Atlantoaxial Research Articles

Preclinical evaluation of a novel anterior non-fusion fixation device for atlantoaxial instability: an in vivo comparison study in a canine model.

The Anterior Atlantoaxial Non-Fusion Fixation System (AANFS) was a novel motion preservation device for atlantoaxial instability to replace traditional fusion techniques. The purpose of this in vivo study was to evaluate the clinical features and biomechanical properties of this new device in a canine model by comparing it with a conventional method. Eighteen adult male canines were randomly divided into group 1, which received the AANFS replacement, group 2 which received the Harms rigid fixation procedures, and group 3, which served as the control group. Routine follow-up evaluations were performed postoperatively. Specimens were harvested 12weeks after the operation. Biomechanical tests were conducted to obtain the range of motion (ROM) and neutral zone (NZ) at C1-C2 segment in different groups. The canines successfully tolerated the entire experimental procedure. No significant differences were found in surgery time, blood loss and recovery time between the AANFS group and the Harms rigid fixation group. Radiological examinations revealed that the position of the implant was good. Biomechanical results showed that, compared with the intact group, the mean ROM and NZ in flexion, extension, lateral bending and rotation were significantly reduced after rigid fixation. However, after the AANFS implantation, ROM and NZ in all directions were similar to those of the intact state. This study for the first time provides an animal model for studying non-fusion strategies of upper cervical spine. The AANFS was able to maintain movement function of the atlantoaxial joint and may be an alternative to traditional fusion techniques. These slides can be retrieved under Electronic Supplementary Material.

Does Additional Bone Grafting of Atlantoaxial Joint Increase Bone Fusion Rate of Iliac Crest Autograft in Posterior Occipitocervical Fusion? Retrospective, Controlled Study with 2-Year Follow-up

We sought to explore whether additional bone grafting of the atlantoaxial joint increases the bone fusion rate of iliac crest autograft in posterior occipitocervical fusion surgery. From January 2012 to January 2016, a total of 78 patients who had basilar invagination with occipitalization of the atlas came to our tertiary spine center. Except for those lost to follow-up (10 cases) or who had a follow-up time <2 years (20 cases), there were 48 patients retrospectively included in this study. In the control group, a piece of autogenous iliac corticocancellous bone was placed between the occipital and C2 vertebral lamina for fusion. In the hybrid fusion group, besides posterior occipitocervical autograft, some granular bone harvested from the iliac crest was packed into the bilateral atlantoaxial joint. X-ray imaging and cervical computed tomography (CT) were performed during follow-up. The operations were completed successfully in all patients without intraoperative complications. Only 21 (87.5%) patients in the control group had confirmed posterior bony fusion on CT, while 24 (100%) patients in the hybrid fusion group had confirmed posterior bony fusion. There were postoperative implant-related complications in 2 patients. Both cases belonged to the control group (8.3%). Three patients (12.5%) complained of transient numbness in the posterior occipital region: 2 patients in the hybrid group and 1 patient in the control group. The mean duration to posterior occipitocervical fusion was 5.5 months in the hybrid fusion group versus 6.1 months in the control group (P = 0.757). Of note, in the hybrid fusion group, the process of atlantoaxial joint fusion was faster than that of posterior occipitocervical fusion (5.1 months vs. 5.5 months, P = 0.823). Additional bone grafting of the atlantoaxial joint could increase the bone fusion rate of iliac crest autograft in posterior occipitocervical fusion.

