Challenges and outcomes of upper cervical spinal tuberculosis surgery in pandemic-Case series study.

INTRODUCTION AND IMPORTANCE: Tuberculosis is a bacterial infection caused by Mycobacterium tuberculosis, primarily affecting the lungs. Conversely, the incidence of spinal tuberculosis (TB) was limited to a mere 6 % of cases of extrapulmonary tuberculosis. Upper cervical spinal TB is an exceptionally uncommon condition, with an incidence rate of approximately 0.3-1 % among all cases of spinal tuberculosis. CASE DESCRIPTION: Three patients diagnosed with upper cervical spinal tuberculosis who underwent Anterior Cervical Corpectomy Fusion (ACCF) or Occipitocervical fusion surgery were reviewed retrospectively. The data was obtained during the pandemic period in Indonesia. The patients were evaluated using pre-operative and post-operative Cobb's angles, Visual Analog Scale (VAS), Frankel scale, and Neck Pain and Disability (NPAD) scale. CLINICAL DISCUSSION: The ACCF surgery was more favourable when the compression was extended to the vertebral body; it showed good clinical and radiological outcomes. Multilevel ACCF and pathologies affecting bone quality seemed to be risk factors for material subsidence and instability. In this case, all the patients had performed ACCF surgery. The mean Cobb's angle pre-operative was 15.30, and Cobb's angle post-operative was 6.50. The mean pre-operative VAS value was 6.3, and the post-operative VAS value was 3. Compared to the post-operative scale, the pre-operative Frankel scale experienced an average increase of 2 levels. In contrast, the mean value of good post-operative NPAD is 29.3. CONCLUSION: Operative procedures on upper cervical spinal tuberculosis cases can improve patient's quality of life significantly, clinically and radiologically.

Craniocervical instability in patients with Ehlers­Danlos syndromes: outcomes analysis following occipito­cervical fusion of published cases.

This critique provides a critical analysis of the outcomes following occipito-cervical fusion in patients with Ehlers-Danlos syndromes (EDS) and craniocervical instability. The study examines the efficacy of the surgical intervention and evaluates its impact on patient outcomes. While the article offers valuable insights into the management of EDS-related craniocervical instability, several limitations and areas for improvement are identified, including sample size constraints, the absence of a control group, and the need for long-term follow-up data. Future research efforts should focus on addressing these concerns to optimize treatment outcomes for individuals with EDS.

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.

Risk factor analysis of perioperative complications in patients with rheumatoid arthritis undergoing primary cervical spine surgery.

BACKGROUND: Rheumatoid arthritis (RA) often causes cervical spine lesions as the disease condition progresses, which induce occipital neuralgia or cervical myelopathy requiring surgical interventions. Meanwhile, patients with RA are susceptible to infection or other complications in the perioperative period because they frequently have comorbidities and use immunosuppressive medications. However, the risk factors or characteristics of patients with RA who experience perioperative complications after cervical spine surgery remain unknown. A risk factor analysis of perioperative complications in patients with RA who underwent primary cervical spine surgery was conducted in the present study. METHODS: A total of 139 patients with RA who underwent primary cervical spine surgery from January 2001 to March 2020 were retrospectively investigated. Age and height, weight, serum albumin, serum C-reactive protein, American Society of Anesthesiologists Physical Status (ASA-PS), Charlson comorbidity index, medications used, cervical spine lesion, surgery time, bleeding volume, and procedures were collected from medical records to compare the patients with complications to those without complications after surgery. The risk factors for perioperative complications were assessed by univariate and multivariate logistic regression analysis. RESULTS: Twenty-eight patients (20.1%) had perioperative complications. Perioperative complications were significantly associated with the following factors [data presented as odds ratio]: lower height [0.928, p=0.007], higher ASA-PS [2.296, p=0.048], longer operation time [1.013, p=0.003], more bleeding volume [1.004, p=0.04], higher rates of vertical subluxation [2.914, p=0.015] and subaxial subluxation (SAS) [2.507, p=0.036], occipito-cervical (OC) fusion [3.438, p=0.023], and occipito-cervical/thoracic (long) fusion [8.021, p=0.002] in univariate analyses. In multivariate analyses, lower height [0.915, p=0.005], higher ASA-PS [2.622, p=0.045] and long fusion [7.289, p=0.008] remained risk factors. High-dose prednisolone use [1.247, p=0.028], SAS [6.413, p=0.018], OC fusion [17.93, p=0.034], and long fusion [108.1, p<0.001] were associated with severe complications. CONCLUSIONS: ASA-PS and long fusion could be indicators predicting perioperative complications in patients with RA after cervical spine surgery. In addition, cervical spine lesions requiring OC fusion or long fusion and high-dose prednisolone use were suggested to be risk factors for increasing severe complications.

