Occipitocervical Fusion Research Articles

Endoscopic transnasal and transoral resection of the odontoid process and C1 combined with occipitocervical fusion for osteoradionecrosis of the upper cervical spine: a case report and literature review

BackgroundOsteoradionecrosis (ORN) of the upper cervical spine is a rare but severe complication of head and neck cancer radiotherapy. To raise awareness of this condition, we describe a patient with a history of nasopharyngeal carcinoma who developed ORN of the upper cervical spine and review the published literature reporting surgical management.Case presentationA 59-year-old female patient with persistent neck pain for one month and limited range of neck motion who had undergone radiotherapy for nasopharyngeal carcinoma with a total dose of 69.96 Gy 15 years ago presented to our hospital. The patient underwent endoscopic transnasal and transoral resection of the odontoid process and C1 anterior arch, combined with occipitocervical fusion. To better understand surgical management of ORN of the upper cervical spine, the literature published in the PubMed, Ovid MEDLINE, and Embase databases was reviewed. Our patient experienced alleviation of cervical pain and did not exhibit any postoperative complications. Since 2005, 11 cases of surgical management of ORN of the upper cervical spine (including the present case) have been published. Basilar invagination and/or atlantoaxial subluxation were observed in 4 /11 cases. Endoscopic procedures were performed in 4/11 cases, and occipitocervical fusion was performed in 8 /11 cases.ConclusionEndoscopic transnasal and transoral resection of the odontoid process and C1 anterior arch is a safe and effective treatment option for ORN of the upper cervical spine. Occipitocervical fusion is useful in patients with basilar invagination and atlantoaxial subluxation.

Stress Maneuver for Basilar Invagination Reduction: A Technical Report

BackgroundBasilar invagination (BI) is a prolapse of the odontoid process cranially and posteriorly towards the foramen magnum. Several surgical treatment options are available for this condition. Herein, we describe a stress maneuver technique for BI reduction using a single-stage posterior approach. MethodsWe described the case of a 56-year-old male diagnosed with type A BI and brainstem compression, who was treated with posterior fossa decompression and occipitocervical fusion. The BI was reduced intraoperatively using a stress maneuver, and cranial traction or atlantoaxial joint distraction was not necessary. ResultsPostoperative imaging revealed a reduction of the odontoid process and adequate brainstem decompression. The patient showed progressive improvement of his symptoms. ConclusionIn selected cases, stress maneuvers for BI reduction can be a less morbid, easier, and replicable option within the already existing technical arsenal.

Recent Global Trends and Hotspots in Occipitocervical Fusion: A Bibliometric Analysis and Visualization Study

Occipitocervical arthrodesis has a variety of indications to treat craniocervical and atlantoaxial pathologies for which a selective cervical fusion would not provide sufficient stability. Over time, the indications for occipitocervical fusions (OCF) have evolved, as new technologies and surgical techniques were developed. In this bibliometric analysis, we aim to explore the progression of OCF literature over time, analyzing the trends in publications and citations, publishing countries and authors, keywords and topics. The Web of Science database was used for data retrieval on July 3rd, 2024, with the search "occipitocervical fusion" OR "occipito-cervical fusion" OR "occipitocervical arthrodesis" OR "occipital cervical fusion" OR "occipital cervical arthrodesis" OR ("OCF" AND "spine surgery"). Excel was used to create the citation analysis and publication trend figures, along with the publishing countries and author analysis. The bibliometric software VosViewer was used to generate the keyword co-occurrence network visualizations. Overall, 762 articles were extracted. The number of pertinent publications and citations increased until 2020 before beginning to decrease. We found that Ehlers Danlos syndrome (EDS) has become a more prevalent topic, as the association between EDS and craniocervical instability has received further scrutiny. "Dysphagia" continues to be a commonly cited topic, while, conversely, rheumatoid arthritis has decreased in publication frequency, possibly related to advances in medical management and surgical techniques. Overall, the United States of America, China, and Japan are the top publishing countries. This analysis of OCF literature provides a helpful overview of emerging trends and clinician concerns, especially as seen through the perspective of time.

