Search Our Scientific Publications & Authors

Vet Comp Orthop Traumatol 2021 May 12. Epub 2021 May 12.

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

Objective:  The study aimed to determine the influence of head neck position on imaging measurements used to assess the craniovertebral junction (CVJ) and to recommend the most appropriate position for the evaluation of the CVJ.

Study Design:  A cross-sectional sample of adult dogs' cadavers was subjected to a computed tomography scan of the cranium and the cranial cervical region in three standardized head positions. Imaging measurements often used to assess the CVJ were measured. Read More

BMC Musculoskelet Disord 2021 May 3;22(1):408. Epub 2021 May 3.

Departments of Orthopaedic Surgery, Yokohama City University Graduate School of Medicine, 3-9, Fukuura, Kanazawa-ku, 236-0004, Yokohama, Japan.

Background: Few reports have described the association between rheumatoid arthritis (RA) cervical lesions and osteoporosis, especially in patients with vertical subluxation (VS) that could be induced by the collapse of lateral masses in the upper cervical spine. Therefore, this study aimed to investigate the prevalence and risk factors for cervical lesions in patients with RA under current pharmacological treatments with biological agents, and to investigate the relationship between osteoporosis and VS development.

Methods: One hundred eighty-five consecutive patients with RA who underwent both cervical plain radiography and bone mineral density (BMD) scanning were enrolled. Read More

J Neurosci Rural Pract 2021 Apr 3;12(2):228-235. Epub 2021 Mar 3.

Department of Neurosurgery, Government Medical College, Kozhikode, Kerala, India.

We retrospectively analyzed atlantoaxial dislocation (AAD) of various pathologies, namely, rheumatoid arthritis (RA), os odontoideum, and trauma. Various techniques were discussed in relation to C1-C2 stabilization. The study aims to share our clinical experience in a series of six cases of C1-C2 instability that underwent posterior C1-C2 fusion, with free hand technique and limited fluoroscopy. Read More

AME Case Rep 2021 25;5:12. Epub 2021 Apr 25.

School of Nursing and Health Studies, The Open University of Hong Kong, Hong Kong, China.

Rheumatoid arthritis (RA) is an autoimmune disease that affects the synovial tissue which lines joints and tendons. The craniocervical junction is made up exclusively of synovial joints and ligaments and especially vulnerable to the inflammatory process of RA. The chronic inflammation of RA leads to loss of ligamentous restriction and erosion of the bony structures and results in craniocervical instability (CCI). Read More

Surg Neurol Int 2021 30;12:135. Epub 2021 Mar 30.

Department of Neurosurgery, Salford Royal Hospital, Stott Lane, Salford, Manchester, M6 8HD, England, United Kingdom.

Background: Dysphagia after occipitocervical fixation (OCF) is a complex phenomenon and revision surgery in this context involves difficult decision-making. The pathogenesis is explored and surgical strategies discussed. A surgical strategy that has not been described before in the management of this condition, is discussed with two illustrative cases. Read More

J Surg Case Rep 2021 Apr 6;2021(4):rjab097. Epub 2021 Apr 6.

Department of Neurosurgery, Tufts Medical Center, Boston, MA 02111, USA.

Extradural atlantoaxial cysts are typically related to C1-2 degeneration. Intradural cysts may cause secondary syringobulbia depending on the size and cerebrospinal fluid flow obstruction. However, medullary syrinxes have not been previously described with extradural cysts. Read More

J Craniovertebr Junction Spine 2021 Jan-Mar;12(1):95-98. Epub 2021 Mar 4.

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

We present a report of two patients having the association of omovertebra, Sprengel's deformity of the shoulder and Klippel-Feil abnormality with craniovertebral junctional instability. Our literature survey did not locate any report of such association. Significance of bone alterations is analyzed. Read More

J Craniovertebr Junction Spine 2021 Jan-Mar;12(1):91-94. Epub 2021 Mar 4.

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

A relatively rare report of an 8-year-old girl with Maroteaux-Lamy syndrome that is Type VI mucopolysaccharidosis who presented with symptoms of spastic quadriparesis related to atlantoaxial instability is presented. Atlantoaxial stabilization resulted in rapid and sustained neurological recovery. Read More

World Neurosurg 2021 Apr 24. Epub 2021 Apr 24.

