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Biomed Res Int 2019 18;2019:5297950. Epub 2019 Mar 18.

Department of Orthopaedics, Spine and Trauma Surgery, Helios Klinikum Siegburg, Siegburg, Germany.

Traumatic atlantoaxial dislocation due to ligamentous and combined osseous injuries rarely occurs in adults. There are only few cases published in the literature. In this level 4 study, a cohort of nine consecutive patients suffering from traumatic atlantoaxial dislocation has been analyzed regarding morphology of injury, trauma mechanism, and outcome since 2007. Read More

J Craniovertebr Junction Spine 2019 Jan-Mar;10(1):1-2

Department of Neurosurgery, Seth G.S. Medical College and K.E.M Hospital, Mumbai, Maharashtra, India.

Ochsner J 2019 ;19(1):49-53

The University of Queensland Faculty of Medicine, Ochsner Clinical School, New Orleans, LA.

Pediatric spinal deformity surgeries are challenging operations that require considerable expertise and resources. The unique anatomy and rarity of these cases present challenges in surgical training and preparation. We present a case series illustrating how 3-dimensional (3-D) printed models were used in preoperative planning for 3 cases of pediatric spinal deformity surgery. Read More

Clinics (Sao Paulo) 2019 8;74:e653. Epub 2019 Apr 8.

Hospital Sao Marcos, Teresina, PI, BR.

Basilar invagination (BI) and Chiari malformation type I (CM-I) are very important anomalies that introduce instability and compression in the occipitocervical transition region and have complex clinical characteristics. These anomalies vary according to the affected structures. The present study revises current knowledge regarding the anatomy, anatomo-physiology, clinical manifestations, and radiological findings of these entities and the associated surgical treatment approaches. Read More

World Neurosurg 2019 Apr 4. Epub 2019 Apr 4.

General Surgery, Senior Resident, Department of Neurosurgery, K.E.M. Hospital and Seth G.S. Medical College, Parel, Mumbai.

Objective: The authors analyse the probable causes of failed craniovertebral junction stabilization procedures. The advantages of the Goel technique in the revision surgery and the positive factors that lead to reduction of the instability and achieve ultimate arthrodesis are evaluated.

Material And Methods: During the period January 2010 to June 2018, the authors treated 30 cases where the previous attempt at craniovertebral stabilization with various fixation techniques had failed and the patients presented with progressively worsening neurological deficits. Read More

World Neurosurg 2019 Apr 4. Epub 2019 Apr 4.

Department of Neurosurgery, Johns Hopkins Hospital, Baltimore, Maryland, USA.

Background: Occipitocervical congential pathologies involving instability of the atlantoaxial joint and basilar invagination are challenging to treat due to the complex anatomy involving the neurovascular structures at the skull base and high-risk nature of operating close to the brainstem.

Case Presentation: We present a patient with Alagille syndrome with multiple segmentation/fusion anomalies of the cervical spine and craniocervical junction, including fusion of the skull base and occipital condyles and partial assimilation of the C1 anterior ring and C2 dens. The head was anteriorly displaced, with C2 located immediately below the foramen magnum. Read More

World Neurosurg 2019 Apr 1. Epub 2019 Apr 1.

Professor and Head of Department, Department of Neurosurgery, K.E.M. Hospital and Seth G.S. Medical College, Parel, Mumbai. and, Consultant Neurosurgeon, Lilavati Hospital and Research Centre, Bandra (E), Mumbai. Electronic address:

Aim: The outcome of neurophysiological motor evoked potential (MEP) monitoring during surgery for Chiari formation by atlantoaxial fixation and without any bone or dural foramen magnum decompression is analyzed.

Material And Methods: During the period August 2017 to October 2018, 20 patients having Chiari formation with or without syringomyelia were surgically treated by atlantoaxial fixation. Apart from other forms of monitoring, MEP monitoring formed the basis of study. Read More

World Neurosurg 2019 Mar 25. Epub 2019 Mar 25.

