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Zhongguo Gu Shang 2022 May;35(5):495-9

Department of Spinal Surgery, China-Japan Friendship Hospital, Beijing 100029, China.

Atlantoaxial dislocation (AAD) is a kind of life-threatening atlantoaxial structural instability and a series of neurological dysfunction caused by common multidisciplinary diseases. The operation risk is extremely high because it is adjacent to the medulla oblongata and the location is deep. With the increase of the number of operations in the upper cervical region, postoperative complications such as failure of internal fixation, non fusion of bone graft and poor prognosis gradually increase. Read More

BMC Vet Res 2022 Jan 18;18(1):46. Epub 2022 Jan 18.

College of Veterinary Medicine, Research Institute for Veterinary Science, Seoul National University, Gwanak-ro, Gwanak-gu, 08826, Seoul, South Korea.

Background: Atlantoaxial instability (AAI) is primarily a congenital neurological disorder affecting young toy-breed dogs. So far, most studies have focused on bones and ligaments related to AAI, and there are no studies on the suboccipital muscles (SOMs) that occupy a large area from the occipital bone to C2 in dogs. This study evaluated the cross-sectional area (CSA) and fat infiltration of the SOMs using magnetic resonance imaging (MRI), specifically, T1-weighted images, in normal dogs (≤ 5 kg) and AAI dogs. Read More

World Neurosurg 2021 05 27;149:e42-e50. Epub 2021 Feb 27.

Department of Orthopedic Surgery, Osaka Medical College, Osaka, Japan.

Objective: To investigate whether biologic agents (BAs) reduce a narrow C-2 pedicle screw trajectory, which is often a key stabilizer in surgical treatment, in patients with rheumatoid arthritis (RA).

Methods: A total of 100 patients with RA treated with and without BAs (BA [+] group [n = 50] and BA [-] group [n = 50]), respectively, were included in the present study. Computed tomography (CT) images of their cervical spine, including C-2, were analyzed. Read More

Biomed Res Int 2020 15;2020:5395071. Epub 2020 Dec 15.

The Department of Spine Surgery, Hong-Hui Hospital, Xi'an Jiaotong University College of Medicine, Xi'an 710054, China.

Background: Many doctors ignored the possibility that there is still a spinal cord compression (SCC) need for decompression after atlantoaxial reduction. Reduction can be achieved on kinematic magnetic resonance imaging (MRI); thus, we want to analyze the role of kinematic MRI in reducible atlantoaxial dislocation and make a preoperative decision whether to perform decompression.

Methods: 36 patients with atlantoaxial reduction on preoperative kinematic MRI in extension postures were enrolled retrospectively. Read More

World Neurosurg 2021 02 4;146:e1287-e1292. Epub 2020 Dec 4.

Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India. Electronic address:

Objective: Atlantoaxial instability, although rarely reported in the literature, can be associated with cervical dystonia (CD) and may lead to compression of the cord at the craniovertebral junction. We present a case series of 4 patients of longstanding CD with neurologic complications. Treatment strategies and challenges are discussed. Read More

World Neurosurg 2021 02 12;146:e837-e847. Epub 2020 Nov 12.

Neurosurgery Department, Adana City Education and Research Hospital, Adana, Turkey.

Background: Foramen magnum decompression (FMD) is the first-choice treatment for Chiari malformation (CM). However, it has been suggested that cerebellar herniation and syringomyelia occur as a natural protective event to prevent neural damage caused by atlantoaxial instability. It is argued that treating instability is the main treatment. Read More

A A Pract 2020 Oct;14(12):e01323

Neurosurgery, National Institute of Mental Health and Neurosciences, Bengalure, Karnataka, India.

Atlantoaxial dislocation (AAD) poses a significant challenge in terms of positioning and surgical fixation as there is increased risk of cord compression and ischemia. Intraoperative neuromonitoring (IONM) provides a useful tool to identify impending position-related dysfunction. Here we demonstrate the utility of using transcranial motor evoked potential (Tc-MEP) to identify and treat suboptimal positioning in a 13-year-old patient with AAD and Arnold-Chiari malformation. Read More

J Manipulative Physiol Ther 2020 Jul - Aug;43(6):579-587. Epub 2020 Aug 26.

