Neurologic injury because of trauma after type II odontoid nonunion

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.

Evidence and Controversies in Geriatric Odontoid Fracture Management

Geriatric odontoid fractures are some of the most common spine injuries in our aging population, and their prevalence is only continuing to increase. Despite several investigational studies, treatment remains controversial and there is limited conclusive evidence regarding the management of odontoid fractures. These injuries typically occur in medically complex and frail geriatric patients with poor bone quality, making their treatment particularly challenging. In this article, we review the evidence for conservative management as well as surgical intervention and discuss various treatment strategies. Given the high morbidity and mortality associated with odontoid fractures in the elderly, thoughtful consideration and an emphasis on patient-centered goals of treatment are critical to maximize function in this vulnerable population.

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.

The demographic, clinical, and management differences between traumatic dens fracture patients with and without simultaneous atlas fractures

Introduction

Atlas fractures often accompany traumatic dens fractures, but existing literature on the management of simultaneous atlantoaxial fractures is limited.

Methods

We examined all patients with traumatic dens fractures at our institution between 2008 and 2018. We used multivariable logistic regression and ordinal logistic regression to identify factors independently associated with presentation with a simultaneous atlas fracture, as well myelopathy severity, fracture nonunion, and selection for surgery.

Results

Two hundred and eighty-two patients with traumatic dens fractures without subaxial fractures were identified, including 65 (22.8%) with simultaneous atlas fractures. The distribution of injury mechanisms differed between groups (χ2 P = 0.0360). On multivariable logistic regression, dens nonunion was positively associated with type II fractures (odds ratio [OR] = 2.00, P = 0.038) and negatively associated with having surgery (OR = 0.52, P = 0.049), but not with having a C1 fracture (P = 0.3673). Worse myelopathy severity on presentation was associated with having a severe injury severity score (OR = 102.3, P < 0.001) and older age (OR = 1.28, P = 0.002), but not with having an atlas fracture (P = 0.2446). Having a simultaneous atlas fracture was associated with older age (OR = 1.29, P = 0.024) and dens fracture angulation (OR = 2.62, P = 0.004). Among patients who underwent surgery, C1/C2 posterior fusion was the most common procedure, and having a simultaneous atlas fracture was associated with selection for occipitocervical fusion (OCF) (OR = 14.35, P = 0.010).

Conclusions

Among patients with traumatic dens, patients who have simultaneous atlas fractures are a distinct subpopulation with respect to age, mechanism of injury, fracture morphology, and management. Traumatic dens fractures with simultaneous atlas fractures are independently associated with selection for OCF rather than posterior cervical fusion alone.

Transoropharyngeal closed reduction for traumatic atlantoaxial dislocation: a novel technique for fast and precise reduction

PURPOSE

The aim of this study is to introduce a new technique for the rapid and accurate reduction of traumatic atlantoaxial dislocation (TAAD) and to investigate its radiological and clinical outcomes.

METHODS

The clinical outcomes of 18 patients who were diagnosed with acute TAAD and underwent rapid transoropharyngeal closed reduction in our hospital were retrospectively analyzed from January 2015 to December 2020. Following general anaesthesia, all patients were immediately treated with oropharyngeal reduction under somatosensory evoked potential monitoring. The Japanese Orthopedic Association score, neck disability index and visual analog scale score for neck pain were used to evaluate clinical efficacy. Atlantodental distance, posterior atlantodental interval, and the clivus-canal angle were used to assess reduction and spinal cord compression.

RESULTS

The mean follow-up time was 23.3 months, with a range of 13-38 months. No neurovascular injury occurred during the operations. For all patients, the closed reduction method through the oropharynx under general anaesthesia was successful, and the success rate of reduction was 100%. All patients recovered uneventfully with marked improvement in clinical outcomes and imaging parameters (P < 0.01). Two patients developed mild postoperative dysphagia. One patient developed postoperative fever and pulmonary infection.

