Aims: To evaluate whether the atlantoaxial disorders (anterior atlantoaxial subluxation and atlantoaxial impaction) associate with destruction of shoulder or peripheral joints, and bone mineral density (BMD) in patients with long-term rheumatoid arthritis (RA). Methods: An inception cohort 67 patients with seropositive and erosive RA were followed up for 20 years. Cervical spine, shoulder, hand and foot radiographs, and the BMD of the lumbar spine and femoral neck were evaluated. Results: A positive relationship was detected between the occurrence of atlantoaxial disorders and the destruction of both shoulder (p < 0.001) and peripheral (p = 0.001) joints. In addition, the severity of atlantoaxial disorders positively correlated with the grade of destruction in the evaluated joints. Furthermore, a positive relationship was found between the occurrence of the atlantoaxial disorders and a decrease in BMD of the femoral neck (p = 0.019). Conclusions: Patients with severe RA and osteoporosis have an increased risk for atlantoaxial disorders, therefore the cervical spine radiographs of these patients should be analysed before major surgery and also at regular intervals. The co-existence of shoulder and cervical spine disorders makes the differential diagnosis of shoulder and neck pain challenging

Background. Rotatory subluxation of the atlantoaxial joint has been thoroughly documented in children. However, pure traumatic atlantoaxial rotatory subluxation (TAARS) is a rare injury in adults with only a few cases reported in the English literature. Aim. To report two cases of TAARS in adults. Methods. A case note, clinical and radiological review. Results. Both patients were female. There was a history of a motor vehicle collision in both cases. There was no neurological impairment at presentation in either case. The injury in both cases was identified by plain X-ray and confirmed by CT scan. Both were managed by conservative treatment, initially with halo traction, followed by immobilisation in a rigid collar. Final clinical reviews occurred at 7 years and 2.5 years following injury. Neither patient had signs of C1-C2 instability or impaired neurology. Both patients, however, suffered headaches and occipital neuralgia, with stiffness and reduction in cervical spine movement. Conclusion. Traumatic rotatory subluxation in adults is a rare injury. It can pose a diagnostic challenge and CT scanning is mandatory for a correct evaluation of the C1-2 complex. Reduction and stability can be achieved through conservative treatment. However, it is evident from this short series that even early diagnosis and prompt reduction may not necessarily result in a good long term outcome in adult patients with TAARS

Objective: To review the clinical outcome of 37 consecutive patients undergoing C1– C2 transarticular fixation for patients with Rheumatoid Arthritis. Design: Prospective Observational Study. Methods: There were 37 patients at 2 centres. Age range was 37– 82 years. The time since diagnosis to treatment was 2– 23 years. Clinical presentation included suboccipital pain in 26/ 37 patients and neck pain in 29/37 patients. 22 patients had presented with myelopathy ( Ranawat grade II or III A). The preoperative imaging included Plain X Rays, CT scans and MRI scans. All patients underwent C1/ C2 transarticular screws ( Stealth guided) except 4 patients in which an aberrant course of the vertebral artery was identified. Outcome measures: Functional outcome, Complications, Postoperative Neurological Status, Neck Disability index, Myelopathy disability index. Results: 1 patient had died at 12 month followup. Neck pain improved in 22( 75%) of patients by > 5 points on the VAS. Suboccipital pain had improved in all patients. 17 patients (80%) improved following operation on the Ranawat Grading, 2 patient were worse and 3 patients remained the same. > 70% patients reported improvement in neck disability index and > 50% patients reported improvement in myelopathy disability index. Conclusions: C1/ C2 Transarticular fixation with spinal navigation is a safe technique for treating atlantoaxial instability in patients with Rheumatoid Arthritis. This study demonstrates improvement in all domains including neck disability, myelopathy scores and functional outcome

