Management of type II dens fractures: a case-control study

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.

Development of a Predictive Model for Persistent Instability Following Conservative Management of Type II Odontoid Fractures

BACKGROUND

Odontoid fractures are common cervical spine fractures; however, significant controversy exists regarding their treatment. Risk factors for failure of conservative therapy have been identified, although no predictive risk score has been developed to aid in decision-making.

METHODS

A retrospective review was conducted of all patients evaluated at a level 1 trauma center. Patients identified with type II odontoid fractures as classified by the D'Alonzo Classification system who were treated with external orthosis were included in analysis. Patients were considered to have failed conservative therapy if they were offered surgical intervention. A machine learning method (Risk-SLIM) was then utilized to create a risk stratification score based on risk factors to identify patients at high risk for requiring surgical intervention due to persistent instability.

RESULTS

A total of 138 patients were identified as presenting with type II odontoid fractures that were treated conservatively; 38 patients were offered surgery for persistent instability. The Odontoid Fracture Predictive Model (OFPM) was created using a machine learning algorithm with a 5-fold cross validation area under the curve of 0.7389 (95% CI: 0.671 to 0.808). Predictive factors were found to include fracture displacement, displacement greater than 5 mm, comminution at the fracture base, and history of smoking. The probability of persistent instability was <5% with a score of 0 and 88% with a score of 5.

CONCLUSIONS

The OFPM model is a unique, quick, and accurate tool to assist in clinical decision-making in patients with type II odontoid fractures. External validation is necessary to evaluate the validity of these findings.

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.

Traumatic Dens Fracture Patients Comprise Distinct Subpopulations Distinguished by Differences in Age, Sex, Injury Mechanism and Severity, and Outcome

BACKGROUND

Dens fractures are an increasingly common injury, yet their epidemiology and its implications remain underexamined.

METHODS

We retrospectively analyzed all traumatic dens fracture patients managed at our institution over a 10-year period, examining demographic, clinical, and outcomes data. Patient subsets were compared across these parameters.

RESULTS

Among 303 traumatic dens fracture patients, we observed a bimodal age distribution with a strong goodness of fit centered at age 22.3 ± 5.7 (R = 0.8781) and at 77.7 ± 13.9 (R = 0.9686). A population pyramid demonstrated a bimodal distribution among male patients, but not female patients, which was confirmed with a strong goodness of fit for male patient subpopulations age <35 (R = 0.9791) and age ≥35 (R = 0.8843), but a weaker fit for a second female subpopulation age <35. Both age groups were equally likely to undergo surgery. Patients younger than age 35 were more likely to be male (82.4% vs. 46.9%, odds ratio [OR] = 5.29 [1.54, 17.57], P = 0.0052), have motor vehicle collision as their mechanism of injury (64.7% vs. 14.1%, OR = 11.18 [3.77, 31.77], P < 0.0001), and to have a severe trauma injury severity score (17.6% vs. 2.9%, OR = 7.23 [1.88, 28.88], P = 0.0198). Nevertheless, patients age <35 were less likely to have fracture nonunion at follow (18.2% vs. 53.7%, OR = 0.19 [0.041, 0.76], P = 0.0288).

CONCLUSIONS

The dens fracture patient population comprises 2 subpopulations, distinguished by differences in age, sex, injury mechanism and severity, and outcome, with male dens fracture patients demonstrating a bimodal age distribution. Young, male patients were more likely to have high-energy injury mechanisms leading to severe trauma, yet were less likely to have fracture nonunion at follow-up.

Sonntag procedure in Atlanto-odontoid fractures type III in restoring Atlanto-axial complex stability: A case report

INTRODUCTION AND IMPORTANCE

Fractures of the second cervical vertebrae (C2) and its odontoid process account for one of the most frequent cervical spine injuries that cause significant mortality and morbidity. The goal of injury treatment is to restore atlantoaxial complex stability. This article reports a young male patient aged 19 years who underwent surgical treatment due to odontoid fractures type III.

CASE PRESENTATION

A 19-year-old male patient came with a chief complaint of weakness in the upper and lower extremities for 3 weeks before admission. The patient underwent a series of physical and radiological examinations and was diagnosed with atlanto-odontoid fracture dislocation Anderson and D'Alonzo classification type III and motoric aphasia due to traumatic subdural hygroma. The patient underwent temporary cervical traction with Garden-Wells tongs and planned for posterior stabilization with the Sonntag procedure. Three and six months follow-ups showed significant clinical improvement in range of motion (ROM).

CLINICAL DISCUSSION

Surgical modalities of stabilization are more commonly chosen in patients with type II and type III odontoid fractures. We performed posterior stabilization with C1-C2 fusion using a modified Gallie (Sonntag) procedure and trans articular screw placement using the Magerl technique. The Gallie procedure was chosen because it could limit atlas displacement effectively which significantly improved Neck Disability Index (NDI) and visual analog score (VAS).

CONCLUSION

We presented a rare case of Atlanto-odontoid fractures treated with a surgical procedure using a posterior approach that resulted in a excellent outcomes.

Surgery Decreases Nonunion, Myelopathy, and Mortality for Patients With Traumatic Odontoid Fractures: A Propensity Score Matched Analysis

BACKGROUND

Existing literature suggests that surgical intervention for odontoid fractures is beneficial but often does not control for known confounding factors.

OBJECTIVE

To examine the effect of surgical fixation on myelopathy, fracture nonunion, and mortality after traumatic odontoid fractures.

METHODS

We analyzed all traumatic odontoid fractures managed at our institution between 2010 and 2020. Ordinal multivariable logistic regression was used to identify factors associated with myelopathy severity at follow-up. Propensity score analysis was used to test the treatment effect of surgery on nonunion and mortality.

RESULTS

Three hundred and three patients with traumatic odontoid fracture were identified, of whom 21.6% underwent surgical stabilization. After propensity score matching, populations were well balanced across all analyses (Rubin's B < 25.0, 0.5 < Rubin's R < 2.0). Controlling for age and fracture angulation, type, comminution, and displacement, the overall rate of nonunion was lower in the surgical group (39.7% vs 57.3%, average treatment effect [ATE] = -0.153 [-0.279, -0.028], P = .017). Controlling for age, sex, Nurick score, Charlson Comorbidity Index, Injury Severity Score, and selection for intensive care unit admission, the mortality rate was lower for the surgical group at 30 days (1.7% vs 13.8%, ATE = -0.101 [-0.172, -0.030], P = .005) and at 1 year was 7.0% vs 23.7%, ATE = -0.099 [-0.181, -0.017], P = .018. Cox proportional hazards analysis also demonstrated a mortality benefit for surgery (hazard ratio = 0.587 [0.426, 0.799], P = .0009). Patients who underwent surgery were less likely to have worse myelopathy scores at follow-up (odds ratio = 0.48 [0.25, 0.93], P = .029).

CONCLUSION

Surgical stabilization is associated with better myelopathy scores at follow-up and causes lower rates of fracture nonunion, 30-day mortality, and 1-year mortality.

Odontoid fracture type and angulation affect nonunion risk, but comminution and displacement do not: A propensity score matched analysis of fracture morphology

OBJECTIVE

Odontoid fractures disproportionately affect older patients who have high surgical risk, but also high rates of fracture nonunion. To guide surgical decision-making, we quantified the effect of fracture morphology on nonunion among nonoperatively managed, traumatic, isolated odontoid fractures.