CONCLUSION

Rapid trans-oropharyngeal closed reduction can safely, effectively, and rapidly reduce acute TAAD. This method provides a new strategy for treatment of the condition.

Fibrous Nonunion of Odontoid Fractures: Is It Safe To Accept Nonoperative Management? A Systematic Review

OBJECTIVE

Nonoperative management of odontoid fractures can result in solid fusion, unstable nonunion, and fibrous nonunion. Odontoid fractures with fibrous nonunion will not demonstrate dynamic instability on imaging studies. However, the safety of accepting this outcome has been debated. We have provided, to the best of our knowledge, the first systematic review of the existing literature to explore the safety of allowing fibrous nonunion as an acceptable outcome for odontoid fractures.

METHODS

The PubMed and Embase databases were searched in January 2022. The outcomes were extracted and categorized according to the mortality, neurologic sequelae, pain, neck disability index, and satisfaction.

RESULTS

Of a total of 700 abstracts screened, the full text of 79 reports was assessed, with 13 studies included. Of the included patients, 141 had had a fibrous nonunion, all described in observational studies. The follow-up ranged from 0.6 to 5.8 years. None of the 141 patients had experienced a neurologic event. One patient had died of trauma-related issues; however, causality was not reported. Most of the studies had reported good to excellent pain scores. Most of the neck disabilities reported had ranged from mild to moderate in severity. However, 1 study of 5 patients had reported severe disability. All the patients reported good or excellent satisfaction.

CONCLUSIONS

The evidence we found supports that it is safe to forgo surgery for carefully selected patients with nonunited odontoid fractures when near-anatomic alignment is present, dynamic instability is lacking on imaging studies, the neurologic examination findings are normal, and the risk of neck injury is low. Further study is needed to define the full natural history of fibrous nonunion of odontoid fractures.

Bilateral medial medullary syndrome following anterior screw fixation of type 2 odontoid fracture, a case report of two patients

INTRODUCTION

Medial medullary syndrome (MMS) has not been reported after anterior screw fixation of an odontoid type 2 fracture.

CASE PRESENTATION

We report on two cases who suffered from an unstable type 2 odontoid fracture following a skiing and a domestic fall accident. Prior to anterior screw fixation surgery both patients presented without neurologic deficits but postoperatively developed a bilateral MMS, including an incomplete tetraparesis, impaired sensation of position and movement as well as tactile discrimination and paralysis of the tongue muscle with deviation to the paralyzed side. MRI showed a typical heart-shaped ischaemic lesion in the medial medulla bilaterally. The search for aetiologic factors was uneventful in both patients except for severe atherosclerosis.

DISCUSSION

Due to the close proximity of the ischaemic area to the surgical site, we here propose the perioperative mechanical manipulation of the upper cervical spine during surgery of patients with atherosclerosis as a new aetiology for MMS.

Odontoid screw placement for Anderson type II odontoid fractures: how do duration from injury to surgery and clinical and radiological factors influence the union rate? A multicenter retrospective study

OBJECTIVE

Anderson type II odontoid fractures are severe conditions, mostly affecting elderly people (≥ 70 years old). Surgery can be performed as a primary treatment or in cases of failed conservative management. This study aimed to investigate how duration from injury to surgery, as well as clinical, radiological, and surgical risk factors, may influence the union rate after anterior odontoid screw placement for Anderson type II odontoid fractures.

METHODS

The authors conducted a retrospective multicenter study. Demographic, clinical, surgical, and radiological data of patients who underwent anterior odontoid screw placement for Anderson type II fractures were retrieved from institutional databases. Study exclusion criteria were prolonged corticosteroid drug therapy (> 4 weeks), polytraumatic injuries, oncological diagnosis, and prior cervical spine trauma.

