Management of odontoid fractures

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.

Treatment of Axis Body Fractures: A Systematic Review

STUDY DESIGN

Evidence-based systematic review.

OBJECTIVES

To define the optimal treatment of fractures involving the C2 body, including those with concomitant injuries, based upon a systematic review of the literature.

SUMMARY OF BACKGROUND DATA

Axis body fractures have customarily been treated nonoperatively, but there are some injuries that may require operative intervention. High-quality literature is sparse and there are few class I or class II studies to guide treatment decisions.

MATERIALS AND METHODS

A literature search was conducted using PubMed (MEDLINE), Cochrane Central Register of Controlled Trials, and Scopus (EMBASE, MEDLINE, COMPENDEX). The quality of literature was rated according to a grading tool developed by the Center for Evidence-based Medicine. Operative and nonoperative treatment of axis body fractures were compared using fracture bony union as the primary outcome measure. As risk factors for nonunion were not consistently reported, cases were analyzed individually.

RESULTS

The literature search identified 62 studies, of which 10 were case reports which were excluded from the analysis. A total of 920 patients from 52 studies were included. The overall bony union rate for all axis body fractures was 91%. Although the majority of fractures were treated nonoperatively, there has been an increasing trend toward operative intervention for Benzel type III (transverse) axis body fractures. Nearly 76% of axis body fractures were classified as type III fractures, of which 88% united successfully. Nearly all Benzel type I and type II axis body fractures were successfully treated nonoperatively. The risk factors for nonunion included: a higher degree of subluxation, fracture displacement, comminution, concurrent injuries, delay in treatment, and older age.

CONCLUSIONS

High rates for fracture union are reported in the literature for axis body fractures with nonoperative treatment. High-quality prospective studies are required to develop consensus as to which C2 body fractures require operative fixation.

Outcome of Bilateral C1 Laminar Hooks Combined With C2 Pedicle Screw Fixation for the Treatment of C1-C2 Instability: A Report of 18 Cases From a Single Chinese Center

STUDY DESIGN

A retrospective technical report.

OBJECTIVE

To assess the effect of bilateral C1 laminar hooks combined with C2 pedicle screw fixation for the treatment of C1-C2 instability.

SUMMARY OF BACKGROUND DATA

Various posterior atlantoaxial fixations for C1-C2 instability have been developed. However, due to anatomic anomalies of the vertebral artery, the smallness of the pedicle, trajectories of broken screws, or a lack of surgical experience, a simple atlantoaxial fixation technique with good safety and effectiveness is urgently needed.

MATERIALS AND METHODS

From January 2007 to September 2012, 18 patients with C1-C2 instability who underwent posterior bilateral C1 laminar hooks combined with C2 pedicle screw fixation were evaluated. Six patients had acute odontoid fractures (Anderson IIc type), 8 patients had odontoid pseudarthrosis, 3 had os odontoideum, and 1 had a traumatic rupture of the transverse ligament. The mean age at the time of surgery was 34.1 years. The clinical and radiographic analyses were performed before and after the operation and at follow-up.

RESULTS

The follow-up period was 12-78 months (with an average follow-up period of 25.6 mo). All patients were relieved of pain and their neurological symptoms were substantially improved. The postoperative JOA score improved significantly (t=-7.234, P<0.001). No neurological or vascular complications occurred in these cases. The device was placed well and had not loosened or broken and plain radiographs revealed bony fusion in 17 patients. One patient had C1 posterior arch fracture 3 weeks postoperatively and she was followed up for 18 months without revision surgery.

CONCLUSIONS

When appropriate patients were selected, bilateral C1 laminar hooks combined with C2 pedicle screw fixation can be an alternative method to treat C1-C2 instability effectively with a relatively simple procedure. Preoperative planning and evaluation were crucial for the solid atlantoaxial fusion.

Emergency department evaluation and treatment of cervical spine injuries

Most spinal cord injuries involve the cervical spine, highlighting the importance of recognition and proper management by emergency physicians. Initial cervical spine injury management should follow the ABCDE (airway, breathing, circulation, disability, exposure) procedure detailed by Advanced Trauma Life Support. NEXUS (National Emergency X-Radiography Utilization Study) criteria and Canadian C-spine Rule are clinical decision-making tools providing guidelines of when to obtain imaging. Computed tomography scans are the preferred initial imaging modality. Consider administering intravenous methylprednisolone after discussion with the neurosurgical consultant in patients who present with spinal cord injuries within 8 hours.

