Autologous rib grafts for craniocervical junction surgery in children: a clinical application.

OBJECTIVE: Autologous iliac bone is commonly used as a bone graft material to achieve solid fusion in craniocervical junction (CVJ) surgery. However, the developing iliac bone of children is less than ideal as a bone graft material. The matured rib bone of children presents a potential substitute material for iliac bone. The aim of this study was to evaluate the efficacy of autologous rib grafts for craniocervical junction surgery in children. METHODS: The outcomes of 10 children with abnormalities of the craniocervical junction who underwent craniocervical junction surgery between January 2020 and December 2022 were retrospectively reviewed. All patients underwent posterior fusion and internal fixation surgery with autologous rib grafts. Pre- and post-operative images were obtained and clinical follow-ups were conducted to evaluate neurological function, pain level, donor site complications, and bone fusion rates. RESULTS: All surgeries were successful. During the 8- to 24-month follow-up period, all patients achieved satisfactory clinical results. Computed tomography at 3-6 months confirmed successful bone fusion and regeneration of the rib defect in all patients with no neurological or donor site complications. CONCLUSION: Autologous rib bone is a safe and effective material for bone grafting in craniocervical junction fusion surgery for children that can reduce the risks of donor site complications and increase the amount of bone graft, thereby achieving a higher bone fusion rate.

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

OBJECTIVE: 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. METHODS: 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). RESULTS: 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. CONCLUSIONS: 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.

[Preoperative Simulation for Complication Control in Spinal Surgery].

The craniovertebral junction not only contains anatomically important structures such as the medulla oblongata, upper cervical spinal cord, and vertebral artery, but also controls the dynamic movements of flexion, extension, and rotation of the head and neck. Consequently, instability and spinal deformities can easily occur in the craniovertebral region, and appropriate treatment should be selected based on the specificity of the lesion. Basilar invagination often involves bone and vascular anomalies and fusion surgery is often required. Therefore, careful pre-operative simulations are necessary. The creation and use of three-dimensional bone models, including image navigation, are useful for surgical simulation.

Novelties for increased safety in cranio-vertebral surgery: a review.

The cranio-vertebral junction (CVJ) was formerly considered a surgical "no man's land" due to its complex anatomical and biomechanical features. Surgical approaches and hardware instrumentation have had to be tailored in order to achieve successful outcomes. Nowadays, thanks to the ongoing development of new technologies and surgical techniques, CVJ surgery has come to be widely performed in many spine centers. Accordingly, there is a drive to explore novel solutions and technological nuances that make CVJ surgery safer, faster, and more precise. Improved outcome in CVJ surgery has been achieved thanks to increased safety allowing for reduction in complication rates. The Authors present the latest technological advancements in CVJ surgery in terms of imaging, biomaterials, navigation, robotics, customized implants, 3D-printed technology, video-assisted approaches and neuromonitoring.

How I do it: lateral approach for craniocervical junction tumors.

BACKGROUND: The far lateral approach has been developed to access lesions at the craniocervical junction and upper cervical spinal canal. Associated morbidity triggered the development of less invasive tailored approaches. METHOD: In this lateral approach to the craniocervical junction, the occipital condyle is kept intact, vertebral artery manipulation is minimized, and the sigmoid sinus is not skeletonized. A linear incision through skin and muscles and use of an abdominal wall fat graft minimize the risk of cerebrospinal fluid leakage. CONCLUSIONS: The exposure provided is sufficient for the majority of tumors in this region and allows for low complication rates.

Occult craniocervical dissociation on cervical CT: an under-appreciated presentation of craniocervical trauma requiring occipital cervical fusion.