Craniovertebral Junction Tuberculosis, a Rare Presentation With Hypoglossal and Facial Nerve Palsy

Case: A 47-year-old man presented with neck pain, restricted neck movements, along with involvement of facial and hypoglossal nerve. On the basis of clinico-radiological correlation, the patient was diagnosed with craniovertebral junction tuberculosis and was started on antitubercular therapy (ATT). Failing the conservative trial, the patient was operated and occipitocervical fusion was done with bone grafting. After 12 months of ATT intake, he showed complete recovery of the facial and hypoglossal nerve, with complete resolution of instability pain. Conclusion: Craniovertebral junction tuberculosis is uncommon, and its manifestation with cranial nerves involvement is even more rare. Meticulous clinico-radiological assessment should be done to diagnose and plan the treatment. Early recognition and prompt initiation of ATT, along with timely surgical intervention, when necessary, are crucial for optimal management and outcomes.

The Feasibility of Condylar Screws for Occipitocervical Fusion in Arabs: Computed Tomography-Based Morphometric Study.

Retrospective, cross-sectional study. Occipitocervical fusion is indicated for various conditions. Some techniques require placement of screws in the occipital condyle. The objective of this study was to analyze the morphometric features of the occipital condyle among Arabs. Computed tomography (CT)-based morphometric analysis of occipital condyles of 200 Arab skeletally mature patients (400 condyles) was done. Axial width of at least 8mm and coronal height of at least 6.5mm are the cutoff values for feasibility of condylar screw placement. The mean age of the patients was 48.0 ± 18.3years. Males were 53.5% (107) of the sample. The mean axial condylar width and length were 8.5 ± 1.5mm and 20.3 ± 2.6mm, respectively, while the mean axial screw angle was 35.9° ± 5.5° from midline. The mean sagittal condylar length and height were 16.1 ± 1.9mm and 8.8 ± 1.5mm, respectively. The mean condylar coronal height was 8.2 ± 1.4mm. Based on axial width and coronal height measurements, 150 (37.5%) condyles could safely fit a 3.5mm condylar screw. One hundred and four (55.9% female condyles) condyles cannot fit a screw in females, while 46 (21.5% male condyles) condyles cannot fit a screw in males. Condylar screw for occipitocervical fusion is feasible for the majority of Arabs in our sample; however, this applies to slightly less than half of the female condyles. Detailed preoperative radiological planning is critical to avoid complications related to occipital condyle screw placement.

Revision Chiari surgery in adults: surgical evaluation algorithm and outcomes in a continuity-of-care practice.

Patients with a prior surgical history for Chiari malformation (CM) as a child or an adult who presents with a recurrence or persistence of symptoms pose a challenging clinical scenario. The authors analyzed preoperative presentations, surgical histories, and outcomes of adult CM revision cases to create an algorithm for the assessment of revision surgery in adult CM patients and contrast this with the care of pediatric CM patients within the context of an integrated continuity-of-care CM practice seeing pediatric and adult patients. The authors retrospectively reviewed the records of patients with CM0, -1, and -1.5 who were 21 years of age or older, had a prior history of CM surgery as either children or adults, and underwent revision surgery as adults at the authors' institution from December 2009 to February 2020. The cohort was divided into three groups depending on the type of revision surgery performed: posterior fossa decompression with or without duraplasty (PFD/D group), occipitocervical fusion without ventral decompression (OCF group), and ventral decompression in the form of endoscopic endonasal odontoidectomy (VD group). A total of 50 adult revision cases were divided into 30 PFD/D cases, 13 OCF cases, and 7 VD cases. Forty cases had previously undergone one CM surgery, and 10 had undergone two. Preoperatively, the PFD/D group had significantly fewer cases of diagnosed craniocervical instability (CCI), Ehlers-Danlos syndrome, and dysautonomia than the OCF and VD groups. A retroflexed odontoid was significantly more common in the VD group than in the PFD/D and OCF groups. Postoperatively, rates of improvement were 60.0% with PFD/D, 84.6% with OCF, and 85.7% with VD, but differences in these rates were not statistically significant. In this challenging group of CM patients, possible etiologies warranting additional surgery included residual dorsal compression, persistent syrinx, CCI, and ventral brainstem compression from a significant retroflexed odontoid. Outcomes after revision were often favorable, but careful evaluation, patient selection, and communication with patients are needed in deciding to reoperate. The suggested algorithm can aid decision-making.

