Flexion-distraction Injuries Research Articles

Management of a Polytrauma Patient with L4 Bony Fracture-Dislocation, Multi-Level L1-L3 Flexion-Distraction (Bony Chance) Injuries, Lateral Compression III Pelvic Injury, and Lower Extremity Fractures

This is the first documented case of a neurologically impaired polytrauma patient with multiple bony Chance injuries, a windswept pelvis, and lower extremity fractures. The patient was a male miner in his mid-30s who incurred multiple injuries in his lower extremities and spine. He initially consulted at a secondary care facility but transferred hospitals for further management. The index surgery was done four days post-injury (beyond 72 hours) and included open reduction, stabilization of the affected spinal segments with pedicle screws/rods from the lumbar spine to both sacroiliac joints. The patient was discharged after having to undergo debridement for a surgical site infection of the spine, and definitive fixation of the right femur and left tibial plateau. At one year follow-up, the patient was ambulatory without assistance without other complications. In dealing with polytrauma patients with multiple spinal, pelvic, and lower extremity fractures, early treatment is recommended to prevent future complications.

Response to "Nonoperative Management of Isolated Thoracolumbar Flexion Distraction Injuries".

Response to "Nonoperative Management of Isolated Thoracolumbar Flexion Distraction Injuries".

Letter to Editor: Nonoperative Management of Isolated Thoracolumbar Flexion Distraction Injuries: A Single-Center Study.

Letter to Editor: Nonoperative Management of Isolated Thoracolumbar Flexion Distraction Injuries: A Single-Center Study.

Nonoperative Management of Isolated Thoracolumbar Flexion Distraction Injuries: A Single-Center Study.

Nonoperative management is an appealing option for purely transosseous thoracolumbar flexion-distraction injuries given the prospects of osseous healing and restoration of the posterior tension band complex. This study seeks to examine differences in outcomes following flexion-distraction injuries after operative and nonoperative management. This study reviews all patients at a single Level 1 trauma center from 2004 to 2022 with AO Spine B1 thoracolumbar injuries treated operatively vs nonoperatively. Inclusion criteria were age greater than 16 years, computed tomography-confirmed transosseous flexion-distraction injuries, and at least 3 months of follow-up with available imaging. The primary outcome assessed was a change in local Cobb angles, with secondary outcomes consisting of complications, time to return to work, and need for subsequent operative fixation. Initial Cobb angles in the operative (n = 14) vs nonoperative group (n = 13) were -5° and -13°, respectively (P = 0.225), indicating kyphotic alignment in both cohorts. We noted a significant difference in Cobb angles between cohorts at first follow-up (2.6° and -13.9°, P = 0.015) and within the operative cohort from presentation to first follow-up (P = 0.029). At the second follow-up, there was no significant difference in Cobb angles between cohorts (3.6° and -12.6°, P = 0.07). No significant differences were noted in complication rates (P = 1), time to return to work (P = 0.193), or resolution of subjective back pain (P = 0.193). No crossover was noted. Nonoperative management of minimally displaced transosseous flexion-distraction injuries is a safe alternative to surgery. Patient factors, such as compliance with follow-up, and location of the injury should be factored into the surgeon's management recommendation. Overall, no significant differences in outcomes and complications were noted following nonoperative management of AO Spine B1 injuries, indicating the potential for these injuries to be managed conservatively.

The Thoracolumbar Injury Classification and Severity Score Appropriately Predicts Treatment in Children Aged 10 and Under.

