Purpose: Odontoid fractures are the most common cervical spine injuries in the elderly. Although octogenarians are the fastest growing age group, limited data exists on the natural history after they sustain odontoid fractures. Published mortality rates vary greatly, but are high enough to elicit comparisons to post-hip fracture mortality. It has also been suggested that halo-vest immobilization independently predicts mortality. Method: All traumatic odontoid fractures (type II or III) seen at our institution between 1996 and 2008 were identified and only patients who were ≥ 80 years of age were selected. A retrospective chart review was performed for injury characteristics, comorbidities, hospitalization details, treatment regimen and documented complications. Patients were stratified using the Charlson comorbidities index. The primary outcome was mortality at one year and was identified using a provincial database. Results: 72 cases were identified. Median age was 86 years (range 80 to 102). Patient treatment regimens included rigid neck collar, Halo vest orthosis, surgery or a combination thereof. 31% percent of the cohort (22 patients) was treated by Halo vest immobilization. Overall 1-year mortality rate was 15% (n=11) with only 1 Halo vest patient dying during this period. The majority of deaths (9 / 11) occurred in first 2 weeks following the injury. Conclusion: Mortality rate in the octogenarian population sustaining an odontoid fracture is high and approaches the 1-year hip fracture mortality rate. The utilization of a Halo vest was not associated with increased mortality rate in our study. Optimal treatment regimens, and strategies to minimize morbidity, particularly in the early post-injury phase, necessitate further study

Between 1994 and 2002, 42 patients aged over 65 years were admitted to the spinal injuries unit with odontoid fractures. Data was retrospectively collected by analysis of the national spinal unit database, hospital inpatient enquiry (HIPE) system, chart and x-ray review. Mean age of patients was 79 years (66–88). Mean following-up with 4.4 years (1–9 yrs). Male to female ratio was 1:1.2 (M=19, F=23). Among the mechanism of injury, simple fall (low-energy) was the commonest underlying cause in 76% of the odontoid fracture, whereas 23% fractures were sustained as a result of motor vehicle accident. Fractures were classified according to Anderson and D’Alonzo method. There were 29 (69%) type 11 fractures, 13 (30%) were type 111 fractures and there was no type 1 fracture. Anterior and posterior displacements were recorded with almost equal frequency. Seven fractures displaced anteriorly and six fractures posteriorly. Primary union occurred in 59% of fractures. Forty (95.3%) fractures were treated non-operatively. Two fractures were stabilized primarily with C1/C2 posterior interspinous fusion. These fractures were odontoid type 11, anteriorly displaced. Three fractures (7.1%) failed to unite and another three fractures (7.1%) united with prolonged interval (9–11 months). Neurological compromise was mainly related to displacement of the fracture. The overall complication rate was significant (48%) with an associated in-hospital mortality of 11.1%. Loss of reduction, non-union after non operative treatment, pin site problems and complication due to associated injuries accounted primarily for this significant complication rate. Most fractures can be managed in orthosis but unstable fractures require rigid external immobilization or surgical fixation. Outcome was assessed using a cervical spine outcome questionnaire from Johns Hopkins School of Medicine. Questionnaires were sent by post to all patients identified. Non responders were subsequently contacted by phone, if possible, to complete the questionnaire. In the follow-up, additional 6(14.2%) patients were found deceased, 4 patients were unavailable for review and the remaining 69% had significant recovery. Functional outcome scores approached pre-morbid level in all patients. Outcome of these patients are related to increasing age, co-morbidity and the severity of neurological deficit

Odontoid fracture of the second cervical vertebra (C2) is the most common spinal fracture type in elderly patients. However, very little is known about the biomechanical fracture mechanisms, but could play a role in fracture prevention and treatment. This study aimed to investigate the biomechanical competence and fracture characteristics of the odontoid process. A total of 42 human C2 specimens (14 female and 28 male, 71.5 ± 6.5 years) were scanned via quantitative computed tomography, divided in 6 groups (n = 7) and subjected to combined quasi-static loading at a rate of 0.1 mm/s until fracturing at inclinations of −15°, 0° and 15° in sagittal plane, and −50° and 0° in transverse plane. Bone mineral density (BMD), specimen height, fusion state of the ossification centers, stiffness, yield load, ultimate load, and fracture type according to Anderson and d'Alonzo were assessed. While the lowest values for stiffness, yield, and ultimate load were observed at load inclination of 15° in sagittal plane, no statistically significant differences could be observed among the six groups (p = 0.235, p = 0.646, and p = 0.505, respectively). Evaluating specimens with only clearly distinguishable fusion of the ossification centers (n = 26) reveled even less differences among the groups for all mechanical parameters. BMD was positively correlated with yield load (R² = 0.350, p < 0.001), and ultimate load (R² = 0.955, p < 0.001), but not with stiffness (p = 0.070). Type III was the most common fracture type (23.5%). These biomechanical outcomes indicate that load direction plays a subordinate role in traumatic fractures of the odontoid process in contrast to BMD which is a strong determinant of stiffness and strength. Thus, odontoid fractures appear to result from an interaction between load magnitude and bone quality

