) vs non-prophylaxis group (4%) (p = 1)). Occasionally, traumatic PR may present with radiculopathy or myelopathy. Traumatic PR is almost always associated with further air distributions and/or underlying injuries. There is insufficient evidence to support the use of prophylactic antibiotic in preventing meningitis in traumatic PR patients.

Abdominal injuries resulting from vehicle crashes can be significant, in particular when undetected. In this study, abdominal injuries for occupants involved in frontal impacts were assessed using crash and medical data.

Injury rates and patterns were first assessed with respect to thoracic injuries. A statistical analysis was then conducted to predict abdominal injury outcome using 18 covariate variables, including 4 vehicle, 4 demographic, and 10 morphomic, derived from computed tomography (CT) scans. More than 260,000 logistic regression models were fitted using all possible variable combinations. The models were ranked using the Akaike information criterion (AIC) and combined through the model-averaging approach to produce the optimal predictive model. The performance of the models was then assessed using the area under the curve (AUC).

The rate of serious thoracic injury was 2.49 times higher than the rate of abdominal injury. The associated odds ratio was 2.31 (P <.01). These results suggest a strong association between serious abdominal and thoracic injuries. The optimal model AUC was 0.646 when using solely vehicle data, 0.696 when combining vehicle and demographic data, 0.866 when combining vehicle and morphomic data, and 0.879 when combining vehicle, demographic, and morphomic data. These results suggest that morphomic variables better predict abdominal injury outcomes than demographic variables. The most important morphomics variables included visceral fat area, trabecular bone density, and spine angulation.

This study is the first to combine vehicle, demographic, and anatomical data to predict abdominal injury rates in frontal crashes.

Safety belts are the most important safety system in motor vehicles and should always be worn to prevent serious injury. The purpose of this study, using Crash Injury Research Engineering Network (CIREN) data, was to assess occupant and crash factors associated with minor contusions and abrasions caused by the safety belt (commonly referred to as seat belt signs) and their association with serious intra-abdominal trauma.

CIREN data were used to determine which factors are associated with seat belt signs. Occupant variables (age, gender, body mass index, proper safety belt use, driver v. passenger status) and crash variables (crash type, crash severity, and airbag deployment) were compared for occupants with seat belt sign who had serious (AIS 3 or greater) intra-abdominal injury and those who did not have intra-abdominal injuries. Adjusted odds ratios were used to quantify the independent association between predictive factors for serious intra-abdominal injury for occupants with seat belt signs.

Of 1539 occupants included in this study, 419 had a positive seat belt signs. Of those 419 occupants, 100 had serious intra-abdominal injury and 319 did not. Being in the passenger seat position increased the odds, whereas front airbag deployment and frontal impact were associated with decreased odds of serious intra-abdominal injury for occupants with seat belt signs. However, multivariate analysis showed only that being a passenger increased the odds (OR = 2.64) of having serious intra-abdominal injury for occupants with seat belt signs when other factors, including crash severity and type of impact, were controlled for in the analysis.

Seat belt signs remain an important physical finding in patients with intra-abdominal injury following motor vehicle crashes. Front seat passengers presenting with seat belt signs were more than twice as likely to sustain intra-abdominal injury; thus, emergency physicians and trauma surgeons should be aware of passenger position when evaluating a seat belt sign.

Chance-type fractures are subtle unstable injuries that are often associated with intraabdominal injuries. CT-based observations made during routine interpretations revealed involvement of a burst component to this fracture pattern and a clue on the transaxial images to its presence. The purpose of this review was to determine how often these features occurred in a retrospective study of a large sample because these findings influence diagnosis and management.

A retrospective review of all patients identified from the University of Maryland Shock Trauma Center trauma registry and IDXRad system diagnosed with flexion-distraction injuries of the thoracolumbar spine over an 8-year period was performed. Three trauma radiologists assessed the admission spinal radiographs, CT studies with multiplanar images, and available MRI examinations. Imaging findings were confirmed by consensus. Abdominopelvic CT studies and surgical reports were reviewed for evidence and type of intraabdominal injury. A literature review of previous similar series was performed.

Fifty-three patients were identified for inclusion in the study. Associated intraabdominal injury occurred in 40% and most commonly involved the bowel and mesentery. A close examination of the fracture patterns on CT revealed that a burst-type fracture with posterior cortex buckling or retropulsion was a common finding (48%). Also, serial transaxial CT images often (76%) showed a gradual loss of definition of the pedicles that we refer to as the "dissolving pedicle" sign. The study showed that the horizontally oriented fracture planes through the posterior elements can often be recognized radiographically, but these fractures can be very subtle.