METHODS

We examined all patients with isolated odontoid fractures treated nonoperatively at our institution between 2010 and 2019. Multivariable regression and propensity score matching were used to quantify the effect of fracture type, angulation, comminution, and displacement on bony healing by 26 weeks from injury.

RESULTS

303 consecutive traumatic odontoid fracture patients were identified, of whom 163 (53.8 %) had isolated fractures that were managed nonoperatively. Selection for nonoperative management was more likely with older age (OR=1.31 [1.09, 1.58], p = 0.004), and less likely with higher fracture angle (OR=0.70 [0.55, 0.89], p = 0.004), or higher presenting Nurick scores (OR=0.77 [0.62, 0.94], p = 0.011). Factors associated with nonunion at 26 weeks were fracture angle (OR=5.11 [1.43, 18.26], p = 0.012) and Anderson-D'Alonzo Type II morphology (OR=5.79 [1.88, 17.83], p = 0.002). Propensity score matching to assess the effect of type II fracture, fracture angulation> 10^o, displacement≥ 3 mm, and comminution all yielded balanced models (Rubin's B<25.0, 0.5 <Rubin's R<2.0). By 26 weeks, controlling for confounders, 77.3 % of type I or III fractures healed, compared to 38.3 % of type II fractures (p = 0.001). 56.3 % of non-angulated fractures healed compared to 12.5 % of fractures angled> 10^o (p = 0.015), and there was an 18.2 % lower rate of bony healing for each 10^o increase in fracture angle. Fracture displacement≥ 3 mm and comminution had no significant effect.

CONCLUSION

Type II fracture morphology and fracture angle > 10^o significantly increase nonunion among nonoperatively managed isolated traumatic odontoid fractures, but fracture comminution and displacement ≥ 3 mm do not.

Risk Factors for Fracture Nonunion and Transverse Atlantal Ligament Injury After Isolated Atlas Fractures: A Case Series of 97 Patients

BACKGROUND

The management of atlas fractures is controversial and hinges on the integrity of transverse atlantal ligament (TAL).

OBJECTIVE

To identify risk factors for atlas fracture nonunion, with and without TAL injury.

METHODS

All isolated, traumatic atlas fractures treated at our institution between 1999 and 2016 were analyzed. Multivariable logistic regression was used to identify variables associated with TAL injury confirmed on MRI, occult TAL injury seen on MRI but not suspected on computed tomography (CT), and with fracture nonunion on follow-up CT at 12 weeks.

RESULTS

Lateral mass displacement (LMD) ≥ 7 mm had a 48.2% sensitivity, 98.3% specificity, and 82.6% accuracy for identifying TAL injury. MRI-confirmed TAL injury was independently associated with LMD > 7 mm ( P = .004) and atlanto-dental interval ( P = .039), and occult TAL injury was associated with atlanto-dental interval ( P = .019). Halo immobilization was associated with having a Gehweiler type 3 fracture ( P = .020), a high-risk injury mechanism ( P = .023), and an 18.1% complication rate. Thirteen patients with TAL injury on MRI and/or LMD ≥ 7 mm were treated with a cervical collar only, and 11 patients (84.6%) healed at 12 weeks. Nonunion rates at 12 weeks were equivalent between halo (11.1%) and cervical collar (12.5%). Only age independently predicted nonunion at 12 weeks ( P = .026).

CONCLUSION

LMD > 7 mm on CT is not sensitive for TAL injury. Some atlas fractures with TAL injury can be managed with a cervical collar. Nonunion rates are not different between halo immobilization and cervical collar, but a strong selection bias precludes directly comparing the efficacy of these modalities. Age independently predicts nonunion.

Too frail is to fail: Frailty portends poor outcomes in the elderly with type II odontoid fractures independent of management strategy

Type-II odontoid fractures are common and highly morbid injuries, particularly among elderly patients. However, few risk stratification resources exist to predict outcomes and guide management decision making. Frailty indices have been increasingly utilized for these purposes in elective surgery, but have not been assessed for trauma. A single-center prospective trauma registry identified patients aged ≥ 80 years with type-II odontoid fractures. Frailty was the independent variable, using three independent indices: modified-5-item frailty (mFI-5), modified Charlson comorbidity (mCCI), and Davies. 97 patients had complete frailty data and sufficient follow up information, with median mIF-5 of 2 (range 0-4; 34 frail, mFI-5 > 2), median mCCI score of 6 (range 4-14), and median Davies score of 2 (range 0-7). For all indices, increasing score was associated with mortality, mIF-5 (HR = 1.76, 95%CI = 1.06-2.88), mCCI (HR = 1.10, 95%CI = 1.01-1.20), and Davies scores (HR = 1.21, 95%CI = 1.08-1.37). Median post-injury survival among patients with mIF-5 of ≤ 2 was 10-fold longer than patients with mIF-5 of > 2 (70 vs. 710 days, p = 0.0026). After adjusting for initial treatment strategy, frailty status remained an independent predictor of patient mortality; mIF-5 (HR = 1.72, 95%CI = 1.02-2.80), mCCI (HR = 1.10, 95%CI = 1.01-1.20), and Davies scores (HR = 1.21, 95%CI = 1.08-1.37). Among octogenarian patients with type-II odontoid fractures, frailty was associated with increased mortality, independent of treatment strategy.

Posterior fusion for fragility type 2 odontoid fractures

OBJECTIVE

The purpose of this study was to evaluate the outcomes of elderly patients with type 2 odontoid fractures treated with an instrumented posterior fusion.

METHODS

Ninety-three consecutive patients older than 65 years of age in whom a type 2 odontoid fracture had been treated with a variety of C1-2 posterior screw fixation techniques were retrospectively reviewed.

RESULTS

The average age was 78 years (range 65-95 years). Thirty-seven patients had an additional fracture, 30 of which involved C1. Three patients had cervical spinal cord dysfunction due to their injury. All patients had comorbidities. The average total hospitalization was 9.6 days (range 2-37 days). There were 3 deaths and 19 major complications, the most common of which was pneumonia. No patient suffered a vertebral artery injury. Imaging studies were obtained in 64 patients at least 12 months postsurgery (mean 19 months). Fusion was assessed by dynamic radiographs in all cases and with a CT scan in 80% of the cases. Four of the 64 patients did not achieve fusion (6.25% overall). All patients in whom fusion failed had undergone C1 lateral mass fixation and C2 pars (1/29, 3.4%) or laminar (3/9, 33.3%) fixation.

CONCLUSIONS

Instrumented posterior cervical fusions may be performed in elderly patients with acceptable morbidity and mortality. The fusion rate is excellent except when bilateral C2 translaminar screws are used for axis fixation.

The use of Grauer classification in the management of type II odontoid fracture in elderly: Prognostic factors and outcome analysis in a single centre patient series

OBJECTIVE

To evaluate the results of Type II odontoid fractures management in the elderly, according to the Grauer classification.

METHODS

Consecutive patients with type II odontoid fracture, age > 65 years and follow-up longer than 3 months were included. Fracture management was proposed according to Grauer classification. Peri-surgical risk factors, NDI, VAS and rate of fusion were evaluated according to the treatment modality and compared between conservative and surgical groups.