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

Objective: The potential significance of relationship of atlantoaxial instability with retro-odontoid pseudotumor, pannus, and/or cyst (RPC) is analyzed.

Methods: We searched the database of patients with craniovertebral junction-related instability treated by atlantoaxial fixation from January 2000 to March 2020. We identified 63 patients in whom there was an RPC in the region posterior to the odontoid process or posterior to the posterior aspect of the C2 body. Read More

J Craniovertebr Junction Spine 2020 Oct-Dec;11(4):276-286. Epub 2020 Nov 26.

Department of Neurosurgery, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India.

Objective: Larsen syndrome (LS) is characterized by osteo-chondrodysplasia, multiple joint dislocations, and craniofacial abnormalities. Symptomatic myelopathy is attributed to C1-C2 instability and sub-axial cervical kyphosis. In this article, we have analyzed the surgical outcome after posterior fixation in LS with craniovertebral junction instability. Read More

Neurospine 2021 Mar 31;18(1):177-187. Epub 2021 Mar 31.

Department of Neurosurgery, Tokyo Metropolitan Neurological Hospital, Tokyo, Japan.

Objective: Although a retro-odontoid pseudotumor associated with rheumatoid arthritis is a well-known clinical entity, little is known about retro-odontoid pseudotumors not associated with rheumatoid arthritis due to their rarity.

Methods: Between 2006 and 2019, consecutive patients with nonrheumatoid pseudotumors were included and retrospectively compared with patients with rheumatoid pseudotumors.

Results: Nineteen patients had nonrheumatoid pseudotumors (mean age, 73 ± 6 years; male, 53%). Read More

Eur Spine J 2021 Mar 18. Epub 2021 Mar 18.

Dept. Spine Surgery, London Bridge Hospital, St Olaf House, 27 Tooley street, London, SE1 2PR, UK.

Purpose: Odontoid process fractures can extend rostral into the C2 arch. We investigated the clinical impact of a concurrent fracture of the pars interarticularis on odontoid failure. To overcome the surgical challenges related to the morphology of these fractures, we describe a novel surgical strategy using atlantoaxial joint distraction arthrodesis. Read More

J Neurol Surg B Skull Base 2021 Feb 4;82(Suppl 1):S2-S3. Epub 2020 Mar 4.

Department of Neurosurgery, University of Insubria, Ospedale di Circolo Fondazione Macchi, Varese, Italy.

 We illustrate endoscopic endonasal odontoidectomy for the Chiari-I malformation respecting craniovertebral junction (CVJ) stability.  Case report of a 12-year-old girl affected by the Chiari-I malformation. Magnetic resonance imaging (MRI) showed tonsillar herniation, basilar invagination, and dental retroversion, causing angulation and compression of the bulbomedullary junction. Read More

Eur Spine J 2021 Mar 11. Epub 2021 Mar 11.

Department of Neurosurgery, The First Medical Center, Chinese PLA General Hospital, 28 Fuxing Road, Haidian District, Beijing, 100853, China.

Purpose: To introduce a novel surgical protocol for safe and accurate placement of C1 lateral mass screws in patients with atlas assimilation, basilar invagination and atlantoaxial instability, and to categorize the screw accuracy and perioperative complications regarding this technique in a large case series.

Methods: Between January 2015 and January 2020, patients who had atlas assimilation, basilar invagination and atlantoaxial instability, and underwent atlantoaxial fixation using C1 lateral mass screws were reviewed. C1 lateral mass screws were placed with a novel surgical protocol following a series key steps, including posterior para-odontoid ligament release, panoramic exposure of the invaginated lateral mass, and diligent protection of the abnormal VA. Read More

J Neurol Surg B Skull Base 2021 Feb 26;82(Suppl 1):S63-S64. Epub 2020 Nov 26.

Institute of Neurosciences, Sri Ramaswamy Memorial Institutes for Medical Sciences, Chennai, Tamil Nadu, India.

 This study aimed to demonstrate the technique of handling the anomalous vertebral artery in congenital atlantoaxial instability. The vertebral artery course can be variable in congenital atlantoaxial instability, especially if there is assimilation of atlas. The surgical technique to stabilize the atlantoaxial joint should ensure the patency and safety of the vertebral artery and prevents devastating stroke. Read More

World J Clin Cases 2021 Feb;9(6):1461-1468

Department of Orthopedics, Yidu Central Hospital, Weifang Medical University, Qingzhou 262500, Shandong Province, China.

