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World Neurosurg 2020 May 10. Epub 2020 May 10.

Department of Neurosurgery, the first Medical Centre, Chinese PLA General Hospital, 28 Fuxing Road, Haidian District, Beijing, 100853, China. Electronic address:

Objective: To investigate the biomechanical effect of C1 lateral mass-C2 pedicle screw-rod (C1LM-C2PS) fixation with and without transverse connectors (TC) in an atlantoaxial instability (AAI) model.

Methods: Ten freshly frozen cadaveric specimens were tested using an industrial robot under the following conditions: intact model, AAI model, C1-C2 model, C1-C2 with one TC model, and C1-C2 with two TCs model. Three types of motions, flexion-extension (FE), lateral bending (LB), and axial rotation (AR), were applied (1. Read More

Oper Neurosurg (Hagerstown) 2020 May 1. Epub 2020 May 1.

Department of Neurosurgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.

Background: C1 pedicle screw insertion is not easy, and more fluoroscopy can be required for safe insertion. Fluoroscopy is time consuming and increases patient radiation exposure. There have been no studies comparing the accuracy of C1 pedicle screw insertion using the fluoroscopy and free-hand techniques. Read More

World Neurosurg 2020 Apr 24. Epub 2020 Apr 24.

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

Objective: This study compared the surgical results of transarticular screw (TAS) fixation for atlantoaxial instability between C-arm fluoroscopy and O-arm.

Methods: Of 58 patients who underwent TAS fixation for atlantoaxial instability, 35 underwent C-arm-assisted surgery (C-group) and 23 underwent O-arm-assisted surgery (O-group). In total, 78 TASs were placed: 39 in the C-group and 39 in the O-group. Read More

J Orthop Surg (Hong Kong) 2020 Jan-Apr;28(2):2309499020918424

Department of Orthopedic Surgery, Toho University School of Medicine, Tokyo, Japan.

Morquio syndrome is a relatively rare entity that is often associated with atlantoaxial instability from early childhood due to odontoid dysplasia based on a mucopolysaccharoidal disorder. Here, we present the case of a 55-year-old male patient with Morquio syndrome who developed cervical myelopathy, which is an extremely rare condition in the older population. Myelopathy developed gradually with upper-limb paresthesia and clumsiness of both hands. Read More

J Orthop Surg Res 2020 Apr 17;15(1):156. Epub 2020 Apr 17.

School of Mechanical Engineering & Automation, Northeastern University, Shenyang, 110819, Liaoning, People's Republic of China.

Background: The biomechanics of C1 posterior arch screw and C2 vertebral lamina screw techniques has not been well studied, and the biomechanical performance of the constructs cannot be explained only by cadaver testing.

Methods: From computed tomography images, a nonlinear intact three-dimensional C1-2 finite element model was developed and validated. And on this basis, models for the odontoid fractures and the three posterior internal fixation techniques were developed. Read More

Eur Spine J 2020 Apr 15. Epub 2020 Apr 15.

Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, University Health Network, 399 Bathurst Street, Toronto, ON, M5T 2S8, Canada.

Objective: The treatment of a retro-odontoid pseudotumor mass associated with severe spinal cord compression is challenging due to the complex regional anatomy. Here, we present an attractive treatment option involving a single-stage posterior transdural microsurgical resection followed by instrumented cervical reconstruction.

Methods: We describe three patients presenting with clinical signs of cervical myelopathy and an imaging finding of mucoid and fibrous soft or semi-soft retro-odontoid pseudotumor mass with significant spinal cord compression at the C1/C2 level. Read More

J Neurol Surg Rep 2020 Jan 31;81(1):e20-e27. Epub 2020 Mar 31.

Division of Neurosurgery, Department of Surgery, National Cheng Kung University Hospital, Tainan, Taiwan, R.O.C.

 Atlantoaxial fixation is technically demanding and challenging, especially in cases with anatomical abnormality. The purpose of this study is to report the effectiveness of the three-dimensional (3D)-customized guiding template for placement of C1 and C2 screws in cases with abnormalities.  Two patients with anatomical abnormality and one without were included. Read More

Acta Neurochir (Wien) 2020 May 24;162(5):985-991. Epub 2020 Mar 24.