RESULTS

Thirty-four patients were considered eligible for the study; 2 patients showed a Type IIa fracture, 30 patients a type IIb, and 2 patients a type IIc. Type IIa patients underwent conservative treatment that resulted in failure. A conservative management was adopted in 9 cases with type IIb due to patient preference or anaesthesiologic reasons with a treatment success at 6 months of 11%. Trans-odontoid stabilization was adopted in 21 type IIb cases with an evidence of bony or fibrous union at 6 months of 95% and a median NDI of 20%. A posterior approach was reserved for 2 type IIc fracture patients and in 6 cases as rescue surgery (bony union at 6 months of 100%; median NDI 37%). Higher Lakshmanan grade, gap and displacement of the fracture were found as significant risk factor for fracture non-union (p < 0.05).

CONCLUSIONS

The surgical group presented better clinical and radiological outcome and the anterior approach proved to achieve the best results in type IIb fractures. The presence of osteoporosis and fracture spatial features should be duly considered in the decision-making process.

Determination and optimization of ideal patient candidacy for anterior odontoid screw fixation

Background:

Odontoid process fractures are one of the most common spine fractures, especially in patients over age 70. There is still much controversy over the ideal candidate for anterior odontoid screw fixation (AOSF), with outcomes affected by characteristics such as fracture morphology, nonideal body habitus, and osteoporosis. Therefore, this systematic review seeks to discuss the optimal criteria, indications, and adverse postoperative considerations when deciding to pursue AOSF.

Methods:

This investigation was conducted from experiential recall and article selection performed using the PubMed electronic bibliographic databases. The search yielded 124 articles that were assessed and filtered for relevance. Following the screening of titles and abstracts, 48 articles were deemed significant for final selection.

Results:

AOSF is often utilized to treat Type IIB odontoid fractures, which has been shown to preserve atlantoaxial motion, limit soft-tissue injuries/blood loss/vertebral artery injury/reduce operative time, provide adequate osteosynthesis, incur immediate spinal stabilization, and allow motion preservation of C1 and C2. However, this technique is limited by patient characteristics such as fracture morphology, transverse ligament rupture, remote injuries, short neck or inability to extend neck, barrel chested, and severe spinal kyphosis, in addition to adverse postoperative outcomes such as dysphagia and vocal cord paralysis.

Conclusion:

Due to the fact that odontoid fractures have a significant morbidity in elderly population, treatment with AOSF is generally recommended for this population with higher risk for nonoperative fusion. Considerations should be made to achieve fracture stability and fusion, while lowering the risk for operative and postoperative complications.

Spine Trauma

Spine trauma is a common indication for diagnostic imaging, and there has been a gradual shift to using cross-sectional imaging techniques for screening and evaluating the injured spine, particularly in elderly patients where radiography can be challenging. The classification of spinal injuries has evolved in the past decades to rely on a combination of fracture morphology as defined by diagnostic imaging in conjunction with the clinical presentation to stratify patients to determine optimal management. Radiologists need to be familiar with these classification systems, which rely heavily on imaging findings using CT and MRI, to accurately describe spinal injury.

Institutional review of the management of type II odontoid fractures: associations and outcomes with fibrous union

OBJECTIVE

Type II odontoid fractures may be managed operatively or nonoperatively. If managed with bracing, bony union may never occur despite stability. This phenomenon is termed fibrous union. The authors aimed to determine associations with stable fibrous union and compare the morbidity of patients managed operatively and nonoperatively.

METHODS

The authors performed a retrospective review of their spine trauma database for adults with type II odontoid fractures between 2015 and 2019. Two-sample t-tests and Fisher's exact tests identified associations with follow-up stability and were used to compare operative and nonoperative outcomes. Sensitivity, specificity, and predictive values were calculated to validate initial stable upright cervical radiographs related to follow-up stability.

RESULTS

Among 88 patients, 10% received upfront surgical fixation, and 90% were managed nonoperatively, of whom 22% had fracture instability on follow-up. Associations with instability after nonoperative management include myelopathy (OR 0.04, 95% CI 0.0-0.92), cerebrovascular disease (OR 0.23, 95% CI 0.06-1.0), and dens displacement ≥ 2 mm (OR 0.29, 95% CI 0.07-1.0). Advanced age was not associated with follow-up instability. Initial stability on upright radiographs was associated with stability on follow-up (OR 4.29, 95% CI 1.0-18) with excellent sensitivity and positive predictive value (sensitivity 89%, specificity 35%, positive predictive value 83%, and negative predictive value 46%). The overall complication rate and respiratory failure requiring ventilation on individual complication analysis were more common in operatively managed patients (33% vs 3%, respectively; p = 0.007), even though they were generally younger and healthier than those managed nonoperatively. Operative or nonoperative management conferred no difference in length of hospital or ICU stay, discharge disposition, or mortality.

CONCLUSIONS

The authors delineate the validity of upright cervical radiographs on presentation in association with follow-up stability in type II odontoid fractures. In their experience, factors associated with instability included cervical myelopathy, cerebrovascular disease, and fracture displacement but not increased age. Operatively managed patients had higher complication rates than those managed without surgery. Fibrous union, which can occur with nonoperative management, provided adequate stability.

Towards Evidence-Based Guidelines in Neurological Surgery

Neurological surgery practice is based on the science of balancing probabilities. A variety of clinical guidance documents have influenced how we collectively practice our art since the early 20th century. The quality of the science within these guidelines varies widely, as does their utility in positively shaping our practice. The guidelines development process in neurological surgery has evolved significantly over the last 30 yr. Historically based in expert opinion, as a specialty we have increasingly relied on objective medical evidence to guide our clinical practice. We assessed the changing practice guidelines development process and the impact of scientifically robust guidelines on patient care. The evolution of the guidelines development process in neurological surgery was chronicled. Several subspecialty guidelines were extracted and reviewed in detail. Their impact on practice patterns was evaluated. The importance of evidence-based research and practice guidelines development was discussed. Evidence-based practice guidelines serve to chronicle multiple acceptable treatment options and help us move towards more standardized care for specific disease processes. They help refute false "standards of care." Guidelines-based care supported by solid medical evidence has the potential to streamline patient care and improve patient outcomes. The guidelines development process identifies areas, issues, and strategies for which little medical evidence exists, as well as topics that need focused scientific investigation and future study. The production of evidence-based practice recommendations is a vital part of furthering our specialty. Guidelines development advances our science, augments the resident education process, and protects our practice from undue external influence.

Odontoid Fractures: A Critical Review of Current Management and Future Directions

Odontoid fractures represent one of the most common and controversial injury types affecting the cervical spine, being associated with a high incidence of nonunion, morbidity, and mortality. These complications are especially common and important in elderly patients, for which ideal treatment options are still under debate. Stable fractures in young patients maybe treated conservatively, with immobilization. Although halo-vest has been widely used for their conservative management, studies have shown high rates of complications in the elderly, and therefore current evidence suggests that the conservative management of these fractures should be carried out with a hard cervical collar or cervicothoracic orthosis. Elderly patients with stable fractures have been reported to have better clinical results with surgical treatment. For these and for all patients with unstable fractures, several surgical techniques have been proposed. Anterior odontoid fixation can be used in reducible fractures with ideal fracture patterns, with older patients requiring fixation with 2 screws. In other cases, C1-C2 posterior fixation maybe needed with the best surgical option depending on the reducibility of the fracture and vertebral artery anatomy. In this paper, current evidence on the management of odontoid fractures is discussed, and an algorithm for treatment is proposed.

