Search Results (42)

Background: The atlanto-axial segment is highly mobile and, therefore, prone to instability in the setting of inflammatory disease, infection, tumor or trauma. While minimally invasive surgical (MIS) techniques have gained acceptance in the thoracolumbar spine due to their advantages over traditional approaches, their use at the atlanto-axial segment is controversial due to the surgical risk associated with its complex anatomy. To evaluate the current evidence on MIS atlanto-axial fixation, we carried out a systematic review of the literature and compared the reported results with those of open procedures. Methods: This systematic review follows PRISMA-DTA 2020 guidelines. A comprehensive search was conducted in November 2023 across PubMed/Medline, Google Scholar and clinicaltrials.gov using specific keywords related to minimally invasive atlanto-axial fixation. Data regarding study characteristics, patient demographics, surgical techniques, and outcomes were extracted from included studies. Results: This systematic review included 13 articles reporting on the results of surgery in 305 patients, in whom a total of 683 screws were inserted through a posterior MIS approach. N = 162 screws were inserted using the Harms–Goel technique, while N = 521 were placed using the Magerl technique. N = 40 screws were inserted using navigation guidance, while N = 643 were introduced with fluoroscopy assistance. Eight screws were misplaced. A Vertebral Artery (VA) injury was reported in three patients. With a mean value of 26.2 ± 15.3 months, the rate of fusion ranged between 80% and 100%. Conclusions: This study highlights the potential of MIS for posterior atlanto-axial fixation, which was achieved using Magerl transarticular screws in a large majority of cases. Despite technical challenges, MIS approaches appear to achieve satisfactory clinical and radiological outcomes with complication rates similar to those of open techniques. Future studies may help refine the indications for MIS and identify those cases better suited for open approaches. Full article

Background: Type 1 basilar invagination (BI) is caused by a structural instability at the craniovertebral junction (CVJ) and has been historically treated with distraction and stabilization through fusion of the C1–C2 vertebrae. Recent advances in 3D printed custom implants (3DPIs) have improved the array of available options for reaching distraction and alignment goals. Case Presentation: We report the case of a 15-year-old male who presented with early signs of cervical myelopathy. Radiographic evaluation revealed type 1 BI with a widened atlantodental interval (ADI) of 3.7 mm and a 9 mm McRae’s line violation (MLV) of the dens, resulting in severe narrowing at the CVJ and brainstem/spinal cord impingement. Of note, the patient had bilateral dysplastic C1 and C2 anatomy, thus requiring a patient-specific 3DPI to conform to this anatomy and enable sufficient distraction and fusion. Custom 3D printed C1–C2 interfacet spacers were created and implemented within 14 days to achieve sufficient distraction, osteoconduction, and stabilization of the C1–C2 joint. Outcome: Postoperatively, the patient remained neurologically intact with myelopathic symptom improvement before discharge on postoperative day 4. Postoperative imaging demonstrated the resolution of BI from successful C1–C2 joint distraction and confirmed intended implant placement with resolution of canal stenosis. During his 6-week follow-up, the patient remained neurologically stable with intact hardware and preserved alignment. Conclusions: This case is the first in the United States demonstrating the use of custom 3D printed interfacet spacers to achieve successful distraction, decompression, and stabilization of type 1 BI. These patient-specific 3DPIs were designed and created in a streamlined manner and serve as proof-of-concept of pragmatic implant design and manufacturing. Future optimization of the workflow and characterization of long-term patient outcomes should be explored for these types of 3DPI. Full article

Background: A pseudotumor adjacent to the odontoid has been reported to be a non-neoplastic mass that is mainly associated with atlantoaxial instability. Methods: Case report. Results: A 72-year-old woman presented to our clinic with a chief complaint of bilateral fine motor dysfunction and gait disturbance. She had rheumatoid arthritis as a comorbidity. Physical examination revealed bilateral hand fine motor dysfunction and signs of myelopathy, including hyperreflexia of the deep tendon reflexes in the lower extremities. Magnetic resonance imaging (MRI) showed a retro-odontoid pseudotumor. Surgery was proposed to the patient, but she did not wish to undergo surgery at this time. At a follow-up visit approximately one year after the initial visit, she complained of the progression of the bilateral hand fine motor dysfunction and gait disturbance. MRI demonstrated a pseudotumor in the space anterior to the odontoid process, indicating that the localization of the pseudotumor around the odontoid process changed from the posterior space to the anterior space in its natural course. Conclusions: The speculated sequential mechanism of the change in the location of the pseudotumor from the posterior space to anterior space to the odontoid process in the natural course is as follows: As the rheumatoid arthritis progressed, the C1-2 joint was immobilized in the dislocated position, and as a result, the retro-odontoid pseudotumor disappeared due to immobilization of the C1-2 joint. Following the disappearance of the retro-odontoid pseudotumor, the odontoid process shifted backward owing to rupture of the transverse annular ligament. Consequently, a new space appeared in front of the odontoid process. Subsequently, damage to the apical and alar ligaments resulted in pseudotumor formation in the new space. Considering our case, the formation of an antero-odontoid pseudotumor occurs only in limited cases, with extreme progression of the pathology. Most cases of retro-odontoid pseudotumors are treated by surgery before such a progression; therefore, we consider that such a case has not yet been reported in the literature. Full article