Surgical outcome of type II odontoid fracture, Harms technique

BackgroundCervical trauma is a common cause of disability following spinal cord injury especially in athletic populations. The biomechanics in the atlantoaxial joint carry more than 50% of the rotational movement which can be affected in transverse ligament tear associated with odontoid fracture type II. Odontoid fracture type II is considered an unstable fracture with a high rate of nonunion in conservative treatment. Limitation of the odontoid screws in some cases gives the chance of posterior cervical fixation to have the superior role. Use of polyaxial screws in Harms technique gives the best results in maintaining majority of the biomechanics.PurposeOur aim in this study is to evaluate Harms technique in patients regarding pain improvement and restoration of the motor power and to report the complications.Study designThis is a retrospective case series study. We used the Frankel grading system to evaluate the postoperative neurological state.Patient and methodsBetween January 2015 and January 2018, 12 patients were introduced to the neurosurgical department at the Sohag University Hospital with post-traumatic type II odontoid fracture with failure of conservative treatment and not suitable for anterior odontoid screws. All patients underwent full laboratory, medical, and neurological evaluation and imaging study on the cervical spine. All patients underwent posterior cervical fixation C1–C2 by polyaxial screw Harms technique.ResultsMale ratio was predominant in our study: 75% with a mean age 34.4 years. Neck pain with limitation of the neck movement was the complaint for the all cases. Three cases came with neurological affection. Postoperative superficial infection reported in one patient; no vertebral artery or neural injuries were noticed in our study.ConclusionHarms technique C1–C2 fixation is a valuable choice in patients with type II odontoid fracture with failure of conservative treatment or not suitable for odontoid screw. Harms technique gives us the highest preservation of the biomechanics among the other posterior approaches.Trial registrationNCT03768843.

Ultrasound criteria for biomechanical component of local and regional level somatic dysfunction in case of myogenic torticollis

Introduction.Myogenic torticollis is the most common injury in children′s musculoskeletal system. Atlantoaxial rotatory subluxation is one of the main reasons for this pathology. In the newborn even a minor injury during pathological delivery can cause this. The ultrasound method allows you to conduct a real time examination and provide the physician by complete information about the state of pulpal nucleus, fi brous ring, and relative position of cervical vertebrae bodies, spinal canal and radicular canals. Also it allows you to estimate neck muscles thickness and area, which is an informative complementary method of osteopathic diagnosis.Goal of research— clarifi cation of the criteria for biomechanical component of local and regional level somatic dysfunction by ultrasound examination of the cervical spine Materials and methods. The paper presents the data of cervical spine ultrasound examination for 57 nursing infants, infants and preschoolers with myogenic torticollis due to birth injury (ICD code X: P 15.8).Results.An ultrasound examination of the cervical spine determined the quantitative parameters of the atlantoaxial joint and the spinal canal, which was 17,57±0,44 mm. By posterior approach, the asymmetric position of theCII odontoid bone with respect to lateral masses of the atlas was determined; a statistically signifi cant width difference in atlantoaxial joint space was revealed (p&lt;0,001). By muscles ultrasound examination, signifi cant thickness differences between left and right larger posterior straight muscles of the head (p&lt;0,05) were found. Signs of instability at theCII–CIII level were detected in all patients, with no instability signs at other levels.Conclusion.The established criteria for ultrasound examination are atlantoaxial joint state, hypermobility of spinal motor segments, as well as muscles thickness and area in region under study. This allows us to verify instrumentally biomechanical SD of both local and regional levels, thus dynamic control over osteopathic treatment effectiveness is possible.

Gerber's Ligament—A Forgotten Structure of the Craniocervical Junction

Ligaments of the craniocervical junction play a critical role in stabilizing this region. Gerber's ligament has more or less been forgotten and, to our knowledge, never studied. Dissection of the craniocervical junction was performed in 15 fresh frozen cadavers. In the prone position, the posterior elements of the upper cervical vertebrae and occiput were removed. After removing the contents of the spinal canal and posterior cranial fossa, the dura mater and tectorial membrane were reflected. The superior band of the cruciform ligament was reflected. When Gerber's ligament was identified, its attachments and morphometry were recorded. Lastly, Gerber's ligament was observed while range of motion of the craniocervical junction was performed. Gerber's ligament was identified in 7 specimens (46.7%). This structure arose anteriorly from the junction of the superior band and transverse part of the cruciform ligament. Gerber's ligament was always found to be just deep to the superior band of the cruciform ligament but traveled more anteriorly to attach onto the posterior aspect of the dens approaching, but not attaching onto, its apex. Mean length was 11 mm, and mean width was 7 mm. Thickness of the ligament was 0.5-1.1 mm. The ligament was found to become taut with minimal rotation of the atlantoaxial joint and extension of the craniocervical junction. A good understanding of all ligaments of the craniocervical junction is important to surgeons and physicians treating patients with injury to the upper cervical spine.