Intraabdominal injuries occurred in 40% of flexion-distraction thoracolumbar fractures in our study cohort, which is slightly lower than previously reported. About half of the patients with this injury displayed a burst-type component that could have a significant influence on surgical management. The dissolving pedicle sign can assist in recognition of this often subtle injury on transaxial CT.

To evaluate retrospectively the magnetic resonance (MR) imaging features of Chance-type flexion-distraction injuries.

The authors' institutional review board does not require its approval or patient informed consent for retrospective studies. Imaging data were reviewed retrospectively for 24 patients (15 male, nine female; mean age, 28 years; range, 9-71 years) who had sustained radiographically typical Chance-type flexion-distraction injuries. The posterior vertebral body height remained unchanged or was increased in these patients. Two radiologists recorded a variety of bone and soft-tissue abnormalities seen with MR imaging. Based on consensus, the documented findings were sequentially analyzed to determine their frequencies.

Combined bone and soft-tissue injuries occurred in 23 (96%) of 24 patients, were more common than soft-tissue damage alone (one [4%] of 24 patients), and occurred primarily at the thoracolumbar junction. Contiguous vertebral injury was seen in 20 (83%) of 24 patients, usually in the form of anterosuperior vertebral endplate edema, while noncontiguous injury occurred in eight (33%) of 24 patients. Extensive subcutaneous and paraspinal muscle edema was seen in all patients and extended over several segments. Posterior osteoligamentous complex disruption also occurred in all patients. Horizontally oriented fractures of the posterior neural arches produced an MR imaging pattern that the authors call the sandwich sign, which consists of linear hemorrhage framed by marrow edema. This sign was seen in 12 (50%) of 24 patients. In seven (29%) of 24 patients, a fracture line extending from a damaged pedicle was seen to exit through the contralateral posterosuperior aspect of the vertebral body, with extension of the fracture fragments into the spinal canal.

A spectrum of features is discernible with MR imaging in Chance-type injuries.

To evaluate the crashworthiness of commercially available hardware that attaches seat surfaces to the wheelchair frame.

A low cost static crashworthiness test procedure that simulates a frontal impact motor vehicle crash.

Safety testing laboratory.

Eleven unique sets of drop-hook hardware made of carbon steel (4), stainless steel (4), and aluminum (3).

Replicated seat-loading conditions associated with a 20g/48 kph frontal impact. Test criterion for seat loading was 16,680 N (3750 lb).

Failure load and deflection of seat surface.

None of the hardware sets tested met the crashworthiness test criterion. All failed at less than 50% of the load that seating hardware could be exposed to in a 20g/48 kph frontal impact. The primary failure mode was excessive deformation, leading to an unstable seat support surface.

Results suggest that commercially available seating drop hooks may be unable to withstand loading associated with a frontal crash and may not be the best option for use with transport wheelchairs.

A method was developed to study the biomechanical response of the lumbar motion segment (Functional Spinal Unit, FSU) under a dynamic (transient) load in flexion. In order to inflict flexion-distraction types of injuries (lap seat-belt injuries) different load pulses were transferred to the specimen by means of a padded pendulum. The load response of the specimen was measured with a force and moment transducer. The flexion angulation and displacements were determined by means of high-speed photography. Two series of tests were made with ten specimens in each and with two different load pulses: one moderate load pulse (peak acceleration 5 g, rise time 30 ms, duration 150 ms) and one severe load pulse (peak acceleration 12 g, rise time 15 ms, duration 250 ms). The results showed that the moderate load pulse caused residual permanent deformations at a mean bending moment of 140 Nm and a mean shear force of 430 N at a mean flexion angulation of 14 degrees. The severe load pulse caused evident signs of failure of the segments at a mean bending moment of 185 Nm and a mean shear force of 600 N at a mean flexion angulation of 19 degrees. Significant correlations were found between the load response and the size of the specimen, as well as between the load response and the bone mineral content (BMC) in the two adjacent vertebrae. Comparisons with lumbar spine response to static flexion-shear loading indicated that the specimens could withstand higher bending moments before injury occurred during dynamic loading, but the deformations at injury tended to be smaller for dynamic loading.

