Objectives. Loss of motion following spine segment fusion results in increased strain in the adjacent motion segments. However, to date, studies on the biomechanics of the cervical spine have not assessed the role of coupled motions in the lumbar spine. Accordingly, we investigated the biomechanics of the cervical spine following cervical fusion and lumbar fusion during simulated whiplash using a whole-human finite element (FE) model to simulate coupled motions of the spine. Methods. A previously validated FE model of the human body in the driver-occupant position was used to investigate cervical hyperextension injury. The cervical spine was subjected to simulated whiplash exposure in accordance with Euro NCAP (the European New Car Assessment Programme) testing using the whole human FE model. The coupled motions between the cervical spine and lumbar spine were assessed by evaluating the biomechanical effects of simulated cervical fusion and lumbar fusion. Results. Peak anterior longitudinal ligament (ALL) strain ranged from 0.106 to 0.382 in a normal spine, and from 0.116 to 0.399 in a fused cervical spine. Strain increased from cranial to caudal levels. The mean strain increase in the motion segment immediately adjacent to the site of fusion from C2-C3 through C5-C6 was 26.1% and 50.8% following single- and two-level cervical fusion, respectively (p = 0.03, unpaired two-way t-test). Peak cervical strains following various lumbar-fusion procedures were 1.0% less than those seen in a healthy spine (p = 0.61, two-way ANOVA). Conclusion. Cervical arthrodesis increases peak ALL strain in the adjacent motion segments. C3-4 experiences greater changes in strain than C6-7. Lumbar fusion did not have a significant effect on cervical spine strain. Cite this article: H. Huang, R. W. Nightingale, A. B. C. Dang. Biomechanics of coupled motion in the cervical spine during simulated whiplash in patients with pre-existing cervical or lumbar spinal fusion: A Finite Element Study. Bone Joint Res 2018;7:28–35. DOI: 10.1302/2046-3758.71.BJR-2017-0100.R1

Background. A cautious outlook towards neck injuries is the norm to avoid missing cervical spine injuries. Consequently there has been an increased use of cervical spine radiography. The Canadian Cervical Spine rule was proposed to reduce the unnecessary use of cervical spine radiography in alert and stable patients. Our aim was to see whether applying the Canadian Cervical Spine rule reduced the need for cervical spine radiography without missing significant cervical spine injuries. Methods. This was a retrospective study conducted in 2 hospitals. 114 alert and stable patients who had cervical spine radiographs done for suspected neck injuries were included in the study. Data on patient demographics, Canadian Cervical Spine rule, cervical spine radiography results and further visits after discharge were recorded. Results. 14 patients were included in the high risk category according to the Canadian Cervical Spine rule. 100 patients were assessed according to the low risk category. If the Canadian Cervical Spine rule was applied, there was a significant reduction in cervical spine radiographs (p<0.001) as 86/100 patients (86%) in the low risk category would not have needed cervical spine radiograph. 2/100 patients who had significant cervical spine injuries would have been identified when the Canadian Cervical Spine rule was applied. Conclusion. Applying the Canadian Cervical Spine rule for neck injuries in alert and stable patients reduced the use of cervical spine radiographs without missing out significant cervical spine injuries. This relates to reduction in radiation exposure to patients and cost benefits

Background: A cautious outlook towards neck injuries has been the norm to avoid missing cervical spine injuries. Consequently there has been an increased use of cervical spine radiography. The Canadian Cervical Spine rule was proposed to reduce the unnecessary use of cervical spine radiography in alert and stable patients. Our aim was to see whether applying the Canadian Cervical Spine rule reduced the need for cervical spine radiography without missing significant cervical spine injuries. Methods: This was a retrospective study conducted in 2 hospitals. 114 alert and stable patients who had cervical spine radiographs done for suspected neck injuries were included in the study. Data on patient demographics, Canadian Cervical Spine rule, cervical spine radiography results and further visits after discharge were recorded. Results: 14 patients were included in the high risk category according to the Canadian Cervical Spine rule. 100 patients were assessed according to the low risk category. If the Canadian Cervical Spine rule was applied, there was a significant reduction in cervical spine radiographs (p< 0.001) as 86/100 patients (86%) in the low risk category would not have needed cervical spine radiograph. 2/100 patients who had significant cervical spine injuries would have been identified when the Canadian Cervical Spine rule was applied. Conclusion: Applying the Canadian Cervical Spine rule for neck injuries in alert and stable patients reduced the use of cervical spine radiographs without missing out significant cervical spine injuries. This relates to reduction in radiation exposure to patients and cost benefits

