Surgical management of odontoid fractures

Odontoid Fractures: A Review of the Current State of the Art

Odontoid fractures (OFs) represent up to 15% of all cervical fractures encountered and present most commonly amongst elderly patients, typically in the setting of low energy trauma such as falls. The Anderson and D'Alonzo classification and Roy-Camille subtype description are the most clinically noteworthy descriptions of OFs used. Even though most patients will not present with neurological injury, mechanical instability can occur with type II and type III (Anderson and D'Alonzo) fractures, particularly if the transverse ligament of the atlas is ruptured; however, this is very rare. Conservative treatment is usually employed for type I and type III injuries, and to a varying degree for non-displaced type II injuries. Surgical treatment is typically reserved for type II fractures, patients with neurological injury, and in the setting of other associated fractures or ligamentous injury. Anterior screw fixation is a viable option in the setting of a favorable fracture line orientation in type II fractures, whereas posterior C1-C2 screw fixation is an option for any type II or type III fracture presentation. There is evidence that surgery for type II fractures has higher rates of union and lower mortality than nonoperative treatments. While surgical options have increased over the decades and the management of OF has been optimized by considering fracture subtypes and patient factors, there remains a significant morbidity and mortality associated with OFs. The aging population and changing demographics suggest that there will be an ongoing rise in the incidence of OFs. Therefore, the appropriate management of these cases will be essential for ensuring optimization of health care resources and the quality of life of affected patients.

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.

RESULTS

A total of 96 patients in the anterior and 352 patients in the posterior surgery group were included in the unmatched analysis. After propensity score matching 1:1, 96 anterior and 96 posterior cases were included in the matched analysis. Operative times were shorter in the anterior group (92.0 vs. 145.0 minutes, P < 0.001). The need for intraoperative or postoperative transfusions was higher in the posterior group (15% vs. 2.1%; P = 0.002). However, there were no significant differences in complications between groups (P > 0.05). Hospital stay was significantly longer in the posterior group (4.5 days vs. 3.0; P = 0.049). Nonroutine discharge was more frequent in the posterior group (55% vs. 40%, P = 0.030). However, the rate of 30-day readmission, reoperation, and mortality did not differ between groups (P > 0.05). Also, the work relative value units were significantly higher in the anterior group (22.7 vs. 20.6, P < 0.001), indicating higher reimbursement trends for this approach.

CONCLUSIONS

In this matched analysis, the anterior approach for type 2 odontoid fractures was superior to the posterior approach. The anterior approach was associated with significantly shorter operation times, hospital stays, fewer transfusions, nonroutine discharges, and higher reimbursements.

Unintended consequences of using collars with occipital extensions in neck support - Snapshot assessment at the largest tertiary spinal referral centre in the UK

INTRODUCTION

Upper cervical spine fractures are commonplace in the elderly following low energy trauma. These injuries carry high mortality rates, similar to patients sustaining hip fractures. A key aspect affecting clinical outcome is effective management in the first 12 weeks following injury. This study aims to assess the understanding of healthcare staff that may be required to care for such patients.

MATERIALS AND METHODS

A survey was carried out over a single day at the UK's largest Spine Specialist referral centre (Salford Royal Foundation Trust, SRFT) assessing the understanding of healthcare staff of the term, 'Collar with occipital extension', by asking staff to identify the safe position of the neck when looking at clinical images of a model in a collar in various different neck positions. The participants demographics were then taken, including profession, grade, spinal/post graduate experience, if English is their first language and their understanding of the term 'Collar with occipital extension'.

RESULTS

102 participants were interviewed and the results showed almost half (45.1%) of participants selecting an incorrect hyperextended neck to be a safe position for conservative treatment and only 37.3% selecting the neutral position as satisfactory. The only positive predictors identified for those selective the neutral safe cervical spine alignment was if participants had >5 years of previous spinal experience (p = 0.0006) or if they understood the term 'Collar with occipital extension' to be describing the collar component (p = 0.000013) and not neck position.

CONCLUSION

Management of spinal injuries are classically poorly managed in non-spinal centres, possibly due to the lack of training and understanding within the spinal speciality. This study shows the importance of clearly communicating with referring hospitals exactly how to conservatively manage patients with high cervical injuries to best improve clinical outcome.

Age-Based Incidence of Dens Fracture Has Unimodal Distribution Rather Than Commonly Claimed Bimodal Distribution

Background

Type-II dens fractures have long been described in the literature as occurring in a bimodal distribution, peaking in young adulthood as well as in older adulthood; however, the origin of this claim is unclear. The primary goal of this study was to examine the incidence of type-II dens fractures and assess for bimodality.

Methods

This is a retrospective cross-sectional review of the National Trauma Data Bank (NTDB) records on traumatic type-II dens fractures between October 2015 and December 2016. Rates were obtained from the NTDB, and the incidence per 100,000 was ascertained by utilizing U.S. Census data from 2016. Subgroupings by gender and Black or White race were also examined.

Results

Dens fractures occur unimodally, peaking around 89 years of age overall, skewed left by high rates in older White adults. The Black subgroup demonstrated trimodality, with the fracture incidence peaking at 25, 62, and 82 years of age. Rates among Black and White patients were similar until age 65, after which dens fractures occurred disproportionately in White patients. Fractures prior to age 75 occurred predominantly in men.

Conclusions

The evidence derived in this study challenges the common belief that type-II dens fractures occur bimodally across the entire population. However, there remains utility in considering younger and older patients as distinct groups for the purposes of management.

Morbidity and mortality related to type II odontoid fractures in octogenarians undergoing surgery: a retrospective study with 5 year follow up

Introduction

The prevalence of trauma is increasing in the geriatric population. The optimal therapy for type II odontoid fractures in the elderly is controversial. This study aims to assess the morbidity and mortality associated with odontoid fractures in octogenarians undergoing C1/C2 posterior screw fixation and describe the perioperative and post-operative complications and risk factors associated with mortality.

Materials and methods

Electronic medical records from a single institution pertaining to the period between September 2005 and December 2020 were retrieved. Data on patient demographics, neurological conditions, surgical characteristics, complications, hospital course, and 90-day mortality were collected.

Results

Over a 16-year period, 60 patients aged ≥80 years diagnosed with type II odontoid fractures were enrolled in the study. The mean age was 85.0 ± 1.9 years. The mean Charlson Comorbidity Index (CCI) was >6 indicating a poor baseline reserve (8.5 ± 1.9), while cardiovascular diseases were the most prevalent among comorbidities. The mean surgical duration was 217.5 ± 65.9 min, with a mean blood loss of 725.5 ± 275.7 mL. The in-hospital was 5-0% and the 90-day mortality rates increased at 10.0%. No revision surgery was needed in any of the cases. Intraoperative and post-operative X-ray and computed tomography (CT) imaging revealed correct screw placement. Proper alignment of the atlantoaxial spine and fusion could be achieved in all cases. The unique risk factors for mortality included the presence of comorbidities and the occurrence of post-operative complications.

Conclusion

The complication and mortality rates associated with odontoid fractures in octogenarians are relatively high. However, the therapeutic goals in this population also include bone union and preservation of neurological status. Despite the often-high comorbidity rate, we still recommend that surgery should be considered in patients over 80 years. However, it is necessary to evaluate several approaches when treating such frail patients.

Surgical Management of Type II Displaced Dens Fractures Improves One-year Mortality in Elderly Patients

STUDY DESIGN

Retrospective cross-sectional analysis of US national data collected by PearlDiver Inc. database.

OBJECTIVE

To determine the rates of surgical/nonsurgical treatments and associated one-year mortality for displaced type II dens fractures without neurological deficit.

SUMMARY OF BACKGROUND DATA

Existing literature on dens fractures includes small series of patients with highly variable surgical rates. These studies contain insufficient data to determine the benefits of surgical or nonsurgical treatment as surgeon bias in treatment and selection of patients have significant effects on the results.

MATERIALS AND METHODS

Displaced type II dens fractures and upper cervical surgeries were identified using their respective International Classification of Diseases, 10th Revision (ICD-10) diagnosis and Current Procedural Terminology (CPT) codes. Inclusion criteria included patients older than 65, diagnosed with a displaced type II dens fracture, absent neurological damage, during the years 2015 to 2018. Age, sex, ICD-10 diagnosis codes, CPT codes, displacement type, and Elixhauser Comorbidity Index scores were obtained through the PearlDiver database. Patient-related variables and one-year mortality associated with surgical versus nonsurgical treatment were compared using univariate χ 2 analysis, odds ratios, and multivariate logistic regression analysis.

RESULTS

Among the 5300 patients who met our inclusion criteria, 59% (n=3108) were female, the mean age was 76.6 (±3.9) years old, and the average Elixhauser Comorbidity Index was 7.1 (±4.0). Only 8.3% (n=437) had surgical treatment for the displaced dens fracture. Multivariate logistic regression analysis for one-year mortality showed surgery was associated with decreased one-year mortality in all patients ( z =-6.26; P <0.001), patients between the ages of 65 and 74 ( z =-2.53; P =0.012), and patients over the age of 75 ( z =-5.81; P <0.001).