Spinal column and cord injuries are rare in children and adolescents, and few reports in the literature that specifically address this subject. A retrospective review of medical records and radiographs of 57 patients was undertaken to identify age-related injury patterns, the incidence of neurologic deficits, and the presence of associated injuries. The most common injury in very young patients was spinal cord injury without radiographic abnormality or spinal cord injury with non-contiguous radiographic abnormality. The most common injury in older children was flexion-distraction injury, often associated with intraabdominal trauma. Adolescents tended to sustain injury patterns similar to adults.

Twenty six patients with seat belt injuries of the lumbar spine were admitted into the Spinal Cord Injury Unit of the University Hospital, University of British Columbia, in the past 10 years. Four patients with pure ligamentous injuries were primarily treated surgically. Sixteen patients were treated with closed methods with a Stryker frame followed by a body cast or brace. Significant angulation with spinal deformity occurred in 6 patients. The common factor of failure of closed treatment was the inadequate reduction of initial angulation. When the initial angulation at the fracture site was adequately reduced, closed methods were associated with satisfactory results with no serious disability seen in long term follow-up. Open reduction with fixation with compression rods or wiring and fusion invariably leads to good results. It is recommended that patients with seat belt fractures of the lumbar spine may be treated by a closed method provided good reduction is obtained initially, otherwise open reduction and posterior fusion is more preferable.

In this paper several concepts of surgical treatment of thoracic and lumbar fractures are reviewed. Most classifications of these fractures are primarily radiologic, but pathomechanical aspects are very important as these guide the insight into and the rationale of the different modes of treatment. The segment of movement can be considered biomechanically as a three-dimensional system, built up from two rings, linked together at five functional points of support. Our principal mode of surgical therapy after closed reduction by halo-femoral traction is anterolateral decompression, stabilization and grafting to induce fusion. In suitable cases, a dorsal or posterolateral approach and instrumentation can be combined with ventral methods. By using the primary anterolateral approach, one can reduce malalignment at the site where it is needed. Decompression can be carried out where it is truly necessary. One can give support within the segment of movement at the logical place from a biomechanical point of view: the weight bearing part, i.e., the anterior ring. By excision of the injured bony and ligamentous tissue, motion in the damaged segment of movement is eliminated, the original height is restored by grafting, and at the same time the load-bearing capacity of the fractured area is repaired. By applying Zielke instrumentation one can compress the grafts in accordance with modern views on fracture treatment. This "philosophy" is illustrated with case histories and a decision making flow chart.

The causes of commonly occurring diagnostic oversights in the multiple injured patient are reviewed. A systematic approach to the multiple injured or unconscious patient is offered which includes a standard series of radiographs, "a trauma survey", and knowledge of commonly associated injuries. The identification of certain skeletal injuries should automatically suggest the possibility of other associated skeletal, visceral, or vascular injuries. Oversights could be significantly reduced by obtaining a standard series of radiographs, specifically looking for evidence of commonly missed injuries and always considering the possibility of frequently associated injuries.

A case of fatal cervical dislocation in a front seat passenger restrained by a retractable three-point belt is described. A biomechanical and technical analysis is given.

In 34 post-mortem examinations of car occupants wearing seat belts and killed in straight or oblique head-on collisions, a thorough investigation of the spine was performed. The autopsy results were correlated with the findings in the cars in order to reconstruct the events when the occupant's body struck the interior of the car. In 2 cases the victims had worn lap belts, in 15 cases shoulder belts and in 17 cases combined shoulder-lap belts (three-point belts). In victims involved in head-on collisions while wearing lap belts, fractures of the neural arch of the axis were found which were probably due to flexion of the neck pivoting round the lower part of the impacting face and simultaneous stretching of the neck. Severe injuries to the cervical spine in those victims wearing shoulder belts were mainly due to the occupant sliding under the belt which then caught the neck and mandible. Such injuries were also caused by the impact of the head against forward parts of the car. In those wearing shoulder-lap belts injuries to the upper part of the cervical spine resulted from the impact of the head against internal parts of the car. When a slight impact of the head occurred minor injuries to the lower cervical spine were seen. Injuries to the thoracolumbar spine in the cases examined were the consequence of a violent extension between the upper part of the trunk held back by the shoulder belt and the pelvis restrained by the lap belt or by the knees striking the fascia panel. In front seat occupants this extension can be increased if either rear seat occupants without belts or heavy objects on the rear seat are projected forwards against their backs.

Two hundred and forty-four motor car occupants involved in road traffic accidents, who sustained injuries sufficiently severe to require admission to hospital, have been investigated in order to assess the value of seat belts. The results indicated that the use of seat belts significantly reduced the mortality and the number of severe, multiple and facial injuries.