Atlantoaxial Instability Research Articles

Rotation Preserving Fixation for the Treatment of C1 Burst Fracture Combined With Type II Odontoid Fracture: 2 Case Reports and Literature Review.

This study aimed to evaluate the clinical feasibility and effectiveness of a monoaxial screw-rod system and anterior screw fixation for C1 and type II odontoid fractures. We conducted a retrospective review of 2 consecutive patients with acute C1 and Anderson-D'Alonzo type II odontoid fractures. Both patients underwent treatment using a posterior monoaxial screw-rod system and anterior screw fixation. We reviewed their clinical records, including the visual analog pain scale and Neck Disability Index scores, as well as pre- and postoperative radiographs. Additionally, pre- and postoperative computed tomography images were used to classify the fracture types and assess the C1 to C2 reduction, rotation, and instability. Both patients presented with type II C1 and type II B odontoid fractures, combined with Dickman type II transverse atlantal ligament injuries. All surgical procedures were successfully performed without complications such as vertebral artery injury, neurological deficit, esophageal injury, or wound infection. Both patients achieved almost complete bone healing of the fractures, and C1 to C2 rotation was well preserved (32° and 49°) without atlantoaxial instability after follow-ups of 21 and 25 months, respectively. A monoaxial screw-rod system and anterior screw fixation could be promising surgical strategies for C1 fractures combined with type II odontoid fractures, even in cases involving transverse atlantal ligament injuries. The preservation of C1 to C2 rotation without atlantoaxial instability was observed after fixation. However, extensive case-finding and long-term follow-up are needed to understand the effectiveness of this treatment. In order to preserve the C1-C2 rotation, a monoaxial screw-rod system and anterior screw fixation may be more suitable for patients with C1 fractures combined with type II odontoid fractures.

Canadian Association of Radiologists Spine Imaging Referral Guideline.

The Canadian Association of Radiologists (CAR) Spine Expert Panel is made up of physicians from the disciplines of radiology, emergency medicine, neurology, neurosurgery, physiatry, a patient advisor, and an epidemiologist/guideline methodologist. After developing a list of 10 clinical/diagnostic scenarios, a rapid scoping review was undertaken to identify systematically produced referral guidelines that provide recommendations for one or more of these clinical/diagnostic scenarios. Recommendations from 23 guidelines and contextualization criteria in the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) for guidelines framework were used to develop 22 recommendation statements across the 8 scenarios (one scenario points to the CAR Trauma Referral Guideline and one scenario points to the CAR Musculoskeletal Guideline). This guideline presents the methods of development and the referral recommendations for myelopathy, suspected spinal infection, possible atlanto-axial instability (non-traumatic), axial pain (non-traumatic), radicular pain (non-traumatic), cauda equina syndrome, suspected spinal tumour, and suspected compression fracture. Spondyloarthropathies and spine trauma point to other CAR Diagnostic Imaging Referral Guidelines, Musculoskeletal and Trauma, respectively.

Upper cervical epidural abscess with emphasis on diabetes as a risk factor: a case report

BackgroundAn upper cervical spine epidural abscess (UCEA) is an epidural abscess that develops in the area between the occiput and the second cervical spine (axis). It is a rare diagnosis that carries the risk of instability of the atlantoaxial joint, and its management is not well-defined. It is known that the skin is the most common source of infection, and that diabetes mellitus (DM) is the most frequently reported risk factor. In this case, we present a patient diagnosed with UCEA, who achieved full neurological recovery postoperatively despite having neurological deficits for over five days prior to surgery.Case presentationWe report the case of a 56-year-old male patient with no history of any prior medical conditions, who presented with headache, neck pain, and weakness of the left side. The weakness started approximately three days prior to his presentation. His initial work up revealed hyperglycemia and elevated HbA1c of 86 mmol/mol (10%). Magnetic resonance imaging (MRI) of the cervical spine revealed spondylitis of the C2 spine with an abscess at the craniocervical junction. He underwent a two-staged surgical approach: decompression and stabilisation. The patient achieved full motor recovery approximately three months postoperatively.ConclusionsWe recommend screening for DM when a spinal epidural abscess (SEA) is diagnosed without readily identifiable risk factors. The optimal management in most SEA cases is surgical, which is particularly true for UCEA because of the risk of atlantoaxial joint instability. Full neurological recovery is possible even when the patient has been having deficits for more than five days.