Department of Neurosurgery, Leiden University Medical Center, PO Box 9600, 2300RC, Leiden, The Netherlands.

Background: Occipitocervical and atlantoaxial instability in the pediatric population is a rare and challenging condition to treat. Variable surgical techniques have been employed to achieve fusion. The study aimed to assess bony fusion with rigid craniocervical fixation using an allograft bone block to serve as scaffold for bony fusion. Read More

J Clin Med 2020 Mar 17;9(3). Epub 2020 Mar 17.

Department of Neurosurgery, Klinikum rechts der Isar, Technical University Munich, 81675 Munich, Germany.

Cervical myelopathy occurs in approximately 2.5% of patients suffering from rheumatoid arthritis (RA) and is associated with notable morbidity and mortality. However, the surgical management of patients affected by cervical involvement in the setting of RA remains challenging and not well studied. Read More

Asian J Neurosurg 2020 Jan-Mar;15(1):236-240. Epub 2020 Feb 25.

Department of Orthopaedics, Seth GS Medical College and KEM Hospital, Parel, Mumbai, Maharashtra, India.

Os odontoideum (OO) was first described by Giacomini in 1886 as separation of the odontoid process from the body of the axis. Instability can consequently occurs at this level due to the failure of the transverse atlantal ligament (TAL) and this atlantoaxial instability can be a cause of progressive neurological deficits. It is considered a rare anomaly of the odontoid process. Read More

Eur Spine J 2020 May 16;29(5):970-976. Epub 2020 Mar 16.

Department of Pediatric Neurosurgery, Altona Children's Hospital, Bleickenallee 38, 22765, Hamburg, Germany.

Purpose: Posterior fusion of the craniocervical junction (CCJ) has always been challenging in children with rare congenital diseases and malformations. At our institution, the introduction of the translaminar C2 screw technique led to a significant improvement in the quality of treatment.

Methods: Retrospective analysis of a pediatric cohort at a single institution who underwent CCJ posterior fusion between 2007 and 2018. Read More

World Neurosurg 2020 Mar 13. Epub 2020 Mar 13.

Department of Neurosurgery, Taipei Medical University, Taipei, Taiwan; Department of Surgery, Taipei Medical University, Taipei, Taiwan; Taipei Neuroscience Institute, Taipei Medical University, Taipei, Taiwan.

Objective: The interlaminar fusion combination involving C1-C2 screwing fixation is one of the most effective techniques for atlantoaxial dislocation or subluxation, and the bone graft is usually stabilized by wiring constructs. However, some adverse events were reported during the insertion of sublaminar wiring, such as accidentally damaging the spinal cord or dura. Thus we used the miniplate to stabilize the harvest bone graft on the C1-C2 laminar, which led to a shorter operation time and prevented spinal canal violation. Read More

Childs Nerv Syst 2020 Mar 14. Epub 2020 Mar 14.

Department of Neurosurgery, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, South Korea.

Mucopolysaccharidosis type IVA, also known as Morquio syndrome, is an autosomal recessive lysosomal storage disease. Skeletal dysplasia with short stature, dysplastic-hypoplastic dens (os odontoideum), ligamentous hyperlaxity, and C1-C2 instability are characteristic features. Most patients with Morquio syndrome present with compressive myelopathy at a young age as a result of a combination of C1-C2 instability and extradural soft tissue thickening; treatment generally consists of anterior decompression with occipito-cervical fusion and external orthosis. Read More

World Neurosurg 2020 Mar 6;138:129-136. Epub 2020 Mar 6.

Department of Neurosurgery, University of Maryland, Baltimore, Maryland, USA.

Background: Intraoperative manipulation of the craniocervical junction with the Cervical Management Base Unit (CMBU) has been used as an adjunct for achieving optimal anatomic alignment during instrumented fusion procedures in a variety of disease settings. Here, we present our experience using the CMBU as a supplement to achieving a successful reduction and fixation of a reducible craniocervical subluxation with associated basilar impression/medullary compression in the setting of Grisel syndrome.