Occipital Screw Placement Using a Navigation System for a Pathological Odontoid Fracture With a Dural Venous Sinus Variation.

Conventional fluoroscopic guidance can provide enough information to precisely insert an occipital screw in ordinary cases. However, the occipital screw creates a potential risk of dural venous sinus injury or thrombosis. In some cases, with dural sinus variation, surgeons must especially be cautious to avoid its injury. We present a rare case of proper occipital screw placement using a navigation system for a pathological odontoid fracture with a high risk of dural venous sinus injury because of anatomical variations in the transverse and occipital sinuses. A 60-year-old man who underwent thyroidectomy at the age of 37 years for thyroid carcinoma developed acute neck pain and quadriparesis due to falling out of bed. He urgently underwent closed reduction and temporary immobilization with a halo-vest for a pathological odontoid fracture and atlantoaxial dislocation. Preoperative contrast-enhanced CT showed an absent right transverse sinus and a prominent occipital sinus as variations of the dural venous sinuses. Occipito-C7 fusion surgery was performed without intraoperative active venous bleeding or postoperative brain disorder by using a navigation system for the occipital screw placement to avoid injury to the dural sinus. Postoperative computed tomography showed bi-cortical occipital screw placement avoiding the prominent occipital sinus. The patient's postoperative course was uneventful. In this case, although rigid occipito-cervical fixation using bi-cortical occipital screws was needed for the pathological odontoid fracture, the variation of the occipital sinus created a high risk of injury during occipital screw placement with conventional fluoroscopic guidance. There is an anatomical variation of the dural venous sinuses between individuals. Prominent occipital sinus injury may notably cause fatal complications such as massive bleeding or occlusion. Thus, we safely inserted the occipital screws using a navigation system that enabled us to avoid occipital venous sinus injury. Occipital screw placement with a navigation system can be a better option to prevent dural venous sinus injury in cases where there is variation in the dural venous sinuses, such as with a prominent occipital venous sinus.

Analysis of diagnostics, therapy and outcome of patients with traumatic atlanto-occipital dislocation.

BACKGROUND CONTEXT: Patients' outcome following traumatic atlanto-occipital dislocation (AOD) has been poor. In recent years, an increasing number of patients surviving the initial trauma are admitted to hospital. In order to further improve the management of these patients, the knowledge of diagnostics and therapy as well as possible complications should be increased. PURRPOSE: The aim of this study was to evaluate diagnostic parameters, therapy, early complications and outcome of patients with traumatic AOD. STUDY DESIGN: Monocentric retrospective cohort study. PATIENT SAMPLE: A total of 12 patients were included in this study. OUTCOME MEASURES: The main outcome measure was functional patient outcome. Furthermore, radiographic and treatment data were analyzed. METHODS: All patients suffering from traumatic AOD within an 8-year time period were included. Demographic data, radiological diagnostic parameters (condylar sum, basion dens interval, basion axis interval, power´s ratio, x-line method), as well as treatment data and complications of every patient were analyzed. Radiological parameters were compared with each other. Outcome was analyzed by a follow up examination. RESULTS: The accident mechanisms were motor vehicle accidents (MVA), fall from high and low height. Basion dens interval, basion axis interval, power's ratio and x-line method were not reliable in identifying traumatic AOD (only up to 33% of the patients were identified). Twelve patients could be reviewed. Three patients were treated with surgery, five patients were treated nonsurgically. Four patients died before surgical therapy. All seven surviving patients (survival rate: 58.3%) were re-examined (mean follow-up time: 6.7 months). All patients had a GCS of 15. Three surviving patients suffered from persisting neurological deficits. CONCLUSIONS: The most reliable way to diagnose AOD in Computer Topography is using the condylar sum. Surgical and nonsurgical measures can be employed with reasonable outcomes. Patient specific injury burden and clinical presentation should be taken into account when making treatment decisions for AOD.