C2 pedicle screw insertion assisted by mobilization of the vertebral artery in cases with high-riding vertebral artery

ObjectiveTo describe the feasibility, safety and efficacy of mobilization of the vertebral artery for C2 pedicle screws in cases with the high-riding vertebral artery (HRVA). MethodsDuring the period January 2020 to September 2022, fifteen patients underwent posterior occipitocervical fixation in our department. All patients had unilateral HRVA on at least one side that prohibited the insertion of C2 pedicle screws. There were 2 males and 13 females aged 47 ± 11.9 years (range: 17–64 years). After the correction of the vertical dislocation during the operation, the C2 pedicle screw insertion and occipitocervical fixation and fusion were performed using the vertebral artery mobilization technique. A routine three-dimensional reconstructed CT examination was executed to confirm the trajectory of C2 pedicle screws post-operation, and a CT angiography examination was performed when necessary. Neurological function was assessed using the Japanese Orthopedic Association (JOA) scale. The preoperative and postoperative JOA score and the main radiological measurements, including anterior atlantodental interval (ADI), the distance of odontoid tip above Chamberlain line, and clivus-canal angle (CCA), were collected and compared by paired t-test. ResultsAll 15 patients had atlas assimilation, among which 12 patients had C2–C3 fusion (Klippel-Feil syndrome). Mobilization of the HRVA was successfully completed, and C2 pedicle screws were then fulfilled after the vertebral artery was protected. There was no injury to the vertebral artery during the operation. Meanwhile, no severe surgical complications such as cerebral infarction or aggravated neurological dysfunction occurred during the perioperative period. Satisfactory C2 pedicle screw placement and reduction were reached in all 15 patients. All the patients achieved bone fusion 6 months after surgery. No looseness and shift of internal fixation or reduction loss was observed during the follow-up period. Compared to the preoperative, the postoperative JOA score and the main radiological measurements were remarkably improved and statistically significant. ConclusionsC2 pedicle screw insertion assisted by mobilization of the vertebral artery is safe and considerably effective, providing a choice for internal fixation in cases with high-riding vertebral arteries.

Anesthetic Management of a Patient with Occipito-Cervical Fusion for Elective Cesarean Section

A 25-year-old primi, with a history of occipto-cervical fusion (OCF) performed at the age of 13 years, presented for an elective cesarean section. A combined spinal–epidural anesthetic (CSE) was administered, with a successful maternal and fetal outcome. The spinal component of the CSE was unsuccessful at providing surgical anesthesia.

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

Absence of the Posterior Element of C1 and C2 Along With Mild Wedge Shape in Body of C3: Case Report

Due to the wide variety of cervical vertebral congenital anomalies, knowledge of their types and related clinical conditions can prove to be helpful for physicians and surgeons in the diagnosis and treatment of patients. The aim of this study is to report on a rare case of unstable cervical vertebral congenital anomaly in which the patient had a defect in the body of the C3 vertebra in addition to defects in the posterior arch of C1 and posterior element of C2. This type of anomaly has not been reported so far in the literature. To reduce the patient’s related neurological disorders, our treatment choice for this patient was occipitocervical fusion (OCF) surgery. At the 3-year postoperative follow-up, all sensory and motor problems related to this anomaly affecting the patient's upper and lower limbs and causing shoulder and neck pain were eliminated. In this rare type of anomaly, OCF surgery seems to be an effective choice in relieving the patient's neurological symptoms.

Implantation of C2 prosthesis with dorsal fusion C0-C4 due to pathologic C2 fracture. Case report and literature review.