CONCLUSION

Despite surgery improving survival in elderly patients with type II dens fractures, surgical management is rarely pursued. Factors that independently increase the likelihood of surgery include younger age, male sex, and posterior displacement.

LEVEL OF EVIDENCE

4.

Reevaluation of a classification system: stable and unstable odontoid fractures in geriatric patients-a radiological outcome measurement

Objectives

We carried out a retrospective cohort study to differentiate geriatric odontoid fractures into stable and unstable and correlated it with fracture fusion rates. Results are based on the literature and on our own experience. The authors propose that the simple Anderson and D’Alonzo classification may not be sufficient for geriatric patients.

Methods

There were 89 patients ≥ 65 years who presented at our institution with type II and III odontoid fractures from 2003 until 2017 and were included in this study. Each patient was categorized with CT scans to evaluate the type of fracture, fracture gap (mm), fracture angulation (°), fracture displacement (mm) and direction (ventral, dorsal). Fractures were categorized as stable [SF] or unstable [UF] distinguished by the parameters of its angulation (< / > 11°) and displacement (< / > 5 mm) with a follow-up time of 6 months.

SFs were treated with a semi-rigid immobilization for 6 weeks, UFs surgically—preferably with a C1–C2 posterior fusion.

Results

The classification into SFs and UFs was significant for its angulation (P = 0.0006) and displacement (P < 0.0001). SF group (n = 57): A primary stable union was observed in 35, a stable non-union in 10, and an unstable non-union in 8 patients of which 4 were treated with a C1/2 fixation. The overall consolidation rate was 79%. UF group (n = 32): A posterior C1–C2 fusion was carried out in 23 patients, a C0 onto C4 stabilization in 7 and an anterior odontoid screw fixation in 2. The union rate was 100%. Twenty-one type II SFs (91%) consolidated with a nonoperative management (P < 0.001). A primary non-union occurred more often in type II than in type III fractures (P = 0.0023). There was no significant difference in the 30-day overall case fatality (P = 0.3786).

Conclusion

To separate dens fractures into SFs and UFs is feasible. For SFs, semi-rigid immobilization provides a high consolidation rate. Stable non-unions are acceptable, and the authors suggest a posterior transarticular C1–C2 fixation as the preferred surgical treatment for UFs.

Level of evidence

Level III.

Short-term posterior C1-C2 pedicle screw fixation without fusion to treat type II odontoid fracture among people under 60 years

INTRODUCTION

Posterior C1-C2 pedicle screw fixation is a reliable technique used in treatment of type II odontoid fracture. However, the loss of cervical range of rotation motion (RORM) was inevitable. There were few studies focusing on the influence of short-term C1-C2 fixation with nonfusion technique to preserve cervical function in patients younger than 60 years. The purpose of this study was to compare cervical RORM which was measured by an improved goniometer, and the clinical outcomes between short-term and long-term C1-C2 fixation techniques in the treatment of Grauer type 2B and 2C odontoid fracture.

MATERIALS AND METHODS

This study represents a retrospective analysis, including patients who underwent primary C1-C2 fixation surgery. These patients were divided into short-term and long-term groups based on whether underwent a fixation removal operation. The clinical results were collected and compared between the two groups. Independent T test and Chi-square analyses were used to identify significant differences between the two groups and dependent T test was used within each group. Statistical significance was set at p < .05.

RESULTS

There were no severe postoperative complications, and all 60 patients achieved spinal stabilization after primary surgery. The mean rotation angle in the short-term group at last follow-up time was 138.39 ± 21.06°, which was better than 83.59 ± 13.06° in the long-term group (p < .05). The same statistical difference was observed in flexion-extension angle, which was 71.11 ± 18.73° in short-term group and 53.34 ± 18.23° in long-term group. The mean NDI score in short-term group at last follow-up time was 1.23 ± 0.86 and better than 8.24 ± 3.17 in long-term group. However, the VAS score in short-term group was 1.82 ± 0.54 which was worse compared to 0.64 ± 0.29 in long-term group.

CONCLUSIONS

The results demonstrated that primary C1-C2 fixation with nonfusion technique could support satisfactory clinical effects. In addition, the removal of instruments after bony fusion could improve the function of cervical movement significantly in patients under 60 years.

Cervical spine trauma: impact of different imaging classification systems in the clinical decision-making

Background and aim:

Considering the high rate of mortality and permanent disability related to vertebral traumas, an early and detailed diagnosis of the trauma and subsequently an immediate and effective intervention are crucial. Cervical vertebral injury classifications guide treatment choice through a severity grade based on radiological information. The purpose of the present study was to define which imaging classification system could provide the best morphological and clinical-surgical correlations for cervical spine traumas.

Methods:

We retrospectively analyzed patients evaluated for cervical spine trauma at our Institution in the period 2015-2020. Information regarding the morphological examination (using CT and MRI), the neurological evaluation, and the therapeutic management were collected. C3-C7 fractures were classified according to the SLIC and AOSpine criteria; axial lesions were classified according to the modified AOSpine for the C1-C2 compartment and through the Roy-Camille and the Anderson D’Alonzo system for the odontoid process of the axis.

Results:

29 patients were included in the final study population. Nine patients with axial spine trauma and 21 with subaxial cervical spine trauma. A conservative approach was applied in 16 patients while nine patients underwent neurosurgery. Considering the therapeutical indications provided by the SLIC system, a 76.9% accordance was found for patients with a <4 score, while a 100% concordance was calculated for patients with a >4 score undergoing neurosurgery. Regarding the AOSspine classification, a 28.6% concordance was observed for patients classified group B being treated with a posterior neurosurgical approach, while for patients belonging to subgroup C, considered for anterior neurosurgical approach, a 66.7% accordance was calculated.

Conclusions:

The study demonstrated a better morphological correlation for the AOSpine classification in subaxial trauma and the AOSpine and Anderson D’Alonzo in axial trauma. The therapeutic indication found a better correlation in the SLIC classification for subaxial trauma and the Anderson D’Alonzo for axial ones. (www.actabiomedica.it)

A Technique for the In Vivo Study of Three-dimensional Cervical Segmental Motion Characteristics After Anterior Screw Fixation for Odontoid Process Fractures

STUDY DESIGN

Kinematics of the cervical spine was investigated using cone beam computed tomography (CBCT) images combined with three dimensions to three dimensions (3D-3D) registration technology in patients after anterior odontoid screw fixation (AOSF) surgery.

OBJECTIVE

The aim of this study was to investigate in vivo 3D cervical motion characteristics of patients who had undergone AOSF surgeries.

SUMMARY OF BACKGROUND DATA

AOSF surgery is a classic surgical method for the treatment of odontoid fracture, but there are few studies that investigated its effect on in vivo biomechanics of the cervical spine. Postoperative biomechanical characters of the atlantoaxial joint (C1-C2) and the caudal adjacent segment (C2-C3) have yet to be clarified.

METHODS

The study involved 14 patients subjected to a procedure of AOSF with lag screw. Subjects were matched with 14 healthy controls. All subjects underwent CBCT scanning of the cervical spine under seven functional positions. A 3D-3D registration was performed for each vertebra at each functional position to calculate the segmental motion characteristics. The ranges of motion (ROMs) of the C1-C2, C2-C3, and the overall cervical spine (C1-C7) for each of the functional positions were determined.

RESULTS

The ROMs of the AOSF group were significantly (P < 0.05) smaller than the control group in flexion-extension positions for the C1-C2 (7.0°vs.11.0°), C2-C3 (3.7°vs.6.7°) and C1-C7 (43.3°vs.54.4°). The twisting ROM of the C1-C2 was 39.3° in the AOSF group and 65.7° in the control (P < 0.05), the bending ROM of the C2-C3 was 2.8° in the AOSF group and 8.9° in the control (P < 0.05). The twisting ROM of C1-C7 segment was 63.2° for the AOSF and 98.1° for the healthy control groups (P < 0.05).

CONCLUSION

Although AOSF surgery reduced the flexion-extension ROMs of all investigated spinal segments, additionally, it reduced twisting ROMs of C1-C2 and C1-C7, but only lateral bending ROM of C2-C3, when compared with the control group. The data implied that the AOSF surgery would result in different biomechanics changes in the atlantoaxial segment and caudal adjacent segment. Longer-term follow-up studies of larger patient cohorts are necessary to evaluate the clinical outcomes of patients after the AOSF surgery.Level of Evidence: 3.

The incidence of odontoid fractures following trauma in a major trauma center, a retrospective study

Background:

Cervical spine injury is the most common vertebral injury after major trauma, 20% of all cervical fractures happen to be odontoid fractures. In young adults, odontoid fracture usually happens as a result of high-energy trauma after a motor vehicle accident (MVA). MVA in Riyadh represents 38.4% of all trauma cases, in which the head-and-neck are the most injured body parts. This research aims to provide information about the incidence of odontoid process fracture post-MVA in Riyadh, Saudi Arabia.