Background/Objectives: Atlantoaxial instability (AAI) affects approximately 20% of individuals with Trisomy 21. Radiological screening has been debated for decades due to its unclear clinical utility and lack of standardized diagnostic criteria. This systematic review evaluates the indications, efficacy, and clinical implications of radiological screening for AAI in children with Trisomy 21. Methods: Following the PRISMA guidelines, we conducted a systematic search in PubMed, Embase, and Google Scholar for studies published between 1990 and May 2024. Studies were included if they assessed AAI screening in pediatric Trisomy 21 populations, defined AAI radiologically, and reported at least two cases. We extracted the demographic data, study design, radiological criteria, screening recommendations, and biases from these studies. Results: Of the 537 identified studies, 8 met the inclusion criteria, encompassing 2536 children (mean age: 7 years). Five studies supported routine screening, while three opposed it. Studies varied significantly in their AAI definitions, using atlanto-dental interval (ADI) thresholds of 4 mm to 6 mm, the space available for cord (SAC), and the basion-axial interval (BAI). No study demonstrated a definitive correlation between radiological findings and neurological symptoms. Conclusions: Routine radiological screening for AAI in asymptomatic children with Trisomy 21 is not supported by consistent evidence. A selective screening approach, focusing on symptomatic patients or those engaging in high-risk activities, may be more appropriate. The standardization of radiological criteria and prospective studies are needed to refine screening recommendations. Full article

Background: Facial features are the first basic sign of medical knowledge of children and adults with congenital malformations. Children born with multiple contractures almost always receive the misdiagnosis of arthrogryposis multiplex. Larsen syndrome can easily be diagnosed at birth via the proper interpretations of its characteristic facial features and multiple dislocations. Comprehensive clinical diagnosis can facilitate an orthopedic strategy for early treatment and can enhance the recognition of unreported craniocervical malformation complexes. Material and Methods: Six children (four boys and two girls, with ages ranging from a few months to 7 years old) were referred to our department for diagnosis and treatment. All children received their first misdiagnosis by the pediatricians as manifesting arthrogryposis multiplex congenita. The clinical phenotype was our first decisive tool for diagnosis. All children exhibited the classical phenotype of dish-like facies associated with multiple joint dislocations. Radiological phenotypic characteristics confirmed our clinical diagnosis of Larsen syndrome. Three children out of six showed unpleasant cervical spine deformities. The first child, a 2-year-old, became tetraplegic after minor trauma. One child presented with progressive rigid cervical kyphosis. The third child was a product of a first-relative marriage and was born with congenital tetraplegia. A genotype was carried out for confirmation. Results: Three children underwent open reduction for congenital hip and knee dislocations. One child underwent spinal fusion CO-C7 because of tetraplegia. A 3D-reformatted and reconstruction CT scan of the craniocervical junction showed two forms of unusual dys-segmentation, firstly along C2-3 effectively causing the development of acute-angle cervical kyphosis. Secondly, an infant with congenital tetraplegia showed a serious previously undescribed atlanto–axial malformation complex. Namely, atlanto–axial maldevelopment (dys-segmentation) of (C1/C2) was associated with hypoplasia of the anterior and the posterior rings of the atlas. Genetic tests of these children were compatible with the autosomal dominant type of Larsen syndrome and manifested a heterozygous mutation in FLNB mapped 3p14.3, encoding an actin-binding protein, filamin B. The child with congenital tetraplegia showed no mutations in FLNB, though his clinical and radiological phenotype and his family history of first-relative marriage were totally compatible with the diagnosis of the autosomal recessive type of Larsen syndrome. Conclusions: Our strategy was and still is based on a coherent clinical and radiological diagnosis, which is based on comprehensive clinical and radiological phenotypic characterizations. We implemented a 3D-reformatted CT scan to further understand the craniocervical junction pathology in three children. Strikingly, prenatal onset of lethal maldevelopment (dys-segmentation) of the atlanto–axial spine segments has been diagnosed in an infant with congenital tetraplagia. A less serious cervical spine malformation was detected in two children who presented with progressive acute-angle cervico and cervico-thoracic kyphosis. Our clinical strategy can form the basis for a thorough clinical assessment for infants and children born with multiple malformation complexes and can lead to recognition of novel understandings. Full article