Background. One of the basic principles in the primary survey of a trauma patient is immobilisation of the cervical spine till cleared of any injury. Lateral cervical spine radiograph is the gold standard initial radiographic assessment. More than often additional radiographs like the Swimmer's view are necessary for adequate visualisation of the cervical spine. How good is the Swimmer's view in visualisation of the cervical spine after an inadequate lateral cervical spine radiograph?. Materials & methods. 100 Swimmer's view radiographs randomly selected over a 2 year period in trauma patients were included for the study. All the patients had inadequate lateral cervical spine radiographs. The radiographs were assessed with regards to their adequacy by a single observer. The criteria for adequacy were adequate visualisation of the C7 body, C7/T1 junction and the soft tissue shadow. Results. Only 55% of the radiographs were adequate. None of the inadequate radiographs provided adequate visualisation of the C7 body and the C7/T1 junction. In 19% radiographs the soft tissue shadow was unclear. Poor exposure accounted for 53% of the inadequacies while overlapping bones accounted for the rest. Conclusion. Clearing the cervical spine prior to removing triple immobilisation is essential in a trauma patient. This needs adequate visualisation from C1 to C7/T1 junction. In our study Swimmer's views did not satisfactorily provide adequate visualisation of the cervical spine in trauma patients. We recommend screening the cervical spine by a CT scan when the cervical spine lateral radiographs and Swimmer's views are inadequate

Reduced cervical spine canal AP diameter is linked to the development of spinal cord injury and myelopathy. This is of particular interest to clinicians in New Zealand, given a unique socio-ethnic make-up and prevalent participation in collision sport. Our study builds upon previous unpublished evidence, by analysing normal cervical spine CT scans to explore morphological differences in the sub-axial cervical spine canal, between New Zealand European, Māori and Paciāca individuals. 670 sub-axial cervical vertebrae (C3-C7) were analysed radiographically using high resolution CT trauma scans, showing no acute pathology with respect to the cervical spine. All measurements were made uPlising mulP-planar reconstruction software to obtain slices parallel to the superior endplate at each vertebral level. Maximal canal diameter was measured in the AP and transverse planes. Statistical analysis was performed using analysis of variance (ANOVA). We included 250 Maori, 250 NZ European and 170 Paciāca vertebrae (455 male, 215 female). Statistically and clinically signiācant differences were found in sagittal canal diameter between all ethnicities, at all spinal levels. NZ European vertebrae demonstrated the largest AP diameter and Paciāca the smallest, at all levels. Transverse canal diameter showed no signiācant difference between ethnicities, however the raatio of AP:transverse diameter was signiācantly different at all spinal levels except C3. Subjective morphological differences in the shape of the vertebral canal were noted, with Māori and Paciāca patients tending towards a flatter, curved canal shape. A previous study of 166 patients (Coldham, G. et al. 2006) found cervical canal AP diameter to be narrower in Māori and Paciāca patients than in NZ Europeans. Our study, evaluating the normal population, conārms these differences are likely reflecPve of genuine variation between these ethniciPes. Future research is required to critically evaluate the morphologic differences noted during this study