Case Description: Under fluoroscopy and neuromonitoring guidance, the elevator and axial translation mechanisms of the CMBU safely allowed for presurgical assessment of reducibility and facilitated complete reduction of the deformity with restitution of a normal atlantodental interval, spinolaminar line, and clivoaxial angle. Read More

World Neurosurg 2020 Mar 4;138:193-196. Epub 2020 Mar 4.

Department of Neurosurgery, Postgraduate Institute of Medical Education & Research (PGIMER), Chandigarh, India.

Background: Posterior circulation stroke resulting from atlantoaxial dislocation (AAD), although uncommon, is a well-described entity. The normally coursed V3 segment of the vertebral artery (VA) is likely to be stretched because of C1-C2 dislocation and further compromised by the C1-C2 translational mobility. The persistent first intersegmental artery (PFIA), an anomalous variant does not course through the C1 transverse foramen, but rather crosses the posterior C1-C2 joints and is unlikely to be affected by the C1-C2 dislocation. Read More

Unfallchirurg 2020 May;123(5):408-412

Neurosurgical Department, Klinikum Dortmund gGmbH, Dortmund, Deutschland.

Fractures of the second cervical vertebra with involvement of the odontoid process can mostly be treated conservatively by immobilization. In the case of high-grade unstable fractures and pseudarthrosis dorsal C1/2 spondylodesis should be considered.Based on established atlantoaxial osteosynthesis techniques for dorsal C1/2 spondylodesis, a polyaxial screw-rod system with C1/2 transarticular screws connected with C1 lateral mass screws was carried out in a 56-year-old male patient with dislocated odontoid fracture. Read More

BMC Musculoskelet Disord 2020 Feb 28;21(1):129. Epub 2020 Feb 28.

Department of Neurosurgery, Chang Gung University, Linkou, 5 Fu-Shin Street, Gui-Shan Dist, Taoyuan City, Taiwan, Republic of China.

Background: Occipitocervical (OC) fusion is indicated for OC instability and other conditions. Surgical complications include infection, malunion, and instrument failure.

Case Presentation: We described a patient who underwent OC fusion and subsequently developed complication of cerebellar abscess and obstructive hydrocephalus. Read More

Eur Spine J 2020 May 19;29(5):1078-1086. Epub 2020 Feb 19.

Department of Neurological Sciences, Christian Medical College, Vellore, India.

Introduction: The course of the vertebral artery after exiting from the C1 foramen transversarium and prior to entering the dura lends itself to compression in C1-2 instability. However, atlantoaxial dislocation presenting with vertebrobasilar insufficiency and posterior circulation stroke (PCS) is rare.

Methods: In this retrospective study, we identified 96 patients with PCS who had complete radiological data. Read More

World Neurosurg 2020 May 14;137:393-397. Epub 2020 Feb 14.

Department of Neurosurgery, Tokushima University, Tokushima, Japan.

Background: Bow hunter's syndrome (BHS) is caused by posterior circulation insufficiency that results from the occlusion or compression of the vertebral artery (VA) during neck rotation. Owing to its rarity, there is no guideline to support the decision of selecting a conservative or a surgical approach. Management of BHS is dependent on each patient. Read More

Neurospine 2020 Feb 2. Epub 2020 Feb 2.

Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.

Objective: Conventional techniques for atlantoaxial fixation and fusion typically pass cables or wires underneath C1 lamina to secure the bone graft between the posterior elements of C1-2, which leads to complications such as cerebrospinal fluid (CSF) leak and neurological injury. With the evolution of fixation hardware, we propose a novel C1-2 fixation technique that avoids the morbidity and complications associated with sublaminar cables and wires.

Methods: This technique entails wedging and anchoring a structural iliac crest graft between C1 and C2 for interlaminar arthrodesis and securing it using a 0-Prolene suture at the time of C1 lateral mass and C2 pars interarticularis screw fixation. Read More

Int J Mol Sci 2020 Feb 10;21(3). Epub 2020 Feb 10.

Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, Asahimachi, Abeno-ku, Osaka 545-8585, Japan.