Methods:

The design of this study was retrospective. A single level one trauma center database (trauma registry) was used to identify odontoid fractures post-MVA. All trauma cases from 2008 to the most recent were included, a total of 17,047 patients, to identify cervical spine fractures and further identify odontoid fracture incidence. The patients' radiographs were reviewed retrospectively, and odontoid fractures were classified by a board-certified spine surgeon. A descriptive analysis was carried out to report basic data distribution. Pearson's correlation was carried out to assess associations.

Results:

A total number of cervical spine fracture was 1195 patients (6.6% of the total sample). The incidence of odontoid fractures during the entire study period from 2008 to 2018 was 42 of 480 patients with C2 cervical trauma, constituting 8.75% C2 fractures, and 3.5% of cervical spine fractures. The mean age was 41.75 ± 18 years. There were three patients (onemale, two females) with type I odontoid fracture, 26 (all males) with type II, and 13 (11 males, 2 females) with type III. Most patients were managed conservatively (83.33%), whereas 16.67% underwent surgical management.

Conclusion:

The incidence of posttraumatic odontoid fractures is low, given the younger population of this study. This does not predict future incidence rates with the continued improvement of road traffic laws and awareness in the population.

Traumatic Anterior Atlantoaxial Rotatory Subluxation (Type III) Associated with Type III Odontoid Fracture: A Case Report

CASE

A 47-year-old man presented with traumatic anterior atlantoaxial subluxation (type III) associated with type III odontoid fracture with no neurological deficit. He was managed surgically with posterior reduction and C1-C2 fixation and fusion. The association of anterior atlantoaxial rotatory subluxation (Fielding type III) with odontoid fracture (Anderson and D'Alonzo type III) is rare with only 7 reported cases in recent literature.

CONCLUSIONS

This report adds important information regarding the management and presentation of such an injury and also describes a serious complication associated with type III odontoid fractures, which was managed conservatively.

Fusion rates for odontoid fractures after treatment by anterior odontoid screw versus posterior C1-C2 arthrodesis: a meta-analysis

OBJECTIVE

For odontoid fractures, surgical treatment approaches including anterior odontoid screw fixation approach and the posterior C1-C2 arthrodesis approach are generally adopted in practice. However, the choice of different surgical procedures remains controversial. In addition to surgical technique, the fusion rate is an important factor contributing to the clinical efficacy. Therefore, this study was aimed to investigate the discrepancy in fusion rate between these two surgical approaches through synthesizing the currently available evidence on the topic.

METHODS

A computerized search of Ovid, Medline, Embase, and the Cochrane library up to December 2017 for literature on the complication rate during odontoid fracture treatment was conducted. Risk ratio (RR) with its 95% confidence interval (CI) was pooled to assess fusion rates after surgical treatments, including anterior odontoid screw fixation approach or posterior C1-2 arthrodesis procedure, for patients with odontoid fractures.

RESULTS

Thirteen studies were enrolled in the meta-analysis. Results show that no significant difference was found in the overall fusion rate (RR = 0.96, 95% CI 0.90-1.01). There was no significant heterogeneity among the studies (p value = 0.60). As to age- and economic-level subgroups, there was no statistical evidence to suggest an association of the patient age and economy development level with the choice of surgical approach. However, it is shown that better fusion rates of patients (≥ 60 years) in developed countries received a better fusion rates after posterior fixation compared with anterior group using the fixed-effect model (RR = 0.88, 95% CI 0.79-0.98).

CONCLUSION

Elderly patients (≥ 60 years) underwent posterior C1-2 arthrodesis fixation shows higher fusion rates in developed countries comparing with patients who underwent anterior odontoid screw fixation. Overall, there is no significant discrepancy between these two surgical approaches. However, the conclusion should be verified by further study enrolling larger sample size.

Performing the screw fixation from C3 to odontoid process in a patient with Klippel-Feil syndrome and type II odontoid fracture

A 56-year-old female patient was admitted with a history of pain during neck movements after cervical injury. Computerized tomography scan revealed type II odontoid fracture and fusion anomaly between C2 and C3 vertebrae. At surgery, the anteroinferior part of C2 vertebra corpus could not be reached; therefore, transodontoid screw was advanced from C3 vertebra toward odontoid process. At follow-up examination, the complaints of the patient had recovered, and fracture line was completely fused. Advancing screw from C3 to odontoid process via anterior cervical approach could be thought an alternative treatment option in the patient with short neck caused from vertebra fusion anomaly and/or obesity.

Incorporating ligament laxity in a finite element model for the upper cervical spine

BACKGROUND CONTEXT

Predicting physiological range of motion (ROM) using a finite element (FE) model of the upper cervical spine requires the incorporation of ligament laxity. The effect of ligament laxity can be observed only on a macro level of joint motion and is lost once ligaments have been dissected and preconditioned for experimental testing. As a result, although ligament laxity values are recognized to exist, specific values are not directly available in the literature for use in FE models.

PURPOSE

The purpose of the current study is to propose an optimization process that can be used to determine a set of ligament laxity values for upper cervical spine FE models. Furthermore, an FE model that includes ligament laxity is applied, and the resulting ROM values are compared with experimental data for physiological ROM, as well as experimental data for the increase in ROM when a Type II odontoid fracture is introduced.

DESIGN/SETTING

The upper cervical spine FE model was adapted from a 50th percentile male full-body model developed with the Global Human Body Models Consortium (GHBMC). FE modeling was performed in LS-DYNA and LS-OPT (Livermore Software Technology Group) was used for ligament laxity optimization.

METHODS

Ordinate-based curve matching was used to minimize the mean squared error (MSE) between computed load-rotation curves and experimental load-rotation curves under flexion, extension, and axial rotation with pure moment loads from 0 to 3.5 Nm. Lateral bending was excluded from the optimization because the upper cervical spine was considered to be primarily responsible for flexion, extension, and axial rotation. Based on recommendations from the literature, four varying inputs representing laxity in select ligaments were optimized to minimize the MSE. Funding was provided by the Natural Sciences and Engineering Research Council of Canada as well as GHMBC. The present study was funded by the Natural Sciences and Engineering Research Council of Canada to support the work of one graduate student. There are no conflicts of interest to be reported.

RESULTS

The MSE was reduced to 0.28 in the FE model with optimized ligament laxity compared with an MSE 0f 4.16 in the FE model without laxity. In all load cases, incorporating ligament laxity improved the agreement between the ROM of the FE model and the ROM of the experimental data. The ROM for axial rotation and extension was within one standard deviation of the experimental data. The ROM for flexion and lateral bending was outside one standard deviation of the experimental data, but a compromise was required to use one set of ligament laxity values to achieve a best fit to all load cases. Atlanto-occipital motion was compared as a ratio to overall ROM, and only in extension did the inclusion of ligament laxity not improve the agreement. After a Type II odontoid fracture was incorporated into the model, the increase in ROM was consistent with experimental data from the literature.

CONCLUSIONS

The optimization approach used in this study provided values for ligament laxities that, when incorporated into the FE model, generally improved the ROM response when compared with experimental data. Successfully modeling a Type II odontoid fracture showcased the robustness of the FE model, which can now be used in future biomechanics studies.

Clinical Results of Odontoid Fractures according to a Modified, Treatment-Oriented Classification

OBJECTIVE

Odontoid fracture is common in cervical injury, representing about 20% of total cervical fractures. Classic odontoid fracture classification focused on anatomy of fracture site has no treatment recommendation and a modified treatment-oriented classification of odontoid fracture was suggested in 2005. We reviewed our odontoid fracture patients to assess the feasibility and efficacy of Grauer's classification.

METHODS

Between October 2000 and September 2015, we collected data from patients who came to our institute for odontoid fracture. Demographic data of patients was reviewed, and neck visual analog scale (VAS) score and fusion rate were assessed by reviewing electronic medical records retrospectively.

RESULTS

Sixty-nine patients out of a total of eighty two odontoid fracture patients were reviewed according to Grauer's classification. Neck VAS of all subtypes in odontoid fracture classification were decreased at last follow-up (p=0.001). Overall fusion rate was 88.4% at last follow-up. Concordance rate between Grauer's recommendation and our treatment was 69.9%, especially in type II with the concordance higher than 80%. Complication was minimal representing 7.2%, only in types I and III.

CONCLUSION

In this study, there were statistically significant improvement in all subtypes in terms of neck VAS at the last follow up, especially in types II and III. Grauer's classification appears to be meaningful to decide treatment plan for odontoid fractures, especially type II odontoid fracture.

Is It Feasible to Treat Odontoid Fractures via Primary Posterior Reduction and Fixation without Fusion?

OBJECTIVE

To evaluate results and feasibility of primary posterior reduction and fixation without fusion using C1-C2 screw-rod system for odontoid fractures.

METHODS

This study comprised a consecutive series of 46 patients with odontoid fractures. Posterior reduction and fixation without fusion using the C1-C2 screw-rod system was performed, and instrumentation was not removed. Radiologic outcomes were assessed on follow-up computed tomography or plain radiographs. Visual analog scale of neck pain, American Spinal Injury Association impairment scale, patient satisfaction, neck disability index, and range of motion of flexion extension and rotation of the cervical spine were recorded and analyzed.

