Perioperative Outcomes and Reimbursement Patterns Associated With the Anterior versus Posterior Approach for Treatment of Type 2 Odontoid Fractures, a National Surgical Quality Improvement Program Analysis.

Objective: To evaluate the short-term surgical outcomes and the reimbursement patterns, after treatment of type 2 odontoid fractures using the anterior or posterior approach.

Methods: The National Surgical Quality Improvement Program database was queried for surgically treated patients with type 2 odontoid fractures by the anterior or posterior approach between 2016 and 2020. Propensity score matching with the optimal approach was used to balance the cohorts.

Surgical versus conservative treatment for odontoid fractures in older people: an international prospective comparative study.

Background: The optimal treatment for odontoid fractures in older people remains debated. Odontoid fractures are increasingly relevant to clinical practice due to ageing of the population.

Methods: An international prospective comparative study was conducted in fifteen European centres, involving patients aged ≥55 years with type II/III odontoid fractures.

How cervical and cervicothoracic scoliosis influence the atlantoaxial joint.

Introduction: Children with cervical or cervicothoracic congenital scoliosis are limited in their ability to compensate for the main curve of the deformity because there are only a few mobile segments in their cervical spine. Over the years, we have frequently observed coronal atlantoaxial dislocation (CAAD) in a lateral direction (from left to right or vice versa) in these patients. It was anticipated that CAAD might compensate for the horizontal position of the head, and it is hypothesized that CAAD depends on the degree of scoliotic deformity.

[3D printing navigation template assisted pedicle screw placement for the treatment of typeⅡold odontoid fractures].

Objective: To compare the safety and clinical efficacy of freehand and 3D printing navigation template assisted screw placement in patients with old odontoid fractures of typeⅡ.

Methods: Total of 38 patients with old odontoid fractures of typeⅡwere treated from November 2018 to December 2022, all of which presented as chronic neck pain. According to the different methods of screw insertion into the pedicle, the patients were divided into a navigation template group and a freehand group.

Two-screw osteosynthesis is biomechanically superior to single-screw osteosynthesis for type II odontoid fractures.

The data on the use of a one- or two-screw technique (1S, 2S) for ventral osteosynthesis of type II dens fractures are contradictory. The aim was to design an apparatus to mimic the physiological conditions and test stability with 1S, 2S, and a headless compression screw (HCS) for osteosynthesis of artificially created type II odontoid fractures. The apparatus was mounted on a Zwick materials testing machine.

A synovial cyst-induced vertebral artery dissection in bow hunter's stroke: illustrative case.

Background: Bow hunter's stroke (BHS) is a rare condition characterized by occlusion of the vertebral artery (VA) due to a head rotation. BHS typically results from neck hyperrotation, often due to anatomical factors. The authors present a case of BHS in a young male patient exacerbated by os odontoideum (OD), resulting in atlantoaxial dislocation, which ultimately led to VA dissection.

Clinical and MR Predictors of Retro-Odontoid Pseudotumor Regression Following Posterior Fixation in Patients with Atlantoaxial Instability.

Purpose: To identify clinical and MR predictors of retro-odontoid pseudotumor (ROP) regression after posterior fixation in patients with atlantoaxial instability.

Materials And Methods: We included patients who had undergone posterior fixation for atlantoaxial instability and preoperative and postoperative MR imaging. Patients were classified into two groups according to the degree of ROP regression after posterior fixation: regression (≥ 10% reduction) and no regression (< 10% reduction).

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

Objective: This retrospective study aims to investigate the effect of the type of atlantoaxial dislocation due to os odontoideum on the sagittal alignment and balance of the cervical spine after posterior atlantoaxial fusion.

Methods: Data of 48 consecutive patients who underwent posterior C1-C2 fusion to treat atlantoaxial dislocation/instability due to os odontoideum were retrospectively reviewed. Radiographic variables, namely the T1 slope (T1S), C1-C2 angle, C2-C7 angle, C1-C2 sagittal vertical axis (SVA), C2-C7 SVA, and modified atlas-dens interval (MADI), were measured preoperatively, immediate postoperatively, and at final follow-up.

Redefining Diagnostic Criteria for Basilar Invagination Using Linear Craniometric Parameters.

Aim: To establish the diagnosis of basilar invagination (BI) on the basis of specific bony landmarks Klaus' index (KI), perpendicular distance between the tip of the odontoid process and palato internal occipital protuberance (PI) line.

Material And Methods: Forty-nine patients were analysed, who underwent surgery for BI, between July 2020 and June 2023. Radiological assessment was done in all the patients using reconstructed midsagittal images on computed tomography scans .

Variation of Odontoid Incidence According to Age in Asymptomatic Children.

Objective: To investigate the effect of age and sex on odontoid parameters and their relationships with cervical sagittal alignment in children.