Management of pediatric clival chordoma with extension to the craniocervical junction and occipito-cervical fusion: illustrative case.

BACKGROUND: Chordomas are rare malignant neoplasms that develop from the primitive notochord with < 5% of the tumors occurring in pediatric patients younger than the age of 20. Of these pediatric chordomas, those affecting the craniocervical junction (C1-C2) are even more rare; therefore, parameters for surgical management of these pediatric tumors are not well characterized. OBSERVATIONS: In this case, a 3-year-old male was found to have a clival chordoma on imaging with extension to the craniocervical junction resulting in spinal cord compression. Endoscopic-assisted transoral transclival approach for clival tumor resection was performed first. As a second stage, the patient underwent a left-sided far lateral craniotomy and cervical laminectomy for resection of the skull base chordoma and instrumented fusion of the occiput to C3. He made excellent improvements in strength and dexterity during rehab and was discharged after 3 weeks. LESSONS: In pediatric patients with chordoma with extension to the craniocervical junction and spinal cord compression, decompression with additional occipito-cervical fusion appears to offer a good clinical outcome. Fusion performed as a separate surgery before or at the same time as the initial tumor resection surgery may lead to better outcomes.

Should we recommend occipital plate fixation using bicortical screws or inverted occipital hooks to optimize occipito-cervical junction fusion? A biomechanical study combining an experimental and analytical approach.

BACKGROUND: Occipito-cervical fusion can be necessary in case of cranio-cervical junction instability. Proximal stabilisation is usually ensured by bi-cortical occipital screws implanted through one median or two lateral occipital plate(s). Bone thickness variability as well as the proximity of vasculo-nervous elements can induce substantial morbidity. The choice of site and implant type remains difficult for surgeons and is often empirically based. Given this challenge, implants with smaller pitch to increase bone interfacing are being developed, as is a surgical technique consisting in inverted occipital hook clamps, a potential alternative to plate/screws association. We present here a biomechanical comparison of the different occipito-cervical fusion devices. METHODS: We have developed a 3D mark tracking technique to measure experimental mechanical data on implants and occipital bone. Biomechanical tests were performed to study the mechanical stiffness of the occipito-cervical instrumentation on human skulls. Four occipital implant systems were analysed: lateral plates+large pitch screws, lateral plates+hooks, lateral plates+small pitch screws and median plate+small pitch screws. Mechanical responses were analysed using 3D displacement field measurements from optical methods and compared with an analytical model. FINDINGS: Paradoxical mechanical responses were observed among the four types of fixations. Lateral plates+small pitch screws appear to show the best accordance of displacement field between bone/implant/system interface providing higher stiffness and an average maximum moment around 50 N.m before fracture. INTERPRETATION: Stability of occipito-cervical fixation depends not only on the site of screws implantation and occipital bone thickness but is also directly influenced by the type of occipital implant.

Fusión occipito-cervical en fractura inestable de atlas tipo Jefferson / Occipito-cervical fusion in unstable fracture of Jefferson type atlas

Resumen Las fracturas del Atlas representan el segundo tipo más común de lesiones de la columna cervical alta. Con este trabajo se persigue describir la fijación occipito-cervical como tratamiento de la fractura de atlas tipo Jefferson inestable. Se presenta paciente que sufre trauma raquimedular, después de aplicarle un minucioso examen físico y la tomografía axial computada de columna cervical se detecta una fractura tipo Jefferson de atlas con más de 7 mm de separación de sus fragmentos. Al ser esta una fractura inestable de la región cervical alta se decide realizar una fijación occipito-cervical como método de tratamiento de esta lesión. La evolución postquirúrgica del paciente transcurrió sin complicaciones (AU).

Summary Atlas fractures represent the second most common type of upper cervical spine injury. This work aims to describe the occipito-cervical fixation as a treatment for the unstable Jefferson-type atlas fracture. A patient suffering from spinal cord trauma is presented, after applying a thorough physical examination and the computed tomography of the cervical spine, a Jefferson type fracture of atlas with more than 7 mm of separation of its fragments is detected. As this is an unstable fracture of the upper cervical region, it was decided to perform an occipito-cervical fixation as a treatment method for this lesion. The postoperative evolution of the patient was uneventful (AU).