School of Materials Science and Mechanical Engineering, Beijing Technology and Business University. Electronic address:

Objective: Occipitalization of the atlas (OA) is often associated with atlantoaxial dislocation and basilar invagination. The purpose of this study is to determine the biomechanical difference between normal and OA conditions in the craniovertebral junction and to further explore the rationale for development of atlantoaxial dislocation and basilar invagination using the finite element model (FEM).

Methods: A ligamentous, nonlinear, sliding-contact, 3-dimensional FEM of the occipitoatlantoaxial complex was generated. Read More

World Neurosurg 2019 Mar 25. Epub 2019 Mar 25.

Department of Orthopaedic Surgery, Shengjing Hospital of China Medical University, Shenyang City, Liaoning Province, P.R. China.

Objective: This study aimed to explore the feasibility and effectiveness of C1 lateral mass fixation via the posterior arch using pedicle screws of 3.5-mm diameter in patients whose atlas in the vertebral artery groove (C1 pedicle) was ≤3.5 mm in height. Read More

World Neurosurg 2019 Mar 20. Epub 2019 Mar 20.

Department of Neuroscience, Neurosurgery, University of Turin, Turin, Italy.

Zhongguo Gu Shang 2019 Feb;32(2):130-135

Department of Acupuncture and Moxibustion, China-Japan Friendship Hospital, Beijing, 100029, China;

Objective: To investigate the clinical characteristics and mechanism of cervicogenic headache.

Methods: Fifty-seven patients with cervicogenic headache who were treated from May 2013 to December 2017 and had complete imaging data were selected, including 18 males and 39 females with an average age of(43.26±10. Read More

J Spinal Cord Med 2019 Mar 15:1-4. Epub 2019 Mar 15.

c Department of Radiology , University of Texas Health Science Center at San Antonio , San Antonio , Texas , USA.

Context: The purpose of this report is to describe the clinical decision-making process for a patient with rheumatoid arthritis with neck pain with underlying atlantoaxial instability.

Findings: The patient was evaluated for worsening upper neck pain that began insidiously 1 year prior. The patient denied numbness or tingling in her upper or lower extremities, dizziness or lightheadedness, difficulty maintaining balance with walking, or muscle weakness. Read More

J Orthop Surg Res 2019 Mar 7;14(1):75. Epub 2019 Mar 7.

Department of Orthopaedic Surgery, Saiseikai Kawaguchi General Hospital, 5-11-5 Nishikawaguchi, Kawaguchi City, Saitama, 332-8558, Japan.

Background: Atlantoaxial subluxation (AAS) is characterized by excessive movement at the junction between the atlas (C1) and axis (C2) as a result of either a bony or ligamentous abnormality. Surgical intervention is a therapeutic choice for AAS. In addition to C1 laminectomy (LAM), surgical fixation for subluxation or instability is performed by various techniques. Read More

Clin Spine Surg 2019 Mar 1. Epub 2019 Mar 1.

Department of Neurosurgery, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.

Study Design: This study was a retrospective analysis.

Objective: The purpose of present study was to evaluate accuracy, efficiency, and safety of intraoperative O-arm-based navigation system for the placement of C1 lateral mass screw (C1LMS) and C2 pedicle screws (C2PSs) in high cervical spine operations.

Summary Of Background Data: High screw misplacement rates, various pedicle morphometry and vertebral body size variations have led to a search of image-guided systems to improve the surgical accuracy of screw insertion in high cervical spine. Read More

Vet Radiol Ultrasound 2019 03;60(2):246

Pediatr Allergy Immunol 2019 Feb 28. Epub 2019 Feb 28.

Department of Pediatrics, Complejo Hospitalario de Navarra. C/ Irunlarrea 4. Planta Baja. Pamplona., 31008, Spain.