Cervical spine facet tropism (CFT) defined as the facets’ joints angles difference between right and left sides of more than 7 degrees. This study aims to investigate the relationship between cervical sagittal alignment parameters and cervical spine facets’ tropism. A retrospective cross-sectional study carried out in a tertiary center where cervical spine magnetic resonance imaging (MRI) radiographs of patients in orthopedics/spine clincs were included. They had no history of spine fractures. Images’ reports were reviewed to exclude those with tumors in the c-spine. A total of 96 patients was included with 63% of them were females. The mean of age was 45.53± 12.82. C2-C7 cobb's angle (CA) and C2-C7 sagittal vertical axis (SVA) means were −2.85±10.68 and 1.51± 0.79, respectively. Facet tropism was found in 98% of the sample in at least one level on either axial or sagittal plane. Axial C 2–3 CFT and sagittal C4-5 were correlated with CA (r=0.246, P 0.043, r= −278, P 0.022), respectively. In addition, C2-C7 sagittal vertical axis (SVA) was moderately correlated with axial c2-3 FT (r= −0.330, P 0.006) Also, several significant correlations were detected in our model Cervical vertebral slopes and CFT at the related level. Nonetheless, high BMI was associated with multi-level and multiplane CFT with higher odd's ratios at the lower levels. This study shows that CFT at higher levels is correlated with increasing CA and decreasing SVA and at lower levels with decreasing CA. Obesity is a risk factor for CFT

Introduction. Missile injuries are very serious injuries particularly in the cervical region. They are classified into high and low missile injuries when it involves the cervical spine. In modern guerrilla warfare, one must be aware of ballistic pathology with bullets as well as from explosives. In particular, improvised explosive devices commonly known as IED's play a new and important pathophysiology whether they are suicided vests or roadside bombs. They usually produce severe or lethal injuries and serious neurovascular deficit is frequent. We present the details of 40 patients with local experience on how to handle serious penetrating cervical missile injuries. Methods. All cases were collected from the record of Basrah University Hospital, Iraq. Healthy military gentlemen with ages ranging between 20–35 years were included. Results. 11 patients had bullet injuries and 29patients had fragments of shell injuries. The sites of injuries were 9: C2–C3, 12: C5–C6, 12: C4–C5 and 7: C7-T1. Bullet entrance was anterior in 23 patients, posterior in 7 patients and lateral in 10 patients. The cervical vertebrae were injured in 37 patients at body or lamina level while in 3 patients it was only neural tissue injuries. Missiles were retained in 13 patients. All injuries showed some degree of neurological deficit with quadriplegia in 26 patients. 9 patients presented with very serious injuries. No relation was found between the size of the missile and the extent of damage. Outcome of treatment in all patients was poor. Conclusion. Gunshot wounds only account for approximately one third of penetrating missile injuries in patients who survive and are well enough to receive medical treatment. 62% of patients' cohort were from explosive devices, consistent with data from 2010, where 58% of fatalities were from IED's occurring in foreign soldiers in Afghanistan. We discuss the importance of general supportive measures, generous wound excision, removal of the retained missiles and heavy cover of antibiotics

Some activities of daily living require that the head be kept level during axial rotation of the cervical spine (Kinematically Constrained Axial Rotation). One such activity is looking over one's shoulder when walking or driving. The kinematic constraint of keeping the head level during axial rotation means that the segmental axis of rotation may not be aligned with the global axis of rotation of the cervical spine. Most of the literature on cervical spine axial rotation is based on experiments where the segmental axis of rotation is aligned with the global axis of rotation (Traditional Axial Rotation). There are only a few clinical and biomechanical studies that have examined kinematically constrained cervical axial rotation. We performed a series of biomechanical experiments in which we tested cervical spines in traditional and kinematically constrained axial rotation. The resulting primary and coupled motions of the segments showed that kinematically constrained axial rotation is distinct from traditional axial rotation. Our findings and the findings of other kinematically constrained axial rotation studies will be compared and contrasted with data from traditional axial rotation studies