School of Health Sciences, The University of Newcastle, Newcastle, Australia.

Objective: The composition of cervical-spine meniscoids may have clinical significance in neck-pain conditions, but the accuracy of assessment of meniscoid composition in vivo using magnetic resonance imaging has not been established. The aim of this study was to compare cervical-spine meniscoid composition by magnetic resonance imaging with histologic composition.

Methods: Four embalmed cadaveric cervical spines (mean [standard deviation] age, 79. Read More

World Neurosurg 2020 08;140:556-563

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

Background: Ossification of the posterior longitudinal ligament (OPLL) is a hyperostotic condition resulting in a progressive narrowing of the spinal canal and subsequent neurologic deficits. Although systemic and local factors in combination with genetic abnormality have been considered in its etiopathogenesis, OPLL remains a poorly understood pathology. Surgical management of OPLL and the choice of the most appropriate treatment are still controversial issues. Read More

Zhongguo Gu Shang 2019 Sep;32(9):819-823

Department of Orthopaedics, Changzheng Hospital Affiliated to Naval Military Medical University, Shanghai 200003, China;

Objective: To evaluate the effect of bilateral atlantoaxial lamina hook and atlantoaxial joint space screw combined with autologous iliac bone graft on atlantoaxial dislocation caused by acute type I transverse ligament injury in school-age children.

Methods: From February 2006 to February 2019, 8 school-age children with atlantoaxial dislocation caused by acute type I transverse ligament injury were systematically reviewed, including 6 males and 2 females; aged 9 to 12 years old; 8 acute injuries included 4 high-level falls, 2 car accidents and 2 sports injuries; the atlantoaxial interval(ADI) was 5 to 8 mm. Eight cases presented with pain, stiffness, numbness and cervical spine dysfunction in different degrees. Read More

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

PM R 2019 04 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

Br J Neurosurg 2020 Oct 19;34(5):508-511. Epub 2018 Nov 19.

Department of Neurosurgery, Mie University Graduate School of Medicine, Tsu, Mie, Japan.

Although dysphagia is known potential complication of cervical spine surgery, it rarely occurs after a posterior approach. We describe an unusual case of a retro-odontoid pseudotumor that suffered dysphagia following a C1 laminectomy and posterior atlantoaxial fixation. A 79-year-old man presented with progressive tetraparesis and bladder and bowel dysfunction due to severe compression to cervical cord at C1 from a retro-odontoid pseudotumor. Read More

J Am Acad Orthop Surg 2019 Mar;27(5):e242-e248

From the Department of Spine Surgery, Honghui Hospital, Xi'an Jiaotong University, Shaanxi, China.

Background: In theory, temporary posterior atlantoaxial screw-rod fixation for type II odontoid fractures is a way to preserve rotatory motion. However, the healing rate of type II odontoid fractures treated in this way is unknown; that is, the risk associated with conducting a temporary screw-rod fixation for type II odontoid fractures is unknown. This study investigates the healing rate of type II odontoid fractures treated with posterior atlantoaxial screw-rod fixation by CT imaging and evaluates the feasibility of conducting a temporary screw-rod fixation for type II odontoid fractures. Read More

Joint Bone Spine 2019 07 4;86(4):519-521. Epub 2018 Oct 4.

Rheumatology, Xarxa Universitària Fundació Althaia, Manresa, Joan Soler, 1-3, Manresa 08243, Barcelona, Spain.

Spine (Phila Pa 1976) 2019 03;44(5):E306-E314

Department of Spine Surgery, Center for Orthopedics, Daping Hospital, Army Medical University.