RESULTS

Mean follow-up time was 4.1 years (range, 12 months to 8 years). Radiographic evaluation indicated solid fusion of odontoid fractures in all cases and no implant failures. No patient reported severe neck pain at follow-up. Neurologicl evaluation showed there was 1- to 2-grade improvement in patients with neurologic deficit. Of patients, 31 reported acceptable outcomes, and 15 reported good outcomes. Range of motion of rotation of the cervical spine and neck disability index score gradually improved significantly during 1 year of follow-up with no obvious change after that. Rate of neck disability index score improvement was 85%.

CONCLUSIONS

Posterior reduction and fixation without fusion can be successfully performed for healing of odontoid fractures with acceptable results and minimal morbidity.

Posterior Bilateral Intermuscular Approach for Upper Cervical Spine Injuries

OBJECTIVE

To investigate a novel intermuscular surgical approach for posterior upper cervical spine fixation.

METHODS

Twenty-three healthy volunteers underwent magnetic resonance imaging. By using the magnetic resonance imaging scans in transverse view at the level of lower edge of atlas, the distances from the posterior midline to lateral margin of trapezius, to the medial margin of splenius capitis, and to middle line of semispinalis capitis were recorded. The angle between posterior middle line and the line crossing the lateral margin of trapezius and middle point of ipsilateral pedicles. From October 2009 to May 2013, 12 patients with upper cervical spine injuries were operated via the bilateral intermuscular approach. The time required for surgery, blood loss, and pre- and postoperative visual analogue scale scores were analyzed.

RESULTS

The average distance of 0-T was 39.2 ± 7.5 mm, the angle between the approach and posterior middle line was 33.2 ± 8.4°. The surgical time was 78.3 ± 22.5 minutes (45-140 minutes), and the mean intraoperative blood loss was 87.5 ± 44.2 mL (30-200 mL). Preoperative and postoperative visual analogue scale scores were 6.4 ± 0.8 and 1.8 ± 0.7, respectively. The average follow-up time was 19.7 ± 11.5 months (9-48 months).

CONCLUSIONS

The posterior bilateral intermuscular approach for upper cervical spine injuries is a valid alternative for Hangmans' fractures type I, type II, and type Ia according to Levine and Edwards classification as well as atlantoaxial subluxation caused by upper cervical spine trauma.

Anterior retropharyngeal plate screw fixation with bilateral anterior transarticular screws for odontoid fractures ... a new comprehensive technique

INTRODUCTION

A certain group of odontoid fractures (Anderson and D' Alonzo Type-2) are usually offered surgical treatment. Common surgical option is an anterior odontoid screw. Some of the fractures are not suitable for anterior odontoid screw (anterior oblique, displaced distal fragments and those with atlantoaxial instability) and these are usually offered posterior transarticular screws (Magerl's) or posterior atlantoaxial screw rod/plate fixation (Goel-Harms technique). Posterior surgery involves atlantoaxial fixation with an indirect attempt to reduce and fuse the fracture . Posterior surgery has a risk of injury to the vertebral arteries, hemorrhage from the paravertebral venous plexus and the C2 root ganglion.

METHODS

A direct anterior submandibular retropharyangeal approach with open reduction and fixation (ORIF) using a customized variable screw placement (VSP) plate was used to realign and fix the fracture fragments in compression mode under direct vision. Twenty patients of type-II odontoid fractures (unsuitable for anterior odontoid screw) underwent an anterior retropharyngeal approach with anterior variable screw position (VSP) plate and screw fixation and eight amongst them, who had associated atlantoaxial instability underwent additional bilateral anterior transarticular screws.

RESULTS

All patients treated by this technique had 100% fracture site bone union without any implant failure. Longest follow-up has been for 3 years.

CONCLUSION

Anterior retropharyangeal approach allows direct fracture fragment realignment under vision with an opportunity to fix in compression mode using the VSP plate, which ensures early fusion across the type-II odontoid fracture. Any associated instability can be treated by additional bilateral anterior transarticular screws. The approach is simple and safe without any risk to the vertebral arteries and biomechanically appealing.

A comparison of anterior screw fixation and halo immobilisation of type II odontoid fractures in elderly patients at increased risk from anaesthesia

Aims

We performed a retrospective, comparative study of elderly patients with an increased risk from anaesthesia who had undergone either anterior screw fixation (ASF) or halo vest immobilisation (HVI) for a type II odontoid fracture.

Patients and Methods

A total of 80 patients aged 65 years or more who had undergone either ASF or HVI for a type II odontoid fracture between 1988 and 2013 were reviewed. There were 47 women and 33 men with a mean age of 73 (65 to 96; standard deviation 7). All had an American Society of Anesthesiologists score of 2 or more.

Results

Patients who underwent ASF had a significantly better outcome than those who were treated by HVI. There was a rate of nonunion of 10% after ASF and 23% after HVI. Failure of reduction or fixation occurred in 11 patients (15%) but there was no significant difference between the two groups. Mortality rates were also similar: 9% (n = 3) after ASF and 8% (n = 4) after HVI.

Conclusion

We conclude that ASF is the preferred method of treatment in this group of elderly patients, having a significantly higher rate of fusion, better clinical outcome and a similar rate of general and treatment-related complications. Cite this article: Bone Joint J 2016;98-B:1222–6.

Morphometric Analysis of Axis and Its Clinical Significance -An Anatomical Study of Indian Human Axis Vertebrae

BACKGROUND

The atlas and axis vertebra have unique shape and complex relationship with vertebral artery. Fracture of dens of axis accounts for 7-27% of all cervical spine fractures, but surgeries in these regions are highly risky because of the reported incidences of vertebral artery injury.

AIM AND OBJECTIVES

The study was designed to measure morphometric data of human axis vertebra, of Indian origin. The different anatomical parameters on dry specimen of human axis vertebrae were established and the results were compared with other studies.

MATERIALS AND METHODS

Thirty intact human axis vertebrae were measured with digital vernier caliper and mini-inclinometer. Various linear and angular parameters of axis were observed.

RESULTS

The mean distance from the midline of body to the tip of transverse process of axis was 29.32 mm on right side and 29.06mm on left side. The mean distance from the midline of body to the lateral most edge of superior articulating facet was 22.8 mm on right side and 22.6 mm on left side. The mean value of anterior and posterior height of axis was 34.33±2.69mm and 30.56±2.78mm respectively. The anterior and posterior height of body of axis was 19.67 mm and 16.67mm respectively. Mean A-P and transverse diameter of inferior surface of axis was 15.42mm and 17.7mm respectively. Mean transverse diameter and mean A-P diameter of odontoid process was 9.32 mm and 10.1 mm respectively. Mean anterior and posterior height of the odontoid process was 14.66 mm and 13.89mm respectively. Mean of dens axis sagittal angle (angle between an axis that was imagined to pass longitudinally through the dens axis and the vertical line on a sagittal plane) was 13.23 degree. The shape of superior articulating facets of C2 varies from oval to circular. In the present study, 84% of SAF were oval and 16% were circular. Inferior articulating facets were circular in shape in 90% cases, and oval in 10% vertebra. Mean pedicle width was 10.07mm on right side and 10.52mm on left side. Mean transverse diameter of vertebral canal was 22.37±1.73mm. Mean of A-P diameter of vertebral canal at inlet was 18.31±2.05mm and mean of A-P diameter of vertebral canal at outlet was 14.84±1.63mm.

CONCLUSION

These results obtained from this study may be helpful for the surgeons in avoiding and minimizing complications such as vertebral artery injury, cranial nerve damage and injury to other vital structures while doing surgery around cranio-vertebral region.

C1-c2 pedicle screw fixation for treatment of old odontoid fractures

Nonunion and C1-C2 instability of odontoid fractures usually result from delayed diagnosis and inappropriate treatment. However, the available treatment options for odontoid fractures remain controversial. The authors evaluated the effectiveness of internal screw fixation via the C1 and C2 pedicle in cases of old odontoid fractures. This retrospective study included 21 patients with old odontoid fractures (13 men and 8 women; mean age, 46.5 years; range, 24-69 years). Internal screw fixation via the C1 and C2 pedicle was performed in all patients. Fracture reduction and C1-C2 fusion were assessed with imaging. The neck pain visual analog scale score and cervical spinal cord functional Japanese Orthopaedic Association score (for those who had cervical spinal cord injury) were used to evaluate the effectiveness of treatment. Postoperative complications were recorded. Postoperative imaging showed that the C1-C2 dislocation was satisfactorily repositioned in all patients. Bone fusion was observed 1 year after surgery in all patients. No loosening or breaking of internal fixation occurred. The preoperative neck pain visual analog scale score was 5.9±1.5 and improved significantly to 1.8±0.8 after surgery (P<.001). The Japanese Orthopaedic Association score in patients with cervical spinal injury (n=14) was 9.2±1.9 and also significantly improved to 13.8±1.9 at the last follow-up examination (P<.001), with an average improvement rate of 61.0%. No iatrogenic vertebral artery injury or severe spinal cord injury occurred. Screw fixation via the C1 and C2 pedicle was found to be an effective and safe surgical approach for the treatment of old odontoid fractures with C1-C2 dislocation or instability.