Bone localization of tuberculosis mainly affects the thoracolumbar spine. The cervical spine is rare. Its diagnosis is often late which exposes to great instability and potentially serious complications. We reported the case of a patient with cervical spine tuberculosis with a rare localisation. A 10-years old boy with no medical history, showed torticolis and high temperature without neurological complication. In the physical examination, he had torticolis and pain in the third, forth and fifth cervical vertebra. The biology showed high CRP 200mg/l. The tomodensitometry of the cervical spine showed a collection of the third cervical spine. The patient took non specific Antibiotics for two months with no radiological improvement. When biopsy was performed, we find an inter apophysis (between C3 and C4) collection. The histological examination confirmed the diagnosis of apophysis tuberculosis. The cervical spine is a rare localisation of the tuberculosis. The apophysis localisation is a more uncommon localisation. The diagnosis is difficult. The histological examination is essential for the diagnosis. The management based on tuberculosis chemotherapy and immobilization started as soon as possible

To compare the complication profile of a muscle splitting approach to the anterior cervical spine with previously described approaches. The authors describe and compare the complications of an approach that exposes the anterior cervical spine by directly splitting the strap muscles in the midline with blunt dissection thereby potentially reducing iatrogenic complications. A retrospective review of 62 operations to the anterior cervical spine, between 2002 and 2009. Indications: Fusion and arthroplasty procedures for brachalgia, axial neck pain and trauma. The postoperative complications. The complication rate was favourable compared to previously described approaches. The muscle splitting approach to the anterior cervical spine has a low complication rate compared to previously described approaches, and allows the cervical spine to be approached with blunt dissection thereby potentially minimising iatrogenic approach related complications

Cervical spine fractures are frequent in impact sports, such as rugby union. The consequences of these fractures can be devastating as they can lead to paraplegia, tetraplegia and death. Many studies have been conducted to understand the injury mechanisms but the relationship between player cervical spine posture and fracture pattern is still unclear. The aim of this study was to evaluate the influence of player cervical spine posture on fracture pattern due to an impact load. Nineteen porcine cervical spines (C2 to C6) were dissected, potted in PMMA bone cement and mounted in a custom made rig. They were impacted with a mean load of 6 kN. Eight specimens were tested in an axial position, five in flexion and six in lateral bending. All specimens were micro-CT imaged (Nikon XT225 ST Scanner, Nikon Metrology, UK) before and after the tests, and the images were used to assess the fracture patterns. The injuries were classified according to Allen-Ferguson classification system by three independent observers. The preliminary results showed that the main fracture modalities were consistent with those seen clinically. The main fractures for the axial orientation were observed in C5-C6 level with fractures on the articular process and endplates. These findings support the concept that the fracture patterns are related to the spine position and give an insight for improvements on sports rules in order to reduce the risk of injury

Information regarding the axes of motion or centers of rotation of the normal cervical spine are necessary to evaluate the similarity of the motion allowed by cervical total disc replacement designs to the natural cervical spine. However, little data has been presented previously regarding the three-dimensional axes of motion of the cervical spine for the three primary motions of flexion/extension, lateral bending and axial rotation. The objective of this study was to measure the three-dimensional axes of motion (Helical axis of Motion) in the natural sub-axial cervical spine using ex-vivo human cadaveric cervical spines. To measure the Helical Axes of Motion (HAM) for the sub-axial cervical spine under flexion/extension, lateral bending and axial torsion moments and evaluate the effect of a physiologic axial preload on the axes locations and orientations. This study demonstrated the feasibility of calculating the HAM in the cervical spine using an ex-vivo experimental protocol. The HAM is a three-dimensional analogue to the two-dimensional center of rotation. The data presented here can be used to evaluate the similarity of the motion allowed by total disc replacement designs to the natural cervical spine. They can also be applied for the characterization of spinal trauma, pathology, instability or surgical devices. The orientation and locations of the HAMs for axial torsion loading are presented in Figure 1. In flexion/extension the HAM penetrated the sagittal plane near the posterior aspect of the vertebral body and near the cranial endplate. The lateral bending results were similar to the axial torsion results. The addition of axial preload had little effect on the position and orientation of the HAM. Sub-axial (level C2-C7) cadaveric cervical spine functional spinal units (n=7) were subjected to pure moments of 1 Nm. Specimens were tested with and without axial preloads of 200 N. Vertebral kinematics were measured using an optoelectronic motion analysis system. These data are particularly applicable to the evaluation and design of “motion-retaining” devices such as total disc replacements, facet joint replacement systems or flexible stabilization systems. Please contact author for figures and diagrams