Pathological destruction of the axis vertebra leads to a highly unstable condition in an upper cervical spine. As surgical resection and anatomical reconstruction of the second cervical vertebrae represents a life threatening procedure, less radical approaches are preferred and only few cases of C2 prosthesis are described in literature. The focus of this case report is a 21-year-old man with a pathological fracture of C2 managed primarily surgically with the C1-C3 dorsal fusion. Due to the progression of giant cell tumor and destruction of the axis vertebra, C2 prosthesis through anterior approach and dorsal occipito-cervical fusion C0-C4 were performed. Postoperative infection was managed surgically with a 2-staged dorsal debridement, ostheosynthesis material change and autologous bone graft. After a 4 week-intravenous therapy with the ceftriaxone in combination with the amoxicillin/clavulanate, followed by 12 week per oral therapy with amoxicillin/clavulanate in combination with ciprofloxacin, the complete recovery of the infection was achieved. Radiotherapy was initiated 2 months after the last revision surgery and the patient showed a good clinical outcome with stable construct at a 1 year follow-up. A review of literature of all reported C2 prosthesis cases was performed CONCLUSION: C2 prosthesis allows a more radical resection in pathological processes involving the axis vertebra. Combined with the posterior fusion, immediate stability is achieved. Anterior surgical approach is through a highly unsterile oral environment which presents a high-risk of postoperative infection.

Circumferential Pannus at C1-C2 Causing Spinal Cord Compression

Periodontoid pannus formation is a pathologic condition caused by a multitude of different etiologies, however, it is most commonly due to rheumatoid arthritis. In these cases, the pannus is typically located in the retro-odontoid space ventral to the spinal cord, leading to progressive neural compression. We describe in this report, a patient who presented with progressive high cervical myelopathy, who on imaging revealed both a retro-odontoid pannus and a posterior C1-C2 mass causing severe circumferential compression of the spinal cord. The patient was successfully treated with a C1-C2 laminectomy and occipitocervical fusion. Periodontoid pannus is a common entity; however, the presence of a C1-C2 posterior pannus is a unique finding. To our knowledge, circumferential pannus at C1-C2 causing neural compression is a clinical entity that has not been previously reported.

Anatomical determinants of occipitocervical fusion in skull base chordoma resection: a systematic review of the literature with illustrative cases.

Skull base chordomas are rare, locally osseo-destructive lesions that present unique surgical challenges due to their involvement of critical neurovascular and bony structures at the craniovertebral junction (CVJ). Radical cytoreductive surgery improves survival but also carries significant morbidity, including the potential for occipitocervical (OC) destabilization requiring instrumented fusion. The published experience on OC fusion after CVJ chordoma resection is limited, and the anatomical predictors of OC instability in this context remain unclear. PubMed and Embase were systematically searched according to the PRISMA guidelines for studies describing skull base chordoma resection and OC fusion. The search strategy was predefined in the authors' PROSPERO protocol (CRD42024496158). The systematic review identified 11 surgical case series describing 209 skull base chordoma patients and 116 (55.5%) who underwent OC instrumented fusion. Most patients underwent lateral approaches (n = 82) for chordoma resection, followed by midline (n = 48) and combined (n = 6) approaches. OC fusion was most often performed as a second-stage procedure (n = 53), followed by single-stage resection and fusion (n = 38). The degree of occipital condyle resection associated with OC fusion was described in 9 studies: total unilateral condylectomy reliably predicted OC fusion regardless of surgical approach. After lateral transcranial approaches, 4 studies cited at least 50%-70% unilateral condylectomy as necessitating OC fusion. After midline approaches-most frequently the endoscopic endonasal approach (EEA)-at least 75% unilateral condylectomy (or 50% bilateral condylectomy) led to OC fusion. Additionally, resection of the medial atlantoaxial joint elements (the C1 anterior arch and tip of the dens), usually via EEA, reliably necessitated OC fusion. Two illustrative cases are subsequently presented, further exemplifying how the extent of CVJ bony elements removed via EEA to achieve complete chordoma resection predicts the need for OC fusion. Unilateral total condylectomy, 50% bilateral condylectomy, and resection of the medial atlantoaxial joint elements were the most frequently described independent predictors of OC fusion in skull base chordoma resection. Additionally, consistent with the occipital condyle harboring a significantly thicker joint capsule at its posterolateral aspect, an anterior midline approach seems to tolerate a greater degree of condylar resection (75%) than a lateral transcranial approach (50%-70%) prior to generating OC instability.