Advance in research on anterior occipitocervical fixation and fusion

The stability of the occipitocervical region mainly depends on the integrity of the bony structure, surrounding ligaments and joint capsules. The instability of this region often leadsto the clinical symptoms of compression injury of nerve and vascular, which requires early surgical intervention to rebuild its stability. Posterior occipitocervical fixations are main surgical treatment for the occipitocervical diseases. However, the posterior fixations are not suitable for some patients with congenital or iatrogenic causes. Recently, the anterior occipitocervical fixation with the screws anchored at clivus or into the occipital condyles have been used for the following operations. 1. Anterior bone graft fusion. One case which was performed by oral approach was reported well fusion, but the stability was poor and there was a possibility of displacement. 2. Anterior shaped titanium cage and plate fixation. The literatures reported that this anterior operation was completed in 35 cases by oral, oral combined with mandibulotomy, and anterior retropharyngeal approaches. This fixation has a good biomechanical stability and is widely used in clinical applications, including occipitocervical tumors and deformities. And the complications including intraoperative vascular, spinal and dural injuries, postoperative drinking cough, non-fusion, deep infection, and death. 3. Anterior occipital-atlantoaxial joint screw fixation. Seven cases were performed by anterior occipital-atlantoaxial joint screw fixation through anterior percutaneous approach. This fixation is less trauma, but required precise placement of screw and not conducive bone fusion, and it is suitable for traumatic instability of the upper cervical spine, atlantoaxial dislocation and basilar invagination. Each procedure of anterior occipitocervical fixation is not suitable for all patients, and it should be adopted according to the patient's condition, surgical hardware conditions and the surgeon's habits.

Quantitative magnetic resonance imaging assessment of lateral atlantoaxial joint meniscoid composition: a validation study.

Lateral atlantoaxial (LAA) joint meniscoid composition may have clinical significance in patients following neck trauma. However, the existing method of radiologically assessing meniscoid composition has an inherent element of subjectivity, which could contribute to measurement variability. The present study sought to investigate the accuracy of two-point Dixon fat/water separation MRI as a quantitative assessment of LAA joint meniscoid composition. Sixteen LAA joint meniscoids were excised from four cadavers (mean [SD] age 79.5 [3.7]years; one female) following cervical spine MRI (two-point Dixon, T1-weighted VIBE and T2-weighted SPACE sequences). Composition of LAA joint meniscoids was undertaken by (1) histological examination by light microscopy, (2) calculation of fat fraction by Dixon MRI (both in-phase/opposed-phase and fat/water methods), and (3) the existing method of considering VIBE and SPACE signal intensities. Analysis was performed using the kappa statistic with linear weighting. Microscopy revealed three, five, and eight meniscoids to be composed of adipose, fibroadipose, and fibrous tissues, respectively. Dixon sequence MRI classified 11 of these meniscoids correctly, with 'substantial' level of agreement (In-phase/Opp-phase kappa statistic = 0.78 [95% CI 0.38, 1.17]; fat/water kappa statistic = 0.72 [95% CI 0.32, 1.11]). Level of agreement between microscopy and the VIBE and SPACE method was 'slight' (kappa statistic = 0.02 [95% CI - 0.34, 0.38]). Findings suggest that Dixon fat/water separation MRI may have superior utility in the assessment of LAA joint meniscoid composition than the existing method of considering VIBE and SPACE signal intensities. These slides can be retrieved under Electronic Supplementary Material.

Effectiveness of posterior reduction and fixation in atlantoaxial dislocation: a retrospective cohort study of 135 patients with a treatment algorithm proposal.