The case for the future role of evidence-based medicine in the management of cervical spine injuries, with or without fractures

The authors believe that the standardized and systematic study of immobilization techniques, diagnostic modalities, medical and surgical treatment strategies, and ultimately outcomes and outcome measurement after cervical spinal trauma and cervical spinal fracture injuries, if performed using well-designed medical evidence-based comparative investigations with meaningful follow-up, has both merit and the remarkable potential to identify optimal strategies for assessment, characterization, and clinical management. However, they recognize that there is inherent difficulty in attempting to apply evidence-based medicine (EBM) to identify ideal treatment strategies for individual cervical fracture injuries. First, there is almost no medical evidence reported in the literature for the management of specific isolated cervical fracture subtypes; specific treatment strategies for specific fracture injuries have not been routinely studied in a rigorous, comparative way. One of the vulnerabilities of an evidenced-based scientific review in spinal cord injury (SCI) is the lack of studies in comparative populations and scientific evidence on a given topic or fracture pattern providing level II evidence or higher. Second, many modest fracture injuries are not associated with vascular or neural injury or spinal instability. The application of the science of EBM to the care of patients with traumatic cervical spine injuries and SCIs is invaluable and necessary. The dedicated multispecialty author groups involved in the production and publication of the two iterations of evidence-based guidelines on the management of acute cervical spine and spinal cord injuries have provided strategic guidance in the care of patients with SCIs. This dedicated service to the specialty has been carried out to provide neurosurgical colleagues with a qualitative review of the evidence supporting various aspects of care of these patients. It is important to state and essential to understand that the science of EBM and its rigorous application is important to medicine and to the specialty of neurosurgery. It should be embraced and used to drive and shape investigations of the management and treatment strategies offered patients. It should not be abandoned because it is not convenient or it does not support popular practice bias or patterns. It is the authors' view that the science of EBM is essential and necessary and, furthermore, that it has great potential as clinician scientists treat and study the many variations and complexities of patients who sustain acute cervical spine fracture injuries.

The Healing Rate of Type II Odontoid Fractures Treated With Posterior Atlantoaxial Screw-rod Fixation: A Retrospective Review of 77 Patients

BACKGROUND

In theory, temporary posterior atlantoaxial screw-rod fixation for type II odontoid fractures is a way to preserve rotatory motion. However, the healing rate of type II odontoid fractures treated in this way is unknown; that is, the risk associated with conducting a temporary screw-rod fixation for type II odontoid fractures is unknown. This study investigates the healing rate of type II odontoid fractures treated with posterior atlantoaxial screw-rod fixation by CT imaging and evaluates the feasibility of conducting a temporary screw-rod fixation for type II odontoid fractures.

METHODS

Patients with type II odontoid fracture who underwent posterior atlantoaxial screw-rod fixation in our spine center from January 2011 to December 2014 were identified. Patients older than 65 years or younger than 18 years were excluded. Those who were confirmed to have healing odontoid fractures on CT imaging were included. Those in whom fracture healing was not confirmed were asked to undergo a CT examination. Fracture healing was confirmed on the basis of the presence of bridging bone across the odontoid fracture site on CT imaging.

RESULTS

Seventy-seven patients (56 men and 21 women) were included in the study. The average age of the patients was 40.7 ± 11.6 years (range, 18 to 64 years). The mean duration of follow-up was 26.4 ± 4.6 months (range, 24 to 40 months). Fracture healing was observed in 73 patients (94.8%).

DISCUSSION

The healing rate of type II odontoid fractures (with an age range of 18 to 64 years) treated with modern posterior atlantoaxial fixation is relatively high. For patients at that age range, posterior atlantoaxial temporary screw-rod fixation for type II odontoid fractures can be conducted with a low risk of nonunion.

LEVEL OF EVIDENCE

Level IV, therapeutic.

Treatment of Odontoid Fractures: Recommendations of the Spine Section of the German Society for Orthopaedics and Trauma (DGOU)

STUDY DESIGN

Narrative review.

OBJECTIVE

To establish recommendations for the treatment of odontoid fractures based on current literature and the knowledge of the experts of the Spine Section of the German Society for Orthopaedics and Trauma (DGOU).

METHODS

Narrative review of the literature. Analyzing treatment algorithms of German trauma and spine centers as members of the Spine Section of the German Society for Orthopaedics and Trauma (DGOU).

RESULTS

There are many influencing factors leading to appropriate treatment of odontoid fractures such as age, bone quality, arthrosis, classification, and type of the fracture. Conservative nonoperative treatment is appropriate for stable undislocated displaced odontoid fractures. Anterior osteosynthesis with 1 or 2 screws leads to good results in the classical unstable type II odontoid fracture in patients with good bone quality. However, modifiers have been identified by the working group leading to higher complication and failure rates. For these cases, more stable constructs and/or posterior approaches are indicated.

CONCLUSIONS

Operation seems to be standard treatment for odontoid fractures. However, in the aged population, conservative treatment should be considered as morbidity and mortality rise significantly in the group of >75 years. Conservative treatment may also be started within stable nondislocated fractures, but then regular controls have to be performed. If operation is indicated, many influencing factors have to be considered for appropriate approach and technique. The classification of Anderson and D'Alonzo is still standard. To create an adequate treatment algorithm, dislocation displacement and instability have to be identified. Stable odontoid fractures are treated conservatively non-operatively, but if so regular controls have to be performed. Unstable and/or dislocated displaced odontoid fractures are treated by anterior osteosynthesis with 1 or 2 screws. The technique is demanding and leads to elevated complication and failure rates if modifiers are apparent. In these cases, posterior instrumentation or fusion of C1 and C2 is favorable. In the aged population (>80 years), operative therapy is critical as postoperative morbidity complication and mortality rates rise significantly. As there is still some bias in the treatment algorithms, the working group recommends establishment of a prospective study to result in more objective statements.

Analysis of Computed Tomography Scan After Anterior Odontoid Screw Fixation with the Herbert Screw: Is It Effective to Reduce Fracture Gap?

OBJECTIVE

To assess computed tomography scans to evaluate the extent of reduction of fracture displacement and fracture gap after anterior odontoid screw fixation using the Herbert screw.

METHODS

Thirty-seven odontoid fractures were reduced and treated by anterior odontoid screw fixation with the Herbert screw. There were 37 patients whose age ranged from 20 to 79 years. Three-dimensional computed tomography scans were obtained for all patients to assess the screw position, the presence of the penetration of superior cortex of dens, the extent of reduction of fracture displacement, and fracture gap.

RESULTS

Mean fracture displacement was 2.6 ± 3.2 mm before surgery; after the operation this value was 1.0 ± 1.5 mm. The difference in fracture gap between the preoperative and the postoperative state was -0.1 ± 1.1 mm, which was not statistically significant (P = 0.667). We achieved cortical purchase in only 16 of 37 patients (43.2%); cortical purchase was not obtained in 21 patients (56.7%) due to the fear of the risk of the damage of neural and vascular structures. Of these 21 patients who had no penetration of the superior cortex of dens, widening of the fracture gap occurred in 12 patients (57%), no change in 6 patients (29%), and there was shortening in 3 patients (14%). However, of the 16 patients with penetration of apical dens tip, we achieved significant reduction of fracture gap (P = 0.002).

CONCLUSIONS

To maximize reduction of fracture gap using the Herbert screw, it is essential to penetrate the apical dens tip.

Unexpected Persistent Dentocentral Synchondrosis of C2

BACKGROUND

The persistence of synchondrosis in adulthood can confound diagnostic decisions made during patient management.

CASE DESCRIPTION

A 59-year-old woman who presented neck pain, acute headache, and acute cervical myelopathy symptoms after suffering whiplash grade 3 in a car rear-end impact underwent a conventional radiologic study that revealed no fracture and no anatomic spine variations. The magnetic resonance imaging study revealed no spinal cord intensity signal changes, but it showed a persistent (remnant) dentocentral synchondrosis that was undetected in a previous conventional radiographic evaluation.