Radiologic Evaluation of Developmental Anomalies of The Odontoid Process: A Cone-Beam-Compated Tomography Study

Background: The odontoid process is an anchoring pivot for the craniovertebral junction and has many congenital anomalies. Ossiculum Terminale Persistans (OTP) and Os Odontoideum (OO) are believed to be rare developmental anomalies of the odontoid process. The OTP is defined as an ossification center that gives rise to the tip of the dens failing to fuse properly with the body of the axis. OO is described as an oval-shaped, well-corticated bony ossicle that is positioned cephalad to the body of the axis. Both of these conditions may cause neurological signs and atlantoaxial instability.

Minimally Invasive Surgery for Posterior Atlantoaxial Lateral Mass Joint Fusion (MIS-PALF): A Muscle-Sparing Procedure for Atlantoaxial Instability or Dislocation.

Conventional surgical procedures for atlantoaxial instability or dislocation (AAI/D) have been associated with a high prevalence of postoperative occipitocervical pain and dysfunction, as well as substantial perioperative blood loss. We hypothesized that minimally invasive surgery for posterior atlantoaxial lateral mass joint fusion (MIS-PALF), a procedure that can largely avoid disruption of suboccipital musculature, would be superior to the standard Goel-Harms technique in terms of postoperative pain and perioperative blood loss. This was a prospective cohort study of patients undergoing MIS-PALF for AAI/D at Peking University Third Hospital's Department of Orthopaedics from January 2021 to December 2021 and a historical control group of patients with the same diagnoses who were treated with the Goel-Harms technique. The duration of surgery, perioperative blood loss, postoperative length of hospital stay, postoperative body temperature, pain, supplementary use of narcotics, spinal cord function/improvement (assessed using the Japanese Orthopaedic Association [JOA] scores), reduction of AAI/D (determined based on radiographic parameters), rate of successful fusion, and complication rate were all compared between the 2 groups. No significant differences were noted between the groups (43 MIS-PALF cases, 86 control cases) regarding baseline data, operative time, spinal cord function or improvement, reduction of AAI/D, rate of successful fusion, and complication rate. MIS-PALF was associated with significantly less perioperative blood loss, a shorter postoperative hospital stay (decreased by 30.8%), lower intensity and frequency of postoperative pain (decreased by 10.6% and 61.9%, respectively), less need for supplementary narcotics, and less frequent postoperative fever (decreased by 48.7%). This was the first prospective cohort study of which we are aware on minimally invasive procedures for atlantoaxial fusion. Clinical efficacy (AAI/D reduction, rate of successful atlantoaxial fusion, JOA score improvement), efficiency (operative time), and safety (complications) of MIS-PALF appeared to be noninferior to those of the Goel-Harms technique. MIS-PALF was superior in terms of postoperative occipitocervical pain and length of hospital stay, both of which directly affect overall patient satisfaction and postoperative recovery of quality of life. Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Individualized C1-2 intra-articular three-dimensional printed porous titanium alloy cage for craniovertebral deformity

BackgroundCongenital craniovertebral deformity, including basilar invagination (BI) and atlantoaxial instability (AAI), are often associated with three-dimensional (3D) deformity, such as C1-2 rotational deformity, craniocervical kyphosis, C1 lateral inclination, among other abnormalities. Effective management of these conditions requires the restoration of the 3D alignment to achieve optimal reduction. Recently, 3D printing technology has emerged as a valuable tool in spine surgery, offering the significant advantage of allowing surgeons to customize the prosthesis design. This innovation provides an ideal solution for precise 3D reduction in the treatment of craniovertebral deformities.ObjectiveThis study aims to describe our approach to individualized computer-simulated reduction and the design of C1-2 intra-articular 3D printed porous titanium alloy cages for the quantitative correction of craniovertebral junction deformities.MethodsA retrospective analysis was conducted on patients with craniovertebral deformities treated at our institution using individualized 3D-printed porous titanium alloy cages. Preoperative CT data were used to construct models for 3D realignment simulations. Cage designs were tailored to the simulated joint morphology following computer-assisted realignment. Preoperative and postoperative parameters were statistically analyzed.ResultsFourteen patients were included in the study, with a total of 28 3D-printed porous titanium alloy cages implanted. There were no cases of C2 nerve root resection or vertebral artery injury. All patients experienced symptom relief and stable implant fixation achieved in all cases. No implant-related complications were reported.ConclusionThe use of individualized computer-simulated reduction and the design of C1-2 intra-articular 3D printed porous titanium alloy cage facilitates precise 3D realignment in patients with craniovertebral deformities, demonstrating effectiveness in symptom relief and stability.