Mortality in elderly patients following operative and nonoperative management of odontoid fractures

STUDY DESIGN

Retrospective matched cohort study.

OBJECTIVE

To compare mortality in elderly patients with odontoid fractures after operative and nonoperative treatment. In addition, to evaluate potential factors that may increase the risk of mortality in the geriatric population after odontoid fracture.

SUMMARY OF BACKGROUND DATA

Odontoid fractures represent the most common cervical spine fracture in patients over 70. In this population controversy exists as to the optimal treatment of odontoid fractures, especially type II fractures.

METHODS

A retrospective review of all odontoid fractures in patients 75 years of age or older at our institution from 1996 to 2010 was performed. Comorbidities were stratified using the Charlson comorbidity index. Mortality was determined at 3 months, 1, and 5 years.

RESULTS

A total of 96 patients were identified of which 75 met inclusion criteria. The average age of patients included was 82.3 years. The average Charlson comorbidity score for those operated on (2.37) was not significantly different from the nonoperative group (2.46), (P=0.45). At 3 months the operative group had a significantly lower mortality rate than the nonoperative group (P=0.024). There was no significant difference in 1-year (P=0.42) or 5-year (P=0.21) mortality between the operative and nonoperative cohorts. Of the patients treated nonoperatively, those who died within 3 months of treatment had a significantly higher Charlson score (3.98) than those who survived (2.14). Patients who survived at least 1 year after surgery had a significantly lower Charlson score (1.53) than those who died (3.22) within that time frame after surgery (P=0.05).

CONCLUSIONS

There was no significant difference between 1- and 5-year mortality in patients treated operatively or nonoperatively. Regardless of treatment Charlson score had a significant impact on mortality. Age significantly affected mortality in patients treated surgically.

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

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

Efficacy of anterior odontoid screw fixation in the elderly patient: a CT-based biometrical analysis of odontoid fractures

In the elderly population, reported union rates with anterior odontoid screw fixation (AOSF) for odontoid fracture (OF) treatment vary between 23 and 93% when using plain radiographs. However, recent research revealed poor interobserver reliability for fusion assessment using plain radiographs compared to CT scans. Therefore, union rates in patients aged ≥60 years treated with AOSF have to be revisited using CT scans and factors for non-union to be analysed. Prospectively gathered consecutively treated patients using AOSF for odontoid fracture with age ≥60 years were reviewed. Medical charts were assessed for demographics, clinical outcomes and complications. Patients' preoperative radiographs and CT scans were analysed to characterize fracture morphology and type, fracture displacement, presence of atlanto-dental osteoarthritis as well as a detailed morphometric assessment of fracture surfaces (in mm(2)). CT scans performed after a minimum of 3 months postoperatively were analysed for fracture union. Those patients not showing CT-based evidence of completely fused odontoid fracture were invited for radiographic follow-up at a minimum of 6 months follow-up. Follow-up CT-scan were studied for odontoid union as well as the number of screws used and the square surface of screws used for AOSF and the related corticocancellous osseous healing surface of the odontoid fragment (in %) were calculated. Patients were stratified whether they achieved osseous union or fibrous non-union. Patients with a non-union were subjected to flexion-extension lateral radiographs and the non-union defined as stable if no motion was detected. The sample included 13 male (72%) and 5 female (18%) patients. The interval from injury to AOSF was 4.1 ± 5.3 days (0-16 days). Age at injury was 78.1 ± 7.6 years (60-87 years) and follow-up was 75.7 ± 50.8 months (4.2-150.2 months). 10 patients had dislocated fractures, 14 had Type II and 4 "shallow" Type III fractures according to the Anderson classification, 2 had stable C1-ring fractures, 8 had displayed atlanto-dental osteoarthritis. Fracture square surface was 127.1 ± 50.9 mm(2) (56.3-215.9 mm(2)) and osseous healing surface was 84.0 ± 6.8% (67.6-91.1%). CT-based analysis revealed osseous union in 9 (50%) and non-union in 9 patients (50%). Union rates correlated with increased fracture surface (P = 0.02). Statistical analysis revealed a trend that the usage of two screws with AOSF correlates with increased fusion rates (P = 0.06). Stability at C1-2 was achieved in 89% of patients. CT scans are accepted as the standard of reference to assess osseous union. The current study offers an objective insight into the union rates of odontoid fractures treated with AOSF using CT scans in consecutive series of 18 patients ≥60 years. Literature serves evidence that elderly patients with unstable OF benefit from early surgical stabilization. However, although using AOSF for unstable OF yields segmental stability at C1-2 in a high number of patients as echoed in the current study, our analysis stressed that using follow-up CT scans in comparison to biplanar radiographs dramatically reduces osseous union rates compared to those previously reported for AOSF.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Anatomical study of axis for odontoid screw thickness, length, and angle

