Isolated fractures of the axis in adults

Early Extrusion of an Anterior Odontoid Screw: A Case Report

Odontoid fractures in the elderly typically require surgical intervention due to poor adaptability to conservative treatment. Anterior screw fixation, despite its high fusion rates under specific conditions, may lead to complications such as screw extrusion, as demonstrated in the case discussed, necessitating subsequent posterior cervical fusion. This study aimed to describe early extrusion of an anterior odontoid screw and the importance of caution and thorough postoperative assessment in elderly patients undergoing anterior screw fixation for odontoid fracture. A 73-year-old female patient with a history of ground-level fall and subsequent cervical pain was diagnosed with an odontoid type II fracture and underwent odontoid screw placement in June 2023. However, in August, follow-up imaging revealed screw displacement and a fracture of the posterior arch of the C1 vertebral, which was initially overlooked. After seeking a second opinion, a new surgical approach was decided, involving removal and replacement of the odontoid screw, posterior and posterolateral C1-C2 spinal instrumentation, arthrodesis, and fusion with the use of morselized allograft. The patient was discharged on postoperative day 3 with mild cervical pain, wearing a soft collar, and neurologically intact. Given the current literature, odontoid screw extrusion rates are still small but can come with enormous potential complications. Also, the present case is a reminder to always double-check preoperative imaging and recognize early failure/malpositioning of hardware.

A Predictive Model to Identify Treatment-related Risk Factors for Odontoid Fracture Nonunion Using Machine Learning

STUDY DESIGN

Multicenter retrospective analysis of routinely collected data.

OBJECTIVE

The underlying aim of this study was to identify potential treatment-related risk factors for odontoid fracture nonunion while accounting for known patient- and injury-related risk factors.

SUMMARY OF BACKGROUND DATA

Type II and III odontoid fractures represent the most common cervical spine fracture in elderly patients and are associated with a relatively high nonunion rate. The management of odontoid fractures is controversial and treatment strategies range from conservative treatment to extensive surgical stabilization and fusion.

METHODS

A total of 415 individuals who sustained odontoid fracture and were treated in either of four tertiary referral centers in Austria and Germany were included in the study. We included the following potential contributing factors for fracture nonunion in cross-validated extreme gradient boosted (XGBoost) and binary logistic regression models: age, gender, fracture displacement, mechanism of injury (high vs. low energy), fracture classification (Anderson II vs. III), presence of comorbidities (Charlson comorbidity index), and treatment (conservative, anterior screw fixation with one or two screws, posterior C1/C2 spondylodesis, cervico-occipital C0-C4 fusion).

RESULTS

In our cohort, 187 (45%) had radiologically confirmed odontoid nonunion six months postinjury. The odds for nonunion increase significantly with age, and are lower in type III compared to type II fractures. Also, odds for nonunion are significantly lower in posterior C1/C2 spondylodesis, and C0-C4 fusion compared to conservative treatment. Importantly, odds are not statistically significantly lower in the group treated with anterior screw fixation compared to conservative treatment. The factors gender, fracture displacement, mechanism of injury, and the presence of comorbidities did not produce significant odds.

CONCLUSION

Higher age, type II fractures, and conservative treatment are the main risk factors for odontoid nonunion. Anterior screw fixation did not differ significantly from conservative treatment in terms of fracture union.

LEVEL OF EVIDENCE

3.

Proposal of Treatment Strategy for Pedicle Fractures of the C2: An Analysis of 49 Cases