Predicting the Need for Occipitocervical Fusion for Patients with Lower Clival Chordoma: A Single-Center Retrospective Study

To assess the impact of tumor extension into the occipital condyle (OC) in lower clival chordoma management and the need for occipito-cervical fusion (OCF). A retrospective analysis was conducted on 35 patients with lower clival chordoma. The preoperative area of the intact OCs, Hounsfield units, and the integrity of the apical ligament and the tectorial membrane were assessed using preoperative imaging. Seven (20%) patients were in the OCF group. The OCF group exhibited a higher prevalence of preoperative pain in the neck or head (p = 0.006), ligament absence (p = 0.022), and increased propensity for postoperative wound issues (p = 0.022) than the non-OCF group. The OCF group had less intact OCs (p < 0.001) and higher spinal instability neoplastic score (p = 0.002) than the non-OCF group. All patients with intact OCs<60% underwent OCF, and those with OCs≥70% were treated without OCF. Those with OCs between 60% and 69% underwent OCF if the ligaments were eroded, and did not undergo OCF if the ligaments were intact. Treatment strategies varied, with endoscopic endonasal approach (EEA) alone being common. Radiation therapy was administered to 89% of patients. All three patients treated with OCF after tumor resection had wound issues; none treated with OCF before resection had wound issues. None developed atlanto-occipital instability. Survival rates did not significantly differ between groups. In the absence of mobility-related neck pain, patients with lower clival chordoma and intact OC≥60%, intact apical ligament, and intact tectorial membrane, may not require OCF.

The role of occipital condyle and atlas anomalies on occipital cervical fusion outcomes in Chiari malformation type I with syringomyelia: a study from the Park-Reeves Syringomyelia Research Consortium.

Congenital anomalies of the atlanto-occipital articulation may be present in patients with Chiari malformation type I (CM-I). However, it is unclear how these anomalies affect the biomechanical stability of the craniovertebral junction (CVJ) and whether they are associated with an increased incidence of occipitocervical fusion (OCF) following posterior fossa decompression (PFD). The objective of this study was to determine the prevalence of condylar hypoplasia and atlas anomalies in children with CM-I and syringomyelia. The authors also investigated the predictive contribution of these anomalies to the occurrence of OCF following PFD (PFD+OCF). The authors analyzed the prevalence of condylar hypoplasia and atlas arch anomalies for patients in the Park-Reeves Syringomyelia Research Consortium database who underwent PFD+OCF. Condylar hypoplasia was defined by an atlanto-occipital joint axis angle (AOJAA) ≥ 130°. Atlas assimilation and arch anomalies were identified on presurgical radiographic imaging. This PFD+OCF cohort was compared with a control cohort of patients who underwent PFD alone. The control group was matched to the PFD+OCF cohort according to age, sex, and duration of symptoms at a 2:1 ratio. Clinical features and radiographic atlanto-occipital joint parameters were compared between 19 patients in the PFD+OCF cohort and 38 patients in the PFD-only cohort. Demographic data were not significantly different between cohorts (p > 0.05). The mean AOJAA was significantly higher in the PFD+OCF group than in the PFD group (144° ± 12° vs 127° ± 6°, p < 0.0001). In the PFD+OCF group, atlas assimilation and atlas arch anomalies were identified in 10 (53%) and 5 (26%) patients, respectively. These anomalies were absent (n = 0) in the PFD group (p < 0.001). Multivariate regression analysis identified the following 3 CVJ radiographic variables that were predictive of OCF occurrence after PFD: AOJAA ≥ 130° (p = 0.01), clivoaxial angle < 125° (p = 0.02), and occipital condyle-C2 sagittal vertical alignment (C-C2SVA) ≥ 5 mm (p = 0.01). A predictive model based on these 3 factors accurately predicted OCF following PFD (C-statistic 0.95). The authors' results indicate that the occipital condyle-atlas joint complex might affect the biomechanical integrity of the CVJ in children with CM-I and syringomyelia. They describe the role of the AOJAA metric as an independent predictive factor for occurrence of OCF following PFD. Preoperative identification of these skeletal abnormalities may be used to guide surgical planning and treatment of patients with complex CM-I and coexistent osseous pathology.