BACKGROUND AND PURPOSE: Craniocervical dissociation is a rare and life-threatening injury that results from a significant hyperflexion-hyperextension force. Occult craniocervical dissociation is defined as an unstable craniocervical injury in the absence of atlanto-occipital joint space widening or other skull base line abnormality. The early and accurate diagnosis of craniocervical dissociation is crucial since the early diagnosis and subsequent stabilization with occipital-cervical fusion has been shown to reduce neurologic morbidity and mortality. Several normative skull base lines have been developed to predict craniocervical dissociation. The purpose of our study was to measure the atlanto-occipital joint space and four other common skull base lines in patients who underwent occipital-cervical fusion for post-traumatic craniocervical instability. MATERIALS AND METHODS: Patients who underwent occipital-cervical fusion for craniocervical injury were identified retrospectively using a keyword search of radiology reports using Nuance mPower software. The cervical CT and MRI exams for these patients were reviewed and the atlanto-occipital joint space, Powers ratio, Wackenheim line, posterior axial line, and basion dens interval were measured. Detailed descriptions of craniocervical ligament injuries on MRI were recorded along with patient demographic information, clinical history, management, and outcome. RESULTS: Nine adult patients who underwent occipital-cervical fusion for an acute craniocervical injury were identified. Six patients demonstrated an atlanto-occipital joint space measuring 2 mm or less on cervical spine CT with no additional abnormality in the Powers ratio, Wackenheim line, posterior axial line, or basion-dens interval. Three patients demonstrated widening of the atlanto-occipital joint space with two patients demonstrating an abnormality in at least two additional skull base lines. Clinical outcomes were variable with nearly half of the patients demonstrating persistent neurologic deficits, including one quadriplegic patient. CONCLUSIONS: A normal atlanto-occipital joint space and skull base line measurements on cervical CT demonstrated a low predictive value for detecting unstable craniocervical injuries. Occult craniocervical dissociation was present in two-thirds of patients who underwent occipital cervical fusion for acute, craniocervical trauma. A high clinical and radiologic index of suspicion for craniocervical trauma with subsequent follow-up cervical MRI to directly evaluate ligamentous integrity is necessary to accurately diagnose and triage patients with high velocity trauma.

Traumatic atlanto-occipital dislocation in children: is external immobilization an option?

OBJECT: Traumatic atlanto-occipital dislocation (AOD) is a relatively uncommon traumatic cervical spine injury characterized by disruption and instability of the atlanto-occipital joint. At many centers, management of pediatric AOD includes occipitocervical arthrodesis, but whether external immobilization without surgery is a viable treatment option for some pediatric patients is unknown. To answer this question, we analyzed our outcomes of pediatric AOD at the Hospital for Sick Children. METHODS: We performed a retrospective chart review of all children with clinical and radiographic evidence of traumatic AOD. A total of 10 patients met criteria for traumatic AOD: 8 were treated with external immobilization alone and 2 were treated with occipitocervical arthrodesis. RESULTS: Eight patients were treated exclusively with 3 months of halo immobilization. Two patients were treated with occipitocervical instrumentation and arthrodesis. No patient undergoing halo immobilization required subsequent operative fusion. CONCLUSION: Halo immobilization is a safe, viable, and definitive treatment option for the selected children with AOD.

Management of post-traumatic craniovertebral junction dislocation: A PRISMA-compliant systematic review and meta-analysis of casereports.

Although historically considered fatal, with the advent of improved pre-hospital care, traumatic dislocation of the craniovertebral junction (CVJ) has been increasing in prevalence in neurosurgical centers. As more survivors are reported each year, a timely review with meta-analysis of their management seems necessary. PRISMA checklist was followed step by step. PubMed and Web of Science databases were searched using words "craniovertebral junction dislocation" and their corresponding synonyms. Study eligibility criteria included research studies from 2015 onwards that delineated adult and pediatric patients with confirmed post-traumatic atlantooccipital dislocation (AOD) or atlantoaxial dislocation (AAD) who survived until proper treatment. Of 1475 initial records, 46 articles met eligibility criteria with a total of 141 patients with traumatic CVJ dislocation. Of the patients, 90 were male (63.8%). Mean age of the cohort was 33.3 years (range 1-99 years). Trauma that most often led to this injury was road traffic accident (70.9%) followed by falls (24.6%). The majority of authors support posterior instrumentation of C1-C2 (45.2%) especially by means of Goel-Harms method. At mean follow-up of 15.4 months (range 0.5-60 months), 27.2% of treated patients remained neurologically intact. Of initially symptomatic, 59% improved, 37% were stable, and 4% deteriorated. Instrumenting the occiput in cases of pure AAD was associated with lower chance of neurological improvement in chi-square test (p = 0.0013) as well as in multiple linear regression (ß = - 0.3; p = 0.023). The Goel-Harms C1-C2 fusion is currently the most frequently employed treatment. Many survivors remain with no deficits or improve, rarely deteriorate. Involving the occiput in stabilization in cases of AAD without AOD might be related with worse neurological prognosis.