Noninvasive management of an odontoid process fracture in a toddler: case report

Study Design Case report. Objective Odontoid process fractures represent an uncommon injury in small children, with their optimal management remaining unclear. We present a case of conservatively managed displaced type 2 odontoid process fracture in a small child. Methods We analyzed clinical and radiographic outcomes of a restrained 2-year-old girl involved in a motor vehicle accident who sustained a displaced type 2 odontoid process fracture and was treated conservatively in a semirigid Aspen collar. Results The fracture progressively healed with callus formation evident at 6 weeks. By 12 weeks, the patient was asymptomatic and had regained head control and a full range of movement. Radiographic remodeling of the fracture was seen to improve over the 6-month follow-up. Conclusion This case illustrates that displaced type 2 odontoid process fractures can be successfully managed conservatively in small children.

Neurologic complications of craniovertebral dislocation

Craniovertebral dislocation is uncommon, but its diagnosis is important taking into account the potential severity of the neurologic complications. A number of causes are known; the most common are Down syndrome, rheumatoid arthritis, Paget's disease, other metabolic bone diseases, and craniocervical trauma. Down's syndrome is a relatively common clinical condition but craniovertebral subluxation is only observed in a small percentage of patients. About half of all cervical spine injuries affect the atlanto-occipital region and C2 vertebra. In rheumatoid arthritis, craniocervical dislocation occurs in up to 40% of patients with severe disease. In Paget's disease, involvement of the craniovertebral region occurs in about 30% of all cases. The clinical neurologic syndrome is characterized by local pain, features of upper spinal cord and medullary compression, positive Lhermitte phenomenon, syncope associated with neck flexion, vertebral artery obstruction or dissection leading to stroke, and asymmetrical lower cranial nerve palsies. Neuroimaging is essential to confirm the clinical diagnosis and to categorize severity. The treatment of this disorder is usually surgical, but traction and external immobilization is relevant in some cases. Specific conditions may require additional treatments such as radiotherapy, antibiotics, or chemotherapy.

Treatment modality in type II odontoid fractures defines the outcome in elderly patients

Background

Odontoid fractures account for approximately 20% of all fractures of the cervical spine. They represent the most common cervical spine injury for patients older than 70 years, the majority being type II fractures (65-74%), which are considered to be relatively unstable. The management of these fractures is controversial. Possible treatment options are either conservative or surgical. Surgical procedures include either anterior screw fixation of the odontoid or posterior C1/C2 fusion. The aim of this study was to compare the outcome of the three treatment modalities in elderly patients.

Methods

Between June 2004 and February 2010, all patients older than 65 years (n = 47) with type II fractures of the odontoid according to the Anderson and D’Alonso classification were retrospectively reviewed.

Results

In the non-operatively managed cohort, 11 patients (79%) died postoperatively within a mean period of 23 months. In all other cases (n = 3), radiographs demonstrated non-union. The mean lateral displacement was 1.9 mm (range 0–5,8 mm) and a mean angulation of 29,1° (range 0-55°) was found.

Anterior screw fixation was carried out in 17 patients. The non-union rate in this cohort was 77%. In patients with a posterior C1-C2 fusion, a bony fusion of the posterior elements was found in 15 of 16 cases (93%). Survival rates were significantly higher among the group of patients who were treated with anterior screw fixation or posterior C1/C2 fusion compared to the conservatively treated group.

Conclusion

We found the best clinical results with low rates of non-union as well as low mortality rates following posterior C1/C2 fusion making this our treatment of choice especially in an elderly patient collective.

Upper cervical spine injuries: a management of a series of 70 cases

Traumatic injuries of the upper cervical spine are often encountered, and may be associated to severe neurological outcome. This is a retrospective study of 70 patients, admitted over a 14 years period (1996 to 2010), for management of upper cervical spine injuries. Data concerning epidemiology, radiopathology and treatment was reviewed, and clinical and radiological evaluation was conducted. Men are more affected than women, with traffic accidents being the major traumatic cause. A cervical spine syndrome of varied intensity was found in about 90% of patients; neurological deficit was noted in 10 patients (21%). Radiological analysis discovered varied and many combined lesions: C1-C2 dislocation (7 cases), C2-C3 dislocation (9 cases), C1 fracture (10 cases) and C2 fracture (44 cases) including 28 odontoid fractures. Orthopedic treatment was carried out exclusively for 31 patients, and surgical treatment for 38 patients. One patient died before surgery because of a polytraumatisme. Posterior approach was performed in 29 cases including hooks and rods in 18 patients, wiring in 9 cases, and 2 transarticular screw fixations. In 9 cases anterior approach was performed: 5 odontoid screwing and 4 cases of C2-C3 discectomy with bone graft. Nearly all patients were improved in post-operative. Elsewhere, the operating results were marked by a persistent neurological deficit in 2 cases, and infection in 2 cases controlled by medical treatment. Mean follow-up was 23 months and showed good clinical and radiological improvement. Early management of cervical spine injuries can optimize outcome. Treatment modalities are well codified; however controversy remains especially with type II odontoid fractures.

The three-dimensional morphometry of the odontoid peg and its impact on ventral screw osteosynthesis

Ventral screw osteosynthesis is a common surgical method for treating fractures of the odontoid peg, but there is still no consensus about the number and diameter of the screws to be used. The purpose of this study was to develop a more accurate measurement technique for the morphometry of the odontoid peg (dens axis) and to provide a recommendation for ventral screw osteosynthesis. Images of the cervical spine of 44 Caucasian patients, taken with a 64-line CT scanner, were evaluated using the measuring software MIMICS. All measurements were performed by two independent observers. Intraclass correlation coefficients were used to measure inter-rater variability. The mean length of the odontoid peg was 39.76 mm (SD 2.68). The mean screw entry angle α was 59.45° (SD 3.45). The mean angle between the screw and the ventral border of C2 was 13.18° (SD 2.70), the maximum possible mean converging angle of two screws was 20.35° (SD 3.24). The measurements were obtained at the level of 66% of the total odontoid peg length and showed mean values of 8.36 mm (SD 0.84) for the inner diameter in the sagittal plane and 7.35 mm (SD 0.97) in the coronal plane. The mean outer diameter of the odontoid peg was 12.88 mm (SD 0.91) in the sagittal plane and 11.77 mm (SD 1.09) in the coronal plane. The results measured at the level of 90% of the total odontoid peg length were a mean of 6.12 mm (SD 1.14) for the sagittal inner diameter and 5.50 mm (SD 1.05) for the coronal inner diameter. The mean outer diameter of the odontoid peg was 11.10 mm (SD 1.0) in the sagittal plane and 10.00 mm (SD 1.07) in the coronal plane. In order to calculate the necessary screw length using 3.5 mm cannulated screws, 1.5 mm should be added to the measured odontoid peg length when anatomical reduction seems possible. The cross-section of the odontoid peg is not circular but slightly elliptical, with a 10% greater diameter in the sagittal plane. In the majority of cases (70.5%) the odontoid peg offers enough room for two 3.5 mm cannulated cortical screws.

Morbidity and mortality of C2 fractures in the elderly: surgery and conservative treatment

BACKGROUND

Closed C2 fractures commonly occur after falls or other trauma in the elderly and are associated with significant morbidity and mortality. Controversy exists as to best treatment practices for these patients.

OBJECTIVE

To compare outcomes for elderly patients with closed C2 fractures by treatment modality.

METHODS

We retrospectively reviewed 28 surgically and 28 nonsurgically treated cases of closed C2 fractures without spinal cord injury in patients aged 65 years of age or older treated at Stanford Hospital between January 2000 and July 2010. Comorbidities, fracture characteristics, and treatment details were recorded; primary outcomes were 30-day mortality and complication rates; secondary outcomes were length of hospital stay and long-term survival.

RESULTS

Surgically treated patients tended to have more severe fractures with larger displacement. Charlson comorbidity scores were similar in both groups. Thirty-day mortality was 3.6% in the surgical group and 7.1% in the nonsurgical group, and the 30-day complication rates were 17.9% and 25.0%, respectively; these differences were not statistically significant. Surgical patients had significantly longer lengths of hospital stay than nonsurgical patients (11.8 days vs 4.4 days). Long-term median survival was not significantly different between groups.

CONCLUSION

The 30-day mortality and complication rates in surgically and nonsurgically treated patients were comparable. Elderly patients faced relatively high morbidity and mortality regardless of treatment modality; thus, age alone does not appear to be a contraindication to surgical fixation of C2 fractures.

Surgical vs nonoperative treatment of Hadley type IIA odontoid fractures

BACKGROUND

Type II odontoid fractures with additional chip fragments are rare in clinical practice, accounting for < 10% of all odontoid fractures. Hadley et al were the first to describe these fractures as an individual subtype (IIA).