Detailed clinical information of 13 adult patients with acute atlantal fractures underwent nonoperative treatment was retrospectively studied. "Rule of Spence" was found inaccurate in predicting either integrity of transverse atlantal ligament (TAL) or atlantoaxial stability, whereas Dickman's classification of TAL injury was more superior to "rule of Spence" on both prediction.

Study Design: A retrospective study. Read More

World Neurosurg 2018 Oct 19;118:e925-e932. Epub 2018 Jul 19.

Department of Neurosurgery, Sahaydri Superspeciality Hospital, Nashik, Maharashtra, India.

Objective: Deliberate C2 nerve root sectioning and its preservation have been described during posterior fusion for atlantoaxial dislocation (AAD). However, the associated outcomes have been less studied, especially in congenital AAD. Our objective was to study the clinical outcomes after C2 nerve root sectioning and the feasibility of C2 preservation in these patients. Read More

Eur Spine J 2019 06 2;28(Suppl 2):9-12. Epub 2018 Jul 2.

Department of Neurosurgery, Southmead Hospital, Bristol, UK.

Purpose: Traumatic atlantoaxial dislocation (AAD) is usually associated with fatal high-velocity road traffic accidents (Xu et al. in Medicine (Baltimore) 94:e1768, 2015). There are few reports of survival following posterior AAD without odontoid fracture (Xu et al. Read More

Clin Neurol Neurosurg 2018 02 21;165:15-20. Epub 2017 Dec 21.

Neurosurgery, PGIMER, Chandigarh, India. Electronic address:

Objectives: Manifestation of congenital anomalies of cranio-vertebral junction (CVJ) in the later half of life is unusual and intriguing. Coexisting cervical spondylotic changes with multilevel compression, poorer bone quality as well as less smooth post-surgical recuperation make management of elderly Congenital Atlantoaxial Dislocation/ Basilar Invagination (CAAD/BI) challenging. The clinico-radiological presentation, pathogenesis and outcome are analysed here. Read More

Acta Orthop Traumatol Turc 2018 May 23;52(3):240-243. Epub 2017 Nov 23.

Department of Orthopaedic Surgery, Gyeongsang National University School of Medicine and Gyeongsang National University Hospital, Jinju, Republic of Korea. Electronic address:

Brown-Sequard syndrome is an uncommon complication of atlantoaxial arthrodesis. A 50-year-old female visited our emergency department after falling from a ladder. Radiologic evaluations revealed chronic C1-2 instability with acute spinal cord injury. Read More

Musculoskelet Sci Pract 2018 02 10;33:46-52. Epub 2017 Nov 10.

Discipline of Physiotherapy, The University of Newcastle, University Drive, Callaghan, 2308, NSW, Australia.

Background: Lateral atlantoaxial (LAA) joints are established sources of nociceptive input in chronic whiplash associated disorder (WAD). These joints contain intra-articular meniscoids that may be damaged in whiplash trauma. LAA joint meniscoid morphology has not been investigated comprehensively in a chronic WAD population, and it is unclear whether morphological differences exist compared to a pain-free population. Read More

Arch Orthop Trauma Surg 2017 Oct 29;137(10):1349-1355. Epub 2017 Aug 29.

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

Introduction: Current surgical methods to treat atlantoaxial instability pose potential risks to the surrounding blood vessels and nerves of operative approach. Therefore, more secure and highly effective methods are expected. This study sought to assess the biomechanical efficacy of a novel unilateral double screw-rod fixation system by comparing with traditional and emerging fixation methods in cadaveric models. Read More

J Spine Surg 2017 Jun;3(2):267-271

1Division of Neurosurgery, Department of Surgery, 2Division of Neuroradiology, Department of Radiology, McMaster University, Hamilton, Ontario, Canada.

Atlantoaxial procedures have been developed in an effort to ensure solid C1-C2 fusion. However, techniques that involve sublaminar wiring have the potential for neural structure injury. We present the management of a patient who previously underwent Gallie fusion 10 years ago and is presenting with a dislodged titanium wire that has migrated into the medulla oblongata. Read More

Childs Nerv Syst 2017 Aug 6;33(8):1253-1260. Epub 2017 Jul 6.