Methods: A total of 155 Chinese children without cervical symptoms were divided into groups by age: 3-12 years (87 participants), 13-18 years (68 participants), and sex: male (91 participants) and female (64 participants). Lateral plain radiographs of the whole spine were analyzed for (1) odontoid parameters: odontoid incidence (OI), odontoid tilt, and C2 slope (C2S); and (2) cervical sagittal parameters: C0-2, C2-3, C2-4, C2-5, C2-6, and C2-7 angles (cervical lordosis [CL]), T1 slope (T1S), and T1S minus CL (T1S-CL).

From medical imaging to 3D printed anatomical models: a low-cost, affordable 3D printing approach.

Objective: To share our experience in creating precise anatomical models using available open-source software.

Methods: An affordable method is presented, where from a DICOM format of a computed tomography, a segmentation of the region of interest is achieved. The image is then processed for surface improvement and the DICOM format is converted to STL.

Contribution of ligaments to intersegmental stability following type II odontoid fracture.

: Management of Anderson and D'Alonzo type II odontoid fractures continues to be controversial despite extensive research and increasing prevalence. To the authors' knowledge, the three odontoid ligaments, the alar ligament, the vertical portion of the cruciate ligament, and the transverse ligament, have not been biomechanically examined in type II odontoid fracture in spite of their potential significance in management. Therefore, this study aims to explore the intersegmental rotations of the craniovertebral junction following Anderson and D'Alonzo type II odontoid fracture and various combinations of ligament ruptures.

The epidemiology of odontoid fractures: a study from the Swedish fracture register.

Purpose: The objective of this study is to characterize the occurrence of odontoid fractures within a Swedish population.

Methods: Prospective data of adults diagnosed with an odontoid fracture between 2015 and 2021 were retrieved from the Swedish Fracture Register (SFR). Epidemiologic data including age, sex, injury mechanism, injury type, fracture type (Anderson and D'Alonzo classification), neurological status and treatment type were requested from the SFR.

Augmented Reality in Spine Surgery: A Case Study of Atlantoaxial Instrumentation in Os Odontoideum.

Despite advancement in surgical innovation, C1-C2 fixation remains challenging due to risks of screw malposition and vertebral artery (VA) injuries. Traditional image-based navigation, while useful, often demands that surgeons frequently shift their attention to external monitors, potentially causing distractions. In this article, we introduce a microscope-based augmented reality (AR) navigation system that projects both anatomical information and real-time navigation images directly onto the surgical field.

Clinical Outcomes Following Operative and Nonoperative Management of Odontoid Fractures Among Elderly Individuals with Dementia.

Background: The incidence of odontoid fractures among the elderly population has been increasing in recent years. Elderly individuals with dementia may be at increased risk for inferior outcomes following such fractures. Although surgical intervention has been maintained to optimize survival and recovery, it is unclear if this benefit extends to patients with dementia.

Is It Meaningful and Necessary to Avoid the Seventh Cervical Vertebra in Long Level Cervical Fusion?

Aim: To compare the clinical and radiological results of patients who underwent multilevel posterior cervical fusion (PCF) with different end levels (C6 or C7).

Material And Methods: We collected radiographs and clinical results of all subjects who underwent 3 level or more PCF for degenerative disease from May 2012 to December 2020. Based on the location of the end of fusion during surgery, patients were divided into C6 (group 1) and C7 patients (group 2).

A Staged Approach for Surgical Management of Basilar Invagination.

Background And Objectives: Patients with basilar invagination (BI) can be treated with several surgical options, ranging from simple posterior decompression to circumferential decompression and fusion. Here, we aimed at examining the indications and outcomes associated with these surgical strategies to devise a staged algorithm for managing BI.

Methods: We conducted a retrospective cohort study in 2 neurosurgical centers and included patients with a BI, as defined by a position of the dens tip at least 5 mm above the Chamberlain line.

Atlantoaxial dislocation due to Os odontoideum in down syndrome: Literature review and case reports.

Introduction And Importance: Os odontoideum is a rare condition commonly associated with atlantoaxial instability (AAI) and leading to atlantoaxial dislocation. The incidence of Os odontoideum is higher in patients with Down syndrome. Similar to odontoid fractures, atlantoaxial dislocation in patients with Os odontoideum can result in neurological deficits, disability, and even mortality.

An exclusionary screening method based on 3D morphometric features to sort commingled atlases and axes.

In forensic commingled contexts, when the disarticulation occurs uniquely at the atlantoaxial joint, the correct match of atlas and axis may lead to the desirable assembly of the entire body. Notwithstanding the importance of this joint in such scenarios, no study has so far explored three-dimensional (3D) methodologies to match these two adjoining bones. In the present study, we investigated the potential of re-associating atlas and axis through 3D-3D superimposition by testing their articular surfaces congruency in terms of point-to-point distance (Root Mean Square, RMS).