Multirod posterior occipitocervical instrumentation constructs: a biomechanical analysis and initial case series of 10 patients with complex craniocervical pathology

BACKGROUND CONTEXTStabilization of the occipitocervical (OC) junction with posterior instrumentation plays a vital role in addressing a spectrum of pathologies. Due to limited bone surfaces of the occiput and C1 lamina, achieving union across the OC junction is challenging. PURPOSETo explore the biomechanics and a clinical series of patients treated with multirod constructs across the OC junction using a novel occipital plate with single- and dual-headed, modular tulip heads. STUDY DESIGN/SETTINGBiomechanical analysis and retrospective case series. PATIENT SAMPLEAdults at a single institution who underwent posterior cervical multirod constructs across the OC junction. OUTCOME MEASURESOC–C4 range of motion (ROM), maximum von Mises stress on the rods, and adjacent segment ROMs and intradiscal parameters. Patient demographics, revision operations, rod breakages, wound complications. METHODSA validated occiput-cervical finite element (FE) model was used to simulate OC–C4 cervical fixation under multidirectional pure moment loading. A total of 4 rod configurations were simulated: (A) 2-rod-Ti (4.0 mm titanium rods); (B) 2-rod-CoCr (3.5 mm cobalt chrome rods); (C) 3-rods (4.0 mm titanium rods); (D) 4-rods (4.0 mm titanium rods). The aforementioned measures were compared. A retrospective analysis was also performed of adults at a single institution who underwent posterior cervical multirod constructs across the OC junction. RESULTSBiomechanically, lowest primary rod stresses were observed for 3- and 4-rod constructs. Compared to 2-rod-Ti (121.8 MPa), 2-rod-CoCr showed a 43.2% stress increase in the rods, while 3- and 4-rods experienced rod stress reductions of 20% and 23.2%, respectively. No appreciable differences in OC–C4 ROM, C4–5 ROM, and C4–5 discal stresses were found between multirod and 2-rod constructs. Maximum occipital and C4 screw stresses were decreased in multirod constructs compared to 2-rods, with least stresses noted in the 4-rod construct. Maximum plate stresses were slightly increased in the 4-rod construct compared to 2- and 3-rod fixation, though the forces were largely similar among the constructs. Ten patients (average age 66.4±10.6 years; 8 males) were assessed clinically. Nine of the ten operations were for primary stabilization of pathological fractures and associated craniocervical and/or atlantoaxial instability using 4-rods across the OC junction. At an average follow-up time of 1.58±0.5 years (range, 1–2.3 years), there were no instrumentation failures, no adjacent segment failures, and no wound complications. CONCLUSIONSIn this proof-of-concept investigation, multiple rods (3- and 4-rods) across the OC junction using a novel occipital plate with single- and dual-headed, modular tulips was safe and effective in stabilizing the OC junction. Accompanying FE analysis demonstrated that multirod constructs decreased primary rod stresses and had lower stresses on occipital and C4 screws compared to 2-rod constructs, while occipital plate stresses were largely similar. Additional clinical studies are needed to confirm these findings and to determine the ultimate utility of multirod constructs across the OC junction.

Improving C1 Pedicle Screw Placement for Atlantoaxial Instability with Ultrasonic Bone Burr Assistance