Type IV A Mucopolysaccharidosis (MPS IV A) is a lysosomal storage disease caused by an autosomal recessive mutation in the gene encoding the enzyme galactosamine-6-sulfatase, which catalyses the degradation of glycosaminoglycans (GAGs). It leads to the accumulation of GAGs keratan sulfate. Symptoms include skeletal dysplasia, atlantoaxial instability, pectus carinatum, short stature, laxity of joints, cervical spinal cord compression, cardiac and pulmonary complications, corneal opacity, impaired hearing but normal cognitive development. Read More

Int J Spine Surg 2019 Jan 22;13(1):79-83. Epub 2019 Feb 22.

Department of Orthopaedic Surgery, University of California Irvine Medical Center, Orange, California.

Background: We report a case of an elderly patient who was diagnosed with lateral atlantoaxial subluxation with type II odontoid fracture, an extremely uncommon upper cervical spine injury that has not been previously reported in the literature to the knowledge of the authors.

Methods: An 87-year-old male reported to the emergency room following a syncopal episode after sustaining a fall. He complained of dizziness, fatigue, disruption of vision and audition, and worsening neck pain. Read More

World Neurosurg 2019 Feb 18. Epub 2019 Feb 18.

Department of Neurosurgery, Loyola University Medical Center, Maywood, Illinois, USA. Electronic address:

Background: Atlantoaxial instability (AAI) is a common cause of neurologic dysfunction and pain in patients with Down syndrome (DS), frequently requiring instrumented fusion of the upper cervical spine. Despite this, optimal treatment strategy is controversial.

Methods: A systematic review of the literature was performed according to the Preferred Reporting Items for Systemic Reviews and Meta-Analysis statement to identify patients with AAI and DS were treated with upper cervical spine fusion. Read More

World Neurosurg 2019 Feb 16. Epub 2019 Feb 16.

Sklifosovsky Research Institute of Emergency Care, Moscow, Russia; A.I. Evdokimov Moscow Medical University, Moscow, Russia.

Objective: To perform a radiological analysis of the degeneration of C1-C2 joints after C1-C2 transarticular fixation (TAF) and compare the long-term results of a routine Magerl technique (RMT) to a posterior transarticular C1-C2 stand-alone screw instrumentation (SAS) application.

Methods: A total of 40 patients (26 men and 14 women) were included in the present retrospective observational cohort study. The mean follow-up period was 61. Read More

PM R 2019 Apr 19;11(4):440-445. Epub 2019 Feb 19.

Division of Neurosurgery, University of Missouri School Medicine, Columbia, MO 65212.

Individuals with spinal cord injury (SCI) have altered neurophysiology and present with symptoms that must be interpreted in the context of their specific neurologic injury. This is a case of a 16-year-old female adolescent with C5 American Spinal Injury Association Impairment Scale A SCI who presented with intractable nausea. Multiple etiologies for her nausea, including medication effect, metabolic and gastrointestinal disorders, autonomic dysreflexia, and mood disorder, were systematically ruled out. Read More

J Neurosurg Spine 2019 Feb 15:1-9. Epub 2019 Feb 15.

2Department of Neurosurgery, Division of Pediatric Neurosurgery, University of Utah, Primary Children's Hospital, Salt Lake City, Utah.

OBJECTIVEThere is contradictory evidence regarding the relative contribution of the key stabilizing ligaments of the occipitoatlantal (OA) joint. Cadaveric studies are limited by the nature and the number of injury scenarios that can be tested to identify OA stabilizing ligaments. Finite element (FE) analysis can overcome these limitations and provide valuable data in this area. Read More

Eur Spine J 2019 Feb 13. Epub 2019 Feb 13.

Department of Orthopaedic Surgery, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, People's Republic of China.

Purpose: 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.

Methods: 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. Read More

J Neurosurg Sci 2019 Feb 4. Epub 2019 Feb 4.