Background: Type II odontoid fractures are the commonest upper cervical spine injury in the elderly, following minor falls. Structural heterogeneity within the axis with deficiency of bone mass in the base of the odontoid process has been attributed for these fractures. Aims: To analyse whether osteoporosis at the dens-body junction is directly related to the occurrence of odontoid fractures in the elderly. Material and Methods: We studied the reformatted CT scan images of 36 patients over the age of 70 years who had cervical spine injuries following minor trauma. In all these patients the severity of osteoporosis at the dens-body junction, and in the peg and body of axis were evaluated. The osteoporosis was graded into none, mild, moderate and severe. Statistical analysis was performed using Pearson’s Chi-square test to find the significance of osteoporosis at the dens-body junction in producing Type II odontoid fractures in the elderly. Results: Type II odontoid fractures was seen in 21 patients. Eleven of the 21 patients with Type II fractures and eight of the 15 patients with no Type II odontoid fractures had significant osteoporosis at the dens-body junction. Five patients with Type II fracture and eight patients with no Type II fractures had significant osteoporosis at the dens and body of axis. Statistical analysis showed that the osteoporosis at the dens-body junction was not significant in patients with Type II odontoid fracture compared to those with no Type II odontoid fracture (χ. 2. = 1.1; df = 3, p = 0.78). Conclusions: Eventhough osteoporosis is one of the factors that increase the incidence of Type II fractures of the odontoid process in the elderly, it is not a direct aetiological factor

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

Background: Type II odontoid fractures are the commonest upper cervical spine injury in the elderly, following minor falls. Structural heterogeneity within the axis with deficiency of bone mass in the base of the odontoid process has been attributed for these fractures. Aims: To analyse whether osteoporosis at the dens-body junction is directly related to the occurrence of odontoid fractures in the elderly. Material and Methods: We studied the reformatted CT scan images of 36 patients over the age of 70 years who had cervical spine injuries following minor trauma. In all these patients the severity of osteoporosis at the dens-body junction, and in the peg and body of axis were evaluated. The severity was graded into none, mild, moderate and severe, depending on the cortical thickness, trabecular pattern, and the size of holes (absence of trabeculae) using sagittal, coronal and transverse sections of CT scan pictures. The osteoporosis was graded into none, mild, moderate and severe. Statistical analysis was performed using Pearsons Chi-square test to find the significance of osteoporosis at the dens-body junction in producing Type II odontoid fractures in the elderly. Results: Type II odontoid fractures was seen in 21 patients. Eleven of the 21 patients with Type II fractures and eight of the 15 patients with no Type II odontoid fractures had significant osteoporosis at the dens-body junction. Five patients with Type II fracture and eight patients with no Type II fractures had significant osteoporosis at the dens and body of axis. Statistical analysis showed that the osteoporosis at the dens-body junction was not significant in patients with Type II odontoid fracture compared to those with no Type II odontoid fracture (Chi-square value = 1.1; df = 3, p = 0.78). Conclusions: Eventhough osteoporosis is one of the factors that increase the incidence of Type II fractures of the odontoid process in the elderly, it is not a direct aetiological factor