Mucopolysaccharidoses (MPS) are a group of inherited, multisystem, lysosomal storage disorders involving specific lysosomal enzyme deficiencies that result in the accumulation of glycosaminoglycans (GAG) secondary to insufficient degradation within cell lysosomes. GAG accumulation affects both primary bone formation and secondary bone growth, resulting in growth impairment. Typical spinal manifestations in MPS are atlantoaxial instability, thoracolumbar kyphosis/scoliosis, and cervical/lumbar spinal canal stenosis. Read More

Asian Spine J 2020 Feb 14. Epub 2020 Feb 14.

Department of Spine Surgery, Ganga Hospital, Coimbatore, India.

Study Design: Prospective observational study.

Purpose: To assess the safety, efficacy, and benefits of computed tomography (CT)-guided C1 fracture fixation.

Overview Of Literature: The surgical management of unstable C1 injuries by occipitocervical and atlantoaxial (AA) fusion compromises motion and function. Read More

Eur Spine J 2020 May 3;29(5):961-969. Epub 2020 Feb 3.

Department of Neurosurgery, Great Ormond Street Hospital, 34 Great Ormond Street, London, WC1N 3JH, UK.

Purpose: Whilst rigid fixation for craniovertebral instability is the gold standard, in very young, small children conventional management may have to be modified. We present a single-centre experience of craniocervical fixation in children under 5 years.

Methods: A retrospective review of cases that had undergone atlantoaxial (AA) or occipitocervical (OC) fixation aged under 5 years. Read More

J Neurosurg Pediatr 2020 Jan 31:1-5. Epub 2020 Jan 31.

Departments of1Orthopaedic Surgery and.

Objective: Patients with trisomy 21 (Down syndrome; DS) often have atlantoaxial instability (AAI), which, if severe, causes myelopathy and neurological deterioration. Children with DS and AAI who undergo cervical spine fusion have a high rate of nonunion requiring revision surgery. Recombinant human bone morphogenetic protein-2 (rhBMP-2) is a TGF-β growth factor that is used to induce bone formation in spine fusion. Read More

Surg Radiol Anat 2020 Jun 27;42(6):701-710. Epub 2020 Jan 27.

Department of Anatomy, School of Medicine, Akdeniz University, 07070, Antalya, Turkey.

Purpose: Os odontoideum is a rare anatomical and morphological variation of the odontoid process and associated with a range of symptoms such as spinal cord and vertebral artery injuries. This study aimed to evaluate the frequency of os odontoideum in Turkish cases by sagittal/coronal cervical magnetic resonance imaging (MRI) and computed tomography (CT) and analyze the relationship with age, gender and related symptoms.

Methods: The incidence of os odontoideum was retrospectively diagnosed by sagittal/coronal cervical CT and MRI out of 16,122 subjects aged 20-70 years (mean 46) in the period between 2014 and 2018. Read More

World Neurosurg 2020 May 22;137:e152-e158. Epub 2020 Jan 22.

Department of Spinal Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China. Electronic address:

Objective: The feasibility of anterior transarticular crossing screws (ATCS) was confirmed in cadaveric specimens and it has been used in clinic. However, no study has documented the morphometric characteristics of ATCS. This study seeks to determine the morphometric characteristics of ATCS in C1-C2 fixation. Read More

J Am Acad Orthop Surg 2020 Feb;28(3):e100-e107

From the Department of Orthopaedic Surgery, Boston Children's Hospital/Harvard Medical School, Boston, MA (Dr. Hedequist), and the Department of Orthopaedic Surgery, Lenox Hill Hospital, New York, NY (Dr. Mo).

Os odontoideum is a rare entity of the second cervical vertebra, characterized by a circumferentially corticated ossicle separated from the body of C2. The ossicle is a distinct entity from an odontoid fracture or a persistent ossiculum terminale. The diagnosis may be made incidentally on imaging obtained for the workup of neck pain or neurologic signs and symptoms. Read More

Oper Neurosurg (Hagerstown) 2020 Jan 20. Epub 2020 Jan 20.