Retrospective cohort study. This study aims to assess the validity of the Thoracolumbar Injury Classification and Severity Score (TLICS) in patients ≤10 years-old. TLICS is a validated measure developed to help facilitate clinical decision-making regarding thoracolumbar spinal trauma in adults. Studies examining the utility of TLICS in children skew towards older pediatric patients, where the spine's biomechanical properties are more similar to adults. Due to differences in a pre-adolescent spine compared to a more mature, adolescent spine, it is unclear if TLICS can be applied to younger patients. A single center spine trauma registry was queried for patients ≤10 with an acute, traumatic thoracolumbar fracture treated at a level-1 pediatric trauma center between 2006 and 2020. Test characteristics and Receiver-Operator Curve were used to evaluate TLICS based on TLICS <4=nonsurgical treatment and TLICS >4=surgery recommendation. We identified 94 patients with traumatic thoracolumbar fractures (surgical=20; non-surgical=74). Despite TLICS-suggested operative management in 28 patients with TLICS>4, 9 (32.1%) were initially treated non-operatively. All patients who deviated from TLICS-suggested treatment had flexion-distraction injuries (FDI). Sensitivity, specificity, positive predictive value, and negative predictive value were 100%, 89.2%, 70.4%, and 100%, respectively. The receiver operating characteristic curve demonstrated strong diagnostic ability of TLICS in predicting need for surgery (area under the curve: 0.97, F1-score: 0.86). TLICS score <4 showed strong validity and is highly specific in predicting non-operative management for patients ≤10 years-old with thoracolumbar fractures. However, TLICS >4 has more limited specificity in indicating the necessity for surgical intervention, as many FDIs were successfully treated without surgery. Additional factors other than TLICS score may need to be considered for these more severe injuries to optimize management in this age group.

Surgeon variation: a south african spinal pathology treatment survey.

To investigate variation in treatment decisions among spine surgeons in South Africa and the association between surgeon characteristics and the treatment they select. We surveyed 79 South African spine surgeons. We presented four vignettes (cervical spine distractive flexion injury, lumbar disc herniation, degenerative spondylolisthesis with stenosis, and insufficiency fracture) for them to assess and select treatments. We calculated the index of qualitative variation (IQV) to determine the degree of variability within each vignette. We used Fisher's exact, and Kruskal-Wallis tests to assess the relationships between surgeons' characteristics and their responses per vignette. We compared their responses to the recommendations of a panel of spine specialists. IQVs showed moderate to high variability for cervical spine distractive flexion injury and insufficiency fracture and slightly lower levels of variability for lumbar disc herniation and degenerative spondylolisthesis with stenosis. This confirms the heterogeneity in South African spine surgeons' management of spinal pathologies. The surgeon characteristics associated with their treatment selection thatwere important were caseload, experience and training, and external funding. Also, 19% of the surgeons selected a treatment option that the Panel did not support. The findings make a case for evaluating patient outcomes and costs to identify value-based care. Such research would help countries that are seeking to contract with providers on value. Greater uniformity in treatment and easily accessible outcomes reporting would provide guidance for patients. Further investment in training and participation in fellowship programs may be necessary, along with greater dissemination of information from the literature.

Fracture-dislocations of the subaxial cervical spine

Fracture-dislocations of the subaxial cervical spine are rare yet potentially devastating injuries often associated with high-energy trauma. These inherently unstable injuries frequently lead to neurologic compromise, necessitating urgent operative intervention. This review provides a comprehensive overview of subaxial cervical spine fracture-dislocations, addressing their epidemiology, anatomy, and classification systems. Classification schemes including Allen and Ferguson, Cervical Spine Injury Severity Score (CSISS), Subaxial Cervical Spine Injury Classification System (SLIC), and AO Spine Subaxial Cervical Spine Injury Classification System are discussed. Prompt recognition and management of these injuries is critical in optimizing long-term functional and neurologic outcomes. Rates of neurologic injury can exceed 50 %, with distractive flexion injuries and bilateral facet injuries often presenting with higher ASIA grades and lower neurologic recovery potential. Minimizing time to reduction is the most important factor in optimizing neurologic outcomes in these injury patterns. We discuss both closed and open reduction methods, timing considerations, technical pearls, and potential complications associated with each strategy. We also discuss the diagnosis and management of concurrent acute disk herniations, the role of advanced imaging, and the debated utility of pre-reduction MRI. Many subaxial cervical fracture-dislocations necessitate surgical intervention, which can be approached from an anterior, posterior, or combined approach. Although no standard surgical treatment algorithm exists, we discuss surgical options and situations where a preferred approach may exist. Selection of the approach depends on injury characteristics and surgeon preference, and there are no clearly defined surgical recommendations based on injury pattern.