Objectives. To demonstrate that instrumented fusion of the paediatric cervical spine is possible and can be performed safely. Study Design. A retrospective review of paediatric patients who had instrumented fusion of the cervical spine. Materials and method. Sixteen paediatric patients (10 male, 6 female) with a mean age of 8 years who underwent instrumented cervical fusion were retrospectively reviewed. Surgery was performed for trauma (5 cases), spinal tuberculosis (3 cases), congenital anomalies (6 cases) and malignancies (2 cases). Fixation methods included occipito-cervical fusion, pedicle and lateral mass screws and anterior cervical plating. Ten posterior approaches, four anterior approaches and four combined anterior and posterior approaches were performed. We looked at fusion rates, blood loss, levels fused, theatre time, technique and complications. Results. All patients achieved radiological and clinical fusion. The average number of levels fused was 2.5, blood loss 418ml and theatre time 222 minutes for all patients. Anterior procedures had an average of 1 levels fused, blood loss 117ml and theatre time 98 minutes. Posterior procedures had an average number of 1.9 levels fused, blood loss of 306ml and theatre time of 131 minutes. For the combined anterior and posterior procedures the average levels fused were 5.5, blood loss 975ml and theatre time 248 minutes. Five surgery related complications were encountered. These consisted of dural leaks and wound sepsis which were all treated effectively. Conclusion. The use of modern segmental spinal instrumentation in the paediatric cervical spine is a viable option in this young population. Although our study sample was small we are able to demonstrate that no major surgical complications were encountered due to the use of cervical spinal instrumentation. NO DISCLOSURES

Clinical investigations show that the cervical spine presents wide inter-individual variability, where its motion patterns and load sharing strongly depend on the anatomy. The magnitude and scope of cervical diseases, including disc degeneration, stenosis, and spondylolisthesis, constitute serious health and socioeconomic challenges that continue to increase along with the world”s growing aging population. Although complex exact finite element (FE) modeling is feasible and reliable for biomechanical studies, its clinical application has been limited as it is time-consuming and constrained to the input geometry, typically based on one or few subjects. The objective of this study was twofold: first to develop a validated parametric subject-specific FE model that automatically updates the geometry of the lower cervical spine based on different individuals; and second to investigate the motion patterns and biomechanics associated with typical cervical spine diseases. Six healthy volunteers participated in this study upon informed consent. 26 parameters were identified and measured for each vertebra in the lower cervical spine from Lateral and AP radiographs in neutral, flexion and extension viewpoints in the standing position. The lower cervical FE model was developed including the typical vertebrae (C3-C7), intervertebral discs, facet joints, and ligaments using ANSYS (PA, USA). In order to validate the FE model, the bottom surface of C7 was fixed, and a 73.6N preload together with a 1.8 N.m pure moment were input into the model in both flexion and extension. The results were compared to experimental studies from literature. Disc degeneration disease (DDD) was used as an example, where the geometry of C5-C6 disc was changed in the model to simulate 3 different grades of disc degeneration (mimicking grades 1 to 3), and the resulting biomechanical responses were evaluated. The average ranges of motion (ROM) were found to be 4.84 (±0.73) degrees and 5.36 (±0.68) degrees for flexion and extension for C5-C6 functional unit, respectively, in alignment with literature. The total ROM of the model with disc generation grades 2 and 3 was found to have decreased significantly as compared to the intact model. In contrast, the axial stresses on the degenerated discs were significantly higher than the intact discs for all 3 degeneration grades. Our preliminary results show that this novel validated subject-specific FE model provides a potential valuable tool for noninvasive time and cost effective analyses of cervical spine biomechanical (kinematic and kinetic) changes associated with various diseases. The model also provides an opportunity for clinicians to use quantitative data towards subject-specific informed therapy and surgical planning. Ongoing and future work includes expanding the studied population to investigate individuals with different cervical spine afflictions