Surgical treatment of atlantoaxial subluxation by intraoperative skull traction and C1-C2 fixation.

BACKGROUND: Atlantoaxial subluxation (AAS) is a not rare abnormality between the atlas (C1) and axis (C2). For AAS patients with persistent neck pain and neurologic symptoms, surgical intervention is a good choice. Nevertheless, there were still few reports about the use of intraoperative skull traction and different fixation methods in treatment of AAS. METHODS: From January 2012 to December 2018, a total of 86 cases were admitted to our hospital and diagnosed as AAS. All the patients received atlantoaxial reduction with the help of intraoperative skull traction and C1-C2 fixation. Clinical and radiological parameters were collected through chart review. RESULTS: There were 86 cases included in this study. The mean operative time was 153.9 ± 73.9 min, and the mean amount of intraoperative blood loss was 219.1 ± 195.6 ml. 81 patients underwent posterior reduction, internal fixation and fusion. 5 patients underwent anterior release, followed by posterior internal fixation and fusion. 82 patients got satisfactory postoperative outcomes while complications occurred in 4 patients. Significant neurologic improvement was observed in these patients. Bone fusion was achieved on the midline sagittal reconstructed CT images at the latest follow-up in all these patients except 1 case. All the patients were followed up for 34.84 ± 15.86 months at average (range 12-60 months). The mean ADI value was 7.55 ± 1.67 mm at average preoperatively, and improved to 4.03 ± 1.21 mm postoperatively, and to 4.21 ± 0.99 mm at the latest follow-up. The mean A-A angle was 15.48 ± 9.82 degrees at average preoperatively, and improved to 21.61 ± 10.43 degrees postoperatively, and to 19.73 ± 8.13 degrees at the latest follow-up. The mean A-A height was 35.61 ± 7.66 mm at average preoperatively, and improved to 40.08 ± 8.5 mm postoperatively, and to 38.83 ± 6.97 mm at the latest follow-up. There were complications in 4 patients, including pedicle misplacement, pedicle screw fracture, infection and one death. CONCLUSION: Intraoperative skull traction can effectively facilitate the surgical procedures for ASS caused by different etiologies. Further research will be needed to investigate the safety and effectiveness of this method in the future.

Integrity of the tectorial membrane is a favorable prognostic factor in atlanto-occipital dislocation.

Objective: Atlanto-occipital dislocation is usually considered to be a fatal injury or one that leaves the victim with serious neurological deficits. The aim of this study is to illustrate a novel positive prognostic factor for atlanto-occipital dislocation, based on cervical MRI studies of patients who suffered this injury.Methods: Over the course of the past year, the authors have treated three consecutive patients with atlanto-occipital dislocation who attained an excellent clinical outcome. We retrospectively evaluated clinical, surgical and radiographic parameters in search of a common denominator to explain the excellent outcome of these patients.Results: All patients presented with severe polytrauma that required urgent surgical intervention including two laparotomies and a thoracotomy. The patients were subsequently treated with an occipitocervical fusion. No patient developed neurological deficits on long-term follow-up. The cervical MRI studies of all patients were notable for a having a preserved tectorial membrane, while other primary stabilizers of the craniocervical junction such as the apical, alar and cruciate ligaments were shown to be severely disrupted. We consider this anatomical distinction to account for their benign clinical course.Conclusion: A preserved tectorial membrane appears to be an important favorable prognostic factor in atlanto-occipital dislocation and may serve to mitigate neurological outcome in such injuries. To determine the integrity of the ligament and consequently affect clinical management, expeditious MRI of the cranio-cervical junction should be considered routinely in such injuries in addition to cervical CT scans.

Complex Chiari malformation: using craniovertebral junction metrics to guide treatment.

The complex Chiari, characterized by abnormal craniocervical bony anatomy in addition to Chiari tonsillar herniation, is a relatively recent addition to the concepts surrounding the Chiari literature. The primary findings of complex Chiari include craniocervical kyphosis and retroflexed odontoid, both of which can be described with radiographic measurements. This manuscript will outline the background literature regarding Chiari craniocervical morphometrics and supply an algorithm for the general management of complex Chiari patients.