Anterior odontoid screw fixation is a safe and effective method for treatment of odontoid fractures. The screw treads should fit into the odontoid medulla, should pass the fracture line, and should pull fractured odontoid tip against body of axis in order to achieve optimum screw placement and treatment. This study has demonstrated optimal anterior odontoid screw thickness, length, and optimal angle for safe and strong anterior odontoid screw placement. Dry bone axis vertebrae were evaluated by direct measurements, X-ray measurements, and computerized tomography (CT) measurements. The screw thickness (inner diameter of the odontoid) was measured as well as screw length (distance between anterior-inferior point body of axis and tip of odontoid), and screw angle (the angle between basis of axis and tip of odontoid). The inner diameter of odontoid bone was measured as 6.5+/-1.9 mm, the screw length was 37.6+/-3.3 mm, and the screw angle was 62.4+/-4.7 on CT. There was no statistical difference between X-ray and CT in the measurements of screw thickness and angle. X-ray and CT measurements are both safe methods to determine the inner odontoid diameter and angle preoperatively. Screw length should be measured on CT only. To provide safe and strong anterior odontoid screw fixation, screw thickness, length, and angle should be known preoperatively, and these can be measured on X-ray and CT.

Anterior screw fixation of odontoid fractures comparing younger and elderly patients

STUDY DESIGN

A retrospective, comparative study.

SUMMARY OF BACKGROUND DATA AND OBJECTIVES

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

MATERIAL/METHODS

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

RESULTS

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

CONCLUSION

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

The contemporary treatment of odontoid injuries

STUDY DESIGN

Review article.

OBJECTIVE

To outline current concepts regarding the assessment and treatment of odontoid fractures.

SUMMARY OF BACKGROUND DATA

Odontoid fractures account for 9% to 15% of adult, cervical spine fractures. These injuries usually result from hyperflexion or hyperextension of the cervical spine during low-energy impacts in the elderly or high-energy impacts in the young and middle aged. Neurologic injury associated with these fractures is rare.

METHODS

A review of pertinent literature was conducted. The information gleaned from this review was summarized.

RESULTS

Odontoid fractures should be evaluated with appropriate imaging to assess the fracture itself as well as exclude other contiguous or noncontiguous fractures. The Anderson and D'Alonzo classification system is most commonly used. True type I and III odontoid fractures are generally thought to be relatively stable and are often treated nonoperatively with immobilization. Type II fractures at the base of the odontoid are less stable, and there are differing opinions regarding the precise definition and optimal treatment of these injuries. Nonoperative treatment options for odontoid fractures include external immobilization with a collar or halo. Operative treatment options for odontoid fractures include one of several posterior C1-C2 fusion constructs or anterior odontoid fixation if the fracture pattern is amenable.

CONCLUSIONS

Despite the frequency of odontoid fractures, there is still much debate regarding the optimal treatment of these fractures, especially the type II fractures. This fact may be because of the absence of an ideal solution for this clinical problem. Certainly, prospective controlled clinical studies are needed.

Surgical management of odontoid fractures

Odontoid fractures account for approximately 20% of all cervical fractures, with the majority being type II fractures according to the Anderson and D'Alonzo classification. The treatment of odontoid fractures is determined by multiple factors, including fracture type, presence of associated injuries, patient age, and patient comorbidities. It is generally well accepted that type I and type III injuries heal well with non-operative treatment. However, some type I injuries can be seen in association with occipito-atlantal dislocation; and some type III fractures can be closer to the neck of the odontoid (high and shallow based), and may act like a type II fracture, that is, with an increased probability of nonunion. The treatment of type II fractures remains controversial. Over the past decade, internal fixation has become an accepted treatment for unstable injuries of the cervical spine. Multiple surgical approaches have been proposed. This article reviews the various alternatives for treating odontoid fractures, attempting to give to the reader a broad perspective on the current techniques, including information taken from evidence-based medicine.