Sarcopenic Dysphagia After Occipito-Cervical Fusion Surgery in an Elderly Patient With High-Cervical Myelopathy Caused by Retro-Odontoid Pseudotumor: A Case Report.

Occipito-cervical fusion surgery may cause dysphagia due to inadequate occipito-cervical alignment. However, little is known about any other mechanisms behind postoperative dysphagia. We present a rare case of severe sarcopenic dysphagia despite appropriate occipito-cervical alignment after occipito-cervical fusion surgery. An 85-year-old man who presented with high-cervical myelopathy due to a retro-odontoid pseudotumor underwent occipito-cervical fusion surgery and developed severe dysphagia immediately after the surgery. Swallowing videoendoscopy revealed stagnation of thick fluid at the larynx. Oral intake was prohibited and swallowing rehabilitation was performed. Subsequently, he showed a gradual improvement in swallowing function. He was allowed to start oral intake in the fourth week after surgery and was able to swallow solid foods in the sixth week after surgery. In this case, several parameters of occipito-cervical alignment such as the occipito-C2 angle (O-C2 angle), swallowing line (S-line), C2-C7 angle, and pharyngeal inlet angle, which are recognized as predictors of postoperative dysphagia after occipito-cervical fusion surgery, were adequate to prevent postoperative dysphagia. However, the patient had sarcopenia and cervical hyperlordosis to compensate for thoracic hyperkyphosis, which induces the hypertonicity of hyoid muscles. These findings led to a diagnosis of sarcopenic dysphagia after surgical invasion. Sarcopenic dysphagia is considered to be associated with skeletal and swallowing muscle weakness, apart from thinness, malnutrition, and surgical invasion. Elderly patients with sarcopenia may present with sarcopenic dysphagia because of surgical invasion after occipito-cervical fusion surgery. In such cases, it is important not only to control intraoperative occipito-cervical alignment but also to evaluate preoperative swallowing function.

The timing of fusion surgery for clival chordoma with occipito-cervical joint instability: before or after tumor resection?

Clival chordoma with occipito-cervical (OC) joint invasion can result in preoperative and postoperative instability. The authors investigate the appropriate timing of OC fusion to prevent instability-, fusion-, and surgery time-related morbidity. Twenty-two consecutive patients underwent surgery for clival chordoma from December 2008 to September 2014. OC fusion was performed for patients with OC joint invasion and instability due to preoperative destruction of the occipital condyle or extensive postoperative condylectomy. The data in relation to OC joint instability, fusion, and surgery time were analyzed retrospectively and compared between OC fusion before and after tumor resection. Of the 22 patients, 8 with tumor invasion of the OC joint underwent OC fusion. OC fusion was performed after tumor resection in one-stage for four patients and before tumor resection in two-stage for four patients. There was OC joint instability from tumor destruction of the occipital condyle in seven patients (87.5%). Patients with OC fusion after tumor resection encountered complications such as surgery site wound dehiscence, encephalitis, and cardiac arrest with consequent mortality in one patient. These complications were avoided in subsequent patients where OC fusion was performed before tumor resection. There were no differences in the extent of tumor resection between OC fusion before and after tumor resection. Two-stage OC fusion before tumor resection can reduce instability-, fusion-, and surgery time-related morbidity and achieve feasible tumor resection when OC joint instability is expected. The extent of tumor invasion and brain stem compression should be considered when fusion precedes tumor resection.

Post-carbon-ion radiotherapy vertebral pathological fractures in upper cervical primary malignant spinal tumors treated by occipito-cervical fusion.

PURPOSE: To describe the characteristic features of post-carbon-ion radiotherapy (CIRT) vertebral pathological fractures (VPFs) in upper cervical primary malignant spinal tumors (PMSTs) treated by occipito-cervical (OC) fusion. METHODS: OC fusion was performed for three consecutive patients with post-CIRT VPFs. The clinical results and imaging findings, including bone single-photon emission computed tomography (SPECT)/CT were prospectively collected. RESULTS: No surgery-related wound complication and surgical site infection were noted. One patient experienced re-fracture and displacement of dens with the loosening of occipital screws and was treated by posterior revision surgery. At the final follow-up, all patients were alive without evidence of disease, and the solid OC fusion was confirmed. Bone SPECT/CT clearly revealed the effect of CIRT on bone turnover in the irradiated field. CONCLUSION: The OC fusion with autologous bone grafts was a reliable option for the treatment of post-CIRT VPCs in the patients with upper cervical PMSTs. In addition, evaluation of the bone turnover at the irradiated field by bone SPECT/CT would help surgeons select an effective plan of care, such as fusion level and postoperative care.