Aims: To examine whether functional radiography and functional magnetic resonance imaging (MRI) are equal to detect the extent of unstabile anterior atlantoaxial subluxation (aAAS) in rheumatic patients. Methods: The series consisted of 23 patients with unstable aAAS (diagnosed by functional radiography) examined by functional MRI because of a neck symptom. Twenty-two patients had rheumatoid arthritis and one had juvenile idiopathic arthritis. aAAS was diagnosed if the anterior atlanto-axial diameter (AAD) was > 3 mm and was considered unstable if the AAD differed > 2 mm between flexion and extension radiographs. The AAD was measured from radiographs (flexion and extension) and MRI images (flexion and neutral). Results: The extent of aAAS during flexion measured by radiography was greater than that found by MRI in all our 23 cases [the mean difference was 3 mm (95% CI: 2 to 4)]. In 4 patients (17%) MRI could not find aAAS. The difference between the AAD measurements during flexion by these two methods was substantial (i.e. , ≥ 4 mm) in 9 cases (39%). Severe aAAS (≥ 9 mm) was seen in 15 patients (65%) by functional radiography and in 4 (17%) by functional MRI. Conclusions: The magnitude of aAAS was often substantially smaller in functional MRI than in functional radiography. Thus one cannot rely on functional MRI alone; functional radiographs are needed to show the size of unstable aAAS

The purpose of this study is the biomechanical comparison of five C1 – C2 posterior arthrodesis techniques. Ten adult human cadaveric upper cervical spine specimens were sectioned at the C3 level. The occiput and C3 vertebra were potted in PMMA. The specimens were tested intact; after destabilizing with odontoid transection and sectioning of the transverse and capsular ligaments; and after stabilization with Brooks-Jenkins cable fixation, Brooks-Jenkins with unilateral transarticular screw, Gallie posterior wire construct with unilateral transarticular screw, Brooks-Jenkins with bilateral screws, and Gallie with bilateral screws. Data were analysed with special attention paid to the motion at C1 – C2. The neutral zone (NZ) and range of motion (ROM) were measured in the main plane of each motion, as well as in coupled planes. In flexion / extension and lateral bending, the ROM and NZ increased significantly in the injured specimens as compared to the intact (p< 0.0001).

In axial torsion, there was no significant difference between the intact and injured spines at C1 – C2 level. In the different fixation systems, the ROM and NZ were significantly lower than in injured and intact spines in all motions (p< 0.01), except the lateral bending in intact spine. Among the 5 instrumentations, the NZ and ROM in flexion / extension for the Gallie construct with one screw were significantly higher than for the Brooks-Jenkins construct with one or two screws (p< 0.05). In axial torsion, the Gallie construct with one screw displayed a larger NZ and ROM than any of the other four constructs (p< 0.05).

Traumatic rotatory atlanto-axial dislocation and subluxations are rare injuries. The diagnosis is often missed or delayed because of subtle clinical signs. Head tilt makes the interpretation of plain radiographs difficult. Delayed diagnosis often results in chronic instability necessitating surgical stabilization. A hitherto undescribed clinical sign was evaluated which should lead to increased awareness and avoid delay in the diagnosis.

Why a new clinical sign?

Easily missed injury

Methods: This study was carried out between 1997 to 2003. The test was applied to 59 patients presenting in Accident and Emergency. All this patients had head tilt even after the application of a hard cervical collar. All the 59 patients had CT scans to confirm or exclude the diagnosis of Rotatory atlanto axial dislocation/subluxation.

Results: The new clinical sign was found to be positive in all the fourteen patients with atlanto- axial rotatory dislocations/subluxations which was confirmed by CT scan. The test was also found to be positive in 5 patients with unilateral facet joint dislocation. The sensivity of the test in our study was 100%. The specificity was 89%, positive predictive value 0.73, negative predictive value 0.9 (90%).

Conclusion: This new clinical sign may help in early recognition of the injury and also act as an effective screen to indicate which patient needs a CT scan to confirm the diagnosis. This can also be applied in places where the CT scan facilities are not readily available especially in the developing nations.