Diving injuries are the cause of devastating trauma, primarily affecting the cervical spine. The younger male population is more often involved in such injuries. This study describes our experience on diving injuries treatment and offers a long follow-up. During a 31-year period (1970–2001) 20 patients, 19 male and one female have been admitted with cervical spine trauma following a diving injury. All admissions have been made between May and September. One patient was lost to follow-up. The mean age of the patients was 23 years (16–47). The lower cervical spine was involved in 13 patients; four patients had lesions in the middle and upper cervical spine, while one patient had combined lesions. The most commonly fractured vertebrae were C5 and C6. Fracture-dislocation was evident in 10 patients, while a teardrop fracture was diagnosed in six patients. Six patients were classified, as ASIA A upon admission and bladder control was absent in 12. Only four patients were treated surgically, two with iliac bone grafting alone, one with posterior plating and one with an anterior plate plus graft. The other patients with initial neurological deficit were treated conservatively, because of their rapid neurological improvement, their lesion being regarded as stable. Fourteen patients were treated conservatively with steroids and Crutchfield skull traction or halo vest, followed by the application of a Minerva or Philadelphia orthosis. The mean follow-up was 11 years (6 mo to 23.8 years). Four patients in the ASIA A category died in the first month of their hospitalization (two of cardiac arrest, one from pulmonary embolism and one from respiratory infection) and two remained unchanged. Six patients with ASIA B and C improved neurologically and one remained unchanged. Nine patients had developed urinary tract infection and two had respiratory infections. Two out of the four operated on developed superficial trauma infection. In conclusion, diving injuries of the cervical spine demonstrate a high mortality and morbidity rate. The initial neurological deficit may improve with appropriate conservative treatment. The indications for surgical management are post-traumatic instability and persistent or deteriorating neurologic deficit

To date the principal focus of the mechanism of cervical spine fracture has been directed towards head/neck circumference and vertebral geometric dimensions. However the role of other measurements, including chest circumference and neck length, in a standard cervical fracture population has not yet been studied in detail. Cervical fractures often involve flexion/extension type mechanisms of injury, with the head and cervical spine flexing/extending, using the thorax as an end point of contact. Thus, the thorax may play an important role in neck injuries. Study design: We prospectively studied all patients with cervical spine fractures who were admitted to the National Spinal Injuries Unit from 1 July 2000 to 1 March 2001. Anthropometrical measurement of head circumference, neck circumference, chest circumference, and neck length were analysed. Ages ranged from 18 to 55 years, and all patients with concomitant cervical pathology were excluded from the study. Mechanism of injury involved flexion/extension type injuries in all cases; those with direct axial loading were excluded. A control group of 40 patients (age 18–50 years) involved in high velocity trauma with associated long bone fractures, in whom cervical injury was suspected, but who were without any cervical fracture, or associated pathology, were similarly measured. Results: Our analysis revealed a statistically significant increase in chest size in the male control group versus the male fracture group (97.89 cm versus 94.19 cm, P < 0.05, Student’s t-test). There was a correspondingly significant increase in chest circumference between the female controls versus the female fracture group (92.33 cm versus 88.88 cm, P < 0.05, Student’s t-test). Our results revealed no statistical difference in head circumference, neck circumference, or neck length between each of the groupings. These results indicate a proportionately larger chest may be a protective factor in cervical spine fractures