C1-C2 Fusion Versus Occipito-Cervical Fusion for High Cervical Fractures: A Multi-Institutional Database Analysis and Review of the Literature.

OBJECTIVE: Type II odontoid fractures of the axis (C2) account for more than 20% of all cervical fractures. If an odontoid screw is contraindicated, the treatment approach for type II C2 fractures typically involves C1-C2 posterior fusion or occipito-cervical (O-C) fusion, each of which has distinct advantages and disadvantages. In this study, postoperative outcomes of C1-C2 fusion and O-C fusion for high cervical fractures were compared. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was queried to determine 30-day surgical outcomes of posterior C1-C2 fusion versus O-C fusion for adult patients with C2 fractures between 2005 and 2016. Demographics, operative factors, and postoperative events were analyzed, including returns to the operating room, readmission, and death. RESULTS: In total, 165 patients were identified. A majority of the patients (142, 86.1%) had independent functional status, although 133 (80.6%) had an American Society of Anesthesiologists classification ranging from 3 to 5, representing poor preoperative health. A significantly greater proportion of O-C (9.1%) versus C1-C2 fusion (1.7%) returned to the operating room (odds ratio 6.465, confidence interval 1.079-38.719, P = 0.041). The length of operation approached statistical significance (P = 0.053) between the 2 groups, with O-C fusion group having a longer average length of operation (196.4 minutes) versus the C1-C2 group (164.0 minutes). CONCLUSIONS: This study provides a snapshot of the risk profiles of C1-C2 and O-C fusion for C2 fracture, demonstrating a statistically higher risk of reoperation in O-C fusion versus C1-C2 fusion. Future randomized trials are needed to identify the preferred technique to improve patient outcomes.

Traumatic occipito-cervical dissociation in adults: a Middle Eastern cohort study.

The objective of this study is to describe a series of cranio-cervical dissociation victims and evaluate their outcomes as well as discuss the clinical dilemmas we faced in the context of current literature evidence. This is a retrospective cohort study of traumatic occipito-cervical dissociation in five patients (three males and two females) encountered between 2010 and 2016 at a tertiary care facility in the Middle East region. All patients underwent occipito-cervical fusion using screws and rods system with mean postoperative follow-up period of 2.5 years. All patients survived, and four were independently mobile and one wheel chair bound. Most had some degree of neurological sequelae, often due to associated injuries and all complained of limited neck range of motion. Contemporary literature review shows that CT scan with MRI is often the best diagnostic modality. Surgery is usually indicated though rare cases treated conservatively have been reported. The commonest predictor of mortality is missed injury, associated head injury and wide separation between the skull base and C1 on imaging studies.

Bicortical facet screws as a new option for posterior C2 fixation: anatomical study and clinical experience.

PURPOSE: C2 fixation is a demanding procedure, particularly in patients with variants of C1-C2 anatomy. The inferior articular process (IAP) of the axis can be an alternative for screw placement. We report the results of a CT study of C2 IAP anatomy and we present the clinical experience of 28 patients operated with this technique. METHODS: Anatomical study: 50 CT angiographies of the vertebral arteries (VA) were used for this study and, therefore, 100 IAPs were considered. We measured on the axial and sagittal planes the length, height and width of the facet, the distance between the anterior cortex and the VA and the distance between the screw entry point and the VA. We also measured the angle between the sagittal plane and the external tangent line of the VA. CLINICAL REPORT: 28 patients were treated with C2 IAP screws at the Spine Surgery Department of the University Hospital in Lyon, France, from January 2014 to January 2016. RESULTS: Anatomical study: the mean length of C2 IAP was 12 ± 2 mm, the mean distance between the anterior cortical layer and the VA was 5.2 ± 1.4 mm, and the mean angle we found was 0.2° ± 5.3°. CLINICAL REPORT: 16 of the 28 patients presented post-traumatic C1-C2 instability, 8 patients presented degenerative disease, 1 patient was treated for pseudoarthrosis, 1 for tumour, 1 for OPLL and 1 for rheumatoid arthritis. All the screws were correctly positioned and there was no VA injury. CONCLUSION: IAP screws can represent a safe alternative option for C2 fixation.