Introduction We review our experience with the use of plate and screw (C1 lateral mass and C2 pedicle) method of fixation in the treatment of 300 patients with disorders of the craniovertebral junction during a 17-year period at our center. We previously described this method of fixation in 1994. Methods Between 1988 and 2004, 250 patients with atlantoaxial instability were treated with the use of a plate and screw method of fixation at our institution. The various aetiologies of atlantoaxial instability were congenital, trauma and rheumatoid arthritis. All patients had mobile, completely reducible atlantoaxial subluxation. The male: female ratio was 3:1. C1 lateral mass screw and C2 pedicle screw were anchored to a plate bilaterally. For 3 months postoperatively, a hard cervical collar was used. The mean follow-up period was 42 months (range, 4 mo–17 yr). Recently, we have modified the technique by distracting the lateral facet joints, placing a cage bilaterally and then performing the lateral mass fixation for a subgroup of 50 patients with either fixed atlantoaxial joint subluxation or basilar invagination. Results Three patients died in the postoperative phase. Successful stabilization of the atlantoaxial region was documented with dynamic radiography in the other patients. In one patient, one screw was found to be broken 18 months after surgery; however, firm bony fusion was documented in this patient. There were no neurological, vascular, or infective complications. Discussion Segmental fixation of lateral masses with plate and screw method of fixation with the use of intra-articular bone grafts in patients with atlantoaxial instability yielded a 100% fusion rate with a low incidence of complications. Direct application of screws into the thick and large cortico-cancellous lateral masses of atlas and axis provides a biomechanically strong fixation of the region

Introduction: The efficacy and complications of the transarticular screw procedure have been reported by many authors. However, few have reported this procedure for child younger than 10 years old. We have treated two children for atlantoaxial subluxation with transarticular screws, using a soft collar without a halo-vest, and have achieved bone union in good reduced position. Methods/results. Case 1: a 5-year-old boy with mental retardation and cerebellar infarction due to an insufficiency of the vertebral artery resulting in severe atlantoaxial instability. He presented with a high degree of congenital atlantoaxial subluxation complicated by Os odontoideum. He has been treated with transarticular screw and iliac bone graft by Brooks procedure. Case 2: an 8-year-old boy with congenital spondyloepiphyseal dysplasia and a right valgus knee. He, too, presented with a high degree of congenital atlantoaxial subluxation complicated by Os odontoideum, and has been treated with transarticular screw and iliac bone graft by Brooks procedure. In both cases, we used two half-thread cortical screws with a diameter of 2.7mm and a length of 30mm for the transarticular screw procedure. Discussion/conclusion: Rigid external fixation was obtained by Halo-vest. This method, however, would be expected to cause mental stress for the child patient and the family. More rigid internal fixation would be required to resolve this problem. More rigid internal fixation can be obtained with the transarticular screw, and postoperative orthosis can be performed easily, without the need for a Halo-vest

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: 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

Craniovertebral tuberculosis accounts for 5% of all cases of tuberculosis and is the commonest infective pathology affecting this region. There are very few published reports discussing the presentation and management of this complex pathology. 30 cases of craniovertrebral tuberculosis treated between 1989–97 were reviewed retrospectively. The average age was 24 years (range 6 – 42 years) with a follow up of 41 months (range 36 – 48 months). Two main groups on the basis of atlantoaxial stability. 18 (60%) had an unstable atlantoaxial articulation and of these 12 (66%) had a fully reducible AAD in extension. 17 patients (56%) had varying degrees of neurological deficit with lower limb spasticity being the commonest. Antituberculous chemotherapy, skeletal traction in extension and prolonged bracing with moulded philadelphia collar were main stays of conservative treatment. Surgery in the form of posterior occipito cervical arthrodesis was needed in 13 patients (43%) and indications included incompletely reduced AAD, non resolving neurological deficit and persistent instability despite 6 weeks in traction. There was 93% success rate with resolution of infection (range 4 – 8 months) and improvement in neurological deficit 2 patients had incomplete neurological recovery and required 2. nd. stage anterior transoral odontoidectomy. Management strategies based on the presence or absence of instability and neurological deficit can give a very satisfactory outcome with judicious combination of drug therapy, bracing and surgical decompression with fusion