Atlantoaxial subluxation (AAS) is a neurosurgical condition caused by joint hyperflexion and is characterized by the development of compressive cervical myelopathy. Various ventral fixation techniques have been described to permanently reduce the subluxation by long-term stabilization of the atlantoaxial joint. However, the rate of complications related to implant failure with these techniques remains high. The aim of this study was to describe a cervical distraction–stabilization technique using screws and PMMA to treat AAS and evaluate the clinical outcomes based on neurological and radiographic follow-up. Magnetic resonance imaging (MRI) was performed to confirm the diagnosis of AAS and identify any associated intraparenchymal lesions. Computed tomography (CT) scans were performed for surgical planning. No complications resulting in irreversible damage, surgical revision, or euthanasia protocol were observed. In the immediate postoperative period, the neurological scores showed an improvement of approximately two points from the preoperative values in all subjects. At the 6-month neurological examination (medium-term follow-up), 93% (13/14) of the dogs showed normal neurological function with no signs of pain. Based on clinical follow-up data, the cervical distraction–stabilization technique described in this study appears to be a valuable surgical alternative to treat AAS in toy-breed dogs. Full article

Background/Objectives: This report details a rare instance of an infant with achondroplasia developing acute tetraparesis after a cervical whiplash injury, highlighting key multidisciplinary management considerations and specific anesthetic strategies to mitigate potential risks. Case presentation: A 1-year-old boy with achondroplasia presented with acute tetraparesis after a whiplash injury. Initial craniocervical computed tomography demonstrated a reduced volume of the posterior fossa, foramen magnum stenosis, and ventriculomegaly, without any fractures or dislocations. Moreover, magnetic resonance imaging (MRI) revealed pathological signal changes in the medulla oblongata, cervical spinal cord in segments C1 and C2, and the posterior atlantoaxial ligament. After initial conservative therapy and head immobilization using a soft cervical collar, partial remission of the tetraparesis was achieved. Two weeks post-injury, microsurgical posterior fossa decompression extending to the foramen magnum and C1 laminectomy was performed under general anesthesia with intraoperative neuromonitoring. Following an unsuccessful intubation attempt using a fiberoptic bronchoscope, successful airway management was achieved using a combined technique incorporating video laryngoscopy. Venous access was secured under ultrasound guidance. The patient exhibited complete remission of neurological symptoms by the third postoperative month during follow-up. Conclusions: This case report underscores the crucial need for a multidisciplinary approach in managing children with achondroplasia, especially with foramen magnum stenosis and complex cervical spine injuries. Anesthetic management required meticulously planned airway strategies using advanced techniques like video laryngoscopy and fiberoptic bronchoscopy to reduce airway risks. It also highlights the importance of conservative therapy paired with timely neurosurgical intervention, resulting in the patient’s full recovery. Full article

Background and Objectives: Atlantoaxial tuberculosis (TB) is rare, and its diagnosis is difficult. Herein, we present a rare case with a challenging diagnostic journey of atlantoaxial TB spanning over two years. Materials and Methods: A 70-year-old immunocompetent female patient presented with a four-week history of nuchal pain, stiffness, and headache. She did not have any TB-associated constitutional symptoms. The result of the initial biopsy indicated only a nonfermenting Gram-negative bacillus and the histopathological report revealed concurrent acute and chronic inflammation. Posterior fusion with bilateral C1 lateral mass and C2 transpedicular screw fixation was performed after a five-week course of antibiotics. Results: However, the atlantoaxial abscess progressed and led to myelopathy two years later. Tuberculous spondylitis was not confirmed until the second biopsy. We chose the transoral approach for prompt abscess evacuation and to prevent unnecessary damage to the nearby vital neurovascular structures. The sputum culture and chest radiograph did not reveal concurrent pulmonary TB. Conclusions: Spinal TB has a greater likelihood of presenting with a cold abscess without the typical constitutional symptoms of pulmonary TB. Distinctive magnetic resonance imaging (MRI) features, such as a thin and smooth abscess wall, subligamentous spread, severe vertebral body destruction, and heterogenous vertebral wall enhancement, might help to differentiate between tuberculous and pyogenic spondylitis. We hope to offer meaningful insights to clinicians facing similar intricate scenarios, including subtle clues that may lead to a quicker diagnosis and the considerations we made while designing a treatment plan. Full article