Background: In general, atlantoaxial dislocation is rare due to the stability of the C1-C2 complex. Traumatic atlantoaxial dislocations are usually anterior and accompanied by odontoid fractures. Posterior atlantoaxial dislocations are rare, and complete posterior dislocation without associated fracture is even more rare. Read More

JBJS Case Connect 2021 02 24;11(1). Epub 2021 Feb 24.

Department of Radiology, Sir H.N. Reliance Foundation Hospital, Mumbai, Maharashtra, India.

Case: An eight-year-old boy presented with acute encephalopathy due to posterior circulation ischemic stroke. He was found to have vertebral artery stenosis secondary to atlantoaxial instability (AAI) due to an os odontoideum. Occipitocervical fusion was performed 4 weeks after stroke. Read More

Autoimmun Rev 2021 Apr 17;20(4):102776. Epub 2021 Feb 17.

Academic Rheumatology Centre, MFRU and Dipartimento Scienze Cliniche e Biologiche, Università degli Studi di Torino, Torino, Italy. Electronic address:

Although synovitis is the pathological hallmark of rheumatoid arthritis (RA), many extra-articular manifestations (EMs) and comorbidities likely occur due to the complex, chronic, inflammatory, and autoimmune features of RA. Cardiovascular (CV) disease is the most common cause of death in patients with RA. Compared to the general population, patients with RA have twice the risk of myocardial infarction and up to 50% increased CV mortality risk. Read More

Spine Deform 2021 Feb 15. Epub 2021 Feb 15.

Department of Otorhinolaryngology, Sir H.N. Reliance Foundation Hospital, Girgaon, Mumbai, India.

Purpose: Revision surgery in an irreducible atlantoaxial dislocation (IAAD) previously operated with a posterior approach is challenging. Multiple modalities using anterior, posterior, and dual approaches have been described. We report a so far unreported technique of revision surgery by posterior implant removal and decompression with anterior transoral release followed by posterior instrumentation. Read More

World Neurosurg 2021 May 1;149:e854-e865. Epub 2021 Feb 1.

Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, USA.

Background: The proclivity to atlantoaxial instability (AAI) has been widely reported for conditions such as rheumatoid arthritis and Down syndrome. Similarly, we have found a higher than expected incidence of AAI in hereditary connective tissue disorders. We demonstrate a strong association of AAI with manifestations of dysautonomia, in particular syncope and lightheadedness, and make preliminary observations as to the salutary effect of surgical stabilization of the atlantoaxial motion segment. Read More

Surg Neurol Int 2021 13;12:15. Epub 2021 Jan 13.

Clinic of Neurosurgery, St. Ivan Rilski Hospital, Sofia, Bulgaria.

Background: The non traumatic, post inflammatory atlantoaxial rotatory instability, also known as Grisel's syndrome is a relatively rare condition usually affecting children. Adult cases are rare and even less frequently reported with separate case reports describing a single patient. Although antibiotic treatment and close neurological monitoring seem to be the gold standard of care, there is no general consensus on the optimal timing and extent of the surgical treatment. Read More

Spinal Cord Ser Cases 2021 Jan 19;7(1). Epub 2021 Jan 19.

Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA.

Introduction: This case report details the surgical treatment of an RA patient who presented with concomitant AAI and subaxial spondylotic stenosis and was subsequently treated via a C1-2 screw-rod construct, semispinalis cervicis sparing C3 laminectomy, and C4-C7 laminoplasty. Our case report is the first to describe a surgical approach for treatment of concomitant AAI and subaxial spondylotic stenosis in a patient with RA.

Case Presentation: A 66-year-old male with a history of rheumatoid arthritis and atlantoaxial instability presented to an outpatient spine clinic with complaints of neck pain and worsening gait imbalance. Read More

Oper Neurosurg (Hagerstown) 2021 Mar;20(4):E322-E325

Robert Mangaliso Sobukwe Hospital, Kimberley, South Africa.

Background And Importance: The article identifies the feasibility of transarticular screw fixation after mobilizing the vertebral artery in cases where it is in a "high-riding" location.