RESULTS

Eighty-five patients were included in the present investigation. The union rate was 76.5%, and 73 patients (85.9%) did not report residual instability. Age ≥ 70 years (p < 0.001, OR 6), female gender (p = 0.016, OR 3.61), osteoporosis (p = 0.009, OR 4.02), diabetes (p = 0.056, OR 3.35), fracture diastasis > 1 mm (p < 0.001, OR 8.5), and duration from injury to surgery > 7 days (p = 0.002, OR 48) independently influenced union rate, whereas smoking status (p = 0.677, OR 1.24) and odontoid process angulation > 10° (p = 0.885, OR 0.92) did not.

CONCLUSIONS

Although many factors have been reported as influencing the union rate after anterior odontoid screw placement for Anderson type II fractures, duration from injury to surgery > 7 days appears to be the most relevant, resulting in a 48 times higher risk for nonunion. Early surgery appears to be associated with better radiological outcomes, as reported by orthopedic surgeons in other districts. Prospective comparative clinical trials are needed to confirm these results.

The comparison of clinical outcome of fresh type II odontoid fracture treatment between anterior cannulated screws fixation and posterior instrumentation of C1-2 without fusion: a retrospective cohort study

Background

Recently, the excellent outcomes of temporary fixation of C1-2 without fusion in the treatment of odontoid fracture had been reported. It is still unclear if this technique could achieve the equivalent outcomes as the golden standard technique of anterior screw fixation. The objective of this study is to compare the clinical outcome of two treatments of fresh type II odontoid fracture: anterior cannulated screws fixation (ACSF) versus posterior instrumentation of C1-2 without fusion (PIWF).

Methods

This is a retrospective study. This series included 28 males and 8 females, and the mean age was 41.5 years (range, 22 to 70 years). Eleven patients were treated with ACSF, and 25 patients with PIWF. For PIWF, the implants were removed after fracture union was confirmed at 0.75~1.5 years later. All patients underwent preoperative and serial postoperative clinical examinations at approximately 3 months, 6 months, and annually thereafter. The neck disability index (NDI) was used to assess the neck discomfort caused by the operation. The range of rotary motion was evaluated at each visit. All fractures were reassessed postoperatively with serial X-films and CT scans of the cervical spine at each follow-up visit, to evaluate screw position, fracture alignment, and fusion status.

Results

All patients achieved immediate spinal stabilization after surgery, and none experienced neurologic deterioration. The follow-up periods ranged from 24 to 60 months. The average range of neck rotation was dramatically lost in PIWF after fixation (46° and 89° respectively in ACSF and PIWF), and recovered to 83° after the implant was removed. The NDI in PIWF was statistically higher than that in ACSF (5 and 13% respectively in ACSF and PIWF) after the first operation and decreased to 8% 1 year after the secondary operation. The fusion rates were 90.9 and 96% respectively in ACSF and PIWF. Both groups had a case of fracture non-union.

Conclusions

For fresh type II odontoid fractures, high rate of fracture union can be achieved by both ACSF and PIWF. For most fresh type II odontoid fractures, anterior screw fixation was the best option for its simplicity and preservation of normal atlanto-axial rotary function. Posterior instrumentation without fusion could preserve most of the atlanto-axial rotary function and lead to moderate neck discomfort and is also a good alternative if anterior screw fixation is contraindicated.

Clinical and radiological union rate evaluation of type 2 odontoid fractures: A comparison between anterior screw fixation and halo vest in elderly patients

Purpose:

Odontoid fracture is a very common cervical injury, especially in elderly patients. Despite the high frequency, the appropriate management is still debated. The aim of this study is to evaluate clinical and radiological outcomes after anterior screw fixation or halo vest (HV) in type II odontoid fracture in elderly patients.

Materials and Methods:

Between January 2013 and December 2015, 135 consecutive patients affected by odontoid process were found. According to inclusion and exclusion criteria, 57 patients were included in the study. Patients were evaluated with visual analog scale (VAS), Smiley–Webster Scale (SWS), Italian Version of the Neck Disability Index (NDI), and patient satisfaction during follow-up. Furthermore, radiological data were evaluated for bone healing. Student's t-test or Fisher's exact test was used between groups, analyzing radiological and clinical results, and level of statistical significance was set at P < 0.05.