Background: Atlantoaxial instability is the most common cervical instability in patients with rheumatoid arthritis (RA). Its course may differ in different patients and may have different degrees of severity and symptoms. Methods: There are a number of studies on systemic factors associated with the development of this instability, but there are few publications in the scientific literature on the influence of biomechanical factors on the development of cervical instability. One of the areas that allows the study of biomechanical factors influencing spine pathologies is the analysis of sagittal balance using radiological parameters. The study of radiological parameters of sagittal balance has contributed to understanding the pathology of selected spine diseases and is currently an indispensable tool in planning surgical treatment. Results: The presented study, conducted on a group of RA patients with cervical instability, was performed to look for a relationship between C1–C2 instability and sagittal balance parameters. Conclusions: Among the examined selected parameters, a statistically relationship between C1–C2 instability and the Cobb angle C1–C7 and OD-HA parameters has been found. This confirms the need for further in-depth research on this areas. Full article

Background: cervicogenic headaches are common and are believed to be the cause of dysfunction in the upper cervical spine. The mobility and the position of the atlas have been identified as a cause of upper cervical dysfunction. The mobility of the atlas is entirely under the control of the suboccipital muscles. The oblique capitis inferior muscle has a rotatory effect on the atlas when contracted. This study evaluated the immediate effects of a dry needling electrical stimulation-induced contraction of the left oblique capitis inferior muscle on the position and mobility of the atlas in the atlantoaxial joint. Methods: thirty-one subjects participated in this within-subject repeated measure study design. Each subject underwent a pre-measures neck flexion rotation test, palpation of the atlas position, and measurement of the length of the right oblique capitis inferior muscle with musculoskeletal ultrasound imaging. The pre-measures were repeated after two five-second tetanic contractions of the oblique capitis inferior muscle. Results: post-intervention analysis revealed significant changes in the length of the right oblique capitis inferior muscle. This length change correlated with the palpated positional default position immediately after the intervention. Conclusions: two five-second tetanic contractions of the left oblique capitis inferior muscle immediately affected the position of the atlas in the atlantoaxial joint. In our subjects, 90% displayed a positional default in the left rotation, and this was correlated with a change in the neck flexion rotation test. This study supports the notion that suboccipital muscle tonicity can result in mobility dysfunction and, thus, conditions such as cervicogenic headaches. Full article

An 8-month-old, 3.4 kg, castrated male Toy Poodle was referred for progressive tetraparesis and respiratory disorder without a history of trauma. Repeated computed tomography (CT) and magnetic resonance imaging (MRI) with different positions of the neck revealed concurrent atlanto-occipital dislocation (AOD) and atlantoaxial instability (AAI) with spinal cord compression. This case was unique due to its congenital nature and the absence of trauma. The surgical treatment involved precise removal of the C1 vertebra’s ventral articular facet, which was compressing on the spinal cord, attributed to its fixed and malaligned position within the atlantooccipital joint. Following facetectomy, the stabilization of the occipital bone to the C2 vertebra was achieved by screws, wire, and polymethyl methacrylate. Two days after surgery, the dog recovered ambulation and showed gradual improvement in gait, despite mild residual ataxia. Postoperative CT and radiographs showed successful decompression of the spinal cord. The screw loosening was confirmed at 114 days, which was managed successfully by extracting the affected screws. Through the 21-month monitoring period, the dog showed a normal gait with a wide-based stance of the pelvic limbs when standing and experienced no pain. This case represents the first report of concurrent congenital AOD and AAI treated with a ventral surgical approach, contributing new insights to the understanding and management of such complex cranio-cervical junction disorders in veterinary neurosurgery. Full article