Over 2 years, 14 patients with C1/2 instability underwent posterior transarticular screw fixation. Pathologies included atlanto-axial subluxation in five rheumatoid patients, atlanto-axial rotatory subluxation and an odontoid fracture in two patients with ankylosing spondylitis, nonunion of odontoid fractures in three patients, three transverse ligament injuries and one type-III odontoid fracture. This study aimed to assess the use of transarticular screw fixation in terms of technique, union rates and functional outcomes. All operations were performed on a Relton-Hall frame with a Mayfield clamp and lateral fluoroscopy. The mean age of the eight men and six women was 48 years. The mean operation time was 112 minutes (65 to 225) and mean blood loss was 270 ml (150 to 700). Autologous posterior iliac crest bone graft was used in all patients. The procedure was aborted in one patient because of difficulty with reduction and screw angulation and in another because of excessive bleeding from the drill hole. Alternative fixation techniques were used in these two patients. All patients wore a Philadelphia collar postoperatively until stability was confirmed. The time to radiological union was 8 to 10 weeks. Clinical outcomes revealed full ranges of flexion and extension in most patients, with a 50% decrease in cervical rotation. There were no neurological complications postoperatively. There was implant failure in one patient, with screw breakage evident at follow-up, but this patient went on to union without further intervention. Transarticular screw fixation is an inexpensive, effective and safe technique for management of C1/2 instability

Objective: The purpose of this communication was to evaluate the long-term outcome of patients with type II odontoid fractures treated with anterior screw fixation. Material and Methods: In our prospective clinical study 34 patients, 21 males and 13 females (with mean age 35.4 + 0.8 years) with type II odontoid fractures of traumatic etiology, underwent anterior cannulated screw fixation, during a period of 36 months. All patients had radiologicaly confirmed intact transverse ligament and a reducible odontoid fracture. All patients were immobilized in a Miami J cervical collar for 4 weeks postoperatively. Radiological examination of the cervical spine with plain X rays and cervical spine CT was performed at 6 weeks and two, six and 12 and 24 months postoperatively. Follow-up time ranged between 36 and 80 months (mean follow-up 54.3+ months). Results: 32 patients had an uneventful postoperative course, while one patient developed pulmonary atelectasis, which resolved without any significant sequelae and another one developed a superficial wound infection, which resolved without removing the implanted hardware. Radiographic evaluation showed satisfactory bony fusion and no evidence of abnormal movement at the fracture site in 31 patients (91.1%). In two patients (5.8%), the radiographic studies showed pseudo-arthrosis and instability while in one patient (2.9%) the implanted cannulated screw was broken but there was no instability shown. Conclusions: In our series anterior odontoid screw fixation constituted a safe therapeutic modality with high stability and low mechanical failure rates in short and long term follow-up period

Odontoid synchondral fractures are considered the most common type of fracture, amounting TO 10% of all subaxial injuries in the under 7 demographic. This injury occurs as typically the result of hyperflexion. Most odontoid fractures in children below 7 years of age involves the odontoid synchondrosis. The following is a report of the management of paediatric synchondral fractures in 2 patients who presented to the Children's Hospital Westmead in 2010. Both patients had displaced synchondral odontoid fractures which were managed by indirect reduction and halo traction. In both patients an anatomical alignment was achieved and maintained. Follow-up was 6 and 9 months respectively and the patients were assessed both clinically and radiologically. We feel the use of the “double mattress” technique is a valuable tool, as a means of achieving and maintaining occipitocervical extension, necessary, in the treatment of odontoid synchondral fractures

To assess the outcome and safety of transarticular C1–C2 screw fixation. The clinical and radiological outcomes of 15 patients treated with posterior atlanto-axial transarticular screw fixation and posterior wiring was assessed at a minimum follow up of 6 months. Indications for fusion were rheumatoid arthritis in 8 (instability in 6 and secondary degenerative changes in 2), non-union odontoid fracture 4, symptomatic os-odontoideum one, C1–C2 arthrosis one and irreducible odontoid fracture one. Fusion was assessed with plain x-rays including flexion extension films. Twenty nine screws were placed under fluoroscopic guidance. Bilateral screws were placed in 14 patients and a single screw in one patient. This patient had a single screw placed due to the erosion of the contralateral C2 pars by an anomalous vertebral artery. All patients had radiological union. Two screws (7%) were malpositioned; neither was associated with clinical sequelae. No neurological or vascular injuries were noted. Transarticular C1–C2 fusion yielded a 100% fusion rate. The risk of neurological or vascular injury can be minimised by thorough assessment of pre operative CT scans to assess position of the vertebral artery and use of intra operative lateral and AP fluoroscopy