Grisel Syndrome and Its Anesthesia Management: A Comprehensive Review

Grisel syndrome is an atraumatic rotatory atlantoaxial subluxation associated with head-and-neck inflammatory conditions. It predominantly affects the pediatric population. Anesthetic management in these patients poses several challenges, and astute management is crucial for a good outcome. We present a case of a young male patient who presented for management of painful torticollis and restricted neck movements. He had a history of inadequate treatment of throat infection for a month and was subsequently diagnosed with Grisel’s syndrome. He underwent occipitocervical fusion. This case report reviews the literature and describes perioperative anesthesia care and concerns in a comprehensive manner in the management of Grisel’s syndrome.

Perioperative Cerebrovascular Accidents in Spine Surgery: A Retrospective Descriptive Study and A Systematic Review with Meta-Analysis.

Perioperative cerebrovascular accidents (CVAs) related to spine surgery, although rare, can lead to significant disabilities. More studies on spine surgeries are required to identify those at risk of perioperative CVAs. The characteristics and outcomes of patients that experienced CVAs during spine surgery were assessed through a retrospective descriptive study and meta-analysis. Patients aged ≥18 years who underwent spine surgery under general anesthesia at a hospital between April 2011 and March 2023 were examined. Of the 2,391 initially identified patients, 2,346 were included after excluding 45 who underwent debridement for surgical site infections. Subsequently, a meta-analysis including the present retrospective descriptive study was conducted. Databases such as PubMed and Google Scholar were searched for original peer-reviewed articles written in English. Of the 2,346 patients, 4 (0.17%) (three men, one woman) exhibited perioperative CVAs associated with spine surgery. The CVAs were diverse in nature: one case of cerebral hemorrhage resulting from dural injury during posterior occipitocervical fusion, two cases of cerebral infarctions after lumbar laminectomy and anterior thoracic fusion due to anticoagulant discontinuation, and one case of posterior reversible encephalopathy syndrome following microscopic lumbar discectomy due to gestational hypertension. The subsequent meta-analysis included three studies (n=186,860). It showed several risk factors for perioperative CVAs, including cervical level (pooled odds ratio [OR]=1.33), hypertension (pooled OR=2.27), atrial fibrillation (pooled OR=8.78), history of heart disease (pooled OR=2.47), and diabetes (pooled OR=2.13). It was speculated that the potential risk factors for the four perioperative CVA cases of spine surgery in this retrospective descriptive study were intraoperative dural injury, preoperative anticoagulant discontinuation, and gestational hypertension history. The meta-analysis revealed that cervical spine surgery, hypertension, atrial fibrillation, heart disease, and diabetes increased the CVA risk. This highlights the need for risk assessment, preoperative optimization, and postoperative care to reduce spine surgery-associated perioperative CVAs.

Craniocervical instability in patients with Ehlers-Danlos syndromes: outcomes analysis following occipito-cervical fusion

Craniocervical instability (CCI) is increasingly recognized in hereditary disorders of connective tissue and in some patients following suboccipital decompression for Chiari malformation (CMI) or low-lying cerebellar tonsils (LLCT). CCI is characterized by severe headache and neck pain, cervical medullary syndrome, lower cranial nerve deficits, myelopathy, and radiological metrics, for which occipital cervical fusion (OCF) has been advocated. We conducted a retrospective analysis of patients with CCI and Ehlers-Danlos syndrome (EDS) to determine whether the surgical outcomes supported the criteria by which patients were selected for OCF. Fifty-three consecutive subjects diagnosed with EDS, who presented with severe head and neck pain, lower cranial nerve deficits, cervical medullary syndrome, myelopathy, and radiologic findings of CCI, underwent open reduction, stabilization, and OCF. Thirty-two of these patients underwent suboccipital decompression for obstruction of cerebral spinal fluid flow. Questionnaire data and clinical findings were abstracted by a research nurse. Follow-up questionnaires were administered at 5–28 months (mean 15.1). The study group demonstrated significant improvement in headache and neck pain (p < 0.001), decreased use of pain medication (p < 0.0001), and improved Karnofsky Performance Status score (p < 0.001). Statistically significant improvement was also demonstrated for nausea, syncope (p < 0.001), speech difficulties, concentration, vertigo, dizziness, numbness, arm weakness, and fatigue (p = 0.001). The mental fatigue score and orthostatic grading score were improved (p < 0.01). There was no difference in pain improvement between patients with CMI/LLCT and those without. This outcomes analysis of patients with disabling CCI in the setting of EDS demonstrated significant benefits of OCF. The results support the reasonableness of the selection criteria for OCF. We advocate for a multi-center, prospective clinical trial of OCF in this population.