Introduction Rheumatoid arthritis also affects the spine and creates conditions that need surgical treatment. As in other parts of the body, the maintenance of function and reduction of pain are primary goals of surgical treatment, however the additional threat to the neurological structures create an additional dimension in the surgical treatment of the spine. Destructive processes of osteoligamentous structures and severe osteoporosis may be blamed as the principle cause for pain, deformity and subsequent neurological deficit in the rheumatoid patient’s spine. Cervical spine Atlantoaxial instability is the most frequently encountered pathology in the cervical spine of the rheumatoid patient. In order to avoid late appearance of myelopathy, the timing of surgery in the presence of significant atlantoaxial instability (ADD < 5mm) has to be carefully evaluated. The tendency is towards early surgical stabilization since no spontaneous improvement is to be expected in cases with aggressive rheumatoid arthritis. Late surgery not only carries the risk of causing myelopathy by repeated micro-trauma of the myelon, but also the need for extensive surgery including the occiput and the lower cervical spine in case of advanced destructive processes. The subaxial cervical spine has a tendency to disintegrate in the presence of aggressive course of rheumatoid arthritis. The extent of instability and site of compression has to be carefully analyzed, using MRI and neurophysiological examinations. Due to weak bone structures anterior and posterior interventions are often necessary. Lumbar spine The rheumatoid pathology in the lumbar spine is mainly influenced by the degree of osteoporosis. Typical osteoporotic fractures, often on several levels, represent the most frequent pathology, which needs surgical help. In case of persistent pain the relatively new technique of vertebroplasty offers an elegant way to reduce pain. If severe deformities occur, the osteoporotic structure of bone limits the surgical possibility of correction of the deformity. Conclusion “Wait and see”-policy in rheumatoid patients with spinal pathology is often not appropriate (as in other joints of the body) if function and neurology should be preserved and maintained. Early surgery represents usually minor intervention and is better tolerated than extensive corrections. Osteoporosis is the main limitation for surgical treatment in the rheumatoid spine

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

Purpose: Ligament laxity is a common feature of trisomy 21 and is incriminated in most of the orthopaedic disorders observed. Early diagnosis and management is essential. C1-C2 instability is a recognised manifestation in trisomy 21 and is associated, at least theoretically, with significant risk of cord complications. The purpose of this work was to provide a descriptive analysis of the C1-C2 joint in trisomy 21 and to analyse instability factors in order to determine the tolerable C1-C2 distance. Material and methods: Within the framework of a French national epidemiology survey of trisomy 21, we focused on the C1-C2 joint. A total of 472 children with trisomy 21 were identified; 458 who were examined were included in this study. Careful history taking and a detailed physical examination with neurological tests (search for even minimal signs of neurological disorders) was conducted. The Carter and Wilkinson method was used to assess joint laxity. The same specialist searched for other orthopaedic disorders. Patients were divided into two groups depending on the presence or absence of neurological signs. Two groups were also distinguished according to the presence or absence of generalised laxity (Carter and Wilkinson). Lateral x-rays centred on C1-C2 were performed by the same technician on the same machine with the patient in a neutral position, hyperflexion and hyperextension. The same technique inspired by the method described by Singer et al. and modified for simplification was used in all cases. The same observer interpreted the images using a single-blinded protocol to search for congenital malformations and signs of degeneration, measure the C1-C2 distance the minimal sagittal diameter and the C1-C2 angle (not reported in the literature and described for this study). These measures were then compared with data in the literature as available and correlated by age, gender, presence of neurological signs and joint laxity. Seven patients were excluded from the study due to insufficient cooperation for the x-rays and nine because of incomplete clinical or radiological data. The statistical analysis was performed on data from 442 patients. Quantitative variables were compared with the Pearson test and parameteric ANOVA was used to search for correlations of quantitative and qualitative variables. Significance was set at p< 0.05. Results: Mean patient age was 13.8 years. There were 184 girls and 258 boys. Minor neurological anomalies were found in 42% of the patients. There were no cases of major motor deficit. Generalised laxity as defined by Carter and Wilkinson was observed in 24% of patients. Other orthopaedic problems, basically of the foot, were found in 85%. The radiograms revealed a very wide range of measures were thus expressed as means. The C1-C2 distance was greater than 4 mm in 34 patients on the flexion films (limit established in the literature for instability in trisomy 21). The maximal C1-C2 distance in the neutral position was 8 mm, 9.6 mm in flexion. The lowest minimal sagittal distance was 8 mm in flexion and 10 mm in the neutral position (the lower limit reported in the literature before considering the cord to be threatened in 14 mm). The greatest variability was found for the C1-C2 angle. Ligament laxity and atlantoaxial distance were inversely proportional to patient age, but there was no significant correlation between atlantoaxial instability (C1-C2 distance > 4 mm) and gender or generalised hyperlaxity. There was no significant correlation between C1-C2 instability or laxity and neurological signs. Discussion and conclusion: Compared with earlier publications, our series offers the advantage of a large unselected population providing epidemiological data on trisomy 21. A standard radiography protocol was used. The large majority of the radiographic measures reported in the literature do not take into account the magnification effect nor position variability between patients. Our findings confirm certain data in the literature and also provide new information suggesting it could be useful to revisit certain pathogenic hypotheses about C1-C2 instability and its neurological consequences in trisomy 21. Two important observations were the absence of a correlation between general laxity and C1-C2 instability and the absence of correlation between C1-C2 instability and the presence of neurological signs