Department of Neurosurgery, MedStar Georgetown University Hospital, Washington, District of Columbia.

This operative video demonstrates a C1 lateral mass instrumentation technique that is an alternative to the traditional Goel and Harms techniques.1,2 The advantages of the alternative technique include minimized blood loss from the rich venous plexus surrounding the C2 dorsal root ganglia (DRG), avoidance and preservation of the C2 DRG, and placement of a robust fully threaded screw without risking neuralgia. These are discussed in detail and presented through a case of atlantoaxial instability. Read More

J Neurosurg Spine 2020 Jan 17:1-7. Epub 2020 Jan 17.

1Department of Neurosurgery, Chinese PLA General Hospital, Beijing; and.

Objective: The authors conducted a study to investigate the biomechanical feasibility and stability of C1 lateral mass-C2 bicortical translaminar screw (C1LM-C2TL) fixation, C1 lateral mass-C2/3 transarticular screw (C1LM-C2/3TA) fixation, and C1LM-C2/3TA fixation with transverse cross-links (C1LM-C2/3TACL) as alternative techniques to the Goel-Harms technique (C1 lateral mass-C2 pedicle screw [C1LM-C2PS] fixation) for atlantoaxial fixation.

Methods: Eight human cadaveric cervical spines (occiput-C7) were tested using an industrial robot. Pure moments that were a maximum of 1. Read More

J Pediatr Orthop 2020 Feb;40(2):65-70

Department of Orthopaedics, The Affiliated Southeast Hospital of Xiamen University, Orthopaedic Center of People's Liberation Army, Zhangzhou, People's Republic of China.

Background: There are few studies reporting the use of atlantoaxial pedicle screws and the long-term effects of C1-C2 posterior fusion in children. Our study is to investigate the initial results of C1-C2 pedicle screw fixation for pediatric atlantoaxial dislocation (AAD) and assessed spontaneous change of postoperative radiography after a long-term follow-up period.

Methods: Posterior pedicle screw fixations were performed in 21 pediatric patients with AAD. Read More

J Spinal Cord Med 2020 Jan 9:1-5. Epub 2020 Jan 9.

Department of Physical Medicine and Rehabilitation, Soonchunhyang University Hospital Seoul, Soonchunhyang University College of Medicine, Seoul, Republic of Korea.

Atlantoaxial instability in an athetoid dystonic cerebral palsy patient due to os odentoideum represents a rare cause of high-level cervical spinal cord injury. There is no evidence-based treatment protocol for this injury and a number of reports have debated whether nonsurgical or surgical treatment is the best option. Here, we report the case of a 32-year-old athetoid dystonic cerebral palsy patient with os odontoideum (OO) causing compressive myelopathy on the C1-2 levels. Read More

Clin Med Insights Case Rep 2019 29;12:1179547619882707. Epub 2019 Dec 29.

New York Chiropractic & Physiotherapy Centre, New York Medical Group, Hong Kong, China.

A variety of age-related problems, including salivary secretory disorders, poor oral motor coordination, neuromuscular weakness, neurodegenerative diseases, stroke, and structural changes, can result in swallowing disorders. Given that causes of dysphagia differ from patient to patient, individualized treatment plans tailored toward patients' specific conditions are needed. Here we present a case of an elderly woman with upper neck stiffness and dysphagia sought chiropractic treatment. Read More

Asian J Neurosurg 2019 Oct-Dec;14(4):1249-1252. Epub 2019 Nov 25.

Department of Orthopedics and Traumatology, La Rabta Hospital, Tunis Medical School, Tunis, Tunisia.

Traumatic dislocation of the atlanto-axial joint in combination with an odontoid fracture remains a rare entity. Beaucause of its instability, it's alsoo a seriuous injury. A fatal outcome is feared especially in elderly. Read More

Childs Nerv Syst 2020 May 4;36(5):975-985. Epub 2020 Jan 4.

Department of Neurosurgery, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, 1824 JPP, Iowa City, IA, 52242, USA.