This study aims to evaluate the safety and efficacy of the ultrasonic bone burr (UBB) in facilitating C1 pedicle screw placement for atlantoaxial instability (AAI) treatment, compared to the conventional high-speed drill (HSD) technique. A retrospective analysis was conducted on patients undergoing posterior screw-rod fixation for AAI between December 2017 and July 2023. The patients were divided into two groups based on the tools used for screw placement: UBB and HSD. Data on surgical duration, estimated blood loss, spinal cord and arterial injury incidence, screw placement accuracy, neurological status measured by the Japanese Orthopedic Association (JOA) score and fusion rates, were collected and analyzed. 13 patients received C1 pedicle screw placement via UBB facilitation, while 8 were treated using the HSD approach. The UBB group showed a significant reduction in blood loss and operation time compared to the HSD group (P=0.002 and P<0.001, respectively). No spinal cord or arterial injuries occurred in either group. Optimal screw placement was confirmed in all UBB cases versus 87.5% in the HSD group (P=0.139). Both groups demonstrated significant improvements in JOA scores with no inter-group difference. The fusion rate was 100% in the UBB group and 87.5% in the HSD group, not statistically different (P=0.381). UBB is a viable alternative for C1 pedicle screw placement, associated with reduced blood loss and shorter operation time, while achieving comparable clinical outcomes to the conventional HSD method. Nevertheless, further research with a larger sample size is needed.

Addressing the challenges of complex type III odontoid fractures: Clinical and radiological outcomes of various treatment modalities

BackgroundUnlike simple fractures, complex Type III odontoid fractures—characterized by intricate morphology and pathomechanics—pose significant management challenges. This study aims to evaluate the clinical and radiological outcomes of conservative and surgical treatment modalities for these complex fractures, with a focus on assessing factors influencing fracture union. MethodsFollowing approval of our institutional review board, this retrospective observational cohort study was conducted. All Patients with complex Type III odontoid fractures who were managed at our center from June 2016 to December 2022 were assessed for eligibility. The primary outcome was union status. Secondary outcomes included the ASIA impairment scale, neck disability index (NDI), and complications. Logistic regression analysis was conducted to identify risk factors for adverse union outcomes. ResultsA total of 39 patients were included in the final analysis, with a mean age of 36.10 years. Nine patients were managed conservatively, 12 patients underwent anterior odontoid screw (AOS) fixation, and 18 patients received posterior fusion (PF). The rate of bony union varied significantly across the treatment groups, 100 % in the PF group, 58 % in the AOS group and 22 % in the conservative group (p = 0.0012). The NDI revealed superior functional outcomes in the PF group compared to the other groups (p = 0.0436). Failure of primary treatment was observed in seven patients (three from the conservative group and four from the AOS), necessitating secondary treatment with PF. Lateral mass gap >2 mm, coronal tilt >5°, and atlantoaxial instability >50 % were identified as significant risk factors for adverse union outcomes. ConclusionsSurgical treatment, particularly PF, offers superior outcomes in terms of union rates and functional recovery for complex Type III odontoid fractures. The identification of specific radiological measurements as significant risk factors for non-union underscores the need for detailed imaging and careful patient selection for conservative versus surgical management.

Influence of the type of atlantoaxial dislocation secondary to os odontoideum on sagittal alignment and balance of the subaxial cervical spine after posterior atlantoaxial fusion.

This retrospective study aims to investigate the effect of the type of atlantoaxial dislocation due to os odontoideum on the sagittal alignment and balance of the cervical spine after posterior atlantoaxial fusion. Data of 48 consecutive patients who underwent posterior C1-C2 fusion to treat atlantoaxial dislocation/instability due to os odontoideum were retrospectively reviewed. Radiographic variables, namely the T1 slope (T1S), C1-C2 angle, C2-C7 angle, C1-C2 sagittal vertical axis (SVA), C2-C7 SVA, and modified atlas-dens interval (MADI), were measured preoperatively, immediate postoperatively, and at final follow-up. Patients were divided into three groups based on the preoperative MADI. Differences within and between groups in radiographic variables and relationships between the investigated variables were analyzed. The MADI was correlated with the preoperative to postoperative changes in the C1-C2 angle (r = 0.776, P < 0.05) and C2-C7 angle (r = -0.357, P < 0.05). In the group with anterior atlantoaxial dislocation, the C1-C2 angle and C2-C7 SVA were significantly enlarged at final follow-up (P < 0.05), while the C2-C7 angle was significantly reduced (P < 0.05). The changes in C1-C2 angle and C2-C7 angle were opposite between the posterior group and the anterior dislocation group. The direction/type of atlantoaxial subluxation correlates with the changes in lower cervical curvature after atlantoaxial fusion. Patients with atlantoaxial posterior dislocation and atlantoaxial instability are less likely than those with atlantoaxial anterior dislocation to develop loss of lordosis after posterior atlantoaxial fusion.