Surgical procedures on atlantoaxial dislocation remain controversial. The aim of this observational retrospective study was to investigate the treatment algorithm of surgical procedures. According to CT and intraoperative evaluation during direct posterior reduction, 135 AAD cases were categorized into three groups: Group I: reducible dislocation; Group II: irreducible dislocation (Group IIa: effective decompression achieved after posterior reduction; Group IIb: no effective decompression after posterior reduction); and Group III: fixed dislocation. Group III presented with extensive bony fusions. Group I and Group IIa were treated with direct posterior reduction and fixation. Group IIb underwent posterior fixation and transoral odontoidectomy. Group III underwent transoral odontoidectomy alone. Japanese Orthopedic Association scores (JOA) were assessed to evaluate clinical status before and 6, 12months after surgery. Our study included 118 Group I cases, 16 Group II cases (Group IIa: 11 cases; Group IIb: 5 cases), and one Group III case. Follow-up ranged from 12 to 36months. Anatomic atlantoaxial reduction was achieved in 118 of 135 patients (87.4%). Clinical improvements were seen in 96.3% (130/135) all the patients. Solid atlantoaxial fusion was shown in 134 patients. Secondary outcome: The overall complication rate was 3.7% (5/135). For Group I, the mean postoperative 6-month JOA was 14.5 versus 12.2 in preoperative patients (paired Student's t test, P < 0.01). This article proposes a clinical procedure that assists with therapeutic decision making and indicates the severity and difficulty of reduction of the atlantoaxial joint. These slides can be retrieved under Electronic Supplementary Material.

A temporary disc-like structure at the median atlanto-axial joint in human fetuses.

During observations of mid-term and late-stage fetuses, we found a joint disk-like structure at the anterior component of the median atlanto-axial joint. At mid-term, the disk-like structure was thick (0.1–0.15 mm) relative to the sizes of bones surrounding the joint. However, it did not completely separate the joint cavity, and was absent in the inferior and/or central part of the cavity. This morphology was similar to the so-called fibroadipose meniscoid of the lumbar zygapophysial joint that is usually seen in adults. In mid-term fetuses, there was evidence suggesting that a mesenchymal tissue plate was separated from a roof of the joint cavity. In late-stage fetuses, the thickness (less than 0.15 mm) was usually the same as, or less than that at mid-term, and the disk-like structure was often flexed, folded and fragmented. Therefore, in contrast to the zygapophysial meniscoid as a result of aging, the present disk-like structure was most likely a temporary product during the cavitation process. It seemed to be degenerated in late-stage fetuses and possibly also in newborns. Anomalies at the craniocervical junction such as Chiari malformations might accompany this disk-like structure at the median atlanto-axial joint even in childhood.

Cervical spondylosis in patients presenting with "severe" myelopathy: Analysis of treatment by multisegmental spinal fixation - A case series.

Background:Surgical strategy of multisegmental spinal fixation that includes atlantoaxial joint for patients having cervical spondylosis-related symptoms of severe myelopathy is analyzed.Objective:Surgical outcome of patients presenting with “severe” symptoms of cervical myelopathy having multisegmental degenerative cervical spondylosis and treated by multisegmental spinal fixation is analyzed. Atlantoaxial joint was included in the fixation construct in majority of patients. No bone, soft tissue, osteophyte, or disc resection for decompression was done.Materials and Methods:Sixty-four patients having multisegmental cervical spondylosis who presented with symptoms of severe myelopathy were surgically treated during the period from March 2013 to December 2018. On the basis of the concept that instability is the primary cause of spinal degeneration, multisegmental spinal fixation was done in all patients. Atlantoaxial joint was included in the fixation construct in 48 patients. The levels of spinal fixation were determined on the basis of direct observation of facet joints and by manual manipulation and were guided by the presenting clinical features and radiological information. Clinical monitoring was done using Goel clinical grading, modified Japanese Orthopedic Association Score, and visual analog score parameters. Patient satisfaction index assessed the functional and symptomatic improvement.Results:During the follow-up that ranged from 6 to 75 months, all patients improved in their clinical status. Fifty-five (85.9%) patients could walk independently or with mild support.Conclusions:Multisegmental spinal fixation that includes atlantoaxial joint in most patients forms a rational treatment strategy for patients of cervical spondylosis presenting with severe symptoms of myelopathy.

Role of Subaxial Spinal and Atlantoaxial Instability in Multisegmental Cervical Spondylotic Myelopathy.