Summary Statement. It is now possible to diagnose osteoporosis using incidental abdominal CT scans; applying this approach to fractures of the cervical spine demonstrates levels of osteoporosis in patients over 65. Introduction. Recently published data now makes it possible to screen for osteoporosis in patients who, in the course of their hospital stay, have had Computed Tomography (CT) scans of their abdomen for reasons other than direct imaging. This is as a result of CT derived bone mineral density (BMD) in the first lumbar vertebra (L1) being correlated BMD derived from Dual-energy X-ray absorptiometry (DEXA) scans. The advantage of this is the reduction in both cost and radiation exposure. Although age has a detrimental effect on BMD, relatively few patients have formal DEXA studies. The aims of this study were to evaluate the utility of this new technique in a cohort of patients with acute fractures of the cervical spine and to compare relative values for BMD in patients aged over 65 with those aged under 65, and thus define the role of osteoporosis in these injuries. Methods & Patients. Following Institutional review board approval, we performed a retrospective study of patients who presented to a level I trauma center with acute fractures of the cervical spine between 2010 and 2013; patients also had to have had a CT scan of their L1 vertebra either during the admission or within 6 months of their admission (for any other clinical reason). Using a picture archiving and communication (PACS) system, we generated regions of interest (ROI) of similar size in the body of L1 (excluding the cortex), in line with the publication by Pickhardt et al., and computed the mean values for Hounsfield units (HU). These values were compared against established threshold values which differentiate between osteoporosis and osteopenia; for a balanced sensitivity and specificity, <135 HU is the threshold and for 90% sensitivity a HU threshold of <160 HU is set. Comparisons were also performed between age stratified groups. Results. A total of 187 patients were reviewed for eligibility, 91 patients met the criteria with 53 patients aged 64 years or younger (range 23–64) and 38 patients aged above 65 years (range 65–98). In the younger cohort, 6/53 (11% were osteoporotic, using the lower threshold, while the higher threshold indicated 5/53 (17%) of patients under 65 years were osteoporotic; mean HU for the group was 195.8 (SD 43.3). In the older cohort, 24/38 (63%) were osteoporotic using the lower threshold, whereas 34/38 (89%) were osteoporotic using the higher threshold. Mean HU for the cohort aged over 65 years was 118.7 (SD 38.4). Age based comparison of the mean values, regardless of threshold, was statistically significant (p<0.001) in both cases. Discussion and Conclusions. This study demonstrates, for the first time in the cervical spine (including C2), the role of age related osteoporosis in acute fractures of the cervical spine. This new technique harnessing the presence of opportunistic CT scans of the abdomen saves on the extra cost and radiation exposure that may be associated with DEXA scanning. In younger patients, the higher threshold indicated 17% were osteoporotic – in the setting of an opportunistic scan, this may afford them the opportunity to commence prophylactic treatment to prevent future fractures. We believe these result have the potential to significantly impact future clinical practice

Introduction and Aims: Odontoid fractures are quite common in the elderly following minor falls. As there are a few articulations in the upper cervical spine, degeneration in any one particular joint may affect the biomechanics of loading of the upper cervical spine. We aimed to analyse the pattern and relationship of odontoid fractures to the upper cervical spine osteoarthritis in the elderly. Method: Between July 1999 and March 2003, 185 patients had CT scan of the cervical spine for cervical spine injuries. Twenty-three out of 47 patients over the age of 70 years had odontoid fractures. The CT scan pictures of these patients were studied to analyse the type of fracture and its displacement, the severity of osteoarthritis in each articulation in the upper cervical spine, namely lateral atlantoaxial, atlantooccipital, atlantoodontoid and subaxial facetal joints, evaluation of osteopenia in the dens-body junction and in the body and odontoid process of the axis, and calcification of the ligaments. Results: Twenty-one of the 23 patients had Type II odontoid fracture with posterior displacement in seven (33.3%) and posterior angulation in nine (42.8%) patients. In these patients with Type II dens fracture, the atlantodens interval was obliterated in 19 (90.48%) patients, with only two of them (9.52%) having lateral atlantoaxial osteoarthritis. Conclusion: Type II fracture is the commonest odontoid fracture in the elderly. Posterior displacement of the fracture is common in elderly, unlike the younger population. There is a significant relationship between the upper cervical spine osteoarthritis, apart from osteopenia, to the incidence of Type II odontoid fractures. Significant atlantoodontoid osteoarthritis in the presence of normal lateral atlantoaxial joints increases the risk of sustaining Type II odontoid fracture