Airway adverse events following posterior occipito-cervical spinal fusion.

Management of the airway may be challenging in patients undergoing occipito-cervical spine fusions (OCF). Changes in the occipito-cervical angle (dOC2A) of fusion after surgery may result in acute airway obstruction, dyspnea and/or dysphagia. Objectives of the study were to review the airway management of patients during posterior OCF, determine the incidence, nature and risk factors for postoperative airway adverse events (AEs), and to determine the relationship between airway AEs and the change in dOC2A. In this retrospective cohort of 59 patients, following extubation in the operating room (OR), there were no complications in 43 (73%) patients (Group 1). Sixteen (27%) patients (Group 2) had airway complications; 4 requiring reintubation and 12 having delayed extubation. The number of vertebral levels fused (>6), presence of difficult intubation and duration of surgery (>5h) were significantly associated with AEs. There was no significant difference in the dOC2A between the groups (-1.070±5.527 versus -4.375±10.788, p=0.127). Airway management in patients undergoing OCF poses a challenge for the anesthesiology and surgical teams. The incidence of AEs was 27%. The decision to extubate immediately after surgery needs to be individualized. Factors such as difficult intubation, number of vertebral levels fused and duration of surgery have to be considered. A significant correlation between dOC2A and postoperative AEs could not be established. Risk factors for postoperative AEs are multifactorial and prospective evaluation of these factors is indicated.

Complications in Craniovertebral Junction Instrumentation: Hardware Removal Can Be Associated with Long-Lasting Stability. Personal Experience.

BACKGROUND: The causes of craniovertebral junction (CVJ) instabilities include trauma, rheumatological diseases, tumors, infections, congenital malformations, and degenerative disease processes; these complex pathologies often require CVJ instrumentation. Hardware complications were analyzed in a personal series of 48 treated patients. In light of the analysis of very unusual radiological and clinical findings, the authors tried to better investigate the related mechanisms and to reach possible useful conclusions. METHODS: In a series of 48 patients who underwent CVJ instrumentation and fusion procedures in our Institution, we describe three cases of hardware failure, due to: (1) infection; (2) radio- and chemotherapy; and (3) incorrect surgical procedure. RESULTS: 1. A stable bone CVJ fusion can occur after instrumentation removal for infection, since this removal can enhance bone fusion mechanisms; 2. Radio- and chemotherapy can cause hardware failure due to interference with local bone metabolism; 3. Although old-fashioned, wiring techniques still deserve consideration, mostly in CVJ re-do surgery after screwing technique failures; nevertheless, although the procedure is simple, safe, and effective, care must be taken in the preparation of the cranial holes in order to avoid sliding complications of the U-shaped rods. CONCLUSIONS: CVJ instrumentations provide reasonably good mechanical stabilization with a high rate of bony fusion. Complications, such as dislocation or rupture of the fixation system, screw loosening, dural fistula, neural or vascular damage, and wound infection, are relatively infrequent. Knowledge and prevention of these complications is fundamental to improve surgical results and outcomes.

Proatlas segmentation anomalies: Surgical management of five cases and review of the literature.

OBJECTIVE: Proatlas segementation anomalies are due to defective re-segmentation of the proatlas sclerotome. These anomalies of the craniovertebral junction are rare and have multiple presentations. The aim of this study is to report this author's personal experience in managing five of these patients with different radiological findings necessitating different surgical strategies and to provide a brief review of the relevant literature. MATERIALS AND METHODS: Five patients, all in the second decade of life were treated between 2010 and 2013. There were three males and two females. All the patients presented with spastic quadriparesis and/or cerebellar signs. Patients underwent plain radiographs, MRI and CT of the craniovertebral junction. CT of the cranioveretebral junction was the key to the diagnosis of this anomaly. Postoperatively, patients were assessed with plain radiographs and CT in all patients and MRI in one. RESULTS: Two patients underwent craniovertebral realignment with occipitocervical fixation, two patients underwent C1-C2 fixation using Goel-Harms technique and one patient underwent craniovertebral realignment with C1-C2 fixation using spacers in the atlanatoaxial joint and foramen magnum decompression. All patients improved during follow up. CONCLUSIONS: Proatlas segmentation defects are rare anomalies of the craniovertebral junction. Routine use of thin section CT of the craniovertebral junction and an awareness of this entity and its multivarious presentations are necessary for clinicians dealing with abnormalities of the craniovertebral junction.