Spine Injuries Sustained After Falls While Crossing the U.S.-Mexico Border.

This study is to report the demographics, incidence, and patterns of spinal injuries associated with border crossings resulting from a fall from a significant height. A retrospective cohort study was performed at a Level I trauma center from January 2016 to December 2021 to identify all patients who fell from a significant height while traversing the U.S.-Mexico border and were subsequently admitted. A total of 448 patients were identified. Of the 448 patients, 117 (26.2%) had spine injuries and 39 (33.3%) underwent operative fixation. Females had a significantly higher incidence of spine injuries (60% vs. 40%; p < 0.00330). Patients with a spine fracture fell from a higher median fall height (6.1 vs. 4.6 m; p < 0.001), which resulted in longer median length of stay (LOS; 12 vs. 7 days; p < 0.001), greater median Injury Severity Score (ISS; 20 vs. 9; p < 0.001), and greater relative risk (RR) of ISS >15 (RR = 3.2; p < 0.001). Patients with operative spine injuries had significantly longer median intensive care unit (ICU) LOS than patients with non-operative spine injuries (4 vs. 2 days; p < 0.001). Patients with spinal cord injuries and ISS >15 sustained falls from a higher distance (median 6.1 vs. 5.5 m) and had a longer length of ICU stay (median 3 vs. 0 days). All patients with operative spine injuries had an ISS >15 relative to 50% of patients with non-operative spine injuries (median ISS 20 vs. 15; p < 0.001). Patients with spine trauma requiring surgery had a higher incidence of head (RR = 3.5; p 0.0353) and chest injuries (RR = 6.0; p = 0.0238), but a lower incidence of lower extremity injuries (RR = 0.5; p < 0.001). Thoracolumbar injuries occurred in 68.4% of all patients with spine injuries. Patients with operative spine injuries had a higher incidence of burst fracture (RR = 15.5; p < 0.001) and flexion-distraction injury (RR = 25.7; p = 0.0257). All patients with non-operative spine injuries had American Spinal Injury Association (ASIA) D or E presentations, and patients with operative spine injuries had a higher incidence of spinal cord injury: ASIA D or lower at time of presentation (RR = 6.3; p < 0.001). Falls from walls in border crossings result in significant injuries to the head, spine, long bones, and body, resulting in polytrauma casualties. Falls from higher height were associated with a higher frequency and severity of spinal injuries, greater ISS, and longer ICU length of stay. Operative spine injuries, compared with non-operative spine injuries, had longer ICU length of stay, greater ISS, and different fracture morphology. Spine surgeons and neurocritical care teams should be prepared to care for injuries associated with falls from height in this unique population.

Flexion–distraction injuries of the spine: Features of diagnostics, clinical picture, and results of surgical treatment of children