In this paper the role of atlantoaxial and multilevel subaxial spinal instability as the primary nodal point of the pathogenesis of degenerative cervical spinal disease-related myelopathy, and the focus of surgical treatment for it, is evaluated. The series analyses the treatment of 73 patients with single or multilevel degenerative cervical spinal disease by fixation of the involved spinal segment(s) alone, aimed at arthrodesis. No bone decompression or disc/osteophyte resection was done. In 23 patients, the atlantoaxial joint was included in the spinal fixation, as atlantoaxial instability was identified by facetal malalignment on imaging or by observations on direct bone manipulation during surgery. There were 70 males and 3 females. The ages of the patients ranged from 35 to 76years (average 57years). The transarticular screw method was deployed for subaxial spinal fixation and a lateral mass plate/rod and screw technique was used for atlantoaxial fixation. During the follow-up period, which ranged from 3 to 42months (average 27months), all patients improved in terms of their clinical symptoms. There were no surgery- or implant-related complications. Atlantoaxial joint instability is frequently associated with subaxial multilevel spinal instability in degenerative spinal disease. Fixation of the spinal segments provides a safe, effective and rational treatment for single or multilevel spinal degeneration.

Atlantoaxial Instability: Evolving Understanding.

The atlantoaxial joint is the most mobile joint in the body. The physical architecture of the joint is characterized by a uniformly round and approximately flat surface, which allows a wide range of unobstructed movements. The standing human posture and lifelong heartbeat like uninterrupted activity of the atlantoaxial joint, and its ability to facilitate saying both 'yes' and 'no' necessarily requires smooth and 'fluid' movements that are supported by strong yet supple ligaments. The magnificent architectural structure that is 'magically' designed and carved by nature to provide both stability and mobility and to allow a smooth and safe transit passage for the most critical neural and vascular structures can only be admired in awe and appreciated.

Differences in fixation strength among constructs of atlantoaxial fixation.

OBJECTIVETo avoid jeopardizing an aberrant vertebral artery, there are three common options in placing a C2 screw, including pedicle, pars, and translaminar screws. Although biomechanical studies have demonstrated similar strength among these C2 screws in vitro, there are limited clinical data to address their differences in vivo. When different screws were placed in each side, few reports have compared the outcomes. The present study aimed to evaluate these multiple combinations of C2 screws.METHODSConsecutive adult patients who underwent posterior atlantoaxial (AA) fixation were retrospectively reviewed. Every patient uniformly had bilateral C1 lateral mass screws in conjunction with 2 C2 screws (1 C2 screw on each side chosen among the three options: pedicle, pars, or translaminar screws, based on individualized anatomical consideration). These patients were then grouped according to the different combinations of C2 screws for comparison of the outcomes.RESULTSA total of 63 patients were analyzed, with a mean follow-up of 34.3 months. There were five kinds of construct combinations of the C2 screws: 2 pedicle screws (the Ped-Ped group, n = 24), 2 translaminar screws (the La-La group, n = 7), 2 pars screws (the Pars-Pars group, n = 6), 1 pedicle and 1 pars screw (the Ped-Pars group, n = 7), and 1 pedicle and 1 translaminar screw (the Ped-La group, n = 19). The rate of successful fixation in each of the groups was 100%, 57.1%, 100%, 100%, and 78.9% (Ped-Ped, La-La, Par-Par, Ped-Par, and Ped-La, respectively). The patients who had no translaminar screw had a higher rate of success than those who had 1 or 2 translaminar screws (100% vs 73.1%, p = 0.0009). Among the 5 kinds of construct combinations, 2 C2 pedicle screws (the Ped-Ped group) had higher rates of success than 1 C2 pedicle and 1 C2 translaminar screw (the Ped-La group, p = 0.018). Overall, the rate of successful fixation was 87.3% (55/63). There were 7 patients (4 in the Ped-La group and 3 in the La-La group) who lost fixation/reduction, and they all had at least 1 translaminar screw.CONCLUSIONSIn AA fixation, C2 pedicle or pars screws or a combination of both provided very high success rates. Involvement of 1 or 2 C2 translaminar screws in the construct significantly lowered success rates. Therefore, a C2 pars screw is recommended over a translaminar screw.

Torticollis and rotatory atlantoaxial dislocation: A clinical review.

Rotatory atlantoaxial instability can manifest as an acute episode following subtle or minor injury or even following a gentle tap on head in young children and can manifest as a painless deformity of the head. Goel technique of direct surgical opening of the atlantoaxial facet joint, manual manipulation of the facets can lead to reduction of rotatory atlantoaxial dislocation and recovery from torticollis. Torticollis can be a protective natural phenomenon in response to atlantoaxial instability and related basilar invagination. Only atlantoaxial fixation can lead to immediate postoperative reduction of torticollis. Spasmodic torticollis related to muscle hyperactivity is unrelated to atlantoaxial instability.