Results:

Seventeen patients were female and 40 were male. Twenty-seven patients were included in surgical group (SG) while 30 were included in HV group with a mean follow-up of 37.74 ± 10.52 months. A significant difference (P < 0.05) between groups was found for pseudoarthrosis, with a lower rate for SG. No significant differences in term of VAS, NDI, and SWS were found between groups (P > 0.05); SG reached higher satisfaction than HV group (P = 0.0271).

Conclusions:

Both treatments are equivalent in terms of clinical outcomes, and they are a valuable choice in the management of type II odontoid fracture. However, it must be considered that patients could slightly tolerate HV and may need a change of treatment.

Management of Odontoid Fractures in the Elderly: A Review of the Literature and an Evidence-Based Treatment Algorithm

Odontoid fractures are the most common fracture of the axis and the most common cervical spine fracture in patients over 65. Despite their frequency, there is considerable ambiguity regarding optimal management strategies for these fractures in the elderly. Poor bone health and medical comorbidities contribute to increased surgical risk in this population; however, nonoperative management is associated with a risk of nonunion or fibrous union. We provide a review of the existing literature and discuss the classification and evaluation of odontoid fractures. The merits of operative vs nonoperative management, fibrous union, and the choice of operative approach in elderly patients are discussed. A treatment algorithm is presented based on the available literature. We believe that type I and type III odontoid fractures can be managed in a collar in most cases. Type II fractures with any additonal risk factors for nonunion (displacement, comminution, etc) should be considered for surgical management. However, the risks of surgery in an elderly population must be carefully considered on a case-by-case basis. In a frail elderly patient, a fibrous nonunion with close follow-up is an acceptable outcome. If operative management is chosen, a posterior approach is should be chosen when fracture- or patient-related factors make an anterior approach challenging. The high levels of morbidity and mortality associated with odontoid fractures should encourage all providers to pursue medical co-management and optimization of bone health following diagnosis.

Anterior endoscopically assisted bone grafting for iatrogenic distraction of odontoid fracture after percutaneous anterior screw fixation: A case report

RATIONALE

The complication of iatrogenic distraction of odontoid fracture after anterior screw fixation has not been reported in the literature. We treated the patient with endoscopically assisted bone grafting with good results. The new technique was not reported in the management of odontoid fracture or nonunion before.

PATIENT CONCERNS

A 22-year-old man presented with neck pain after a motorcycle crash. The cervical spine radiograph and computed tomographic scan demonstrated the base of dens displaced 2 mm anteriorly.

DIAGNOSES

Radiographic images showed a type II odontoid fracture.

INTERVENTIONS

The patient was treated by percutaneous anterior screw fixation. The postoperative radiograph and CT demonstrated an iatrogenic distraction of the odontoid with a gap of 6 mm.The follow-up radiograph did not show any sign of bone union 1 month and a half later. A revision surgery was given by anterior endoscopically assisted bone grafting. The patient was encouraged to sit out of bed immediately after the surgery with the protection of a soft cervical collar for 3 months.

OUTCOMES

No complications such as neural structures or vascular injuries were found. Bone union was achieved at the 1-year follow-up CT scans. Physical examination showed a full range of motion in the neck.

LESSONS

We reported a case of iatrogenic odontoid distraction that was managed by anterior endoscopically assisted bone grafting. It is a technically feasible and minimally invasive procedure.

Anterior Versus Posterior Approaches for Odontoid Fracture Stabilization in Patients Older Than 65 Years: 30-day Morbidity and Mortality in a National Database

STUDY DESIGN

Retrospective cohort analysis.

OBJECTIVE

To compare 30-day perioperative clinical outcomes of surgical odontoid stabilization by an anterior or posterior operative approach in elderly patients.