BACKGROUND: Flexiondistraction injuries of the spine result from high-energy trauma (traffic accidents and falls from a height). This type of injury is commonly found in the thoracolumbar junction. Among combined injuries in the presence of flexiondistraction fractures of the vertebral column, injuries of the chest or abdominal organs are often observed, which are crucial for patient survival, and their diagnostic measure is complex because of the severe and unstable conditions of the patients.&#x0D; AIM: To analyze a cohort of pediatric patients who underwent surgery for flexiondistraction injury of the spine.&#x0D; MATERIALS AND METHODS: We analyzed the data of clinical and instrumental studies and surgical outcomes of 28 pediatric patients (aged 217 years) with flexiondistraction injuries of the spine. The standard preoperative examination included clinical and laboratory studies, spondylography, multislice spiral computed tomography and magnetic resonance imaging of the damaged area, electrocardiography, and ultrasonography of the abdominal organs and kidneys. All patients underwent surgery for the correction and stabilization of traumatic spinal deformity with a multisupport metal structure and posterior local fusion. The analysis included an assessment of the mechanism of injury, concomitant injuries, time elapsed after the injury before admission to the hospital, level of the damaged segment, and treatment. Data were processed statistically using an online calculator. The nonparametric MannWhitney method was used.&#x0D; RESULTS: Catatrauma was the leading cause of injury in 50% of the patients, compared with traffic accidents in 36%. In 80% of the patients, spinal injury was localized at the thoracolumbar junction and lumbar spine. Moreover, 71% of the patients were transferred to the National Research Center for Childrens Orthopedics and Trauma Surgery for surgical treatment on the spine in the early stages after injury (up to 7 days), and 8 children (19%) were admitted within 1045 days (average 16 days). In 19 (68%) patients, in addition to spinal injury, concomitant injuries occurred, with skeletal trauma and injuries of the abdominal cavity organs as the most frequent. All patients achieved complete correction of the deformity at the level of the damaged segment.&#x0D; CONCLUSIONS: Flexiondistraction fractures of the spine in children are characterized by a high incidence of concomitant injuries, which dictates the need for a full examination to identify them and correctly interpret the data. The elimination of mechanical instability in the early stages in this type of injury can reduce the extent of fixation and contribute to the restoration of the physiological profile and disk apparatus of the spinal column.

Clinical Characteristics and Intraoperative Reduction Technique of Thoracolumbar Fractures Combined with Posterior Column Injury.

To analyse the clinical characteristics of thoracolumbar fractures combined with posterior column injury, and explore its intraoperative reduction technique with clinical efficacy. Descriptive study. Place and Duration of the Study: Department of Orthopaedics, Fuyang People's Hospital, Anhui, China, from December 2017 to 2021. A total of 60 patients met the inclusion criteria, they were divided into two categories according to injury mechanism and imaging characteristics: flexion-distraction injury (FDI) and burst fracture with lamina fracture (BFLF), and their clinical characteristics were analysed. All patients were treated with posterior pedicle screw internal fixation, and different intraoperative reduction methods were adopted for reduction. Measurements of anterior vertebral heights (AVH), local kyphotic angles (LKA), visual analog scale (VAS) and oswestry disability index (ODI) were evaluated preoperative, after operation, and the last follow-up. The two groups of thoracolumbar fractures combined with posterior column injury had different clinical characteristics, and there were significant differences in preoperative imaging related parameters (p<0.05). All patients in the two groups successfully completed the operation, and there were no direct complications related to the operation. The patients were followed up for 12-24 months. Compared with those before the operation, the AVH, LKA, VAS, and ODI immediately after the operation and at the last follow-up were significantly improved (p<0.05). Bone fusion was achieved in all patients. Careful and comprehensive preoperative clinical data analysis is the key to diagnosis of thoracolumbar fractures combined with posterior column injury. According to the type of fracture, reasonable selection of intraoperative reduction technique can obtain satisfactory clinical results. Burst fracture, Pedicle screw, Internal fixation, Thoracic, Lumbar.

Fracture Dislocation in the Cervical Spine – A Case Series Analysis of 32 Cases and Review of Literature

Abstract Complex cervical spine injuries result from road traffic accidents, fall from height, diving in the swimming pool, fall along with the ladder etc. This is a major cause of disability, morbidity and mortality and dependence. Most of these injuries are preventable by proper care, social reforms, teaching civic sense to students at an early age, adoption of safety measures while climbing heights, enforcement of traffic rules, building up of infrastructure, educating the people and mandatory emergency room service for the offenders. Fracture dislocations of the cervical spine mostly flexion distraction injuries. Dislocations can range from perched facets, unilateral facet dislocations to bilateral facet dislocations and spondyloptosis. These result in varying degrees of neurological deficit. The recovery of these patients depend on the initial magnitude of the injury, the safe transport of the victim to the trauma centre, careful management of the injuries and rehabilitation. Here a case series of 32 patients with varying degrees of fracture dislocations of the cervical spine are analyzed retrospectively.