Objective: To analyze the varied presentation and management of atlas assimilation with associated radiographic abnormalities in children in the MRI era METHODS: Database analysis of 313 children (less than 10 years) RESULTS: Atlas assimilation (AA) was associated with atlantoaxial dislocation in 12, abnormal skull base and Chiari I abnormality in 42, C2-C3 segmentation failure and instability and Chiari I abnormality in 74, and condylar hypoplasia and basilar invagination in 74. Proatlas segmentation failures were 54, atlantoaxial rotary dislocation in 26 with Goldenhar's syndrome, abnormal C1 atlas posterior arch causing dynamic compression of cord in 31 children. Vascular compromise was documented in 26 children. Read More

World Neurosurg 2020 Apr 30;136:e234-e244. Epub 2019 Dec 30.

Department of Neurosurgery, Postgraduate Institute of Medical Education and Research, Chandigarh, India.

Objective: The recently described C1-C2 fixation without foramen magnum decompression (FMD) for the management of Chiari malformations (CMs) has sparked a controversy. C1-C2 fixation has been reported to be more effective than traditional FMD. However, the results after such a procedure have not been as well validated. Read More

World Neurosurg 2020 Apr 30;136:e223-e233. Epub 2019 Dec 30.

Department of Neurosurgery, Brown University, Rhode Island Hospital, Providence, Rhode Island, USA. Electronic address:

Objective: Assessment of transverse ligament (TL) competence in patients with suspected atlantoaxial instability is performed via indirect radiograph measurements or direct TL visualization on magnetic resonance imaging (MRI). Interpretation of these images can be limited by unique patient anatomy or imaging technique variability. We report a novel technique for evaluating TL competence using flexion-extension computed tomography (feCT) scan with 3-dimensional (3D) segmentation and quantitative analysis. Read More

J Neurosurg Pediatr 2019 Dec 27:1-10. Epub 2019 Dec 27.

1Department of Orthopaedic Surgery, Boston Children's Hospital.

Objective: Halo-gravity traction (HGT) is an effective and safe method for gradual correction of severe cervical deformities in adults. However, the literature is limited on the use of HGT for cervical spine deformities that develop in children. The objective of the present study was to evaluate the safety and efficacy of HGT for pediatric cervical spine deformities. Read More

World Neurosurg 2020 Mar 24;135:241-244. Epub 2019 Dec 24.

Department of Neurosurgery, King Edward Memorial Hospital and Seth Gordhandas Sunderdas Medical College, Mumbai, India.

Background: To the best of our knowledge, the presence of Chiari formation and Hirayama disease in the same patient has not been previously reported. On the basis of the presented case, we have attempted to identify the common pathogenesis of both of these clinical entities.

Case Description: We have reported a case of a 23-year-old male patient who had presented with complaints of pain in the nape of neck and shoulders of 9 months' duration, weakness and stiffness in all 4 limbs, and wasting and weakness of muscles of both hands of 6 months' duration. Read More

J Craniofac Surg 2020 Jan/Feb;31(1):e67

Department of Radiology, Medical Faculty, Ataturk University, Erzurum, Turkey.

Os odontoideum is a rare anomaly of the second cervical vertebra. The odontoid process is separated by a wide gap from the vertebral body in this anomaly. It can be associated with atlantoaxial instability. Read More

World Neurosurg 2020 Mar 4;135:330-334. Epub 2019 Dec 4.

Department of Neurosurgery, University of Cincinnati Medical Center, Cincinnati, Ohio, USA.

Instability of the craniovertebral junction (CVJ) following odontoidectomy is relatively common. Traditionally, separate stage posterior atlantoaxial ± occipitocervical fusion is used for treatment. A transmucosal approach using a clean-contaminated route is associated with hypothetical risks of infectious complications. Read More

BMJ Case Rep 2019 Nov 28;12(11). Epub 2019 Nov 28.

Neurosurgery, NSW Health, Kogarah, New South Wales, Australia.

Syncopal events are a concerning presentation and timely evaluation is warranted. Common aetiologies include cardiac and neurological pathology such as arrhythmias, vertebrobasilar arterial disease and vasovagal syncope. We describe the case of a 65-year-old man who presented to our emergency department with symptoms of vertigo and syncope. Read More

J Craniovertebr Junction Spine 2019 Jul-Sep;10(3):144-151

Lilavati Hospital and Research Centre, Mumbai, Maharashtra, India.