Purpose. In stabilisations of atlantoaxial instabilities it holds risks to injure the A. vertebralis as well as neurological structures. Furthermore the posterior approach of the upper part of the cervical spine requires a huge and traumatic preparation of the soft tissue. However the anterior transarticular C1-2 fusion (ATF) is less traumatic and offers almost the same strengh of the stabilisation. Methods. Since the 01/2007 22 multimorbid patients with atlanto-axial instabilities of different entities were treated via the ATF, were regular examined radiologicaly (x-ray/CT) and the procedure critically judged. Results. C1-2 fusions were performed in 22 patients (17f, 5m, Ø 81,67 years). Main symptoms was pain radiating in the upper cervical spine and the occiput, 2 Patients complaining radiating pain with paraesthesia. The average operation-time took 64,5 min. Leftside the screws of Ø 39,5mm (32–44mm), rightside of 36mm (32–44mm) were inserted in addiction to the point of access and the angle of insertion (mediolateral angle Ø 32,0°, ventrodorsal Ø17,6°). No introperative complications occured, one revision had to be done because of p.o. bleeding, one because of screw dislocation. Postoperative x-ray and CT control of the upper cervical spine showed 30/44 screws in 22 patients in correct position. 8 (18,2%) screws were too long, 3 (6,8%) screws were placed too anterior and 3 (6,8%) too medial. 8 additional positionated dens-screws were in correct position. After a clear learning curve both screws of the 6th patient were positoinated correct. Two aspects are important for success: Correct entry point and right insertion of the angle in the coronar and sagittal view. A low intraoperative blood loss, a non traumatic access as well as an immediate pain decrease have to be valued positively for this procedure. Conclusions. The gentle procedure of the ATF requires-despite of the huge experience in anterior surgery of dens fractures - a learning curve, because of the more proximate insertion point, the flat insertion angle and the closeness of the A. vertebralis. If these aspects are going to be noticed, failed screw positioning and excessive length as well as injuries of the A. vertebralis can be avoided