Department of Neurosurgery and Gamma Knife Radiosurgery, I.R.C.C.S. San Raffaele Scientific Institute, Vita-Salute University, Milan, Italy.

J Neurosurg Spine 2019 Jan 25:1-4. Epub 2019 Jan 25.

Departments of1Neurosurgery and.

The authors present a case report of a patient discovered to have a rotatory subluxation of the C1-2 joint and a large retroodontoid pannus with an enhancing lesion in the odontoid process eventually proving to be caused by gout. This patient represented a diagnostic conundrum as she had known prior diagnoses of not only gout but also sarcoidosis and possible rheumatoid arthritis, and was in the demographic range where concern for an oncological process cannot fully be ruled out. Because she presented with signs and symptoms of atlantoaxial instability, she required posterior stabilization to reduce the rotatory subluxation and to stabilize the C1-2 instability. Read More

Pediatr Neurosurg 2019 24;54(1):12-20. Epub 2019 Jan 24.

Children's Hospital of Los Angeles, Los Angeles, California, USA.

Background/aims: Down syndrome is the most common inherited disorder. Some patients develop atlantoaxial instability. Existing screening guidelines were developed prior to availability of MRI. Read More

Asian Spine J 2019 Jan 24. Epub 2019 Jan 24.

Department of Orthopedic Surgery, Busan Korea Hospital, Busan, Korea.

Study Design: Retrospective case analysis.

Purpose: We hypothesized that larger the C1-C2 fusion angle, greater the severity of the sagittal malalignment of C0-C1 and C2- C7.

Overview Of Literature: In our experience, instances of sagittal malalignment occur at C0-C1 and C2-C7 following atlantoaxial fusion in patients with Os odontoideum (OO). Read More

Spine Deform 2019 03;7(2):298-303

Servicio de Patología Espinal, Hospital de Pediatría Prof. Dr. Juan P. Garrahan, CABA, Buenos Aires, Argentina.

Study Design: Descriptive retrospective cohort of 52 pediatric patients with mucopolysaccharidosis (MPS) and spinal cord disease and surgical outcomes in a reference hospital.

Objectives: To describe clinical manifestations and surgical management and outcomes of spinal lesions.

Methods: All medical records of 52 patients with mucopolysaccharidosis (I, II, III, IV, and VI) diagnosed between 1992 and 2011 were identified and followed at a single spine center of a pediatric hospital. Read More

Neurospine 2018 Oct 2. Epub 2018 Oct 2.

Department of Neurosurgery, Tokyo Women's Medical University, Tokyo, Japan.

Introduction: It is difficult to treat atlanto-axial instability in cases with high riding vertebral artery or anomalies of craniocervical junction. We report two successful cases with trans-spinal canal screwing technique because of difficulty to perform conventional fixation methods. Case presentation. Read More

Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi 2019 01;33(1):35-40

Operating Room, West China Hospital, Sichuan University, Chengdu Sichuan, 610041,

Objective: To assess the application and the effectiveness of a strategy of combining posterior occipitocervical angle (POCA) with occipital-C (O-C ) angle for adjustment of occipitocervical fixation angle in posterior instrumented occipitocervical fusion.

Methods: The clinical data of 22 patients undergoing posterior instrumented occipitocervical fusions between March 2013 and January 2016 were retrospectively analysed, and all patients were performed by using a strategy combining with POCA and O-C angle for adjustment of occipitocervical fixation angle. All patients suffered from occipitocervical instability, including 7 males and 15 females with an average age of 44. Read More

Acta Neurochir Suppl 2019;125:279-288

, New York, USA.

Background: In children, when unresponsive neck rigidity and distress are observed after ear, nose and throat (ENT) surgical treatment or nasopharyngeal inflammation, Grisel's syndrome should be suspected. This is a rare syndrome involving non-traumatic rotatory subluxation of the atlantoaxial joint. Conservative management with external cervical orthoses and empirical antibiotic, muscle relaxant and analgesic therapy should be the first choice of treatment. Read More

Acta Neurochir Suppl 2019;125:259-264

Department of Neurological Surgery, Policlinico "Gaspare Rodolico" University Hospital, Catania, Italy.