CONCLUSIONS

The localization and level of the remnant of the dentocentral synchondrosis are extremely important from the clinical viewpoint because of odontoid and C2 fractures. Neurosurgeons should thus be aware of the possible presence of a persistent (remnant) C2 dentocentral synchondrosis in adult subjects in order to avoid misdiagnosis with C2 fracture.

The magnitude of angular and translational displacement of dens fractures is dependent on the sagittal alignment of the cervical spine rather than the force of injury

BACKGROUND CONTEXT

Although it is generally believed that the magnitude of dens fracture displacement is proportional to the amount of force applied to the cervical spine during injury, the factors responsible for displacement have not been studied.

PURPOSE

Our aim was to determine factors that contribute to horizontal and angular displacement of dens fractures.

STUDY DESIGN/SETTING

We conducted a retrospective review of adult patients who were admitted to our level 1 trauma center between January 1, 2008 and December 31, 2013.

PATIENT SAMPLE

Angular and horizontal displacements of the fractured dens in 57 patients were measured. Subjects were grouped based on mechanism of fracture: motor vehicle accident, ground level fall, and higher falls.

OUTCOME MEASURES

Cervical lordosis was measured between C2 and T1. C3-C4, C4-C5, C5-C6, and C6-C7 disc inclination angles were measured. Anteroposterior sagittal balance was assessed by comparing the sagittal position of the C2 body with the C7 body.

METHODS

Data were analyzed using Pearson correlations, independent t tests, and support vector regression to construct predictive models that determine factors contributing to the angular and horizontal displacements.

RESULTS

The mean horizontal displacement of the fractured dens was not significantly different among groups. However, the dens in those with ground level falls had a significantly greater mean fracture angle compared with the higher energy trauma groups (p=.01). There were positive correlations between angular displacement and C5-C6 disc space inclination angle (r=0.67, p<.01) and C6-C7 disc space inclination angle (r=0.61, p<.01). There were positive correlations between horizontal displacement and C6-C7 inclination angle (r=0.40, p<.01) and sagittal alignment (r=0.32, p<.01). The predictive model using all variables demonstrated that angular fracture displacement was only dependent on C5-C6 disc space inclination angle. Horizontal displacement was only dependent on C6-C7 inclination angle and anteroposterior sagittal balance.

CONCLUSIONS

Disc space inclination angles of the lower cervical spine and the cervical sagittal balance most contribute to the magnitude of angular and horizontal displacement of the dens after fracture.

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.

Predisposing Factors of Fracture Nonunion After Posterior C1 Lateral Mass Screws Combined with C2 Pedicle/Laminar Screw Fixation for Type II Odontoid Fracture

INTRODUCTION

The aim of this study was to explore the predisposing factors for fracture nonunion after a lateral screw was combined with C2 pedicle/laminar screw for a type II odontoid fracture and hopefully provide references in decision making and surgical planning for spinal surgeons.

METHODS

This is a retrospective study. By retrieving the medical records from January 2010 to July 2015 in our hospital, 117 type II odontoid fracture patients were reviewed. According to the occurrence of fracture union at the final follow-up, patients were divided into 2 groups: union and nonunion. To investigate the predisposing factors for fracture nonunion, 3 categorized factors were analyzed statistically: patient characteristics-age, sex, body mass index, preoperative Japanese Orthopaedic Association (JOA) scores, duration, comorbidity, and complicated injuries; surgical variables-surgery time, blood loss, C2 fixation manner, vertebral artery injury, bone source for fusion between the posterior arch of C1 and the laminae and spinous process of C2; radiographic parameters-preoperative and immediate postoperative data of C_0-2 curvature, C_2-7 curvature, C_2-7 sagittal vertical axis, C7 slope, fracture classification, congenital hypoplastic vertebral artery, and the separation and displacement of the odontoid fracture. Other variables including JOA and visual analog scale scores for neck pain, neck stiffness, and patient satisfaction at final follow-up were recorded and compared between the 2 groups.

RESULTS

Postoperative fracture nonunion was detected in 76 of 117 patients (65%) at final follow-up. There was no statistically significant difference between the 2 groups in patient characteristics of sex, body mass index, JOA score, comorbidity, and complicated injuries. The mean age at operation was younger in the union group than in the nonunion group, and the mean duration was shorter in the union group than in the nonunion group. There was no difference in surgical variables of surgery time, blood loss, C2 fixation manner, vertebral artery injury, bone source for fusion between the posterior arch of C1 and the laminae and spinous process of C2. There was no difference in radiographic parameters of fracture classification, congenital hypoplastic vertebral artery, preoperative and immediate postoperative C_0-2 curvature, C_2-7 curvature, C_2-7 SVA, and C7 slope. No difference was found in preoperative and immediate postoperative displacement of the odontoid fracture or immediate postoperative separation of the odontoid fracture, while the preoperative separation of the odontoid fracture was shorter in the union group than in the nonunion group. The logistic regression analysis revealed that advanced age (>45 years), long duration (>2 months), and preoperative separation of the odontoid fracture (>4 mm) were independently associated with the postoperative fracture nonunion. There were no differences between the 2 groups in JOA, neck pain, neck stiffness, and patient satisfaction at final follow-up.

CONCLUSIONS

Advanced age, long duration, and preoperative separation of odontoid fracture >4 mm are predisposing factors for fracture nonunion after posterior C1 lateral screw combined with C2 pedicle/laminar screw fixation for type II odontoid fracture. Our findings did not demonstrate any evidence of lower functional outcome and patients satisfaction for those patients who had odontoid nonunion.

Intraoperative Navigation Is Associated with Reduced Blood Loss During C1-C2 Posterior Cervical Fixation

OBJECTIVE

Traumatic injuries, degenerative/rheumatologic conditions, tumors, or infections of the upper cervical spine may in certain circumstances require surgical stabilization. C1 lateral mass screws (Harms technique) in combination with C2 instrumentation (pars, pedicle, translaminar screws) have become a mainstay of surgical treatment. The surgical anatomy of the C1 lateral mass can be challenging especially with the robust venous plexus that often causes significant bleeding with exposure of the C1-C2 articular complex. The purpose of this study was to examine whether the use of navigation reduced intraoperative blood loss during atlantoaxial fixation.

METHODS

We reviewed our institutional experience with atlantoaxial instrumentation with and without navigation from 2007 to 2016. We limited our cases to those requiring C1-C2 stabilization in traumatic and degenerative cases and not as part of more extensive surgical stabilizations. We identified 45 consecutive patients and compared intraoperative blood loss, need for transfusion, and time of procedure with and without the use of navigation.

RESULTS

There was a significant reduction in the amount of intraoperative blood loss in the navigated (n = 20) versus non-navigated cases (n = 25). In addition, although the navigated cases initially were longer, currently there is no significant difference in the length of the cases.

CONCLUSIONS

In our series, surgical navigation significantly reduced blood loss compared with non-navigated cases without increasing surgical time or risk of complication. Furthermore, navigation has the potential to reduce operative times due to a reduction in blood loss.