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

Goals: Advantage of the dorsal fixation of C1/2. Materials and Methods: From 01/2006 to 12/2006 22 patients with a traumatic fracture of C1/2 were operativly stabilized. The avarage age was 79 year (66–92). No neurological deficit. Diagnostic was always a CT-scan for classification of fracture typ. 7 patients were temporarily immobilized with HALO fixateur. Within th next 8 days final operation hab been carried out. 7 patients with Anderson fractures typ II were stabilized with open fixation from ventral (group 1). 4 Jefferson fractures and 2 combined C1/2 fractures were were stabilized with open fixation from dorsal (Magerl) (group 2). Percutanous fixation from dorsal was done in 5 patients with fractures of the atlas, 4 with Anderson fractures typ II (group3). Clinical and radiological follow up was done in 18 patients. Results: Duration for operation was in 64min in group1, 134min in group 2 and in 42min in group3. No neurological deficit or damage of A.vertebralis occurred. Blood loss was in group 1 and 3 under 50ml in group 2 750ml. In group3 one slightly dislocation of screw happened without need of revision. Movement of cervical spine was reduced in group 2 and 3. During follow up 3 of seven ventral stabilized Anderson fractures typ II (group1) were dislocated. Dorsal percutanous fixation for operatively revision was done. Discussion: Percutanous dorsal transarticular screw fixation C1/2 is a challanging procedure for stabilization of atlantoaxial fractures. Main advantages compared to other operation techniques are less blood loss, short operation time, high rate of success

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

Objective: To reassess whether the Ranawat IIIB (quadriparetic, non-ambulant) rheumatoid arthritis (RA) with cervical myelopathy patients should be surgically treated. Study Design: Retrospective study. Subjects: Over a 12-year period (1988–1999), 51 patients [15 M: 36F; mean age 64 years] in Ranawat IIIB with RA were diagnosed to have cervical myelopathy. These included 47 patients with atlantoaxial subluxation (AAS) [15 with AAS alone, 10 with basilar invagination (BI), 18 with associated subaxial subluxation (SAS) and four patients with BI and SAS] and four patients with SAS alone. Results: Thirty-two patients considered fit for surgery successfully underwent operative treatment (Group 1). All underwent posterior instrumented fixation with or without transoral odontoid peg excision. Postoperatively 22/27 patients were pain free and 21/32 patients initially non-ambulant were able to walk. 3/26 patients died within six months of surgery. 13/19 patients managed conservatively (Group 2) because of medical complications died within six months of presentation. Conclusions: Even in advanced stages of cervical myelopathy in RA, surgical intervention is beneficial with significantly higher morbidity/mortality in conservatively managed patients

Introduction: Atlanto-Occipital dislocation is rare and usually fatal. Stabilisation is typically from Occiput to C2; sacrificing atlantoaxial movement. To preserve movement, screw fixation from the articular mass of C1 to the occipital condyle has been described. Amongst other structures, the hypoglossal nerve is at risk. No previous study has addressed the anatomy of the hypoglossal canal in relation to screw trajectory. We aim to identify landmarks to aid safe screw passage into the occipital condyle. Methods: 20 dry skulls provided 40 hypoglossal canals (HCs) and 40 occipital condyles (OCs). No distinction was made between sex, race or age. 9 parameters were measured for each HC, and relation to skull base was noted. Results: The mean length of the HC was 10mm (range 8 to 14). The extra-cranial foramen of the HC is located lateral to the intra-cranial foramen (30° range 19 to 45). 19 out of 20 skulls had HCs with intra-cranial foramina more caudal than their extra-cranial foramina, ie the HC angled cranially (22° range 7 to 51). 36 of 40 OCs were found to be wholly inferior to the rim of the foramen magnum, with 4 (in 2 skulls) whose bodies lay largely below, but extended above, this landmark. Every single HC studied was situated, in its entirety, superior to the rim of the foramen magnum. Conclusions: The trajectory of the hypoglossal canal from its intra-cranial foramen is antero-supero-lateral. It is situated, in its entirety, superior to the rim of the foramen magnum. The thickest portion of the occipital condyle is antero-medial. Screw passage from posterior through the C1 articular mass ought to aim for the anterior, superior, medial quadrant of the occipital condyle, and should not pass cranial to the rim of the Foramen Magnum in order to minimise the risk to the Hypoglossal Nerve