Background: A retro-odontoid pseudotumour compressing the spinal cord and causing myelopathy is often associated with an inflammatory condition such as rheumatoid arthritis. A degenerative non-inflammatory retro-odontoid pseudotumour responsible for clinically relevant spinal cord compression is a rare condition described in small clinical series and is likely associated with craniovertebral junction hypermobility or instability-like conditions. For several years, direct removal of the lesion through an anterior or lateral approach has been advocated as the best surgical option. Read More

Acta Neurochir Suppl 2019;125:101-110

Department of Neurosurgery, KEM Hospital and Seth GS Medical College, Mumbai, India.

Aim: In this paper we evaluate the role of atlantoaxial instability in the pathogenesis of Chiari formation type I and the role of atlantoaxial stabilization for treatment of this condition in cases with no obvious bone malformation in the region of the craniovertebral junction.

Materials, Methods And Results: During the period from January 2010 to July 2016, we identified 57 cases of Chiari formation where there was no bone malformation or evidence of craniovertebral junction instability that could be diagnosed on the basis of an abnormal increase in the atlantodental interval on dynamic imaging. Forty-eight of these patients had syringomyelia. Read More

Acta Neurochir Suppl 2019;125:79-86

Department of Experimental Biomedicine and Clinical Neurosciences, School of Medicine, Neurosurgical Clinic, University of Palermo, Palermo, Italy.

Rheumatoid arthritis (RA) is a chronic inflammatory disorder, characterized by polyarticular inflammation causing progressive joint damage and disability. The mechanisms underlying its pathogenesis involve activation of innate and adaptive immunity, microvascular endothelial cell activation, and inflammatory infiltration of lymphocytes and monocytes into the synovium. Spinal involvement in RA is not typical; when it occurs, the main radiological features are (1) atlantoaxial subluxation (AAS), which is the most typical form of cervical spine involvement; (2) cranial settling-also known as basilar impression, atlantoaxial impaction or superior migration of the odontoid-which is the most severe form of associated spinal instability; and (3) subaxial subluxation. Read More

Acta Neurochir Suppl 2019;125:71-78

Department of Neurosurgery, Seth GS Medical College and KEM Hospital, Mumbai, India.

Aim: 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.

Materials And Methods: 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. Read More

Acta Neurochir Suppl 2019;125:63-70

Department of Neurosurgery, Seth GS Medical College and KEM Hospital, Mumbai, India.

Background: 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. Read More

Acta Neurochir Suppl 2019;125:59-62

Department of Neurosurgery, King Edward VII Memorial Hospital and Seth GS Medical College, Mumbai, India.

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. Read More

Medicine (Baltimore) 2019 Jan;98(1):e13780

Department of Medical Chemistry, Medical University of Vienna, Vienna, Austria.

Spondyloepiphyseal dysplasia congenita (SEDC) is an autosomal dominant disorder, characterized by disproportionate dwarfism with short spine, short neck associated with variable degrees of coxa vara. Cervical cord compression is the most hazardous skeletal deformity in patients with SEDC which requires special attention and management.Ten patients with the clinical and the radiographic phenotypes of spondyloepiphyseal dysplasia congenita have been recognized and the genotype was compatible with single base substitutions, deletions or duplication of part of the COL2A1 gene (6 patients out of ten have been sequenced). Read More

Surg Neurol Int 2018 28;9:240. Epub 2018 Nov 28.

Department of Ortho-Spine Surgery, Sir Ganga Ram Hospital, New Delhi, India.