Why the Craniovertebral Junction?

The craniovertebral junction (CVJ) has unique anatomical bone and neurovascular structure architecture. It not only separates the skull base from the subaxial cervical spine but also provides a special cranial flexion, extension and axial rotation pattern. Stability is provided by a complex combination of osseous and ligamentous supports, which allow a large degree of motion. Perfect knowledge of CVJ anatomy and physiology allows us to better understand instrumentation procedures of the occiput, atlas and axis, and the specific diseases that affect the region. Therefore, a review of the vascular, ligamentous and bony anatomy of the region, in relation to all possible surgical approaches to this anatomically unique segment of the cervical spine, appears to be absolutely mandatory in order to preview and to overcome possible anatomy-related complications of CVJ surgery; moreover, knowledge of the basic principles of instrumentation and of the kinematics of the region, since they interact with the anatomy, seems to be strategic in preoperative planning.Historically considered a no man's land, CVJ surgery, or the CVJ specialty, has recently attracted strong consideration as a symbol of challenging surgery as well as selective top-level qualifying surgery.Although many years have passed since the beginning of this pioneering surgery, managing lesions situated in the anterior aspect of the CVJ still remains a challenging neurosurgical problem. Many studies are available in the literature, aiming to examine the microsurgical anatomy of both the anterior and posterior extradural and intradural aspects of the CVJ, as well as the differences in all possible surgical exposures obtained by the 360° approach philosophy. In this paper the author provides a short but quite complete at-a-glance tour of personal experience and publications and the more recent literature available.

The Decision-Making Process in Traumatic Lesions of the Craniovertebral Junction: An Evidence-Based Approach? Part I.

Evidence-based medicine is a rather young concept, which entered the scientific literature in the early 1990s.

Comparison of radiological and clinical outcomes after surgical reduction with fixation or halo-vest immobilization for treating unstable atlas fractures.

BACKGROUND: Unstable atlas fractures with concomitant transverse atlantal ligament (TAL) injury may be conservatively managed by halo-vest immobilization (HVI) or surgically treated by various fixation techniques. Many surgeons prefer surgical management due to complications, nonunion, and further dislocations with HVI. There are no comparative studies on surgical and nonsurgical management of unstable atlas fractures. We retrospectively assessed the radiological and clinical outcomes of surgical reduction with fixation vs. non-operative treatments for unstable atlas fractures with TAL rupture. METHODS: We analyzed records of 24 patients (15 men, 9 women; mean age, 48.3 years) with at least 1 year of follow-up. They underwent HVI or surgical reduction with fixation for unstable atlas fracture combined with TAL injury. Clinical outcomes, including neck visual analog scale and neck disability index (NDI), and radiological measurements, including degree of fracture displacement, atlantodental interval (ADI), range of motion (ROM), cervical alignment, fusion rate, and time-to-fusion, were assessed. RESULTS: Of the 24 patients, 13 were treated by surgical reduction with fixation (C1 lateral mass screw-C2 pedicle screw with a cross-link) and 11 by HVI. A significant reduction in lateral displacement of fractured lateral masses was identified in surgical reduction with fixation (3.21 ± 1.21 mm) compared with HVI (0.97 ± 2.69 mm). The mean reduction in ADI was 1.47 ± 1.08 mm with surgical fixation and 0.66 ± 1.02 mm with HVI. The bony rate and time-to-fusion were 100% and 14.91 ± 3.9 weeks with surgical reduction, and 72.7% and 22.31 ± 10.85 weeks with HVI. The postoperative neck pain relief and NDI after surgical fixation were higher than those after HVI. CONCLUSIONS: Compared with HVI, surgical reduction with fixation reduces fractured lateral mass displacements, increases fusion rate, and reduces time-to-fusion while maintaining cervical curvature and improving neck pain and daily activities.

Arthroscopic approach and intra-articular anatomy of the equine atlanto-occipital joint.