Clinical Presentation: A 42-yr-old male patient had a 4-yr history of progressive quadriparesis. Investigations revealed severe basilar invagination. Read More

World Neurosurg 2021 Apr 7;148:38-43. Epub 2021 Jan 7.

Department of Surgery, Maimonides Medical Center, Brooklyn, New York, USA.

Background: Occipitocervical fusion is an important surgical procedure to treat instability of the upper cervical and craniocervical junction. Fixation to the dense cortical bone of the occiput, contemporaneously typically accomplished with a plate and screws, is known to be strong and durable, but there are many competing methods used to secure an adequate number of fixation points of sufficient strength at the cervical end. Extension of hardware to the midcervical region to acquire additional fixation points, however, results in loss of subaxial motion segments and additional potential morbidity. Read More

Eur Spine J 2021 Jan 2. Epub 2021 Jan 2.

Equipo de Cirugía de Columna Clínica Redsalud Vitacura Y Clínica Redsalud Providencia, Universidad de Chile, Santiago, Chile.

Purpose: To review the literature, analyze and discuss diagnostic and treatment options for the Bowhunter Syndrome. A clinical case of idiopathic rotatory C1-C2 subluxation causing dynamic vertebral artery occlusion is presented.

Methods: Literature review between 1960 and 2019, discussion of diagnostic methods and treatment options. Read More

Pol Merkur Lekarski 2020 Dec;48(288):410-414

Department of Orthopedics, Mazovian Rehabilitation Center STOCER, Konstancin-Jeziorna, Poland.

Spinal injuries can be divided into contusions, sprains of intervertebral joints, their dislocation and also damage to ligaments and muscles attachment, and fractures. Typical injuries of the cervical spine include trauma caused by a rapid hyperextension of the neck with the following hyperflexion, often referred to as "whiplash" injury, mostly as a result of traffic accidents. The annual incidence is estimated to be up to 600 per 100 000 inhabitants of Western Europe and North America. Read More

Oper Neurosurg (Hagerstown) 2021 Mar;20(4):E312-E313

Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York.

Traditionally, lateral mass screws (LMSs) have been the mainstay of posterior fixation in the subaxial spine. Although LMSs provide adequate fixation, cervical pedicle screws (CPSs) facilitate high fusion rates (90.5%) and provide for greater bone purchase, better reduction, lower rates of screw loosening or pull out, 2 times greater biomechanical advantage, superior stabilization, decreased development of pseudarthrosis, and decreased revision surgeries compared to LMSs. Read More

World Neurosurg 2021 Mar 15;147:e324-e333. Epub 2020 Dec 15.

Department of Orthopaedics and Traumatology, University of Helsinki, Helsinki, Finland.

Objective: The outcomes of conservative and operative treatment of os odontoideum in children remain unclear. Our objective was to study the outcomes of conservative and surgical treatment of idiopathic os odontoideum in children and compare these outcomes in age- and treatment-matched nonidiopathic children with os odontoideum.

Methods: A retrospective multicenter review identified 102 children with os odontoideum, of whom 44 were idiopathic with minimum 2-year follow-up. Read More

Beijing Da Xue Xue Bao Yi Xue Ban 2020 Dec;52(6):1034-1039

Department of Rheumatology & Immunology, Peking University Third Hospital, Beijing 100191, China.

Objective: To investigate the population distribution of cervical spine instability in rheumatoid arthritis (RA) patients, and to analyze the clinical characteristics in RA patients with cervical spine instability.

Methods: A total of 439 RA patients who had completed cervical spine X-ray examination from Department of Rheumatology and Immunology of Peking University Shenzhen Hospital and Peking University Third Hospital from August 2015 to March 2019 were enrolled. The clinical data, laboratory data and cervical radiographic data were collected and analyzed by -test, rank sum test and Chi-square test to clarify the clinical characteristics in the RA patients with cervical spine instability. Read More

Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi 2020 Dec;34(12):1545-1549

Department of Orthopaedics, Puning Overseas Chinese Hospital, Puning Guangdong, 515300, P.R.China.

Objective: To evaluate the stability of the fixation technique for the crossed rods consisting of occipital plate and C bilateral lamina screws by biomechanical test.

Methods: Six fresh cervical specimens were harvested and established an atlantoaxial instability model. The models were fixed with parallel rods and crossed rods after occipital plate and C bilateral laminae screws were implanted. Read More