OBJECTIVE

To analyze the outcome of patients after surgical or nonoperative treatment of Hadley type IIA odontoid fractures.

METHODS

We analyzed the records of 46 patients at an average of 64 years of age at the time of injury. Twenty-five patients underwent surgical stabilization by anterior screw fixation and were entered into study group A; 21 patients were treated nonoperatively by halo vest immobilization and included in study group B.

RESULTS

Thirty-seven patients (84%) returned to their preinjury activity level and were satisfied with their treatment. Using the Cervical Spine Outcomes Questionnaire to quantify the clinical outcome, we had an overall outcome score of 21.8. We did not find a significant difference in the overall clinical outcome between study groups. Bony fusion was achieved in 35 patients (80%). We had a nonunion rate of 13% after anterior screw fixation and a significantly higher rate of 30% after halo vest immobilization. Failure of reduction or fixation occurred in 12 patients (27%), with a significantly higher failure rate after halo vest immobilization.

CONCLUSION

Hadley type IIA odontoid fractures are inherently unstable and impede proper realignment. These fractures have a significantly increased risk for secondary loss of reduction and bony nonunion, particularly after nonoperative management. Early surgery should be considered to avoid further complications.

Nonoperative treatment of displaced type II odontoid peg fractures with a Philadelphia collar

Although a consensus exists on the nonoperative management of types I and III odontoid peg fractures, treatment of type II fractures remains controversial. An increasing trend exists toward primary fixation of type II peg fractures due to a high rate of nonunion, especially if the displacement is >4 mm. This article reports the results of nonoperative treatment of patients with displaced odontoid peg fractures (>4 mm) using a Philadelphia collar.A retrospective review of clinical and radiological records was performed for nonoperatively treated patients who sustained displaced type II peg fractures between January 2003 and April 2008. The study group comprised 9 patients (2 men and 7 women), and all patients were treated with Philadelphia collars. Patients were followed up for an average of 24.8 months (range, 8-28 months) for clinical and radiological outcomes. Functional outcomes were measured according to the Smiley-Webster scale. Fractures united uneventfully in 6 patients, but nonunion developed in 3 patients. Average time to union was 12.3±2.94 weeks (95% confidence interval, 9.97-14.68 weeks; range, 10-16 weeks). No patient had clinical or radiological signs of instability or delayed onset myelopathy at follow-up. Three patients had excellent, 4 had good, and 2 had fair results as per the Smiley-Webster functional scoring system.Displaced type II peg fractures can be managed nonoperatively in patients who refuse surgery or those with multiple comorbidities. Adequate patient counseling and compliance with close clinicoradiological follow-up is paramount to avoid adverse clinical events and achieve an optimal functional outcome.

Surgical vs Nonoperative Treatment of Hadley Type IIA Odontoid Fractures

Background:

Type II odontoid fractures with additional chip fragments are rare in clinical practice, accounting for &lt; 10% of all odontoid fractures. Hadley et al were the first to describe these fractures as an individual subtype (IIA).

Objective:

To analyze the outcome of patients after surgical or nonoperative treatment of Hadley type IIA odontoid fractures.

Methods:

We analyzed the records of 46 patients at an average of 64 years of age at the time of injury. Twenty-five patients underwent surgical stabilization by anterior screw fixation and were entered into study group A; 21 patients were treated non-operatively by halo vest immobilization and included in study group B.

Results:

Thirty-seven patients (84%) returned to their preinjury activity level and were satisfied with their treatment. Using the Cervical Spine Outcomes Questionnaire to quantify the clinical outcome, we had an overall outcome score of 21.8. We did not find a significant difference in the overall clinical outcome between study groups. Bony fusion was achieved in 35 patients (80%). We had a nonunion rate of 13% after anterior screw fixation and a significantly higher rate of 30% after halo vest immobilization. Failure of reduction or fixation occurred in 12 patients (27%), with a significantly higher failure rate after halo vest immobilization.

Conclusion:

Hadley type IIA odontoid fractures are inherently unstable and impede proper realignment. These fractures have a significantly increased risk for secondary loss of reduction and bony nonunion, particularly after nonoperative management. Early surgery should be considered to avoid further complications.

Clinical outcomes of halo-vest immobilization and surgical fusion of odontoid fractures

OBJECTIVE

In the present study, authors retrospectively reviewed the clinical outcomes of halo-vest immobilization (HVI) versus surgical fixation in patients with odontoid fracture after either non-surgical treatment (HVI) or with surgical fixation.

METHODS

From April 1997 to December 2008, we treated a total of 60 patients with upper cervical spine injuries. This study included 31 (51.7%) patients (22 men, 9 women; mean age, 39.3 years) with types II and III odontoid process fractures. The average follow-up was 25.1 months. We reviewed digital radiographs and analyzed images according to type of injury and treatment outcomes, following conservative treatment with HVI and surgical management with screw fixation.

RESULTS

There were a total of 31 cases of types II and III odontoid process fractures (21 odontoid type II fractures, 10 type III fractures). Fifteen patients underwent HVI (10 type II fractures, 5 type III fractures). Nine (60%) out of 15 patients who underwent HVI experienced successful healing of odontoid fractures. The mean period for bone healing was 20.2 weeks. Sixteen patients underwent surgery including anterior screw fixation (6 cases), posterior C1-2 screw fixation (8), and transarticular screw fixation (2) for healing the odontoid fractures (11 type II fractures, 5 type III fractures). Fifteen (93.8%) out of 16 patients who underwent surgery achieved healing of cervical fractures. The average bone healing time was 17.6 weeks.

CONCLUSION

The overall healing rate was 60% after HVI and 93.8% with surgical management. Patients treated with surgery showed a higher fusion rate and shorter bony healing time than patients who received HVI. However, prospective studies are needed in the future to define better optimal treatment and cost-effective perspective for the treatment of odontoid fractures.

Optimal use of the halo-vest orthosis for upper cervical spine injuries

PURPOSE

Upper cervical fractures can heal with conservative treatments such as halo-vest immobilization (HVI) and Minerva jackets without surgery. The most rigid of these, HVI, remains the most frequently used treatment in many centers despite its relatively high frequency of orthosis-related complications. We conducted this study to investigate the clinical outcome, effectiveness, patient satisfaction, and associated complications of HVI.

MATERIALS AND METHODS

From April 1997 to December 2008, we treated 23 patients for upper cervical spinal injuries with HVI. For analysis, we divided high cervical fractures into four groups, including C1 fracture, C2 dens fracture, C2 hangman's fracture, and C1-2 associated fracture. We evaluated the clinical outcome, complications, and patient satisfaction through chart reviews and a telephone questionnaire.

RESULTS

The healing rate for upper cervical fracture using HVI was 60.9%. In most cases, bony healing occurred within 16 weeks. Older patients required longer fusion time. We observed a 39.1% failure rate, and 60.9% of patients experienced complications. The most common complications were frequent pin loosening (34.8%; 8/23) and pin site infection (17.4%; 4/23). The HVI treatment failed in 66.7% of patients with pin site problems. The patient approval rate was 31.6%.

CONCLUSION

The HVI produced frequent complications and low patient satisfaction. Bony fusion succeeded in 60.9% of patients. Pin site complications showed a tendency to influence the outcome of HVI, and would be promptly addressed to prevent treatment failure if they develop. The decision to use HVI requires an explanation to the patient of potential complications and constant vigilance to prevent such complications and unsatisfactory outcomes.

Odontoid plate fixation without C1-C2 arthrodesis: biomechanical testing of a novel surgical technique and comparison to the conventional screw fixation procedure

BACKGROUND

Odontoid plate fixation without C1-C2 arthrodesis appears to be a practicable option for the management of odontoid fractures that are not amenable for conventional screw fixation. The purpose of this study was to measure the mechanical stability of odontoid plate fixation using a specially designed plate construct, and to compare the results to those after conventional screw fixation.

METHODS

The second cervical vertebra was removed from twenty fresh human spinal columns. Stiffness and failure load of the intact odontoid were measured, and type II odontoid fractures were created. Afterward, the specimens were randomly assigned to one of the following four groups: Group I: plate-fixation; Group II: 2-AO-screw-fixation; Group III: 1-AO-screw-fixation; Group IV: Herbert-screw-fixation. In a second series, stiffness and failure load of the stabilized odontoid fractures were assessed for comparison and statistical analysis.

FINDINGS

Group I showed a significantly higher mean failure load than the other groups. The mean failure load of Group I after fixation of the odontoid fracture was 86% of the mean failure load of the intact odontoid. Comparing Groups II, III and IV, there was no significant difference regarding the failure load. In these three groups the mean failure load after odontoid fixation was approximately 50% of the mean failure load of the intact odontoid.

INTERPRETATION

Odontoid plate fixation as an alternative procedure in certain fracture patterns provided a significantly higher biomechanical stability than the technique of odontoid screw fixation. Using a specially designed plate construct, 86% of the original stability of the intact odontoid was restored.