Halo jacket in odontoid fractures type II and III

The treatment of odontoid fractures remains controversial. The late results of 14 patients with Anderson D'Alonzo type II and III treated with halo jacket from 1995 to 1999 are presented. The fractures were reduced under image intensifier and stabilized by halo jacket. The immobilization period was 12 weeks. After 1 year, the fracture was roentgenologically consolidated in 12 out of 14 patients (85.7%), and all the patients were without neurological deficit. Nine patients (64.3%) were without subjective complaints, five had a reduced range of motion. Painful motion appeared in four patients (28.6%), and cervical stiffness was noted in five (35.7%). We recommend halo jacket for the treatment of most type II and III odontoid fractures which are unstable or displaced 6 mm and more, except for patients with tetraplegia. Fractures with minimal displacement and without neurological deficit were treated conservatively with rigid collars. In our institution, internal fixation was performed in selected cases. The presence of neurological deficit and the anatomic properties of the fracture site crucially influence the choice of treatment.

Experimental investigation of failure load and fracture patterns of C2 (axis)

The injury mechanism and magnitude of failure load of C2 fractures are important in the clinical treatment of its fixation. The magnitudes of the failure load of C2 and the mechanism of injury in vivo are uncertain. Accordingly, nine C2 vertebrae obtained from cadaver spines, ranging in age from 51 to 80 years, were used for the study. Special restraint conditions were applied to yield specific fracture of C2. With the posterior element potted postero-anteriorly up to one-quarter of the inferior facet, posterior shear force ranging from 840 to 1220N was required to cause fracture across the pars interarticularis. For odontoid fracture study, a special rig was fabricated to encapsulate the body of C2 in a cell using ISOPON, and a thin layer of ISOPON sandwiched between the inferior facets and two lateral plates. The assembled rig permits slight sagittal movement of C2 about the cup lateral pivot supports. Failure load of between 900 and 1500N was recorded for odontoid fracture. These values are in agreement with published data. The experiment carried out under these two different restraint conditions had specifically resulted in different fractures of C2. In reality, depending on factors such as the inclination of this force vector applied to the head, the precise posture at the time of trauma, the spinal geometry, and the physical properties, different types of fracture patterns of C2 may be produced. This additional data will be useful in the biomechanical study of C2 vertebra using analytical approaches, and in surgical anterior/posterior fixation using screws.

Use of calcitonin for the treatment of an odontoid fracture. Case report

The authors report on the efficacy of nonsurgical treatment of an older patient with a fractured odontoid process. The patient, an 85-year-old woman, had multiple medical problems that put her at an increased surgery-related risk. Therefore, an alternative approach was elected, including immobilization with a Philadelphia collar and the provision of calcitonin nasal spray. Bone union and clinical recovery were achieved within 8 weeks of initiating the nasal calcitonin therapy (12 weeks postinjury). Considering the patient's age, comorbidities, and the severity of the fracture, the recovery period was unusually short. The authors believe that calcitonin played a pivotal role in the healing process of the fractured odontoid bone. There is no question that the fusion in this patient could be unrelated to the medical therapy. This description of one patient, as well as the lack of a large randomized study, precludes any scientific conclusions. Nevertheless, the authors believe that the development of a successful fusion in this high-risk patient should be reported as an observation that merits confirmation and study. The authors also discuss the physiological effects of calcitonin and the research and clinical experience with this hormone in different conditions affecting bone.

Validation and use of a finite element model of C-2 for determination of stress and fracture patterns of anterior odontoid loads

OBJECT

The finite element (FE) method is a powerful tool for the analysis of stress patterns of anatomical structures. In this study a highly refined FE model of C-2 was created and validated. The model was then used to characterize stress patterns, predicted fracture patterns, and transitions between Type II and Type III odontoid fractures.

METHODS

An anatomically accurate three-dimensional model of C-2 was created from computerized tomography data obtained from the Visible Human Project. The C-2 model was broken down into an FE mesh consisting of 32,815 elements and 40,969 nodes. For validation, the FE model was constrained and loaded to simulate that used in previous biomechanical studies. The validated model was then loaded in an iterative fashion, varying the orientation of the load within the validated range. A matrix of stress plots was created for comparative analysis. Results of the validation testing closely correlated with those obtained in previous biomechanical testing. Pure extension loading produced a Type III stress pattern with maximum stress of 134 MPa. Loading at 45 degrees produced a Type II stress distribution with a maximum stress of 123 MPa. These stresses are within 3% and 11%, respectively, of the reported yield stress of cortical bone (138 MPa). In the second portion of the study, systematic variation in the orientation of the load vector revealed that higher stresses were associated with increased lateral angulation and increasing upward inclination of the load vectors. A transition from a Type III to Type II pattern occurred with lateral orientations greater than 15 degrees and with compressive loads of 45 degrees.