Spine surgeons often confuse C2 pedicle fractures (PFs) with pars interarticularis fractures. In addition, little information is available about the characteristics and treatment strategies for C2 PFs. We sought to investigate the characteristics of C2 PFs and to propose an appropriate treatment strategy. A total of forty-nine patients with C2 PFs were included in this study. We divided these patients into unilateral and bilateral C2 PF groups. The incidence rates and characteristics of other associated C2 and C2-3 injuries, and other cervical injuries, were evaluated. In addition, treatment methods and outcomes were analyzed. Twenty-two patients had unilateral C2 PFs and twenty-seven patients had bilateral C2 PFs. Among the cases of unilateral C2 PFs, all patients had one or more other C2 fractures, and twenty patients (90.9%) had one or two C2 body fractures. Meanwhile, among the cases of bilateral C2 PF, all patients had two or more other C2 fractures and one or two C2 body fractures. In unilateral C2 PFs, three patients with C2-3 anterior slip or adjacent cervical spine (C1-3) injury underwent surgery and nineteen patients (86.4%) were treated with conservative methods. In bilateral C2 PFs, three patients with C2-3 anterior slip or SCI at C2-3 underwent surgery and twenty-four patients (88.9%) were treated with conservative methods. Our results showed that C2 PFs do not occur alone and are always accompanied by other associated C2 injuries. C2 PFs should, generally, be thought of as a more complex fracture type than hangman's fracture or dens fracture. Despite the complex fracture characteristics, most C2 PFs can be managed with conservative treatment. However, surgical treatments should be considered if the C2 PFs are accompanied by the C2-3 anterior slip and adjacent cervical spine injury.

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

STUDY DESIGN

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

OBJECTIVE

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

SUMMARY OF BACKGROUND DATA

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

STUDY DESIGN

Retrospective cohort analysis.

OBJECTIVE

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

SUMMARY OF BACKGROUND DATA

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

C2 Body Fracture: Report of Cases Managed Conservatively by Philadelphia Collar

Study Design

Case series.

Purpose

To present results of conservative management in patients with pure C2 body fractures.

Overview of Literature

Axis body fractures, a less common subgroup of C2 fractures, are commonly classified as vertical coronal, vertical sagittal, and transverse subtypes. While the treatment paradigm for other C2 fractures is clear, there is insufficient evidence to support treatment guidelines for C2 body fractures.

Methods

Eleven patients with pure C2 body fractures were managed with external immobilization and followed thereafter.

Results

All neurologic examinations were normal. In computed tomography (CT) scans, four, two, three, and two patients had a coronal, sagittal, horizontal, and burst fracture, respectively. Magnetic resonance imaging showed hematoma and partial rupture in the anterior longitudinal ligament in four patients, posterior ligamentous complex injury in one, and normal ligamentous structure in six. All fractures were managed conservatively using the Philadelphia collar, which was continued until complete disappearance of symptoms (within 1–3 months in all patients). The decision to discontinue the neck collar was made by a dynamic neck X-ray and CT scan that showed complete bony fusion. All patients were then followed for an additional 1.5 years (mean follow-up of 21 months for all patients). No patient showed any neurologic symptoms or deficits during the follow-up period.

Conclusions

In patients with pure C2 body fracture, non-operative management with Philadelphia neck collar is a safe and efficacious option, even in the presence of some sort of ligamentous injury.

Impact of associated injuries in conjunction with fracture of the axis vertebra on inpatient outcomes and postoperative complications: a Nationwide Inpatient Sample analysis from 2002 to 2011

BACKGROUND CONTEXT

There are limited data available on the impact of associated spinal (other spinal injuries [OSIs]) and extra-spinal injuries (ESIs) occurring in conjunction with fractures of the axis vertebra (C2) on clinical outcomes.

PURPOSE

This study aimed to compare outcomes in patients with isolated C2 fractures versus patients with associated injuries in conjunction with C2 fractures.

STUDY DESIGN/SETTING

A retrospective cohort study.

PATIENT SAMPLE

A total of 30,472 adult patients with C2 fractures (International Classification of Diseases, Ninth Revision, Clinical Modification code 805.02) registered in the Nationwide Inpatient Sample (NIS) database (2002-2011) comprised the patient sample.

OUTCOME MEASURES

Inpatient mortality, unfavorable discharge, prolonged length of stay (LOS) and high-end hospital charges in the non-operative and operative cohorts, and postoperative complications (deep venous thrombosis [DVT]; acute renal failure [ARF]; respiratory complications and wound infections) for the operative cohort were the outcome measures.

METHODS

Patients were stratified into four categories based on injury type: (1) isolated C2 fracture (n=10,135; 33.3%); (2) C2 fracture+OSI (8.7%); (3) C2 fracture+ESI (37.2%); and (4) C2 fracture+OSI+ESI (20.8%). Multivariable logistic regression fitted with generalized estimating equations using the sandwich variance-covariance matrix estimator to account for clustering of similar outcomes within hospitals was used to examine the association of primary endpoints for each of the associated injury categories with reference to isolated C2 fractures.