Morphometric analysis of atlas lateral mass in Down syndrome cases with relevance to surgical intervention.

Surgical stabilization of the Atlas vertebrae is indicated for severe atlantoaxial instability (AAI) in patients with Down syndrome (DS). This study aims to evaluate the morphological characteristics of the Atlas lateral mass (ALM) in patients with DS with regard to safe instrumentation for surgical stabilization and to compare them with non-syndromic group. This multicenter, retrospective, case-control study included age- and sex-matched patients with and without DS aged > 7 years with a cervical computed tomography (CT) scan. After three-dimensional CT reconstruction, nine parameters were evaluated for both groups. All included measurements were performed by a neuroradiologist who was blinded to clinical data. Forty-three of 3,275 patients with DS were included in this study. Matching number of consecutive patients without DS were identified (mean age: 16 years). Patients with DS were significantly shorter than those without DS. Seven of nine parameters related to ALM were significantly lower in patients with DS than in those in the control group, including anterior wall height (AH), posterior wall height (PH), their ratio, and arch-ALM angle. On adjusting data for patient height, patients with DS had a smaller PH, lower PH/AH ratio, and steeper arch-ALM angle than the control group. Patients with DS had a smaller posterior ALM wall and a steeper arch-ALM angle than the control group without DS. This information is important for surgical planning of safe posterior ALM exposure and safe instrumentation for surgical stabilization in patients with DS.

The New Alternative Technique Outcomes: Atlas Lateral Mass Screw and C2-3 Transfacet Screw Fixation for Complex Atlantoaxial Instability in Patients with Thin C2 Pedicle or High-Riding Vertebral Artery

The study aimed to evaluate the safety, feasibility, effect on fusion, and clinical efficacy of atlas lateral mass and C2-3 transfacet screw fixation technique, serves as an alternative method to traditional posterior atlantoaxial fixation. Patients with atlantoaxial instability who underwent atlas lateral mass and C2-3 transfacet fixation surgery were included. The duration of the surgery and the quantity of blood lost during the operation were recorded. Patients were monitored via X-ray and computed tomography scans to evaluate the degree of fusion at the 1-month and 12-month follow-up. The Neck Visual Analog Scale and Neck Disability Index were evaluated preoperatively, in the postoperative first week, and at the 12-month follow-up for clinical follow-up. A total of 8 patients with atlantoaxial instability due to odontoid fracture or Arnold- Chiari malformation accompanied by bony or vascular abnormalities were included in the study between 2017 and 2024. All 8 patients underwent successful atlas lateral mass and C2-3 transfacet screw fixation, with no neurovascular injury noted during surgery. All patients with fracture exhibited fusion at the 12-month mark, and both the Neck Visual Analog Scale and Neck Disability Index scores demonstrated significant improvement at both the 1-week and 12-month postoperative periods (P < 0.05). The atlas lateral mass and C2-3 transfacet screw fixation technique, an alternative to conventional posterior fixation, has been demonstrated to be an efficacious method for providing adequate stabilization and fusion in patients with atlantoaxial instability, even in the cases of thin C2 pedicle, high-riding vertebral artery, previous failed surgeries, or reoperation.

A novel technique for C1-C2 posterior screw insertion using patient-specific guides created by CT-based 3D printing.

C1-C2 fixation has been developed for the rigid fusion of atlantoaxial instability. C1 lateral mass screw (C1 LMS)-C2 pedicle screw fixation is used more frequently due to its rigid fixation and high bone fusion rate. However, C1 screw placement is relatively unsafe even with recently developed image-based navigation systems. Patient-specific screw guide templates (PSGT) were developed to improve the accuracy and safety of C1 screw placement. Herein, we investigated the outcomes of the C1-C2 posterior fixation technique using PSGT. This was a retrospective study of six patients who underwent posterior cervical spinal fusion using the PSGT between January 2022 and April 2023. Operative time, estimated blood loss, intraoperative radiation dose, surgical cost, and screw placement accuracy were evaluated and compared with those achieved with preoperative CT-based navigation (navigation group, n = 15). Screw accuracy was assessed using Neo's classification. PSGT showed good results, although the differences were not statistically significant (operation time: 104.3 ± 9.7 min vs 116.4 ± 20.8 min; estimated blood loss: 56.7 ± 72.4 mL vs 123.2 ± 162.3 mL; and radiation dose: 1.8 ± 1.2 mSv vs 2.6 ± 0.8 mSv, respectively). PSGT was particularly better in terms of the accuracy of C1 LMS (PSGT: 100%, navigation: 83.3%). The deviation at the entry point was minimal, and the difference between the sagittal and transversal angles from the preoperative plan was small. We investigated the clinical efficacy of using the PSGT for C1-C2 posterior fixation. PSGT improved the accuracy of C1 LMS insertion.