Background: Concurrent injuries to both the odontoid and transverse atlantal ligament are rare and can be easily missed. Failure to diagnose both lesions potentially leads to the late onset of sagittal plane instability and acute myelopathy. Here, we present a patient with an odontoid fracture whose transverse atlantal ligament (TAL) injury was originally missed on magnetic resonance imaging (MRI) and computed tomography (CT) scans. Read More

J Vet Med Sci 2019 Feb 24;81(2):229-236. Epub 2018 Dec 24.

The Laboratory of Veterinary Surgery, Nippon Veterinary and Life Science University, 1-7-1 Kyonan, Musashino-shi, Tokyo 180-0023, Japan.

This study investigated cerebral ventricle size and concurrent craniocervical junction abnormality in relation to atlantooccipital overlapping (AOO) in dogs with atlantoaxial instability (AAI). A total of 61 dogs were treated with atlantoaxial ventral fixation. Medical records of each dog, including magnetic resonance (MR) and computed tomography (CT) images, were retrospectively reviewed. Read More

Case Rep Orthop 2018 15;2018:2809546. Epub 2018 Nov 15.

Department of Orthopaedic Surgery, Chiba University, Graduate School of Medicine, 1-8-1 Inohana Chuou-ku, Chiba, Chiba 260-8670, Japan.

An occipital condyle fracture (OCF) is a relatively rare trauma that is now increasingly diagnosed because of the wide availability of computed tomography. For nondisplaced OCFs, conservative treatment is generally recommended, and there is no previous report of a nondisplaced OCF requiring surgery. We report a patient who had a nondisplaced OCF with craniocervical misalignment (a condyle-C1 interval > 2. Read More

Neurospine 2018 Dec 19;15(4):323-328. Epub 2018 Dec 19.

Department of Neurosurgery, K.E.M. Hospital and Seth G.S. Medical College, Parel, Mumbai, India.

The author reviews the various types of cervical fusion that are associated with instability of the craniovertebral junction. Assimilation of the atlas, C2-3 fusion, the Klippel-Feil abnormality, and pancervical fusion are amongst the more common types of bone abnormalities. It is conceptualised that these types of cervical fusion are not related to any kind of embryological dysgenesis or fault, but instead emerge due to longstanding muscle spasms of the neck in response to atlantoaxial instability. Read More

J Neurosurg Spine 2018 Dec;30(3):314-322

4Department of Neurological Surgery, University of California, Davis, Sacramento, California.

OBJECTIVEC1-2 is a highly mobile complex that presents unique surgical challenges to achieving biomechanical rigidity and fusion. Posterior wiring methods have been largely replaced with segmental constructs using the C1 lateral mass, C1 pedicle, C2 pars, and C2 pedicle. Modifications to reduce surgical morbidity led to the development of C2 laminar screws. Read More

Eur Spine J 2019 Feb 11;28(2):362-369. Epub 2018 Dec 11.

Department of Orthopedics, The Second Affiliated Hospital of Chongqing Medical University, No. 76 Linjiang Road, Yuzhong District, Chongqing, 400010, People's Republic of China.

Purpose: To investigate the anatomical and biomechanical feasibility of the unilateral C1 double screw [pedicle screw (PS) + lateral mass screw (LMS)] and ipsilateral C2 PS combined with contralateral C2 laminar screw (LS)-rod fixation for atlantoaxial instability by comparison with traditional posterior fixation methods.

Methods: Fifteen sets of complete dry bony specimens of atlas were used for morphometric analysis. The working length, width and thickness of the C1 PSs and LMSs were manually measured. Read More

J Forensic Leg Med 2019 Feb 29;61:92-96. Epub 2018 Nov 29.

Department of Legal Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba city, Chiba Prefecture, 260-8670, Japan; Department of Forensic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.