OBJECTIVE: To develop arthroscopic approaches to the atlanto-occipital (A-O) and describe associated arthroscopic anatomy. STUDY DESIGN: Experimental ex vivo study and clinical case report. ANIMALS: Ten equine cadaver joints and 1 clinical case. METHODS: CT arthrograms of 8 A-O joints were performed to determine the placement of an arthroscopic portal. Arthroscopy was performed via dorsal and/or ventral approaches (dorsal or ventral to the longissimus capitis tendon) in 10 cadaveric A-O joints and the A-O joint of a 2-week-old foal with septic arthritis. Accessible cartilage was debrided in 3 cadaver joints. Accessibility and risks were assessed by review of arthroscopic images, postoperative necropsy, and computed tomography (CT). RESULTS: Dorsal and ventral outpouchings of the A-O joint were identified with CT. Arthroscopy of the dorsal pouch provided access to 50% of the dorsocranial occipital condyle and 15% of the dorsocranial atlas articular surfaces. Joint distension caused displacement of the dura. Dura perforation occurred with a blind dorsal approach in 2 of 5 joints. Dura perforation did not occur after ultrasonography-guided approaches. Arthroscopic debridement of septic arthritis and osteomyelitis was successful in 1 clinical case. CONCLUSION: Approaches to the A-O joint were determined from CT examinations. The cranial aspect of the dorsal pouch of the A-O joint was accessed via arthroscopic triangulation in all horses of this study. Ultrasound-guided joint access prevented perforation of vital structures, including the spinal canal. CLINICAL SIGNIFICANCE: Advanced imaging improves the diagnosis of A-O joint pathology. Descriptions of arthroscopic anatomy and accessibility provide important information for surgical intervention.

Instrumented fusion in a 12-month-old with atlanto-occipital dislocation: case report and literature review of infant occipitocervical fusion.

BACKGROUND: The treatment of atlantoaxial dislocation in very young children is challenging and lacks a consensus management strategy. DISCUSSION: We review the literature on infantile occipitocervical (OC) fusion is appraised and technical considerations are organized for ease of reference. Surgical decisions such as graft type and instrumentation details are summarized, along with the use of bone morphogenic protein and post-operative orthoses. ILLUSTRATIVE CASE: We present the case of a 12-month-old who underwent instrumented occipitocervical (OC) fusion in the setting of traumatic atlanto-occipital dislocation (AOD). CONCLUSION: Occipitocervical (OC) arthrodesis is obtainable in very young infants and children. Surgical approaches are variable and use a combination of autologous grafting and creative screw and/or wire constructs. The heterogeneity of pathologic etiology leading to OC fusion makes it difficult to make definitive recommendations for surgical management.

The changes of syrinx volume after posterior reduction and fixation of basilar invagination and atlantoaxial dislocation with syringomyelia.

PURPOSE: The purpose of this study focuses on the changes of the syrinx volume after posterior reduction and fixation of the basilar invagination (BI) and atlantoaxial dislocation (AAD) with syringomyelia. METHODS: We retrospectively analyzed the clinical outcome and syrinx volume changes in 71 patients with BI, AAD and syringomyelia treated with the posterior reduction and fixation technique. RESULTS: Clinical improvement was observed in 64 (90.1 %) patients postoperatively; 5 (7.0 %) were stable and 2 (2.8 %) were clinically aggravated. The postoperative Atlantodental interval became normal in 61 patients (86.0 %); showed reduction that was greater than 50 % but not complete in 5 patients (7.0 %); and reduction which was less than 50 % in 5 patients (7.0 %). The size of the syrinx was reduced postoperatively in 66 patients (93.0 %) while no change in the remaining 5 patients (7.0 %). CONCLUSIONS: Posterior reduction and fixation of the AAD and BI can effectively enlarge the foramen magnum, improve the cerebrospinal fluid circulation and consequently reduce the volume of the syrinx.

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.

[Injuries of the upper cervical spine : Update on diagnostics and management]. / Verletzungen der oberen Halswirbelsäule : Update zu Diagnostik und Management.

Injuries to the upper cervical spine represent a diagnostic and therapeutic challenge to the treating surgeon due to the complex anatomical relationships and biomechanical features. In this further education article the diagnostic principles, established classifications and therapeutic recommendations as well as injury-specific characteristics of bony and ligamentous injuries to the upper cervical spine (C0-C2) are presented.