Surgical outcome of locked facet in distractive flexion injury of the subaxial cervical spine: Single institution retrospective study.

The optimal surgical treatment for patients suffering from distractive flexion injury of the subaxial cervical spine with a locked facet (LF) is unknown. Closed reduction via an anterior or posterior approach is a treatment option for LF. We examined the surgical outcomes of patients treated for locked facet distractive flexion injury (LF-DFI) in this case series, with a particular emphasis on the surgical approach and reduction maneuver. We retrospectively analyzed the patients with distractive flexion injury of the subaxial cervical spine who underwent surgery at our hospital between November 2006 and April 2021. Patients who did not have facet subluxation or dislocation or those who achieved LF reduction prior to skin incision were excluded from this study. The patients were divided into 2 groups based on their initial approach, anterior or posterior approach. Perioperative clinical outcomes, including the American Spinal Cord Injury Association scale score, radiological changes, and complications were analyzed. This study enrolled 12 patients with LF-DFI. Four and 8 patients underwent the anterior and posterior approaches, respectively. The LF was reduced using an anterior approach with traction between the vertebral bodies in the anterior approach group and using a posterior approach with partial facetectomy in the posterior approach group. The preoperative American Spinal Cord Injury Association scale scores were as follows: A, 1 patient; B, 1 patient; C, 3 patients; D, 4 patients; and E, 3 patients. Nine patients showed no neurologic deterioration after surgery, whereas 2 had an aggravated neurologic status. Postoperatively, patients who underwent posterior open reduction did not exhibit worsened neurologic symptoms, whereas 2 patients who underwent the anterior approach showed worsened neurologic symptoms. At the final follow-up, all patients achieved radiological fusion, and no complications other than neurologic deterioration were identified. In terms of worsening postoperative neurologic status, a posterior approach using partial facetectomy for LF reduction is considered a safer surgical technique than an anterior approach. To avoid iatrogenic intraoperative cord injury, we recommend posterior approach in patients with LF-DFI.

Temporary Monosegmental Fixation Using Multiaxial Percutaneous Pedicle Screws for Surgical Management of Bony Flexion-Distraction Injuries of the Thoracolumbar Spine: A Technical Note.

The efficacy of minimally invasive surgeries for thoracolumbar flexion-distraction injuries (FDIs) has been reported, but those surgeries were monosegmental fusion surgeries of two adjacent vertebrae with bone grafts or temporary fixations using percutaneous pedicle screws (PPSs) that were at least bisegmental. Our idea was to fuse the fracture itself, not to fuse the fractured vertebra with an adjacent vertebra or to stabilize the fractured vertebra by bridging rostrally/caudally adjacent intact vertebrae, specifically when the displacement is minimal. This study aimed to present the surgical techniques of reduction and temporary monosegmental fixation of neurologically intact thoracolumbar bony FDIs using multiaxial PPSs, which can minimize the surgical invasiveness and preserve all motion segments, as well as report three cases treated with this procedure. When the fracture extended from the vertebral body to the spinous process at the same level, screws were placed into the fractured vertebra rostrally to the fracture along the rostral endplate, and the caudally adjacent vertebra was instrumented beyond the fracture line. When the fracture extended from the vertebral body to the spinous process of the rostrally adjacent vertebra, screws were placed into the fractured vertebra caudally to the fracture line, and the rostrally adjacent vertebra was instrumented. The kyphotic deformity was reduced through ligamentotaxis by using MPPSs in the rostral vertebra as rigid joysticks to apply direct buttress leverage to the rostral endplate. Intraoperative blood loss was minimal. The correction of kyphotic deformity and its durability were acceptable, and the segmental range of motion of the two affected vertebrae from flexion to extension was maintained after implant removal. This surgery can act as the least-invasive option for the management of thoracolumbar bony FDIs to allow early ambulation without external bracing and to preserve all the motion segments.