To assess the outcome and safety of transarticular C1-C2 screw fixation. The clinical and radiological outcomes of 15 patients treated with posterior atlantoaxial transarticular screw fixation and posterior wiring was assessed at a minimum follow up of six months. Indications for fusion were rheumatoid arthritis in eight (instability in six and secondary degenerative changes in two), non union odontoid fracture four, symptomatic osodontoideum one, C1-C2 arthrosis one and irreducible odontoid fracture one. Fusion was assessed with plain x-rays including flexion – extension films. Twenty nine screws were placed under fluroscopic guidance. Bilateral screws were placed in 14 patients and a single screw in one patient. This patient had a single screw placed due to the erosion of the controlateral C2 pars by an anomolous vertebral artery. All patients had radiological union. Two screws (7%) were malpositioned, neither was associated with clinical sequelae. No neurological or vascular injuries were noted. Transarticular C1-C2 fusion yielded a 100% fusion rate. The risk of neurological or vascular injury can be minimised by thorough assessment of pre operative CT scans to assess position of the vertebral artery and use of intra operative lateral and AP fluroscopy

Aims: The optimal treatment of Type II odontoid fractures remains controversial. Our retrospective multicentric study of 114 odontoid process fractures documents experience with management of these fractures and discuss a new classification subtype II T and its surgical treatment. Methods: Fractures were defined using plain radiographs and CT reconstructions as per the Anderson- D’Alonzo classification. We have surgically treated 114 consecutive patients suffering from C2 odontoid fracture. 104 fractures were classified as Type II and 10 as Type III. Two cases of atypical, horizontal, mid-shaft odontoid process fractures were reported. In 55% an anterior two-screw fixation technique was chosen, remaining 45% underwent single-screw fixation. Results: One year follow-up data were available in 86.8% of cases and no major complications were found. Fusion rate calculated 6 months following surgery was 93%. We encountered cases, where the fracture line passes transversally through the middle of the shaft of odontoid process, below the level of transverse atlantal ligament, and we suggest to classify these cases as Type II T fractures. Also we analysed series of 75 surgically treated C1-2 instabilities and out of 11 pseudoarthrosis of the odontoid process 7 unrecognised Type II T fractures were found. Conclusions: Reported atypical fractures, newly classified as Type II T, are highly unstable (especially in rotations). In the authors’ opinion, two- screw technique should be the treatment of choice when internal fixation indicated

Evaluating the effectiveness of conservative treatment of odontoid fractures, from 1997 to 1999 we reviewed 22 cases. All were treated first in halo traction and subsequently by halo thoracic brace immobilisation. We used Anderson and D’Alonzo’s classification of types I to III. The mean follow-up time was seven months. Initial displacement was measured radiologically and union was evaluated. In type-II fractures, the incidence of pseudarthrosis was 40%. Fractures with more than 5 mm of initial displacement and more than 10° angulation all went on to nonunion, suggesting that type-II fractures should be treated by internal fixation

Purpose of the study: Computed tomography is recommended for the preoperative work-up of joint fractures as it allows an optimisation of the access as a function of the injury. During the operation, 2D radiographic or fluoroscopic controls are still widely used. After one year’s experience, we evaluated the potential pertinence of using 3D reconstructions intraoperatively with a mobile isocentric fluoroscope (iso-C-3D). Material and methods: All operations for which the amplifier was used were collected prospectively. The type of fixation as well as the details of the installation and measures taken intraoperatively were noted. Results: At one year, intraoperative 3D reconstructions were made during 48 operations in 47 patients: fracture of the calcaneum (n=13), thoracolumbar spin (n=12), acetabulum (n=11), tibial condyles (n=9), odontoid (n=2), pelvis (n=1). The installation was habitual for the calcaneum and odontoid fractures. For the other localizations, use of a carbon plateau table facilitated good quality imaging for spinal and tibial condyle fractures; a carbon orthopaedic table was useful for acetabulum and pelvis fractures. With the intraoperative 3D reconstruction the surgeon was able to check the freedom of the canal after reduction and fixation. For the calcaneum fractures, reduction of the thalamic fragment was revised in one patient; in another, an intra-articular screw was replaced. One intra-articular screw stabilizing the posterior wall was also changed during an acetabulum fixation. Discussion: During our first year of use, 3D reconstruction intraoperatively has allowed us to avoid three early reoperations (for two calcaneums and one acetabulum). Classical 2D imaging of these two localizations is difficult to interpret because of the spherical form of the hip joint and, for the calcaneum, the difficulty in obtaining quality retrotibial images. Quality images requires specific installation, limiting interference with metallic supports. Conclusion: The results we have obtained in our first year of use of the ISO-C-3D amplifier has led us to generalise its use for percutaneous fixation procedures involving the acetabulum and the calcaneum