Purpose: The biomechanical behaviour of the cervical spine was studied in vitro with an optoelectronic system in order to better understand its physiology. Material: Twenty fresh cervical spines (occiput-D1) from fourteen men and six women, mean age 66.5 years, were sterilised with ß radiation (2.5 Mrad) and stored at −24°C then studied after slow thawing and excision of the paraspinal muscles. Methods: Three-point reflecting markers were rapidly attached to each vertebral segment (4 or 5 vertebrae). The inferior vertebra was blocked. Six pure moment couples (2 N.m maximum, 10 increments) were applied in the three anatomic planes using a loading device lodged on the superior vertebra. Displacements were measured with the VICON 140 using a kinematic software. Results: The three-dimensional behaviour curves of each functional unit (FU) were recorded for each solicitation to analyse the principal movement and coupled movements (maximum mobility, neutral zones, rigid zones, rigidity). Mean maximal flexion-extension movements were C0/C1= 28.7°; C1/C2 = 22.3°; C2/C3 = 7.3°; C3/C4 = 10.6°; C4/C5 = 13.8°; C5/C6 = 13.4°; C6/C7 = 10.8°; C7/T1 = 6.4°. Maximum overall lateral inclinations were: C0/C1= 8.7°; C1/C2 = 9.3°; C2/C3 = 8.7°; C3/C4 = 6.7°; C4/C5 = 10.5°; C5/C6 = 12.2°; C6/C7 = 8.6°; C7/T1 = 5.7°. Maximal overall axial rotations were: C0/C1= 11°; C1/C2 = 71°; C2/C3 = 9.5°; C3/C4 = 10.8°; C4/C5 = 12.3°; C5/C6 = 9°; C6/C7 = 5.6°; C7/T1 = 5.7°. All the FU exhibited flexion-extension movement. Lateral inclination coupled important controlateral rotation for C1/C2 and minimal ipsilateral rotation (< 10°) in the lower FU of the cervical spine. Axial rotation of the C1/T1 functional unit was coupled with homolateral rotation (< 10°). Discussion: Our experimental protocol provided precision of < 1° and good reproducibility allowing simultaneous three-dimensional analysis of the spinal functional units. Making measurements without direct contact is particularly useful for the cervical spine. Our results are within the experimental corridor defined by Goel, Panjabi and Wen. Conclusion: This work on a large number of functional units adds further support to data in the literature concerning the biomechanical behaviour of the cervical spine. Our protocol could be applied to analyse the impact of surgical procedures used for the cervical spine, particularly for the evaluation of new fixation systems or prostheses

Purposes of the study and background: This study tests the hypothesis that it is possible to visualise the cervical spine musculature using ultrasound. The use of diagnostic ultrasound is well established for assessing other anatomical regions; whereas the cervical spine has received little attention. Other available imaging procedures can be resource intensive with recognized risks and do not give an indication of structural detail. Ultrasound has the potential to resolve these inadequacies and would therefore be appealing. Summary of the methods and the results: 10 healthy volunteers (age range: 21–36 years, 6 females, 4 males) were evaluated using a 8-16MHz linear array transducer (Diasus Dynamic Imaging, UK) and a 16MHz CL15-7 linear array scanhead transducer (Phillips ATL HDI 5000 SonoCT, Netherlands). Subjects were seated with their neck in a neutral position. The transducer was orientated transversely, and initially placed on the thyroid cartilage. Successive images were taken as the transducer was moved laterally across the anterior triangle, over the sternocleidomastoid, into the posterior triangle, ending in the posterior midline. Landmarks, with characteristic ultrasonic appearances, were identified to aid orientation e.g. carotid artery. Both machines produced images that clearly displayed the musculature of the cervical spine. Composite images were obtained of the anterior and posterior aspects of the neck (Figure 1) to provide information regarding the spatial orientation and relationship between the muscles. Conclusion: This study concludes that modern ultrasound equipment provides cervical spine soft tissue images of a quality suitable for diagnostic applications. It also has the advantages of being a risk free, economic and portable procedure