Methodological systematic review: mortality in elderly patients with cervical spine injury: a critical appraisal of the reporting of baseline characteristics, follow-up, cause of death, and analysis of risk factors

STUDY DESIGN

Methodologic systematic review.

OBJECTIVE

To determine the validity of reported risk factors for mortality in elderly patients with cervical spine injury.

SUMMARY OF BACKGROUND DATA

In elderly patients with cervical spine injury, mortality has frequently been associated with the type of treatment. To date, however, no review evaluating the validity of reported risk factors for mortality in elderly patients with cervical spine injury has been published.

METHODS

Studies evaluating the treatment of cervical spine injuries in elderly (>/=60 years of age) patients were searched through the Medline and EMBASE databases. In addition to standard methodologic details, reporting of putative confounding baseline characteristics and analysis of risk factors for mortality were appraised critically. For this purpose, patient data presented in included studies were pooled. Exploratory descriptive statistics were used for data analysis.

RESULTS

Twenty-six eligible studies were identified, including a total of 1550 pooled elderly subjects. Except for 2, all studies reported presence or absence of spinal cord injury. Details concerning the severity and/or extent of the injury were reported in 12 (46%) studies. Pre-existing comorbidities were reported in 9 studies (35%). In the pooled subjects, the cause of death was not reported in 155 of 335 deceased patients (42%). Based on own results, 18 (69%) studies reported on risk factors for mortality. Of these studies, 6 (23%) performed statistical analyses of risk factors for mortality outcomes. Only 1 study statistically adjusted potential risk factors for mortality for confounding.

CONCLUSION

Overall, pre-existing comorbidities, concomitant injuries, follow-up and cause of death have been underreported in studies investigating the treatment of cervical spine injuries in elderly patients. To strengthen the validity of risk factors for mortality in future clinical trials, adjustments for appropriately reported putative confounders by regression analysis are mandatory.

The long-term functional outcome of type II odontoid fractures managed non-operatively

Odontoid fractures currently account for 9-15% of all adult cervical spine fractures, with type II fractures accounting for the majority of these injuries. Despite recent advances in internal fixation techniques, the management of type II fractures still remains controversial with advocates still supporting non-rigid immobilization as the definitive treatment of these injuries. At the NSIU, over an 11-year period between 1 July 1996 and 30 June 2006, 66 patients (n = 66) were treated by external immobilization for type II odontoid fractures. The medical records, radiographs and CT scans of all patients identified were reviewed. Clinical follow-up evaluation was performed using the Cervical Spine Outcomes Questionnaire (CSOQ). The objectives of this study were to evaluate the long-term functional outcome of patients suffering isolated type II odontoid fractures managed non-operatively and to correlate patient age and device type with clinical and functional outcome. Of the 66 patients, there were 42 males and 24 females (M:F = 1.75:1) managed non-operatively for type II odontoid fractures. The mean follow-up time was 66 months. Advancing age was highly correlated with poorer long-term functional outcomes when assessing neck pain (r = 0.19, P = 0.1219), shoulder and arm pain (r = 0.41, P = 0.0007), physical symptoms (r = 0.25, P = 0.472), functional disability (r = 0.24, P = 0.0476) and psychological distress (r = 0.41, P = 0.0007). Patients >65 years displayed a higher rate of pseudoarthrosis (21.43 vs. 1.92%) and established non-union (7.14 vs. 0%) than patients <65 years. The non-operative management of type II odontoid fractures is an effective and satisfactory method of treating type II odontoid fractures, particularly those of a stable nature. However, patients of advancing age have been demonstrated to have significantly poorer functional outcomes in the long term. This may be linked to higher rates of non-union.

Plate fixation of odontoid fractures without C1-C2 arthrodesis: practice of a novel surgical technique for stabilization of odontoid fractures, including the opportunity to extend the fixation to C3

OBJECTIVE

Surgical treatment of odontoid fractures that do not allow interfragmentary fracture compression involves either posterior atlantoaxial arthrodesis or additional anterior stabilization using a plate construct. The purpose of this study was to determine the clinical and radiographic outcome after anterior plate fixation of odontoid fractures that were not suitable for anterior screw fixation.

METHODS

We reviewed the clinical and radiographic records of 9 patients with an average age of 54 years at the time of surgery who had undergone anterior plate fixation of an odontoid fracture. Indications for using a plate construct were odontoid fractures with anterior oblique fracture lines, fractures with comminution or major displacement, and pathological fractures.

RESULTS

Eight patients returned to their preinjury activity level and were satisfied with their treatment. One patient reported chronic pain symptoms and a notable decrease in cervical spine motion. Using the Smiley-Webster Scale to quantify their clinical outcome, we achieved an overall outcome score of 1.6. Bony fusion was achieved in all patients. Reduction or fixation failed in 2 patients. Reoperation for technical failures was not necessary in any of the patients.

CONCLUSION

We had promising results using anterior plate fixation for surgical treatment of odontoid fractures that did not allow interfragmentary fracture compression. Because this method avoids the rigid fixation of the atlantoaxial joint in contrast to techniques of posterior cervical arthrodesis, it seems to be a practical option for the management of fracture types that require additional stabilization of the odontoid.

Biomechanics of halo-vest and dens screw fixation for type II odontoid fracture

STUDY DESIGN

An in vitro biomechanical study of halo-vest and odontoid screw fixation of Type II dens fracture.

OBJECTIVE

The objective were to determine upper cervical spine instability due to simulated dens fracture and investigate stability provided by the halo-vest and odontoid screw, applied individually and combined.

SUMMARY OF BACKGROUND DATA

Previous studies have evaluated posterior fixation techniques for stabilizing dens fracture. No previous biomechanical study has investigated the halo-vest and odontoid screw for stabilizing dens fracture.

METHODS

A biofidelic skull-neck-thorax model was used with 5 osteoligamentous whole cervical spine specimens. Three-dimensional flexibility tests were performed on the specimens while intact, following simulated dens fracture, and following application of the halo-vest alone, odontoid screw alone, and halo-vest and screw combined. Average total neutral zone and total ranges of motion at C0/1 and C1/2 were computed for each experimental condition and statistically compared with physiologic motion limits, obtained from the intact flexibility test. Significance was set at P < 0.05 with a trend toward significance at P < 0.1.

RESULTS

Type II dens fracture caused trends toward increased sagittal neutral zone and lateral bending range of motion at C1/2. Spinal motions with the dens screw alone could not be differentiated from physiologic limits. Significant reductions in motion were observed at C0/1 and C1/2 in flexion-extension and axial rotation due to the halo-vest, applied individually or combined with the dens screw. At C1/2, the halo-vest combined with the dens screw generally allowed the smallest average percentages of intact motion: 3% in axial rotation, 17% in flexion-extension, and 18% in lateral bending.

CONCLUSION

The present reduction in C1/2 motion observed, due to the halo-vest and dens screw combined is similar to previously reported immobilization provided by the polyaxial screw/rod system and transarticular screw fixation combined with wiring. The present biomechanical data may be useful to clinicians when choosing an appropriate treatment for those with Type II dens fracture.

Treatment of remote type ii axis fractures in the elderly: feasibility of anterior odontoid screw fixation

OBJECTIVE

This preliminary study considers the feasibility and the results of anterior screw fixation in elderly patients with remote Type II axis fractures. Odontoid fractures are the most common fractures of the cervical spine in people 70 years of age or older. In developing countries, direct anterior fracture fixation is replacing posterior fusion in many cases. Recently, it has been demonstrated that patient age does not influence the outcome in terms of fusion after odontoid screw fixation. There is considerable disagreement about correct treatment in the case of remote fractures. In the literature, there have been no studies considering the feasibility and results of anterior screw fixation in elderly patients with remote Type II axis fractures.

METHODS

From 1989 to 2005, we observed 9 patients over the age of 65 years with isolated Type II remote fractures of the dens. All fractures were considered to be inveterate, as the traumatic events had occurred 6 to 12 months earlier. All fractures were treated with anterior infibulation of the dens with single 3.5-mm cannulated screws.

RESULTS

A bony fusion was radiologically documented in 7 patients (77%) 4 to 16 months after the intervention. In 1 patient, a fibrous union was observed. The neurological status remained unchanged in all patients, and no patients showed any neurological impairment at the time of follow-up.

CONCLUSION

According to our preliminary study, the technique appears to be feasible for remote axis fractures within 12 months of trauma, and it seems to be safe for elderly patients. Further data from additional studies are needed.

Direct transoral manipulation to reduce a displaced odontoid fracture: a technical note

BACKGROUND CONTEXT

Irreducible anteriorly displaced odontoid fractures are usually treated with posterior atlantoaxial fusion.

PURPOSE

To present an alternative for fracture reduction and anterior stabilization for displaced odontoid fractures.

STUDY DESIGN

A technique for reduction of odontoid fractures is reported.

PATIENT SAMPLE

Case study of a single patient with an odontoid fracture.

OUTCOME MEASURES

Only fracture reduction and fracture healing were evaluated.