"Direct vision" operation of posterior atlantoaxial transpedicular screw fixation for unstable atlantoaxial fractures: A retrospective study

BACKGROUND

The posterior screw fixation in atlas via posterior arch and lateral mass, also called C1 "pedicle" screw, combined with C2 pedicle screw fixiation has shown better biomechanical stability in unstable atlantoaxial fractures. However, its popularization has to fulfill the limitation imposed by anatomical characteristics. The aim of this study was to explore the manipulation, effect, and safety of the atlantoaxial transpedicular screw fixation under "direct vision" for the treatment of unstable atlantoaxial fracture.

METHODS

All the patients diagnosed with unstable atlantoaxial fracture, who received surgery treatment of C1,C2 internal fixation from January 2012 to December 2014 were reviewed. Only these patients that were diagnosed with atlantoaxial unstability secondary to trauma and were treated with atlantoaxial transpedicular screw fixation under "direct vision" and iliac autograft were included. The safety of transpedicular screw placement, postoperative outcome, atlantoaxial stability, autograft fusion, and complications was observed and analyzed retrospectively. The pain visual analog scale (VAS) and the Japanese Orthopedic Association (JOA) score were used as surgical curative effect evaluation standards.

RESULTS

We reviewed a total of 92 patients diagnosed with unstable atlantoaxial fracture, who received surgery treatment of C1,C2 internal fixation from January 2012 to December 2014, and 87 patients were treated with atlantoaxial transpedicular screw fixation under "direct vision" and were included this analysis. A total of 306 transpedicular screws in atlas and axis were placed successfully. All cases were followed-up >12 months. The overall breach rate was 11.36%. None of the breaches resulted in new-onset neurological sequela. The neurological status in cases with bilateral upper extremities numbness and lower extremities weakness had improved after surgery. At the latest follow-up, the neck VAS and JOA scores were significantly improved (P < .01) than those preoperatively. No cases demonstrated implantation failure and bone graft absorption on the postoperative x-ray films and CT scans.

CONCLUSION

Atlantoaxial transpedicular screw fixation under "direct vision" and iliac autograft for the treatment of unstable atlantoaxial fracture has shown simple manipulation and efficient performance. Thus, the technique of C1-C2 fixation is feasible in treating unstable atlantoaxial fracture.

Craniovertebral junction injuries in children. A Review

The craniovertebral junction (CVJ) is the most complex and dynamic region of the cervical spine. The wide range of movements possible at this region makes it vulnerable to injury and instability. The special anatomical features make children more prone to injuries of CVJ than adults where lower cervical spine is involved more frequently. The classical clinical manifestation in CVJ injury patients are pyramidal signs including weakness and spasticity, stigmata of CVJ anomalies (short neck, low hair line, facial or hand asymmetry, high arched palate, ), torticolis and neck movement restriction. The history of transient loss of consciousness or sudden neurological deterioration following minor trauma may be elicited. Most authors advocate conservative management (in form of immobilization) of CVJ injuries in children as is true in adults. Halo vest provides superior immobilization in upper cervical and CVJ injuries and can be used in a child as young as 1 year of age with minimal difficulty. Early surgical intervention, i.e. within 2 weeks of injury include is indicated in injuries that cannot be reduced and stabilized by external means, partial spinal cord injury with progressive neurological deficit and in children with extradural hematoma.

Morbidity and Mortality Associated with Surgery of Traumatic C2 Fractures in Octogenarians

BACKGROUND: Management of axis fractures in the elderly remains controversial. As the US population increasingly lives past 80 years, published C2 fracture morbidity/mortality profiles in younger cohorts (55+) have become less applicable to octogenarians.

OBJECTIVE: To report associations between surgery and mortality, hospital length of stay and discharge disposition in octogenarians with traumatic C2 fractures.

METHODS: Retrospective cohort study of 3847 patients age ≥ 80 years representing 17 702 incidents nationwide, divided into surgery/nonsurgery cohorts, using the National Sample Program of the National Trauma Data Bank from 2003 to 2012. Inpatient complications, mortality, length of stay, and discharge disposition are characterized; multivariable regression was utilized to determine associations between surgery and outcomes.

Institutional Review Board (IRB): The National Sample Program dataset from the National Trauma Data Bank is fully deidentified and does not contain Health Insurance Portability and Accountability Act identifiers; therefore, this study is exempt from IRB review at the University of California, San Francisco.

RESULTS: Incidence of surgery was 10.3%. Surgery was associated with increased pneumonia, acute respiratory distress syndrome, and decubitus ulcer risks (P &lt; .001). Inpatient mortality was 12.8% (nonsurgery—13.0%; surgery—10.3%; P = .120). Length of stay was 8.31 ± 9.32 days (nonsurgery 7.78 ± 9.21; surgery 12.86 ± 9.07; P &lt; .001) and showed an adjusted mean increase of 5.68 days with surgery (95% confidence interval [4.74-6.61]). Of patients surviving to discharge, 26% returned home (nonsurgery—26.8%; surgery—18.8%; P = .001); surgery patients were less likely to return home (odds ratio 0.59 [0.44-0.78]).

CONCLUSION: The present study confirms that surgery of traumatic C2 fractures in octogenarians does not significantly affect inpatient mortality and increases discharge to institutionalized care. Patients undergoing surgery are more likely to require longer hospitalization and suffer increased medical complications during their stay. Given the retrospective nature of this study, it is unclear whether these conclusions reflect differences in injury severity between surgery cohorts. This question may be considered in a future prospective study.

Traumatic cervical spine fractures in the adult

This article reviews fractures of the cervical spine, highlighting the pertinent goals of initial management, the indications for different imaging modalities and the different fracture patterns. Basic principles of management of these different fracture patterns are outlined.

Conservative Management of Odontoid Peg Fractures, long term follow up

OBJECTIVE

The aim of the study was to look at the long-term effects of conservative management of odontoid peg fractures.

METHODS

We reviewed 48 consecutive patients with type II (32) and 16 type III, odontoid peg fractures. The clinical & radiological outcomes were assessed over an average period of follow up of 8 years. Union rate was determined and we discussed several factors that may affect it. Patients were treated conservatively with an average period of bed rest of 4 weeks followed by bracing for an average of 9 weeks.

RESULTS

Bony union was established in 25 of 32 (78%) type II fractures. Of 7 cases of no bony union 4 were stable probably with fibrous union. 3 remained unstable. In 13 of 16(83%) type III fractures bony union was established. 2 of the 3 with no bony union were considered stable.

CONCLUSION

Osseous non-union was higher in patients with displacement of >5 mm, but there is no correlation between union and age, gender or angulation of the fracture in both types.

Treatment of Odontoid Fractures in the Aging Population

Odontoid fractures are the most common cervical fracture type among the elderly population. Several treatment options exist for these patients, ranging from immobilization with a semirigid orthosis to surgical arthrodesis. This report reviews the key points in the management of odontoid fractures in the aged patient, including diagnosis, the various forms of conservative therapies, and the options for surgical intervention.

The craniocervical junction: embryology, anatomy, biomechanics and imaging in blunt trauma

Imaging of the blunt traumatic injuries to the craniocervical junction can be challenging but central to improving morbidity and mortality related to such injury. The radiologist has a significant part to play in the appropriate management of patients who have suffered injury to this vital junction between the cranium and the spine. Knowledge of the embryology and normal anatomy as well as normal variant appearances avoids inappropriate investigations in these trauma patients. Osseous injury can be subtle while representing important radiological red flags for significant underlying ligamentous injury. An understanding of bony and ligamentous injury patterns can also give some idea of the biomechanics and degree of force required to inflict such trauma. This will assist greatly in predicting risk for other critical injuries related to vital neighbouring structures such as vasculature, brain stem, cranial nerves and spinal cord. The embryology and anatomy of the craniocervical junction will be outlined in this review and the relevant osseous and ligamentous injuries which can arise as a result of blunt trauma to this site described together. Appropriate secondary radiological imaging considerations related to potential complications of such trauma will also be discussed.