Rheumatoid arthritis and ankylosing spondylitis with cervical involvement and characteristics

Rheumatoid Arthritis and Ankylosing Spondylitis are systemic, inflammatory and chronic diseases. Cervical vertebra involvement is common and may cause disability in patients. The aim of this study; to determine the clinical and radiological features of cervical vertebrae involvement in patients with Rheumatoid Arthritis and Ankylosing Spondylitis and to assess the disability and quality of life of patients with different measurement methods. Forty-two patients with Ankylosing Spondylitis (AS) were diagnosed according to Modified New York criteria and 54 Rheumatoid Arthritis (RA) patients meeting the American College of Rheumatology (ACR) criteria were included. Cervical vertebra joint range of motion and neurological examination of all patients were evaluated. Open odontoid radiographs, lateral cervical graphs in the flexion and extension positions and MRI images were taken. Values such as erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and Rheumatoid factor (RF) were determined in all patients. Disease activity was assessed in patients with RA using DAS 28 and BASDAI (Bath Ankylosing Spondylitis Disease Activity Index) in AS patients. In the evaluation of quality of life and disability for RA patients, the health assessment questionnaire (HAQ), the Rheumatoid Arthritis Quality of Life Scale (RAQOL), Short Form 36 (SF36), AS patients were interviewed for the Quality of Life Scale-SPA (SPA-QOL), Ankylosing Spondylitis Life Quality Scale (ASQOL), Short Form 36. 48 of the RA patients were female and 8 were female. The average age was 50.7 years Six patients with RA and AS had AAS identified by radiography. Pannus was detected on MRI of 5 patients with RA and 7 patients with AS. 80% of our patients with RA and 71% of our patients with AS who detected pannus formation by MRI were AA joint range was below 3 mm. There was no significant relationship between disease activity criteria and AAS. There was a significant relationship between AAS and age in RA patients (p < 0.05). Patients with RA had a worse quality of life. Cervical vertebral involvement can lead to deterioration of the quality of life of patients. For this reason, cervical spine involvement should be specifically investigated following the disease. Plain radiographs can provide reliable and practical measurements in determining cervical involvement MRI can be consulted if needed. Assessment of atlantoaxial joint integrity in patients with minimal cervical symptoms. Early diagnosis and treatment of cervical spine disorders is important.

Ossification of the Posterior Longitudinal Ligament: Analysis of the Role of Craniovertebral and Spinal Instability.

This paper reviews an experience of surgically treating ossification of the posterior longitudinal ligament (OPLL) with fixation of the involved spinal segments alone, without resorting to any bony or soft tissue decompression or attempts at direct resection of the OPLL. While in the early part of the experience, stabilization of only the involved subaxial cervical spinal segments was done, in the later part of the experience, atlantoaxial fixation was included in the multisegmental spinal fixation construct. This treatment is based on the understanding that spinal instability that includes atlantoaxial instability forms the nodal point of the pathogenesis and development of OPLL, and maturation of the presenting clinical symptoms. Twenty-nine patients were treated in this series. There were 28 males and one female, and their ages ranged from 28 to 75years (average 57years). All patients presented with symptoms of neck pain, and progressive and disabling myelopathy-related quadriparesis. In the early part of the series (from 2012 to 2014), 14 patients underwent multilevel subaxial cervical spinal fixation by a transarticular technique of facetal fixation. After November 2014, atlantoaxial lateral mass fixation was included in the fixation construct in the subsequent 15 patients. Clinical assessments were done using a visual analogue scale (VAS), the Japanese Orthopaedic Association (JOA) scale and Goel's clinical grading scale. All patients' clinical symptoms improved in the immediate postoperative period, and the improvement was sustained and progressive in 28 patients. Atlantoaxial and subaxial spinal instability seems to be the nodal pathogenetic factor in OPLL. Only stabilization of spinal segments that includes the atlantoaxial joint can provide a safe, simple and rational form of treatment.