CONCLUSIONS

The validated C-2 FE model described in this study both qualitatively and quantitatively was able to simulate the behavior of the C-2 vertebra in biomechanical testing. In this study the authors demonstrate the utility of the FE method when used in conjunction with traditional biomechanical testing.

Type II odontoid fractures in the elderly: early failure of nonsurgical treatment

The optimum treatment of Type II odontoid fractures in the geriatric population remains controversial. Coexisting medical conditions encountered in the elderly patient often increase operative risk and make cervical immobilization difficult to tolerate. Previous studies have shown increased morbidity and mortality and decreased fusion rates for Type II odontoid fractures treated with cervical orthoses in the geriatric population, whereas low morbidity and mortality rates with operative management have recently been documented. To investigate the role of surgical and nonsurgical treatment, a retrospective analysis was performed of patients with Type II odontoid fractures who were at least 65 years old and were consecutively admitted to a single medical center from 1994 to 1998. Twenty patients met inclusion criteria. In 12 patients nonsurgical management with a cervical orthosis was attempted. The nonsurgical management failed early in six patients, with one associated death. Eleven patients were treated surgically with either anterior odontoid screw fixation or posterior C1–2 transarticular screw fixation and modified Gallie fusion. Postoperatively one patient required revision of the C1–2 transarticular screws, and there was one death. In conclusion Type II odontoid fractures in this elderly population were associated with early 10% morbidity and 20% mortality rates. Nonsurgical management of Type II odontoid fractures failed early in six (50%) of 12 patients, whereas surgical treatment failed early in one of 11 (9%) patients. Both the nonsurgical and surgical treatments resulted in approximately 10% morbidity and 10% mortality rates.

Efficacy of anterior odontoid screw fixation in elderly patients with Type II odontoid fractures

Object

Type II odontoid fractures are the most common trauma-related dens fracture. Although Type III odontoid fractures have a high union rate when external immobilization is applied, Type II fractures are associated with high rates of nonunion, particularly in elderly patients and those with posteriorly displaced fractures or fractures displaced by more than 6 mm. Because elderly patients may not also tolerate external immobilization in a halo vest, alternative techniques should be explored to identify a method for managing these higher-risk patients. In this study the authors examine the efficacy of anterior odontoid screw fixation in a high-risk group of 10 elderly patients (> 65 years of age) treated for Type II odontoid fractures.

Methods

A retrospective review of all patients with Type II odontoid fractures treated at two institutions between September 1997 and March 2000 was performed. Demographic data, neurological examination, fracture type and degree of displacement, treatment method, and outcome data were examined at discharge. Ten patients older than 65 years who had sustained a trauma-related odontoid fracture and had undergone an anterior odontoid screw placement procedure were retrospectively reviewed. Fracture displacement (mean 6.6 mm) was observed in all but one patient, and in seven there were posteriorly displaced fractures. Seven were successfully treated with anterior screw fixation and external orthosis alone; in one patient in whom poor intraoperative screw purchase had been observed, the fracture healed after undergoing halo vest therapy. Only one patient was shown to develop a nonunion requiring a subsequent posterior fusion procedure.

Conclusions

Odontoid screw fixation can be safely performed in elderly patients, and frequent bone union is demonstrated. However, osteopenia may preclude adequate screw fixation in some patients.

Emergency department evaluation and treatment of the neck and cervical spine injuries

In the United States, nearly 5 million patients per year require spinal immobilization. The emergency physician (EP) must be able to efficiently and effectively manage these patients. To do so, the EP must have an understanding of cervical spine anatomy, spinal immobilization techniques, specific injury patterns, optimal imaging studies, and associated injuries and treatment modalities. This article addresses these important issues and discusses other challenges in the management of cervical spine injuries.

Survey of state EMS-DNR laws and protocols

Author presents the results of a survey of state emergency medical services do-not-resuscitate laws and protocols that have been implemented statewide and describes their structural and operational characteristics, as well as responses from key state contacts on program challenges and issues.