Existing techniques of posterior multi-point C1/2 stabilisation are technically demanding and can be hazardous. The coauthors have recently reported successful atlantoaxial fusion using a novel C1/2 stabilisation technique employing C1 multi-axial posterior arch screws (MA-PAS) in a clinical series of three patients where anatomical anomalies precluded established techniques. The technically less demanding nature of this new technique, and possible wider application in patients with normal anatomy, led the authors to investigate its biomechanical stability compared to other established techniques. Twenty-four human fresh-frozen cadaveric spines were harvested C0-C5. Motion was restricted to between C0 and C4. Each spine was non-destructively tested in flexion/extension, lateral bending and axial rotation, firstly in the intact state and then after Type 2 odontoid fracture destabilisation and insertion of Magerl-Gallie, Unicortical Harms, Bicortical Harms or MA-PAS instrumentation. ROM between C1 and C2 was monitored using two digital cameras. Results for each technique were compared statistically compared using ANOVA. The C1-C2 joint of the intact spines demonstrated high flexibility in flexion/extension (16.5deg). After instrumentation all specimens showed significantly reduced ROM in flexion/extension (Magerl-Gallie FE = 4.2deg, Unicort Harms FE = 7.2deg, Bicort Harms FE = 4.4deg). Lateral bend ROM of instrumented specimens (Magerl-Gallie LB =3.8deg, Unicort Harms LB = 3.8deg, Bicort Harms LB =2.3 deg) was, however, similar or slightly greater than intact (2.7 deg) . MA-PAS showed similar ROM in flexion/extension (4.2 deg) as the Magerl-Gallie and Harms techniques but was slightly higher in lateral bend (5.3 deg). The MA-PAS technique was shown to have similar biomechanical stability to the Magerl-Gallie and Harms techniques. Given the demonstrated biomechanical stability of the MA-PAS technique, it may be a suitable alternative to the existing technically demanding, and possibly more hazardous, multi-point fixation techniques in patients with normal, as well as anomalous, C1/2 segmental anatomy

Introduction: The management of cervical spine fracture, subluxation or dislocation in the elderly may present difficulties in decision-making. Frequently, the elderly suffer from medical comorbidity and a limited physiological reserve, which need to be considered in deciding on surgical versus conservative management of fractures and dislocations. Debate exists regarding the merits of surgical versus nonsurgical management of these injuries. 1,. 2,. 4. Methods: Retrospective analysis of 16 patients with traumatic cervical spine fractures with or without dislocation or subluxation in patients greater than 65 years of age, spanning 1994 to the present were carried out. Success of spine stabilisation, time in hospital, ability to return to pre-injury function and medical or surgical complications were measured. Results: The average age of the patients was 76 years with a range of 67–86 years of age. A variety of cervical injuries and fixation methods were identified, the most common injury being odontoid fracture requiring transarticular screw fixation. One patient died eight days post-operatively of cardiac arrest and a second patient died of pneumonia. One other complication of wound hematoma while the patient was taking anticoagulation therapy occurred. All other patients were discharged independent in activities of daily living. There were no cases of failure of surgery to restore stability. No post-operative neurological deterioration in any of the patients occurred. Discussion: This study shows that surgical fixation of cervical fractures in the elderly can be performed as a safe and efficient form of management. Surgery decreases the period of both immobility and hospitalisation with subsequent decrease in the risk of complications such as deep vein thrombosis, pulmonary embolism and pneumonia. 3. Complications from immobilisation devices such as the halo-thoracic brace may also be avoided