Division of Pediatric Neurosurgery, Dell Children's Hospital, Austin, TX, USA.

Background: The treatment of atlantoaxial dislocation in very young children is challenging and lacks a consensus management strategy.

Discussion: We review the literature on infantile occipitocervical (OC) fusion is appraised and technical considerations are organized for ease of reference. Surgical decisions such as graft type and instrumentation details are summarized, along with the use of bone morphogenic protein and post-operative orthoses. Read More

Z Orthop Unfall 2017 Jun 6;155(3):318-323. Epub 2017 Jul 6.

Klinik und Poliklinik für Orthopädie und Unfallchirurgie, Uniklinik Köln.

The odontoid process and the transverse ligament are the most important structures stabilising the atlantoaxial complex. It has not been fully elucidated how injuries of these structures contribute towards instability and a potential narrowing of the spinal canal. Therefore, our investigation aimed to perform a biomechanical analysis of spinal width and dislocation of the odontoid process depending on injuries of the aforementioned structures. Read More

Osteoporos Int 2017 06 2;28(6):1931-1938. Epub 2017 Mar 2.

Department of Neurosurgery, Hanyang University Medical Center, 222-1, Wangsimni-ro, Seongdong-gu, Seoul, 133-792, South Korea.

Osteopenia and osteoporosis were independent predictive factors for higher atlantoaxial subluxation occurrence in patients with lower body mass index. Our findings suggest that patients with rheumatoid arthritis with osteopenia or osteoporosis, particularly those with lower body mass index (BMI), should be screened regularly to determine the status of their cervical spines.

Introduction: Cervical spine involvement in rheumatoid arthritis (RA) patients may cause serious adverse effects on quality of life and overall health. Read More

Biomed Eng Online 2016 Dec 28;15(Suppl 2):168. Epub 2016 Dec 28.

School of Biomedical Engineering, Capital Medical University, Beijing, 100069, China.

Background: Basilar invagination (BI) combined with atlantoaxial dislocation (AAD) leads to foramen magnum stenosis and medullary spinal cord compression, causing nerve dysfunction. The purpose of the surgery is to remove the bony compression at brainstem ventral side and fix the unstable spinal segment and make it fused stably. Occipital cervical internal fixation system that simultaneously reduces atlantoaxial horizontal and vertical dislocation are established. Read More

J Orthop Sci 2017 Mar 12;22(2):213-217. Epub 2016 Nov 12.

Department of Orthopedic Surgery, Tokyo Women's Medical University, Tokyo, Japan.

Background: C1 lateral mass screw was widely used for fixation of the upper cervical spine. However, massive bleeding from the C1-2 venous plexus is sometimes encountered. In this study, we proposed an alternate method for C1 lateral mass screw insertion, which involves insertion of the screws caudally from the C2 nerve root to reduce bleeding from C1-2 venous plexus. Read More

World Neurosurg 2016 Sep 23;93:293-8. Epub 2016 Jun 23.

Department of Orthopedics, The Second Affiliated Hospital, The Second Military Medical University, Shanghai, China. Electronic address:

Objective: To evaluate the biomechanical stability of 3 atlantoaxial proactive vertebral artery injury prevention fixation combinations.

Methods: We used 6 fresh human cadaveric C0-C4 specimens for the biomechanical test with moment control in 6 loading directions. First, range of motion (ROM) was measured in the intact specimens before they were destabilized; next, ROM of the 4 conditions fixed with 4 different fixation combinations were tested in alternating sequence: bilateral transarticular screw (TAS) and 3 test combinations: C1 laminar hook (C1LH) and C2 intralaminar screw (C2ILS) on 1 side combined with TAS (C1LH-C2ILS/TAS) or C1LH and TAS (C1LH-C2ILS/C1LH-TAS) or C1LH and C2ILS on the other side (C1LH-C2ILS/C1LH-C2ILS). Read More