A 5-year-old boy with a chromosome-9 abnormality and multiple external and visceral malformations was found in cardiopulmonary arrest during a regular visit to the hospital; he did not respond to cardiopulmonary resuscitation and died. An odontoid process fracture and calcification and fibrosis of the muscles around the superior cervical vertebra were observed during the autopsy. Postmortem computed tomography revealed an anterior dislocation of the atlas; odontoid synchondrosis fracture; and delayed, incomplete bony fusion of the odontoid process relative to his age. Read More

Kaohsiung J Med Sci 2018 Dec 19;34(12):700-704. Epub 2018 Sep 19.

Spinal Surgery Unit, Shengjing Hospital of China Medical University, Shenyang, PR China. Electronic address:

Atlanto-axial instability (AAI) is a congenital or developmental condition that leads to instability/subluxation of the atlantoaxial joint. This study is performed to determine anatomic feasibility of trajectory L and help select an optimal screw trajectory in treating patients with AAI with a narrow C1 posterior arch. Sixty patients who underwent cervical three dimensional-computed tomography (3D-CT) were chosen from the hospital's picture archiving and communication system (PACS). Read More

Asian Spine J 2019 Apr 7;13(2):233-241. Epub 2018 Dec 7.

Department of Orthopedic Surgery, College of Medicine, The Catholic University of Korea, Seoul, Korea.

Study Design: Retrospective case analysis.

Purpose: We retrospectively evaluated the clinical and radiological outcomes of posterior sublaminar wiring (PSLW) and/or transarticular screw fixation (TASF) for reducible atlantoaxial instability (AAI) secondary to os odontoideum.

Overview Of Literature: Limited information is available about the surgical outcomes of symptomatic os odontoideum with AAI. Read More

Vet Comp Orthop Traumatol 2019 Jan 28;32(1):33-40. Epub 2018 Nov 28.

Department of Clinical Veterinary Medicine, Clinical Radiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.

Objective:  The main purpose of this study was to define criteria to systemically describe craniovertebral junction (CVJ) anomalies and to report the prevalence of CVJ anomalies in small breed dogs with and without atlantoaxial instability (AAI).

Materials And Methods:  Retrospective multicentre matched case-control study evaluating magnetic resonance imaging and computed tomographic images of small breed dogs with and without AAI for the presence of CVJ anomalies.

Results:  One hundred and twenty-two dogs were enrolled (61 with and 61 without AAI). Read More

J Clin Neurosci 2019 Apr 22;62:260-263. Epub 2018 Nov 22.

Department of Anatomy, Histology and Embryology, Medical University of Innsbruck, Innsbruck, Austria.

Purpose: Atlantoxial fusion with screw rod constructs traditionally requires subperiostal dissection of the C1/C2 muscle attachments, which may lead to postoperative axial neck pain and intraoperative blood loss. We evaluate a potentially less invasive, muscle splitting approach for atlantoaxial fusion in a cadaver model.

Methods: A technical feasibility study was performed in a human cadaveric specimen with standard surgical instruments and an operating microscope. Read More

World Neurosurg 2019 Feb 22;122:e1511-e1518. Epub 2018 Nov 22.

Department of Orthopedics, Peking University Third Hospital, Beijing, China.

Objective: Atlantoaxial stabilization procedures in high-riding vertebral artery (HRVA) cases are challenging. C2 translaminar screws are rigid and pose no risk to the vertebral artery. The aim of this study was to present clinical outcomes of atlantoaxial dislocation combined with HRVA using C2 translaminar screws. Read More

Eur Spine J 2018 Nov 17. Epub 2018 Nov 17.

Department of Orthopedic Surgery, Orthopedic Hospital of Xingtai, Xingtai, 054000, Hebei, China.

Background: Atlantoaxial dislocation usually results from hyperextension trauma and is almost always accompanied by odontoid fracture and neurological symptoms. In most cases, patients with atlantoaxial dislocation die instantly. This is a rare report of posterior atlantoaxial dislocation without fracture and neurological symptoms effectively treated by transoral-posterior approach surgery, and only eleven similar cases have been previously reported. Read More