Purpose: The current gold-standard for atlanto-axial fixation is C1-C2 Transarticular Screw (TS) fixation. In certain cases, the complicated nature of vertebral artery injury could make the application of bilateral transar-ticular screws impossible. This study biomechanically compares three atlantoaxial transarticular salvaging fixation techniques. Method: Nine Fresh ligamentous human cervical spine specimens (C0-C4) were thawed and the tissue surrounding the spine, except the ligaments and discs, was carefully removed. Pure moments were applied to skull in increments of 0.5 Nm from 0 Nm to 2.0 Nm with the help of loading arms, nylon strings and pulleys. The specimens were tested in extension (EXT), flexion (FLEX), left lateral bending (LB), right lateral bending (RB), left axial rotation (LR) and right axial rotation (RR) for all the cases. The positions of the LEDs were recorded using an Optotrak Motion Measurement System (Northern Digital, Waterloo, Ontario, Canada) and was converted into three rotations (flexion/extension, lateral bending and axial rotation) using rigid body kinematic principles in relation to the fixed base. The specimens were tested intact and after type II odontoid fracture, were instrumented and tested with three fixation constructs:. C1-C2 TS on right side and C1LMS-C2PS on contralateral side. C1-C2 TS on right side and C1LMS-C2IL on the contralateral side and. C1-C2 TS on right side with sublaminar wire. Results: All of the three instrumented cases significantly reduced motion across C1-C2 segment in all the modes when compared to intact (P< 0.005, two-tailed unpaired t-test at confidence interval of ninety-five percent) except in extension. TS+C1lM+C2PS is significantly stiffer than TS+ Wire only in axial rotation (P< 0.05) and equivalent in flexion/extension (P=0.75/P=0.51) and left/right bending (P=0.22/P=0.58). TS+C1LM +C2PS is equivalent to TS+C1LM+C2IL in all the loading modes (P> 0.05). TS+C1LM+C2IL is significantly stiffer than TS+Wire in axial rotation (P < 0.05) and equivalent in flexion/extension (P=0.93) and left/right bending (P=0.69/P=0.84). Conclusion: This study showed that TS+C1LMS+C2PS fixation is equivalent to TS+C1LMS+C2ILS fixation in all the rotation modes and superior to TS+Wire fixation in axial rotation averaged over all ranges of motion. Also, TS+C1LMS+C2ILS fixation is superior to TS+Wire fixation in axial rotation averaged over all ranges of motion

Introduction: The complex anatomy and biomechanics of the atlantoaxial motion segment impose technical challenges in the achievement of safe and successful surgical stabilization and fusion. The coauthors have recently reported successful clinical results using a novel C1-C2 stabilization technique employing C1 multi-axial posterior arch screws (MA-PAS). This study compares biomechanical stability of MA-PAS with two established multi-point fixation techniques (Magerl-Gallie and Harms) using non-destructive and destructive testing. Methods: 15 human fresh-frozen cadaveric occipital-C5 cervical spines (average age 77.4 [51–95], sourced from ScienceCare, USA) were randomly allocated to 3 equal groups. Screws were passed up through adjacent end vertebrae such that motion was limited to between C0 and C4. Each spinal column was non-destructively tested in flexion/extension (±1.5Nm), lateral bend (±1.5Nm) and axial rotation (±1.5Nm), firstly in their INTACT state and then after Type 2 odontoid fracture destabilization combined with MAGERL-GALLIE (n=5), HARMS (n=5) or MA-PAS (n=5) instrumentation. All 15 reconstructed spines were finally loaded to failure in forward flexion only. Results: Non-destructive testing: The C1-C2 joint of the INTACT spines all demonstrated high flexibility in flexion/ extension (ave 16.5deg) and axial rotation (ave 52.6 deg) while lateral bending (ave 2.7deg) was less compliant (see Fig.3). After instrumentation all specimens showed significantly reduced ROM in flexion/extension (MAGERL-GALLIE=4.2deg, HARMS=4.4deg, MA-PAS=4.2deg) and axial rotation (MAGERL-GALLIE=4.05deg, HARMS=0.59deg, MA-PAS=3.7deg) while lateral bend ROM of all instrumented specimens was similar or slightly greater than INTACT (HARMS=2.3deg, MAGERL-GALLIE=3.8deg, MA-PAS=5.3deg). There was no significant difference between the instrumented groups in each loading direction. Destructive testing: MAGERL-GALLIE was the strongest requiring an average of 13.5Nm to cause failure while HARMS was the weakest requiring 7.8Nm of torque. MA-PAS technique averaged 12.2Nm of torque to cause failure. Conclusions: The MA-PAS technique was shown to have similar ultimate strength in flexion to the MAGERL-GALLIE and HARMS techniques and stability in flexion-extension, axial rotation and lateral bend. The MA-PAS failure load in flexion was greater than the HARMS technique, and nearly as high as the MAGERL-GALLIE. Given the biomechanical stability of the MA-PAS technique, it is proposed that this technique is an alternative to the technically demanding, and possibly more hazardous, conventional multi-point fixation techniques in patients with normal, as well as anomalous, C1/2 segmental anatomy