Database Review of 514 Patients with Os Odontoideum. Detailed Analysis of 258 Surgically Treated (1978-2019).

Database review (1978-2019) is to identify the cause of os odontoideum, its presentation, associated abnormalities, and management recommendations. Review of referral database of 514 patients and 258 surgically treated patients ages 4-64years. Detailed history of early childhood trauma and initial encounter record retrieval were made. Patients had dynamic motion radiographs, dynamic motion MRI and also CT to identify pathology and reducibility of craniocervical instability. Preoperative crown halo traction was made before the year 2000 except in children. Intraoperative traction with O-arm/CT documentation was made since 2001. Reducible and partially reducible cases underwent halo traction under general anesthesia distraction, dorsal stabilization, and rib graft augmentation for fusion. Later semi-rigid instrumentation and subsequently rigid instrumentation was made. Irreducible compression of cervicomedullary junction was treated with ventral decompression. The follow up was 3-20years. Database; acute worsening after trauma 262, insidious neurological deficit 252. Minimal/normal motion with neurological deficit was present in 18, previous C1-C2 fusion with worsening in 18. 28 patients of 64 without treatment worsened in 4years. An intact odontoid process was seen in 52 children of 156 who had early craniovertebral junction trauma and later developed os odontoideum. There were 174 patients with reducible lesions and partially reducible were 22. Irreducible lesions were 62. Of the reducible, 50 underwent transarticular C1-C2 fusion, 26 C1 lateral mass, and C2 pars screw fixation. 182 had occipitocervical fusion (19 had extension of previous C1-C2 fusion and 43 after transoral decompression). 62 with irreducible ventral compression of the cervicomedullary junction underwent transoral decompression; 43 had a trapped transverse ligament between the os and C2 body and 19 previous C1-C2 fusions. Compression was by the axis body, os odontoideum, and the posterior C2 arch. Syndromic and skeletal/connective tissue abnormalities were found in 86 (36%). 2 patients worsened, age 10 and 62, due to failure of semi-rigid construct. The etiology of os odontoideum is multifactorial considering the associated abnormalities, reports of congenital-familiar occurrence, and early childhood craniovertebral trauma which also plays a role in the etiology. Patients with reducible lesions require stabilization. Asymptomatic patients are at risk for later instability. Patients who underwent childhood C1-C2 fusion must be followed for later problems. The irreducibility was seen due to trapped transverse ligament, pannus, or previous dorsal C1-C2 fusion.

Surgical strategies in the management of atlantoaxial dislocation in Down syndrome.

To study the clinicoradiological features and treatment outcomes of atlantoaxial dislocation (AAD) in Down syndrome. Retrospective case series. A retrospective chart and radiology review of 9 Down syndrome patients with AAD managed at our center from 2007 to 2018. Chi-squared/Fisher's exact test. There were 4 males and 5 females (n = 9). The median age was 14 years (interquartile range [IQR]: 7-15.5). 77.7% (7/9) of patients had severe spasticity (Nurick Grades 4 and 5). The median duration of symptoms was 9 months (IQR: 5-39). The AAD was reducible in all (n = 9) cases. Eight (88.8%) patients had os odontoideum. The mean atlantodental interval (ADI) was 8.5 mm (±2.9). T2W cord hyperintensity was seen in 66.6% (6/9). Posterior C1-2 transarticular fixation was done in 8 and occipitocervical fusion in 1 patient. Follow-up of more than 6 months (7-57 months) was available in 8/9 (88.9%) patients. There was a significant improvement in spasticity (n = 8, mean Nurick Grade 1.7 (±1.1), P = 0.003). Follow-up radiographs (n = 8) showed good reduction and fusion. A preoperative bedbound patient with poor respiratory reserve expired at 10 months following surgery. There were no other complications. Posterior surgical approach for AAD in Down syndrome resulted in good alignment and fusion, with excellent clinical improvement. Patients with elevated PCO2 are poor surgical candidates and require home ventilation facility.