Association between Brachycephaly, Chiari Malformation, and Basilar Invagination

Background There is evidence that Chiari malformation (CM) and basilar invagination (BI) are largely due to disproportion between the content and volume of the posterior fossa. A recent study identified an increased association between brachycephaly and BI. In several types of craniosynostosis, the posterior fossa volume is smaller than normal, and this is more pronounced in coronal synostosis. The aim of this study is to evaluate the association between CM and BI. Methods The cephalic index (CI) measured on magnetic resonance imaging (MRI) from a sample of patients with craniocervical malformation was compared with that of normal subjects. Results The average CI in the craniovertebral junction malformation (CVJM) group was significantly higher in BI patients than in normal subjects. The BI patients also had the highest CI among the whole sample of patients (p = 0.009). Conclusions In this study, BI patients had the highest CI among patients with CVJM and a significantly higher CI than those in the control group. Our data confirm the association between BI and brachycephaly.

Craniofacial and Craniocervical Features in Cartilage-Hair Hypoplasia: A Radiological Study of 17 Patients and 34 Controls

BackgroundBiallelic mutations in the non-coding RNA gene RMRP cause Cartilage-hair hypoplasia (CHH), a rare skeletal dysplasia in which the main phenotypic characteristic is severe progressive growth retardation.ObjectiveThis study compared the cranial dimensions of individuals with CHH to healthy subjects.MethodsLateral skull radiographs of 17 patients with CHH (age range 10 to 59 years) and 34 healthy individuals (age range 10 to 54 years) were analyzed for relative position of the jaws to skull base, craniofacial height and depth, as well as vertical growth pattern of the lower jaw, anterior cranial base angle, and the relationship between the cervical spine and skull base.ResultsWe found that the length of the upper and lower jaws, and clivus were significantly decreased in patients with CHH as compared to the controls. Anterior cranial base angle was large in patients with CHH. Basilar invagination was not found.ConclusionThis study found no severe craniofacial involvement of patients with CHH, except for the short jaws. Unexpectedly, mandibular deficiency did not lead to skeletal class II malocclusion.Clinical ImpactAlthough the jaws were shorter in patients with CHH, they were proportional to each other. A short posterior cranial base was not associated with craniocervical junction pathology.

Radiologic Cervical Parameters To Determine Ligamentous Injuries in Patients With Ankylosing Spondylitis – Are They Different?

Introduction: Cervical ligamentous injuries in patients with ankylosing spondylitis (AS) may be difficult to detect, even with the utilization of computed tomography (CT) scans. The purpose of this study was to investigate the influence AS has on various radiologic parameters used to detect traumatic and degenerative pathologies of the cervical spine. Methods: A matched, case-control retrospective analysis of patients with AS and controls without AS admitted at two level-1 trauma centers was performed. All patients were admitted via shock room and received a polytrauma CT. Study patients were included if they had no injury to the cervical spine. Twenty-four CT parameters of atlanto-occipital dislocation/ instability, traumatic and degenerative spondylolisthesis, basilar invagination, and prevertebral soft-tissue swelling were assessed. Study patients were matched by age and sex. Results: A total of 78 patients were included (AS group, n=39; control group, n=39). The evaluated cervical radiologic parameters were largely within normal limits and showed no significant clinical or morphologic differences between the two groups. Conclusion: In this analysis, CT measurements pertaining to various cervical pathologies were not different between patients with and without ankylosing spondylitis. Parameters to assess for atlanto-occipital dislocation/ instability, spondylolisthesis, or basilar invagination may reliably be used in patients with AS.

P.203 Clinical outcomes of endoscopic endonasal odontoidectomy: A single center experience

Background: Odontoidectomy for basilar invagination and craniovertebral junction pathology has traditionally been performed using a transoral route. However, the endoscopic endonasal approach to the anterior craniovertebral junction may offer safer and more effective access when compared to transoral approaches. Methods: This study is a retrospective chart review of all adult patients who underwent an endoscopic endonasal odontoidectomy at a single tertiary care center between January 2011 and May 2019. Results: Seventeen patients were included in the study. The median admission age was 67 years (range: 33-84 years) and 65% of the patients were female. One patient (1/17, 6%) had vertebral artery injury which was coiled with no neurological deficits, and 4 patients (4/17, 24%) had intraoperative CSF leaks with no postoperative leak. Fourteen patients (14/17, 82%) were extubated by POD 1. Three patients (3/17, 18%) developed postoperative sinus infections and required antibiotics. Eight patients (8/17, 47%) developed transient postoperative dysphagia. One patient (1/17, 6%) had postoperative epistaxis and one patient (1/17, 6%) had postoperative lower cranial nerve symptoms. The median length of hospital stay was 13 days (range: 2-44 days). Conclusions: Endoscopic endonasal odontoidectomy is a feasible and well-tolerated procedure for anterior decompression of craniovertebral junction, associated with satisfactory patient outcomes and low morbidity.

A combined approach for stabilization and endoscopic/ endonasal odontoid and clivus resection for treatment of basilar invagination

Background: Basilar invagination (BI) is a complex condition characterized by prolapse of the odontoid into the brain stem/upper cervical cord. This lesion is often associated with Chiari malformations, and rheumatoid arthritis (RA). Treatment options for BI typically include cervical traction, an isolated anterior transoral odontoidectomy, anterior endonasal odontoidectomy, an isolated posterior fusion, or combined anterior/ posterior surgical approach. Case Description: A 45-year-old female with a Chiari I malformation and RA underwent a combined posterior C0-C5 posterior decompression/fusion, followed by an anterior odontoidectomy (i.e. endoscopic/endonasal under neuronavigation). Postoperatively, the patient’s symptoms and neurological signs resolved. Conclusion: BI in was successfully managed with a combined posterior C0-C5 decompression/fusion followed by an anterior endoscopic/endonasal odontoidectomy performed under neuronavigation.