Rare case of real-time observation of paralytic deterioration after cervical dislocation in the hyperacute phase

BackgroundThere have been no prior reports of real-time detailed records leading to complete quadriplegia immediately after fracture dislocation in high-energy trauma. Here, we report a case of cervical dislocation in which the deterioration to complete motor paralysis (modified Frankel B1) and complete recovery (Frankel E) could be monitored in real time after reduction in the hyperacute phase.Case presentationA 65-year-old man was involved in a car accident and sustained a dislocation at the C5/6 level (Allen–Ferguson classification: distractive flexion injury stage IV). His paralysis gradually deteriorated from Frankel D to C 2 hours after the injury and from Frankl C to B 5 hours after the injury. His final neurological status immediately before reduction was Frankel B1 (complete motor paralysis with sensation only in the perianal region). Reduction was completed within 6 h and 5 min after injury, and spinal fusion was subsequently performed. The patient exhibited rapid motor recovery immediately after surgery, and was able to walk independently on postoperative day 14.ConclusionsThis case suggests that there is a mixture of cases in which the spinal cord has not been catastrophically damaged, even if the patient has complete motor paralysis. Prompt reduction has the potential to improve neurological function in such cases.

Chasing the Cup: A Comprehensive Review of Spinal Cord Injuries in Hockey.

Ice hockey is a high-speed sport with a high rate of associated injury, including spinal cord injury (SCI). The incidence of hockey-related SCI has increased significantly in more recent years. A comprehensive literature search was conducted with the PubMed, Medline, Google Scholar, and Web of Science databases using the phrases “hockey AND spinal cord injuries” to identify relevant studies pertaining to hockey-related SCIs, equipment use, anatomy, and biomechanics of SCI, injury recognition, and return-to-play guidelines.Fifty-three abstracts and full texts were reviewed and included, ranging from 1983 to 2021. The proportion of catastrophic SCIs is high when compared to other sports. SCIs in hockey occur most commonly from a collision with the boards due to intentional contact resulting in axial compression, as well as flexion-related teardrop fractures that lead to spinal canal compromise and neurologic injury. Public awareness programs, improvements in equipment, and rule changes can all serve to minimize the risk of SCI.Hockey has a relatively high rate of associated SCIs occurring most commonly due to flexion-distraction injuries from intentional contact. Further investigation into equipment and hockey arena characteristics as well as future research into injury recognition and removal from and return to play is necessary.

A Mechanistic Based Analysis of Clinicoradiological and Functional Outcome in C7-T1 Translational Injury

C7-T1 translational injuries are relatively rare, unstable, and usually associated with neurological impairment. We aim to analyze the C7-T1 translational injury based on Allen and Ferguson's classification and to highlight the clinicoradiologic and neurologic outcomes in these patients. Patients with C7-T1 translational injury were retrospectively analyzed and demographic data, mechanism, mode of injury, surgery details, and associated injuries were obtained. The initial neurologic status was recorded as American Spinal Injury Association (ASIA) grade. All the injuries were classified as per Allen and Ferguson classification and stage 4 compressive extension (CE) injury was further classified into stage 4a and stage 4b according to Rebich etal. Among 44 patients, the most common mechanism of injury was CE injury seen in 27 patients (61.4%) followed by distractive flexion (DF) in 16 patients (36.4%) and compressive flexion in 1 patient (2.2%). Neurologic deficit was noted in 14 of 27 patients (51.85%) with CE injury, which was less compared to 12 of 16 patients (75%) with DF injury. However, there was no significant difference in terms of neurologic recovery. One patient with standalone anterior fixation had implant loosening and underwent additional posterior fixation. We present the largest series of C7-T1 translational injuries in the literature to our best knowledge. CE injury is nearly 2 times more common than DF injury and is associated with a lower incidence of neurologic deficit and easier fracture reduction techniques. Staging the injury severity aids in better planning in terms of surgical approach and levels of fixation.