SUMMARY OF BACKGROUND DATA

Surgical stabilization of odontoid fractures is superior to nonoperative management in geriatric patients. How elderly patients with odontoid fractures fare after anterior and posterior approaches, however, is not well defined.

MATERIALS AND METHODS

Retrospective review of the prospectively collected American College of Surgeons National Surgical Quality Improvement Program database (2005-2013). Elderly patients (≥65 y) with odontoid fractures who underwent odontoid stabilization through anterior or posterior approaches were identified by International Classification of Diseases 9th Revision/Common Procedure Terminology codes. Exclusion criteria included concomitant subaxial spine surgery, instrumentation noncontiguous with the atlantoaxial interval, and combined approaches. Baseline demographics and perioperative details were compared. Adverse events, mortality, reoperation, discharge, and readmission rates within 30 days of operation were compared using bivariate and multivariate generalized linear regressions.

RESULTS

One hundred forty-one patients (male-81; female-60; average age: 77.8±6.5 y; anterior approach-48; posterior approach-93) were analyzed. Patients scheduled to have a posterior approach had significantly more nonunions preoperatively and higher body mass indices. Operative times for posterior surgeries were significantly longer. Age, comorbidities, functional dependence, time to surgery, and length of hospital stay were similar between groups. There were no significant differences in the relative risk (RR) of the composite outcome of "any adverse event" after adjusting for differences in baseline characteristics. Patients who underwent an anterior approach were more likely to have an unplanned hospital readmission (RR=8.95; 95% confidence interval, 2.21-36.29; P=0.002) and have significantly more revision operations (RR=19.51; 95% confidence interval, 2.49-152.62; P=0.005) than patients who had a posterior operation.

CONCLUSIONS

An anterior approach for odontoid fracture stabilization in patients ≥65 years old were associated with shorter operative times and greater RRs of unplanned readmissions and revision operations within 30 days of surgery relative to a posterior approach.

Longer-Term Outcomes of Geriatric Odontoid Fracture Nonunion

INTRODUCTION

Longer-term outcomes of patients with geriatric type II odontoid fracture nonunion remain unclear.

METHODS

Thirty-four consecutive geriatric patients (>70 years old) with minimally displaced (<50% displacement) type II odontoid fractures were treated 24 hours a day for 12 weeks with rigid collar immobilization between the years 2003 and 2011. Radiographic and medical record reviews were performed on all 34 patients. Additionally, 7 patients were available for clinical longer-term follow-up (>4 years).

RESULTS

In all, 30 (88%) of the 34 patients had nonunion after 12 weeks of treatment, 2 (6%) patients had union, and 2 (6%) patients died during the first 12 weeks. Twenty-one of the 30 patients with nonunion had a displaced or mobile nonunion (70%), and 4 (12%) patients were lost to follow-up. At longer-term follow-up, 23 (68%) patients had died. The average time death occurred was 3.8 years with a range of 0.17 years to 9.42 years postinjury. Twenty of the 23 deaths were attributed to medical comorbidities not related to the patient's odontoid nonunion. We were unable to determine the cause of death in 3 patients. None of the patients who died had identifiable clinical myelopathy prior to their death on chart review. Of the 7 patients who were alive, all were determined to have odontoid nonunion, of which 5 (70%) were mobile odontoid nonunion. Visual Analog Scale (VAS) and Neck Disability Index (NDI) scores were low (VAS averaged 0.57 and NDI averaged 6.9%) and treatment satisfaction was high (averaged 9.7 of 10). Scores for pain and function did not differ significantly when compared to age-matched controls (P = .08, t test).

CONCLUSION

Rates of odontoid nonunion are high in patients with geriatric odontoid fractures that are treated with continuous rigid collar for 12 weeks. The majority of patients with nonunion appear to achieve high functional outcomes. In this study, mortality did not appear to be related to adverse neurologic events after treatment.