Purpose: We present the midterm results of conservative treatment of upper (atlas and axis) cervical spine injuries and we propose a CT-based radiological follow-up study. Material and Methods: In a 12 year period (1990–2001), 45 patients (33 male and 12 female) with a mean age 37.2 years (range 15–75) were presented with an acute injury of the upper cervical spine. There were 19 fractures of the atlas (8 Jefferson’s fractures, 6 isolated lateral mass fractures and 5 posterior arch fractures) and 26 axial fractures (12 odontoid fractures, types I–III according to Anderson’s classification and 14 traumatic spondylolisthesis, types I–II according to Effendi classification). Twenty (20) patients were immobilized using halo-vest and 25 Minerva orthosis. Two (2) patients presented with Brown-Sequard syndrome. All patients were retrospectively reviewed and had clinical and radiological follow-up study (plain films and CT spiral reconstruction films). Mean follow-up was 6.2 years. Mean immobilization time was 3.8 months range. Results: Patients with incomplete neurological lesion did not recover. One patient with an isolated atlas lateral mass fracture, developed a hemiparesis during his hospitalization, which was partially resolved. In the final follow-up study, all patients presented a stable upper cervical spine, on the dynamic flexion/extension plain films. In the final CT spiral reconstruction films, fracture line was evident in 12 patients (27%), while atlantoaxial joint incongruity was obvious in 5 patients. Seven (7) patients (16%) complained for residual neck pain and stiffness and presented reduced range of motion. Conclusion: Conservative treatment of atlantoaxial injuries is effective and offers a stable upper cervical spine. Solid fracture union is not always present. CT spiral reconstruction is very helpful in detecting transverse ligament efficacy and atlantoaxial joint incongruity

Introduction: C1-2 polyaxial screw-rod fixation is a relatively new technique. While recognising the potential for inadvertent vertebral artery injury there have been few reports in the literature outlining all the possible complications. Aim:To review all cases of C1 lateral mass screw insertion with emphasis on the evaluation of the potential structures at risk during the procedure. Methods: We retrospectively reviewed all patients in our unit who has C1 lateral mass screw insertion over a 2 year period. The C1 lateral mass screw was inserted as part of an atlantoaxial stabilisation or incorporated into a modular occiput/subaxial construct. Outcome measures included clinical and radiological parameters. Clinical indicators included age, gender, neurologic status, surgical indication and the number of levels stabilised. Intraoperative complications including blood loss, vertebral artery injury or dural tears were recorded. Radiological indicators included post-operative plain radiographs to assess sagittal alignment and to check for screw malposition or construct failure. Results: A total of 18 C1 lateral mass screws were implanted in 9 patients. There were 3 male and 6 female patients who had C1 lateral mass screws inserted in this tertiary referral centre. Two patients had atlantoaxial stabilisation of a C2 odontoid fracture. There were 4 patients with rheumatoid arthritis whose C1 lateral mass screws were inserted as part of an occipitocervical or subaxial cervical stabilisation. The other pathologies included trauma and spinal tumours. There was no vertebral artery injury and no cerebrospinal fluid leak. Three patients developed post operative occipital neuralgia. This neuralgia was transient in one of the patients having settled at 6-week follow up. In the other 2 patients the neuralgia was unresolved at the time of latest follow up but was adequately controlled with appropriate pain management. Post operatively no patient had radiographic evidence of construct failure and all demostrated excellent sagittal alignment. Conclusion: It has been reported that the absence of threads on the upper portion of the long shank screw may protect against neural irritation. However insertion of the C1 lateral mass screw necessitates careful caudal retraction of the C2 dorsal root ganglion. The insertion point for the C1 lateral mass screw is at the junction of the C1 posterior arch and the midpoint of the posterior inferior part of the C1 lateral mass. Two patients in our series suffered occipital neuralgia post insertion of the C1 lateral mass screws. This highlights the potential for C2 nerve root irritation during and after the insertion of the C1 lateral mass screw