TEACHING POINTS

• The craniocervical junction is a distinct osseo-ligamentous entity with specific functional demands. • Understanding the embryology of the craniocervical junction may prevent erroneous radiological interpretation. • In blunt trauma, the anatomical biomechanical demands of the ligaments warrant consideration. • Dedicated MRI sequences can provide accurate evaluation of ligamentous integrity and injury. • Injury of the craniocervical junction carries risk of blunt traumatic cerebrovascular injury.

Surgical Intervention for Instability of the Craniovertebral Junction

Surgical approaches for stabilizing the craniovertebral junction (CVJ) are classified as either anterior or posterior approaches. Among the anterior approaches, the established method is anterior odontoid screw fixation. Posterior approaches are classified as either atlanto-axial fixation or occipito-cervical (O-C) fixation. Spinal instrumentation using anchor screws and rods has become a popular method for posterior cervical fixation. Because this method achieves greater stability and higher success rates for fusion without the risk of sublaminar wiring, it has become a substitute for previous methods that used bone grafting and wiring. Several types of anchor screws are available, including C1/2 transarticular, C1 lateral mass, C2 pedicle, and translaminar screws. Appropriate anchor screws should be selected according to characteristics such as technical feasibility, safety, and strength. With these stronger anchor screws, shorter fixation has become possible. The present review discusses the current status of surgical interventions for stabilizing the CVJ.

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.

The Dens: Normal Development, Developmental Variants and Anomalies, and Traumatic Injuries

Accurate interpretation of cervical spine imagining can be challenging, especially in children and the elderly. The biomechanics of the developing pediatric spine and age-related degenerative changes predispose these patient populations to injuries centered at the craniocervical junction. In addition, congenital anomalies are common in this region, especially those associated with the axis/dens, due to its complexity in terms of development compared to other vertebral levels. The most common congenital variations of the dens include the os odontoideum and a persistent ossiculum terminale. At times, it is necessary to distinguish normal development, developmental variants, and developmental anomalies from traumatic injuries in the setting of acute traumatic injury. Key imaging features are useful to differentiate between traumatic fractures and normal or variant anatomy acutely; however, the radiologist must first have a basic understanding of the spectrum of normal developmental anatomy and its anatomic variations in order to make an accurate assessment. This review article attempts to provide the basic framework required for accurate interpretation of cervical spine imaging with a focus on the dens, specifically covering the normal development and ossification of the dens, common congenital variants and their various imaging appearances, fracture classifications, imaging appearances, and treatment options.

Surgical treatment of Type II odontoid fractures: anterior odontoid screw fixation or posterior cervical instrumented fusion?

Odontoid fractures comprise as many as 20% of all cervical spine fractures. Fractures at the dens base, classified by the Anderson and D’Alonzo system as Type II injuries, are the most common pattern of all odontoid fractures and are also the most common cervical injuries in patients older than 70 years of age. Surgical treatment is recommended for patients older than 50 years with Type II odontoid fractures, as well as in patients at a high risk for nonunion. Anterior odontoid screw fixation (AOSF) and posterior cervical instrumented fusion (PCIF) are both well-accepted techniques for surgical treatment but with unique indications and contraindications as well as varied reported outcomes. In this paper, the authors review the literature about specific patients and fracture characteristics that may guide treatment toward one technique over the other.

AOSF can preserve atlantoaxial motion, but requires a reduced odontoid, an intact transverse ligament, and a favorable fracture line to achieve adequate fracture compression. Additionally, older patients may have a higher rate of pseudarthrosis using this technique, as well as postoperative dysphagia. PCIF has a higher rate of fusion and is indicated in patients with severe atlantoaxial misalignment and with poor bone quality. PCIF allows direct open reduction of displaced fragments and can reduce any atlantoaxial subluxation. It is also used as a salvage procedure after failed AOSF. However, this technique results in loss of atlantoaxial motion, requires prone positioning, and demands a longer operative duration than AOSF, factors that can be a challenge in patients with severe medical conditions. Although both anterior and posterior approaches are acceptable, many clinical and radiological factors should be taken into account when choosing the best surgical approach. Surgeons must be prepared to perform both procedures to adequately treat these injuries.

National trends of incidence, treatment, and hospital charges of isolated C-2 fractures in three different age groups

OBJECT

Incidence of C-2 fracture is increasing in elderly patients. Patient age also influences decision making in the management of these fractures. There are very limited data on the national trends of incidence, treatment interventions, and resource utilization in patients in different age groups with isolated C-2 fractures. The aim of this study is to investigate the incidence, treatment, complications, length of stay, and hospital charges of isolated C-2 fracture in patients in 3 different age groups by using the Nationwide Inpatient Sample (NIS) database. methods The data were obtained from NIS from 2002 to 2011. Data on patients with closed fractures of C-2 without spinal cord injury were extracted using ICD-9-CM diagnosis code 805.02. Patients with isolated C-2 fractures were identified by excluding patients with other associated injuries. The cohort was divided into 3 age groups: < 65 years, 65–80 years, and > 80 years. Incidence, treatment characteristics, inpatient/postoperative complications, and hospital charges (mean and total annual charges) were compared between the 3 age groups.

RESULTS

A total of 10,336 patients with isolated C-2 fractures were identified. The majority of the patients were in the very elderly age group (> 80 years; 42.3%) followed by 29.7% in the 65- to 80-year age group and 28% in < 65-year age group. From 2002 to 2011, the incidence of hospitalization significantly increased in the 65- to 80-year and > 80-year age groups (p < 0.001). However, the incidence did not change substantially in the < 65-year age group (p = 0.287). Overall, 21% of the patients were treated surgically, and 12.2% of the patients underwent nonoperative interventions (halo and spinal traction). The rate of nonoperative interventions significantly decreased over time in all age groups (p < 0.001). Regardless of treatment given, patients in older age groups had a greater risk of inpatient/postoperative complications, nonroutine discharges, and longer hospitalization. The mean hospital charges were significantly higher in older age groups (p < 0.001).

CONCLUSIONS

The incidence of hospitalization for isolated C-2 fractures is progressively increasing in older age groups. Simultaneously, there has been a steadily decreasing trend in the preference for nonoperative interventions. Due to more complicated hospital stay, longer hospitalizations, and higher rates of nonroutine discharges, the patients in older age groups seem to have a higher propensity for greater health care resource utilization.

Upper cervical injuries: Clinical results using a new treatment algorithm

Introduction:

Upper cervical injuries (UCI) have a wide range of radiological and clinical presentation due to the unique complex bony, ligamentous and vascular anatomy. We recently proposed a rational approach in an attempt to unify prior classification system and guide treatment. In this paper, we evaluate the clinical results of our algorithm for UCI treatment.

Materials and Methods:

A prospective cohort series of patients with UCI was performed. The primary outcome was the AIS. Surgical treatment was proposed based on our protocol: Ligamentous injuries (abnormal misalignment, facet perched or locked, increase atlanto-dens interval) were treated surgically. Bone fractures without ligamentous injuries were treated with a rigid cervical orthosis, with exception of fractures in the dens base with risk factors for non-union.