Atlantoaxial Instability in the Course of Rheumatoid Arthritis in Relation to Selected Parameters of Sagittal Balance.

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.

Modified Atlantoaxial Arthrodesis Technique for Atlantoaxial Instability via Intraarticular Autografting Using Structural Iliac Bone: Technical Nuances and Case Series

ObjectiveThe present study described a modified technique of atlantoaxial arthrodesis in patients with atlantoaxial instability (AAI) along with the postoperative clinical and radiological results. MethodsFive patients underwent this method for their AAI concurrent with C1 arch hypoplasia and/or the development of odontoid pannus causing myelopathy. After thorough exposure of the posterior surface of the C1-2 complex, the bilateral C2 nerve roots were sectioned to allow for easier access to the C1/2 facet joints. To prepare a suitable grafting bed, the C1/2 facet capsule was opened, then the articular cartilaginous and synovial tissues were thoroughly removed. After being properly fashioned to match the gap between the C1/2 facet joint spaces, the structural bone grafts from the iliac crest were directly inserted into the facet joint spaces. To alleviate cord compression caused by concomitant odontoid pannus and/or hypoplastic C1 arch, C1 laminectomy was necessitated in all cases. Subsequently, posterior screw-rod instrumental fixation was conducted. ResultsAll five patients underwent this procedure successfully. Clinical and radiological follow-up data of all patients indicated favorable relief of clinical symptoms and early rigid C1-2 stability. The sequelae of C2 nerve resection were not remarkable. No other neural or vascular damage associated with this technique was observed. ConclusionModified atlantoaxial arthrodesis via intraarticular autografting using the structural iliac bone combined with posterior instrumentation appears to be an efficient alternative treatment method for AAI patients with concurrent pathologies, even when the C1-2 posterior arches are unavailable for the grafting bed.

Intraoperative Ultrasonography for the Surgical Treatment of Grisel Syndrome of the Adult: Management of A Rare Condition.

This is a narrative review and case report. To review the literature concerning Grisel syndrome physiopathology, diagnosis, and surgical reports, highlighting the decision-making for treatment and its timing. We describe the role of intraoperative US in the management of 2 cases of GS of the adult. GS is a rare nontraumatic post inflammatory C1-C2 rotatory instability usually affecting children; adult cases are even rarer, and the role of surgical treatment is not well defined. Case 1: A 72-year-old man with upper cervical pain and no neurological deficit; radiologic examination revealed C1-C2 spondylitis and epidural abscess. After antibiotic therapy, the patient developed cervical instability. Hence, surgical decompression and C1-C2 stabilization were performed. Case 2: An 82-year-old woman with progressive right hemiparesis. CT and MRI showed C1-C2 spondylitis with retro-odontoid epidural abscess. Atlanto-axial rotatory instability was evident so surgery was achieved. In both cases, intraoperative US was useful for localizing retro-odontoid abscess and allowing safe puncture of the collection, leading to its remarkable radiologic reduction. GS in adults remains a challenge: Patients should be closely monitored concerning neurological and inflammatory status. We describe the successful use of intraoperative US for draining retro-odontoid abscess for the first time, with satisfactory postoperative outcome without need of circumferential approach.