C1 Arch Reconstruction: A Novel Alternative to Fusion in Maintaining Mobility of the Atlanto-Axial Joint

First decribed by Sir Goeffrey Jefferson in London in 1924, the term Jefferson’s fracture has become an eponym for all fractures of the Atlas. Complex Jefferson fractures and unstable Jefferson fractures require surgical fusion to maintain stability of the spinal axis. This however results in debilitating loss of movement at the crucial C1C2 joint, the most versatile of spinal joints where stability and mobility are intricately balanced into a complex yet supremely agile structure. The desire to attempt in some way to preserve a degree of movement and to spare the patient the crippling loss of movement at this joint has led to many attempts at innovation, both surgical and technological. This has led to the discovery of C1 osteosynthesis. This revolutionary technique enables the anatomical fixation of the defect thus allowing motion preservation without compromising on stability, which is a major advantage given the extreme importance of both to the proper functioning of the C1C2 and C1C0 joints. We present a case report of a 54 year old man with an isolated Jefferson’s fracture which was treated successfully by this technique. We also present an overview of the biomechanics of C1 injury and the relevant review of literature regarding options for management of complex C1C2 injuries.

Clinical characteristics and risk factors of coronary artery abnormities in 320 children with Kawasaki disease

Objective To compare the clinical features of classic Kawasaki disease (CKD) and incomplete Kawasaki disease (IKD), and to explore the risk factors of coronary artery abnormities in Kawasaki disease. Methods We collected the clinical data of 320 children with Kawasaki disease from July 1, 2017 to June 30, 2018, including 244 children with CKD (CKD group) and 76 children with IKD (IKD group). The risk factors of coronary artery abnormities in children with Kawasaki disease were explored. Results In addition to coronary artery injury(5%), some patients showed other rare complications such as cholestasis (1.6%), intestinal obstruction(0.6%), atlantoaxial subluxation (0.9%), macrophage activation syndrome (0.9%) and Kawasaki disease shock syndrome (0.3%). The age onset in CKD group was earlier than that in IKD group.WBC, CPR, NT-proBNP in CKD group were significantly higher than those in IKD group (P<0.05). After one week of treatment, WBC and CRP decreased significantly in group IKD, and there was no significant difference in PLT count.Multivariate logistic model was used to analyze the risk factors of coronary artery abnormities in Kawasaki disease.It was found that 25-OH VitD reduction (OR=2.851, P<0.05) was a high risk factor for coronary artery injury in KD. Conclusion Kawaski disease should be diagnosed early, treated for organ damage and supplemented with vitamin D. After discharge, coronary artery changes should be monitored regularly. Key words: Kawasaki disease; Coronary artery abnormities; Risk factors,

Axial osteochondroma causing myelopathy – A technical note and discussion on atlantoaxial fusion following C2 laminectomy

Abstract Osteochondromas are one of the commonest benign bone tumours, but are rarely found in the spine. Cord compression due to these lesions is even rarer. We describe a case of a C2 lamina osteochondroma causing cord compression in a 20 year old patient who presented with progressive myelopathy. We report on the technical aspects of the operation which resulted in a good decompression and complete excision. Post-operatively the patient made an uncomplicated recovery. We recommend spinal cord monitoring as routine for such procedures. However, whether or not fusion is necessary following a C2 laminectomy is unclear. Given the unique nature of the atlantoaxial joint, we elected to do this, but the literature is uncertain on the biomechanical aspects of this subject. Biomechanical data exists on single and multi-level subaxial laminectomies, but we argue that dedicated studies into post C2 laminectomy biomechanics should be undertaken.

Grisel Syndrome: Prompt Diagnosis, Prompt Management Equals Happy Ending

Grisel syndrome is a rare cause of torticollis resulting from subluxation of the atlanto-axial joint (C1-C2 vertebra) joint from surrounding soft tissue inflammation. Atlanto-axial joint injuries typically occur in the setting of trauma. However, here we report a case of a non-traumatic cause of atlanto-axial joint subluxation in a child. The child initially presented to our centre with 5 days history of torticollis preceded by a few days of upper respiratory tract symptoms. The initial radiograph of the cervical spine did not demonstrate any obvious abnormality. However, due to a high index of suspicion by the attending physician, a CT of the cervical spine was performed, which indeed revealed an atlanto-axial subluxation. The patient was put on cervical traction for a few days, and discharged well with soft collar and analgesia.