Results:

Twenty-three patients treated initially conservatively had some follow-up (mean of 171 days, range from 60 to 436 days). All of them were neurologically intact. None of the patients developed a new neurological deficit. Fifteen patients were initially surgically treated (mean of 140 days of follow-up, ranging from 60 to 270 days). In the surgical group, preoperatively, 11 (73.3%) patients were AIS E, 2 (13.3%) AIS C and 2 (13.3%) AIS D. At the final follow-up, the American Spine Injury Association (ASIA) score was: 13 (86.6%) AIS E and 2 (13.3%) AIS D. None of the patients had neurological worsening during the follow-up.

Conclusions:

This prospective cohort suggested that our UCI treatment algorithm can be safely used. Further prospective studies with longer follow-up are necessary to further establish its clinical validity and safety.

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.

Odontoid balloon kyphoplasty associated with screw fixation for Type II fracture in 2 elderly patients

Anterior screw fixation is a well-recognized technique that is used to stabilize Type IIB fractures of the odontoid process in the elderly. However, advanced age and osteoporosis are 2 risk factors for pseudarthrosis. Kyphoplasty has been described in the treatment of lytic lesions in C-2. The authors decided to combine these 2 techniques in the treatment of unstable fractures of the odontoid. Two approximately 90-year-old patients were treated for this type of fracture. Instability was demonstrated on dynamic radiography in one patient, and the fracture was seen on static radiography in the other. Clinical parameters, pain, range of motion, 36-Item Short Form Health Survey (SF-36) score (for the first patient), and radiological examinations (CT scans and dynamic radiographs) were studied both before and after surgery. After inflating the balloon both above and below the fracture line, the authors applied a high-viscosity polymethylmethacrylate cement. Some minor leakage of cement was noted in both cases but proved to be harmless. The screws were correctly positioned. The clinical result was excellent, both in terms of pain relief and in the fact that there was no reduction in the SF-36 score. The range of motion remained the same. A follow-up CT scan obtained 1 year later in one of the patients showed no evidence of change in the materials used, and the dynamic radiographs showed no instability. This combination of kyphoplasty and anterior screw fixation of the odontoid seems to be an interesting technique in osteoporotic Type IIB fractures of the odontoid process in the elderly, with good results both clinically and radiologically.

Reliability of the STIR sequence for acute type II odontoid fractures

BACKGROUND AND PURPOSE

The STIR sequence is routinely used to assess acute traumatic osseous injury. Because the composition of the odontoid in older individuals may be altered with osteopenia and decreased vascularity, the STIR sequence may not accurately depict the acuity of an odontoid fracture. The purpose of this study was to evaluate the reliability of the STIR sequence to differentiate acute-versus-chronic type II odontoid fractures in older patients, particularly those with osteopenia.

MATERIALS AND METHODS

A retrospective review was performed for patients with type II odontoid fractures during a 10-year period with both CT and MR imaging performed within 24 hours of injury. Patients were paired with controls of similar ages and were grouped by age. The STIR images were evaluated in a blinded fashion for the presence of hyperintensity in the odontoid. Demographic and clinical characteristics were also recorded.

RESULTS

Seventy-five patients with type II odontoid fracture and 75 healthy controls (mean and median age of 57 years) were identified. The sensitivity of STIR to detect fracture in the age group 57 years and older was significantly worse than that in the age group younger than 57 years (54% and 82%, respectively; P = .018).

CONCLUSIONS

Older patients, particularly those with osteopenia, may have acute odontoid injuries without corresponding STIR hyperintensity. Additionally, interobserver agreement in STIR interpretation decreases with increasing patient age. As such, in this patient population, in which the presence of bone marrow edema as an indicator of fracture acuity may impact therapeutic decisions, correlation with CT findings and clinical history is crucial.

Injury patterns and outcomes of open fractures of the proximal ulna do not differ from closed fractures

BACKGROUND

The incidence and injury patterns of open fractures of the proximal ulna are poorly elucidated and little evidence exists to guide management.

QUESTIONS/PURPOSES

The purpose of this study was to compare the (1) bony injury patterns; (2) range of motion (ROM) and frequency of union; and (3) postoperative complications between open and closed fractures of the proximal ulna.

METHODS

Seventy-nine consecutive open fractures of the proximal ulna were identified. After excluding fracture-dislocations, penetrating injuries, and pediatric injuries, 60 were compared in a retrospective case-control study with an age- and sex-matched group of 91 closed fractures to compare the bony injury patterns based on radiographic review. In a subset of 39 open and 39 closed fractures with sufficient followup, chart and radiographic review was performed by someone other than the operating surgeon to compare differences in final ROM, union, and postoperative complication rates at a minimum followup of 3 months (mean, 22 and 15 months; range, 3-86 months and 3-51 months for open and closed fractures, respectively). A total of 12% of the fractures were open (79 of 671) at the three study centers, and the majority of fractures were intraarticular (45 of 60 [75%]) with Gustilo-Anderson Type I and II wounds (54 of 60 [90%]).

RESULTS

Overall, open fractures of the proximal ulna overall did not have more complex bony injury patterns, but there were more anterior olecranon fracture-dislocations among the open fracture group (nine of 60 [15%] versus two of 91 [2%]; p = 0.004) and more posterior olecranon fracture-dislocations in the closed fracture group (31 of 91 [34%] versus seven of 60 [12%]; p = 0.002). Final ROM was not different in both groups and all fractures healed. There was no difference in wound infection rate but a higher secondary procedure rate among open fractures of the proximal ulna (39% versus 23%, p = 0.014).

CONCLUSIONS

In contrast to open fractures of the distal humerus, open fractures of the proximal ulna present with mild soft tissue injuries and do not have more complex bony injury patterns than closed fractures. Our findings suggest that open fractures of the proximal ulna are the result of tension failure of the skin secondary to the limited soft tissue envelope around the proximal ulna. Open fractures of the proximal ulna should be regarded as relatively mild injuries that are not different in severity and prognosis compared with closed fractures.

LEVEL OF EVIDENCE

Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Upper cervical injuries - a rational approach to guide surgical management

CONTEXT

The complex anatomy and the importance of ligaments in providing stability at the upper cervical spine region (O-C1-C2) require the use of many imaging modalities to evaluate upper cervical injuries (UCI). While separate classifications have been developed for distinct injuries, a more practical treatment algorithm can be derived from the injury pattern in UCI.

OBJECTIVE

To propose a practical treatment algorithm to guide treatment based on injuries characteristic of UCI.

METHODS

A literature review was performed on the Pubmed database using the following keywords: (1) "occipital condyle injury"; (2) "craniocervical dislocation or atlanto-occipital dislocation or craniocervical dislocation"; (3) "atlas fractures"; and (4) "axis fractures". Just articles containing the diagnosis, classification, and treatment of specific UCI were included. The data obtained were analyzed by the authors, dividing the UCI into two groups: Group 1 - patients with clear ligamentous injury and Group 2 - patients with fractures without ligament disruption.

RESULTS

Injuries with ligamentous disruption, suggesting surgical treatment, include: atlanto-occipital dislocation, mid-substance transverse ligament injury, and C1-2 and C2-3 ligamentous injuries. In contrast, condyle, atlas, and axis fractures without significant displacement/misalignment can be initially treated using external orthoses. Odontoid fractures with risk factors for non-union are an exception in Group 2 once they are better treated surgically. Patients with neurological deficits may have more unstable injuries.

CONCLUSIONS

Ascertaining the status of relevant ligamentous structures, fracture patterns and alignment are important in determining surgical compared with non-surgical treatment for patients with UCI.