Contiguous-Level Unilateral Cervical Spine Facet Dislocation-A Report of a Less Discussed Subtype.

Unilateral facet dislocation of subaxial cervical spine trauma is characterized by dislocation of inferior facet of superior vertebra over the superior facet of inferior vertebra. The injury is due to high-velocity trauma and associated with instability of spinal column. Such unilateral facet dislocations occurring at multiple adjacent levels for some reason are not reported or studied frequently. We have reported two cases of multiple-level dislocation of unilateral facets managed in our hospital with a review of available literature. The injury occurs as one side of the motion segment translates and rotates around an intact facet on the contralateral side. The major mechanism of injury is distractive flexion injury with axial rotation component. The injury is associated with instability secondary to loss of the discoligamentous complex. In cases with multiple-level dislocations of unilateral cervical facets, there are multiple mechanisms associated with significant neurological injury and most of them succumb at the site of injury. Only three other cases are available in English language literature. The neurological outcome is invariably poor. Multiple-level facet dislocations of subaxial cervical spine are reported sparsely in literature. We suspect that due to high-velocity nature of these injuries, most of them succumb soon after injury and not often reported. This article reports two cases of contiguous-level unilateral facet dislocation of subaxial cervical spine with associated injuries and the outcomes with review of literature.

Fracture and Bilateral Facet Dislocation after Anterior Cervical Fusion in a Patient with a Distraction-Flexion Injury at the Lower Cervical Level

Fracture and Bilateral Facet Dislocation after Anterior Cervical Fusion in a Patient with a Distraction-Flexion Injury at the Lower Cervical Level

Risk Factors for Reduction of Facet Joint Dislocation by Preoperative Traction in Distractive-Flexion Injury of the Lower Cervical Spine

Risk Factors for Reduction of Facet Joint Dislocation by Preoperative Traction in Distractive-Flexion Injury of the Lower Cervical Spine

Cervical spine injury response to direct rear head impact

BackgroundDirect rear head impact can occur during falls, road accidents, or sports accidents. They induce anterior shear, flexion and compression loads suspected to cause flexion-distraction injuries at the cervical spine. However, post-mortem human subject experiments mostly focus on sled impacts and not direct head impacts. MethodsSix male cadavers were subjected to a direct rear head impact of 3.5 to 5.5 m/s with a 40 kg impactor. The subjects were equipped with accelerometers at the forehead, mouth and sternum. High-speed cameras and stereography were used to track head displacements. Head range of motion in flexion-extension was measured before and after impact for four cadavers. The injuries were assessed from CT scan images and dissection. FindingsMaximum head rotation was between 43 degrees and 78 degrees, maximum cranial-caudal displacement between −12 mm and − 196 mm, and antero-posterior displacement between 90 mm and 139 mm during the impact. Four subjects had flexion-distraction injuries. Anterior vertebral osteophyte identification showed that fractures occurred at adjacent levels of osteophytic bridges. The other two subjects had no anterior osteophytes and suffered from C2 fracture, and one subject also had a C1-C2 subluxation. C6-C7 was the most frequently injured spinal level. InterpretationAnterior vertebral osteophytes appear to influence the type and position of injuries. Osteophytes would seem to provide stability in flexion for the osteoarthritic cervical spine, but to also lead to stress concentration in levels adjacent to the osteophytes. Clinical management of patients presenting with osteophytes fracture should include neck immobilization and careful follow-up to ensure bone healing.