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. Read More

Oper Neurosurg (Hagerstown) 2019 Nov 26. Epub 2019 Nov 26.

Department of Orthopedics, Changzheng Hospital, The Second Military Medical University, Shanghai, People's Republic of China.

Background: A C1 laminar hook can theoretically avoid vertebral artery injury and is less technically demanding. However, only few studies with small samples analyzed the short-term outcomes of C2 pedicle screws combined with C1 laminar hooks (C2PS-C1LH) technique in the treatment of atlantoaxial dislocation. Furthermore, it is not confirmed whether similar clinical outcomes can be achieved with C1-C2 pedicle screw and rod construct (PSRC). Read More

Res Vet Sci 2020 Feb 13;128:76-85. Epub 2019 Nov 13.

Division of Small Animal Surgery, Department of Clinical Veterinary Medicine, University of Berne, Switzerland. Electronic address:

The atlantoaxial joint can be affected by instability, in most cases a congenital pathology in young small breed dogs. Causes of atlantoaxial instability (AAI) are variable but are usually attributed to a lack of ligamentous support. The purpose of the present study was to specify the role of the ligamentous structures in the stabilisation of the atlantoaxial joint and to find possible adaptations of the ligaments' internal structure to their specific function. Read More

Childs Nerv Syst 2020 Jan 3;36(1):19-26. Epub 2019 Nov 3.

Russian Ilizarov Scientific Center, 6, M. Ulyanova Street, Kurgan, 640014, Russia.

Purpose: To clarify etiology, clinical features, and diagnostic and treatment options of atlantoaxial dislocation (AAD) due to os odontoideum (OsO) in patients with Down's syndrome (DS).

Methods: We described and analyzed three clinical cases of AAD due to OsO in DS patients and reviewed descriptions of similar cases in the scientific sources.

Results: According to literature review, more than 80% of DS patients with odontoid ossicles had atlantoaxial instability (AAI). Read More

World Neurosurg 2020 Feb 26;134:e512-e523. Epub 2019 Oct 26.

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

Objective: The aim of this study was to report an experience with 190 cases of os odontoideum over 20 years. The management outcome following atlantoaxial fixation was analyzed.

Methods: From January 2000 to September 2018, 190 patients with os odontoideum were surgically treated. Read More

Neurospine 2019 Sep 30;16(3):456-461. Epub 2019 Sep 30.

Department of Orthopedic Surgery, Columbia University, New York, NY, USA.

C1 stenosis is often an easily missed cause for cervical myelopathy. The vast majority of cervical myelopathy occurs in the subaxial cervical spine. The cervical canal is generally largest at C1/2, explaining the relatively rare incidence of neurological deficits in patients with odontoid fractures. Read More

J Clin Neurosci 2020 Jan 9;71:263-270. Epub 2019 Oct 9.

Department of Orthopedic Surgery, University of Pennsylvania Hospital System, Philadelphia, PA, United States.

Occipital neuralgia typically arises in the setting of nerve compression by fibrosis, surrounding anatomic structures, or osseous pathology, such as bone spurs or hypertrophic atlanto-epistropic ligament. It generally presents as paroxysmal bouts of sharp pain in the sensory distribution of the first three occipital nerves. Due to the long course of the greater occipital nerve (GON), and its peculiar anatomy, and location in a mobile region of the neck, it is unsurprising that the GON is at high risk for compression. Read More

J Neurosurg Pediatr 2019 Oct 4:1-7. Epub 2019 Oct 4.

6Department of Pediatric Neurosurgery, Primary Children's Hospital, University of Utah, Salt Lake City, Utah.

Objective: Hypermobility of the craniocervical junction (CCJ) in patients with Down syndrome (DS) is common. Whereas atlantoaxial (C1-2) hypermobility is well characterized, occipitoatlantal (Oc-C1) laxity is recognized but poorly defined. A clear understanding of the risks associated with DS-related hypermobility is lacking. Read More