METHODS

After a failed trial of closed reduction with skeletal traction, a patient with an anteriorly displaced odontoid fracture was taken to the operating room for attempted closed reduction and odontoid screw placement.

RESULTS

Fracture reduction was achieved with routine maneuvers supplemented by posterior translation through direct oropharyngeal pressure with a padded laryngoscope blade.

CONCLUSIONS

Direct transoral reduction of odontoid fractures is safe and feasible and can be used to assist in reduction of anteriorly displaced fractures.

Brain abscess and generalized seizure caused by halo pin intracranial penetration: case report and review of the literature

The objective of our study is to report a rare complication of halo pin insertion associated with an epileptic seizure and brain abscess, and to discuss the diagnostic and therapeutic approach to its management. The treatment of unstable cervical spine injuries with a halo vest is an established procedure. Complications of pin penetration such as brain abscess and seizure are rare, and need to be urgently treated. Intracranial abscess and seizure associated with the use of the halo device is an unusual complication, and only a few cases have been reported in the literature. A 21-year-old male had a halo vest placed for the management of an odontoid type II fracture, which he sustained from a motor vehicle accident. Ten weeks after halo ring placement he complained of headaches which relieved by analgesics. After 2 weeks he was admitted at the emergency unit in an unconscious condition after a generalized tonic-clonic seizure. The halo pins were displaced during the seizure and were removed at his admission. No drainage was noted from the pin sites, and a Philadelphia cervical collar was applied. A brain CT and MRI revealed intracranial penetration of both posterior pins and a brain abscess in the right parietal lobe. Computed tomography of the cervical spine revealed stable fusion of the odontoid fracture. Cultures from the pin sites were negative; however, intravenous wide spectrum antibiotic treatment was administered to the patient immediately for 4 weeks followed by oral antibiotics for additional 2 weeks. Anti-epileptic medication was also started at his admission. The patient was discharged from the hospital in 6 weeks without symptoms, continuing anti-epileptic medication. On the follow-up visits he had fully recovered without any neurologic sequelae. In conclusion, complications of halo pin penetration are rare which need immediate intervention. Any neurologic or infectious, local or generalized, symptom need to be investigated urgently with available imaging techniques and treated promptly. Pin over-tightening may cause bone penetration and possible deep cranial infection with serious complications.

Posterior atlanto-axial arthrodesis for fixation of odontoid nonunions

STUDY DESIGN

A retrospective case series.

OBJECTIVE

To determine the clinical and radiographic long-term results after posterior atlanto-axial arthrodesis of odontoid nonunions.

SUMMARY OF BACKGROUND DATA

Nonunion of odontoid fractures is a relatively common and dreaded complication after surgical and nonoperative treatment of these injuries. Although there might be a significant rate, which require surgical stabilization due to atlanto-axial instability, only few publications have covered this issue and presented reliable long-term results.

METHODS

We retrospectively analyzed the clinical and radiographic records of 9 (4 women and 5 men) patients with an average age of 68 (42-78) years at the time of injury who had undergone posterior atlanto-axial arthrodesis for surgical treatment of odontoid nonunions between 1988 and 2004. For posterior atlanto-axial arthrodesis, we performed either C1-C2 transarticular screw fixation, or posterior wiring and bone grafting, or a combination of these 2 techniques.

RESULTS

Eight patients achieved a satisfactory clinical outcome and returned to their preinjury activity level. The Smiley-Webster scale showed an overall functional outcome score of 2.2, which was 0.9 points superior to the outcome score before surgery. Neurologic deficits after operative treatment of the odontoid nonunion were evaluated in 2 patients. In all the other patients with primary neurologic deficits or delayed neurologic sequelae we saw a full recovery. Solid bony fusion of the cervical arthrodesis was achieved in all of the patients. Failures of reduction or fixation were noted in 2 patients, but no reoperations were necessary.

CONCLUSION

In summary, we had a satisfactory outcome after surgical treatment of odontoid nonunions in patients with atlanto-axial instability and severe motion pain at the cervical spine. With a bony union rate of 100% and a noticeable improvement of clinical results and neurologic function, posterior atlanto-axial arthrodesis seems to be an appropriate option for nonunited odontoid fractures that require surgical stabilization.

Odontoid fractures in the elderly: dorsal C1/C2 fusion is superior to halo-vest immobilization

BACKGROUND

Odontoid fractures in geriatric patients occur frequently and are associated with a high morbidity and mortality. The decision for operative or nonoperative therapy is still controversial. Recent studies confirmed that external stabilization with halo-vest immobilization is associated with high complication rates and mortality. An operation has a high perioperative risk because of comorbidities, but previous data suggest improved outcome in this group.

METHODS

To test this hypothesis, we retrospectively analyzed geriatric patients that underwent operation for isolated unstable type II odontoid fractures (Anderson and D'Alonzo classification) in our institution between March 2003 and March 2005. Twenty-seven patients (17 female, 10 male) with a median age of 85.5 (range, 63-98) years were stabilized by posterior C1/C2 fusion with transarticular screws and an additional modified Gallie fusion with a bone graft. Postoperatively, a rigid cervical collar was applied for 6 to 12 weeks.

RESULTS

Six patients died during the observation period (median, 40 days after trauma). Three patients (11%) died perioperatively (cardiac or pulmonary failure, pneumonia), and the other three died as a result of the same after discharge. All 21 surviving patients were reevaluated an average of 3 months after trauma. All but one showed a stable fusion, and all reported no or minor neck pain. No wound infections occurred; one reoperation was necessary for screw misplacement. An initial neurologic deficit improved in two of three cases. Patients were mobilized on day 1 after operation. About two-thirds of patients were discharged directly home.

CONCLUSIONS

Posterior stabilization of unstable odontoid fractures with transarticular screws and modified Gallie fusion in old patients can be performed safely, with good clinical results and few complications. However, mortality remains high, but is lower than reported after halo-vest immobilization alone. Dorsal C1/C2 Fusion is superior to halo-vest immobilization in terms of nonunion rate and mortality. Thus, it might be the treatment of choice in this high-risk patient population.

Anterior screw fixation of odontoid fractures comparing younger and elderly patients

STUDY DESIGN

A retrospective, comparative study.

SUMMARY OF BACKGROUND DATA AND OBJECTIVES

Anterior screw fixation has become an accomplished treatment option for the management of odontoid fractures. In younger patients, it has shown encouraging results with low complication rates; whereas in geriatric trauma victims, it remains the subject of controversy. The purpose of this study was to determine functional and radiographic results after anterior screw fixation of Type II odontoid fractures, with the particular interest to compare the outcome between younger and elderly patients.

MATERIAL/METHODS

We reviewed clinical and radiographic records of 110 patients with an average age of 54 years at the time of surgery after anterior double screw fixation of their odontoid fractures between 1990 and 2004. To compare functional and radiographic results between nongeriatric and geriatric patients, they were divided by age into 2 groups: Group A included patients 65 years of age or younger and Group B contained patients older than 65 years.

RESULTS

A total of 95 patients had returned to their preinjury activity level and were satisfied with their treatment. The Smiley-Webster scale showed an overall outcome score of 1.42 with similar results in both groups (Group A, 1.34; Group B, 1.50). Bony fusion was achieved in 102 patients, failures of reduction or fixation occurred in 12 patients. Comparing between the 2 groups, we had a nonunion rate of 4% in younger individuals and a significantly higher rate of 12% in geriatric patients. Reoperation due to nonunion or technical failures was necessary in 8 patients.

CONCLUSION

We had encouraging results using anterior screw fixation for surgical treatment of odontoid fractures and favor this method as preferred management strategy for stabilization of these fractures. Comparing between age groups, we had similar results on cervical spine function. With regards to fracture healing as well as morbidity and mortality, younger patients had a superior outcome.

Die subdentale Synchondrose

BACKGROUND

During development of the axis, four different ossification centers are formed. The two cranial ossification centers are demarcated from the ossification center of the vertebral corpus by a subdental synchondrosis. During further development the subdental synchondrosis--which is thought to close spontaneously--might not close completely, which leads to the necessity for differentiating synchondrotic remnants from a fracture at the base of the dens (type II according to Anderson and D'Alonzo).

RESULTS

To characterize the architecture of the axis with particular attention to the subdental synchondrosis, the axis was harvested from 36 age- and gender-matched patients covering the human aging process from adolescence to senescence. In all specimens bone mineral density (BMD) was measured by peripheral quantitative computed tomography (pQCT). Morphological analysis after undecalcified processing of all specimens revealed a persistency of the subdental synchondrosis in 87% of all patients. Histological characterization of the subdental synchondrosis showed a cartilaginous structure interspersed with focal mineralization. Furthermore, static histomorphometric analysis revealed that trabecular bone volume and cortical thickness were significantly reduced within the base of the axis as compared to the dens and the corpus, respectively.

CONCLUSION

Taken together, these results provide evidence that the base of the axis is a structurally distinct region. Besides well-recognized biomechanical aspects, these results suggest that the structure of the base of the axis might contribute to the occurrence of fractures of the axis and offer an additional explanation for the observation of nonunion after type II dens fractures.