Current insights and surgical interventions in craniovertebral junction instability

Abstract Background: The Craniovertebral Junction (CVJ) is prone to various pathologies, including instability and congenital anomalies. Understanding these conditions and their management strategies is critical for effective treatment. Materials and Methods: A systematic search was conducted in Science Direct and PubMed databases following PRISMA guidelines. Inclusion criteria encompassed studies addressing craniovertebral instability and associated pathologies. Six systematic investigations were assessed for methodological quality. Data extraction involved 702 patients with CVJ issues, among which 129 had related conditions, while 279 displayed normal CVJ. Surgical interventions encompassed various techniques such as C1-C2 fixation, posterior decompression, and screw placements. Results: Among 702 patients studied, atlantoaxial subluxation, basilar invagination, and odontoid fractures were observed in 129 cases. Surgical treatments showed favorable outcomes, with fusion achieved within a year post-surgery for both C1-C2 fixation techniques and posterior decompression strategies. Studies highlighted successful outcomes in cases of cervical myelopathy, especially with early occipitocervical fusion. Conclusion: Managing atlantoaxial instability remains a debated topic, with varying success rates observed in different surgical interventions. Recommendations emphasize the importance of stabilization techniques and imaging modalities for effective preoperative planning and postoperative care. However, limitations in the available data underscore the need for further research to refine treatment strategies for better patient outcomes in this complex area of spinal pathology. Keywords: Craniovertebral junction, atlantoaxial instability, Basilar invagination, fusion, CVJ pathologies

Cranio-vertebral junction anomalies with Atlanto-axial instability: Management and complications- Our experience of 63 cases at a tertiary care center in India

IntroductionManagement of complex cranio-vertebral junction anomalies with atlanto-axial instability require extensive pre-operative work up with various intra-operative (and/orpreoperative)manouvres and bony fusion procedures and post-operative rehabilitation and support. This study focuses on various management strategies in terms of its outcome and complications. Materials and methodology:This clinical analytical study shares our experience of 63 cases of cvjunction anomalies with atlanto-axial instability operated at tertiary care center in india. 63 patientsoperated during the period spanning from June-2019 to November-2021 who had atlanto axial instability (AAD WITH/WITHOUT BI). Patients were assessed pre-operatively and post-operativelyup to 3 months objectively and subjectively in terms of outcome and post op radiology was also done. Results:Out of 63 atlanto-axial operated patients, 42 improved, 3 had stable disease and 12deteriorated clinically some of whom required also secondary procedures for it. Out of 63 ,8 patientshad died,4 of them were pediatric and 4 were adults. Various procedure related complicationsoccurred in 12 patients. Conclusion: Thus, with proper pre-operative diagnosis of type of congenital anomaly combined with appropriate surgical plan can give impacting results in these pathologies withminimal complications. Key words: cranio-vertebral junction anomalies, atlanto-axial instability, DCER, C1-C2 fusion

Post-operative morbidity after C2 nerve root sacrifice during C1-2 fixation in pediatric atlantoaxial instability

Post-operative morbidity after C2 nerve root sacrifice during C1-2 fixation in pediatric atlantoaxial instability

Post-Traumatic Central or Axial Atlantoaxial Dislocation Presenting with “Atypical” Symptoms—Analyzing the Role of Dynamic Imaging on the Basis of Experience with 14 Patients Treated by Atlantoaxial Fixation surgery

This is a report of a series of 14 patients who presented with a range of "atypical" cranial, spinal, and systemic symptoms that started after they suffered a relatively severe injury to the head and/or neck several months or years before surgical treatment. The implications of diagnosing and treating central or axial atlantoaxial dislocation (CAAD) is discussed. Also, the role of dynamic rotatory and lateral head tilt imaging in the diagnosis and treatment is analyzed. Of the 14 patients, 7 were men and 7 were women, with an age range of 21-64 years (average, 42 years). Due to the severity of the presenting neurological and non-neurological symptoms, all the patients had lost their occupation and were heavily dependent on painkillers and/or antidepressant drugs. In addition to other characteristic clinical and radiological evidence, CAAD was diagnosed made based on the facetalignments on lateral profile imaging in the neutral head position. Dynamic head flexion-extension, lateral head tilt, and neck rotation imaging findings confirmed and subclassified CAAD. All 14 patients underwent atlantoaxial fixation surgery. A personalized self-assessment clinical scoring parameter and the World Health Organization Disability Assessment Schedule 2.0 was used to evaluate the outcome. One patient did not follow-up after surgery. At a minimum follow-up of 6 months after atlantoaxial fixation surgery, the remaining 13 patients experienced relief from all major symptoms. Diagnosing and treating CAAD can have major therapeutic implications for patients presenting with progressively worsening disabling clinical symptoms following relatively severe head and/or neck trauma.