Despite advancement in surgical innovation, C1-C2 fixation remains challenging due to risks of screw malposition and vertebral artery (VA) injuries. Traditional image-based navigation, while useful, often demands that surgeons frequently shift their attention to external monitors, potentially causing distractions. In this article, we introduce a microscope-based augmented reality (AR) navigation system that projects both anatomical information and real-time navigation images directly onto the surgical field. In the present case report, we discuss a 37-year-old female who suffered from os odontoideum with C1-C2 subluxation. Employing AR-assisted navigation, the patient underwent the successful posterior instrumentation of C1-C2. The integrated AR system offers direct visualization, potentially minimizing surgical distractions. In our opinion, as AR technology advances, its adoption in surgical practices and education is anticipated to expand. Full article

(1) Background: In elderly patients with type II odontoid fractures, accompanying severe atlantoaxial instability (AAI) is discussed as a marker possibly warranting more aggressive surgical therapy. This study aimed to characterize adverse events as well as the radiological and functional outcomes of surgical vs. conservative therapy in patients with odontoid fracture and AAI. (2) Methods: Patients aged 65 years and older with type II odontoid fracture and AAI treated were included. AAI was assumed if the mean subluxation across both atlantoaxial facet joints in the sagittal plane was greater than 50%. Data on demographics, comorbidities, treatment, adverse events, radiological, and functional outcomes were analyzed. (3) Results: Thirty-nine patients were included. Hospitalization time was significantly shorter in conservatively treated patients compared to patients with ventral or dorsal surgery. Adverse events occurred in 11 patients (28.2%), affecting 10 surgically treated patients (35.7%), and 1 conservatively treated patient (9.1%). Moreover, 25 patients were followed-up (64.1%). One secondary dislocation occurred in the conservative group (11.1%) and three in the surgical group (18.8%). (4) Conclusions: Despite the potential for instability in this injury, conservative treatment does not seem to lead to unfavorable short-term results, less adverse events, and a shorter hospital stay and should thus be considered and discussed with patients as a treatment option, even in the presence of severe AAI. Full article

Background and Objectives: C-arm-free MIS techniques can offer significantly reduced rates of postoperative complications such as inadequate decompression, blood loss, and instrumentation misplacement. Another advantageous long-term aspect is the notably diminished exposure to radiation, which is known to cause malignant changes. This study emphasizes that, in some cases of spinal conditions that require a procedural intervention, C-arm-free MIS techniques hold stronger indications than open surgeries guided by image intensifiers. Materials and Methods: This study includes a retrospective analysis and review of various cervical and thoracic spinal procedures, performed in our hospital, applying C-arm-free techniques. The course of this study explains the basic steps of the procedures and demonstrates postoperative and intraoperative results. For anterior cervical surgery, we performed OPLL resection, while for posterior cervical surgery, we performed posterior fossa decompression for Chiari malformation, minimally invasive cervical pedicle screw fixation (MICEPS), and modified Goel technique with C1 lateral mass screw for atlantoaxial subluxation. Regarding the thoracic spine, we performed anterior correction for Lenke type 5 scoliosis and transdiscal screw fixation for diffuse idiopathic skeletal hyperostosis fractures. Results: C-arm-free techniques are safe procedures that provide precise and high-quality postoperative results by offering sufficient spine alignment and adequate decompression depending on the case. Navigation can offer significant assistance in the absence of normal anatomical landmarks, yet the surgeon should always appraise the quality of the information received from the software. Conclusions: Navigated C-arm-free techniques are safe and precise procedures implemented in the treatment of surgically demanding conditions. They can significantly increase accuracy while decreasing operative time. They represent the advancement in the field of spine surgery and are hailed as the future of the same. Full article

The feasibility of a newly developed augmentation of ventral fixation technique for surgical stabilization of atlantoaxial instability was clinically evaluated in a cohort of eleven dogs, and long-term clinical outcomes were retrospectively analyzed. The new technique combines wire/suture fixation through a transverse hole in the axis anchored by two screws placed in the alae atlantis or at the cranial end of plates used to bridge the atlantoaxial joint ventrally. A previous biomechanical study demonstrated good stability of this technique during shear loading, comparable to the stability achieved with other standard techniques. Ten dogs improved clinically after surgery and returned to a normal life within 3–6 months of surgery. One dog developed aphonia, dysphagia, and died of aspiration pneumonia three days after surgery. The augmentation of conventional ventral atlantoaxial fixation with the transverse bony corridor of the proximal axis body may be a valuable way to enhance stabilization of the atlantoaxial joint. Full article