Focusing on the delayed complications of fusing occipital squama to cervical spine for stabilization of congenital atlantoaxial dislocation and basilar invagination.

OBJECTIVES: Occipito-cervical(OC) fusion is often practiced for congenital atlanto-axial dislocation (CAAD) and basilar invagination (BI) with claims of good long term outcome. Little has been discussed about the delayed complications following fusing occipital squama to cervical spine (OC fusion). We have described and analyzed delayed complications with OC fusion in our patients that helps us understand the underlying dynamics and biomechanics. PATIENTS AND METHODS: Twenty seven patients of CAAD and BI underwent OC fusion (between 2008 and 11) after transoral odontoidectomy or direct posterior reduction with OC distraction. OC fusion was achieved using either sublaminar wiring or with precurved rods and screws or contoured loop. One patient was referred after OC fusion with contoured loop and wires with additional C1 laminectomy. The outcome (>12months) and delayed complications in these patients were analyzed. RESULTS: Five types of delayed complications were noticed in 6 of the 28 patients who underwent OC fusion. Five of 6 patients were adults. Vertical redislocation with posterior midline fusion (n=2), adjacent level angular listhesis (n=1) and swan neck deformity (n=1) was seen in cases of OC fusion with sublaminar wires alone. Progressive C1 dislocation was seen in the lone patient who was referred after OC fusion with loop and wires. Vertical and angular dislocation was seen in 1 patient of OC fusion with precurved rod and screws. CONCLUSION: Progressive redislocation and adjacent level dislocation are delayed complications seen after OC2 fusion. These complications are more often seen in adults, especially with sublaminar wiring/semi rigid OC fixation.

Allograft versus autograft for pediatric posterior cervical and occipito-cervical fusion: a systematic review of factors affecting fusion rates.

OBJECT Fusion rates are high for children undergoing posterior cervical fusion (PCF) and occipito-cervical fusion (OCF). Autologous bone has been widely used as the graft material of choice, despite the risk of donor-site morbidity associated with harvesting the bone, possibly because very low fusion rates were reported with posterior allograft cervical fusions in children several decades ago. Higher overall fusion rates using allograft in adults, associated with improvements in internal fixation techniques and the availability of osteoinductive substances such as bone morphogenetic protein (BMP), have led to heightened enthusiasm for the use of bank bone during pediatric PCF. A systematic review was performed to study factors associated with successful bone fusion, including the type of bone graft used. METHODS The authors performed a comprehensive PubMed search of English-language articles pertaining to PCF and OCF in patients less than 18 years old. Of the 561 abstracts selected, 148 articles were reviewed, resulting in 60 articles that had sufficient detail to be included in the analysis. A meta-regression analysis was performed to determine if and how age, fusion technique, levels fused, fusion substrate, BMP use, postoperative bracing, and radiographic fusion criteria were related to the pooled prevalence estimates. A systematic review of the literature was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. RESULTS A total of 604 patients met the specific inclusion and exclusion criteria. The overall fusion rate was 93%, with a mean age of 9.3 years and mean follow-up of 38.7 months. A total of 539 patients had fusion with autograft (94% fusion rate) and 65 patients with allograft (80% fusion rate). Multivariate meta-regression analysis showed that higher fusion rates were associated with OCF compared with fusions that excluded the occiput (p < 0.001), with the use of autograft instead of allograft (p < 0.001), and with the use of CT to define fusion instead of plain radiography alone. The type of internal fixation, the use of BMP, patient age, and the duration of follow-up were not found to be associated with fusion rates in the multivariate analysis. CONCLUSIONS Fusion rates for PCF are high, with higher rates of fusion seen when autograft is used as the bone substrate and when the occiput is included in the fusion construct. Further study of the use of allograft as a viable alternative to autograft bone fusion is warranted because limited data are available regarding the use of allograft in combination with more rigid internal fixation techniques and osteoinductive substances, both of which may enhance fusion rates with allograft.