RESULTS

Mean age of the cohort was 66.27±21.67 years and 52% were female. Of the cohort, 52% underwent surgical intervention for C2 fracture. In a pooled regression analysis involving the operative cohort, the risks for inpatient mortality (odds ratio [OR]: 3.77; 95% confidence interval [CI]: 3.02-4.70; p<.001), unfavorable discharge (OR: 1.83; 95% CI: 1.66-2.01; p<.001), prolonged LOS (OR: 1.33; 95% CI: 1.18-1.50; p<.001), high hospital charges (OR: 1.49; 95% CI: 1.31-2.69; p<.001), DVT (OR: 2.08; 95% CI: 1.61-2.68; p<.001), and ARF (OR: 1.46; 95% CI: 1.16-1.83; p=.001) were significantly higher in patients with additional injuries when compared with patients with C2 fractures alone. Likewise, increased chances of inpatient mortality (OR: 1.40; 95% CI: 1.21-1.62; p<.001), unfavorable discharge (OR: 1.24; 95% CI: 1.15-1.34; p<.001) and high hospital charges (OR: 1.31; 95% CI: 1.21-1.43; p<.001) were observed in a pooled analysis of patients with concomitant associated injuries in the non-operative cohort.

CONCLUSIONS

Associated injuries occurring concomitantly with C2 fractures adversely influence postoperative outcomes. In comparison to isolated C2 fractures, patients with associated injuries tend to have a greater propensity for higher health-care resource use because of more complicated and longer hospital inpatient stay.

A Novel Anterior Odontoid Screw Plate for C1-C3 Internal Fixation: An In Vitro Biomechanical Study

STUDY DESIGN

A biomechanical in vitro study was performed using a standardized experimental protocol in a biomechanical spine testing apparatus.

OBJECTIVE

The aims of this study were to evaluate the biomechanical stability afforded by 4 cervical fixation techniques: anterior cervical plate+odontoid screw+cage (ACP+OS+cage), anterior odontoid screw plate+bone graft (AOSP+bone graft), posterior C2-3 fixation+odontoid screw (C2PS+C3LMS+OS), and posterior C1-3 fixation (C1PS+C2PS+C3LMS).

SUMMARY OF BACKGROUND DATA

Unstable axis injuries with multiple fracture lines are uncommon injuries, and their management is still challenging for surgeons who aim to achieve primary stability, early mobilization, preserved cervical range of motion (ROM), and favorable outcome. We designed a novel AOSP to assist in this challenging clinical scenario.

METHODS

Eight fresh-frozen cadaveric spine specimens (C1-C3) were subjected to stepwise destabilization of the C1-3 complex, with serial replication of a type II Hangman fracture, a type II odontoid fracture, and a C2 to C3 disc injury. Intact specimens, destabilized specimens, and destabilized specimens with various stabilization techniques including anterior and posterior techniques, some using our AOSP, were each tested for stability. Each spine was subjected to flexion, and extension testing, left and right lateral bending, and left and right rotation.

RESULTS

After AOSP+bone graft fixation, the ROMC2-C3 during all loading modes were reduced to values that were significantly less than normal. During all loading modes, AOSP+bone graft fixation significantly outperformed the ACP+OS+cage fixation in limiting ROMC2-C3. During flexion and extension, AOSP+bone graft fixation significantly outperformed the C1PS+C2PS+C3LMS fixation and C2PS+C3LMS+OS fixation in limiting ROMC2-C3.

CONCLUSION

The AOSP has excellent biomechanical performance when dealing with type I Hangman fractures, type II odontoid fractures, and C2-3 disc injuries. The AOSP+one graft fixation can preserve the function of atlanto-axial joint, which may be a valuable stabilization strategy for these unique injuries.

Delayed pharyngeal extrusion of an anterior odontoid screw

A 27-year-old woman with a type II odontoid fracture was treated by anterior odontoid screw fixation. Radiographic union at the fracture site was obtained 3 months after surgery. Nearly 3 years after surgery, she presented at a local Ear, Nose, and Throat (ENT) clinic with a 2-month history of dysphagia. Laryngoscopy identified the head of the odontoid lag screw. Plain radiography showed that the head of the screw had migrated into the pharyngeal soft tissue. The atlantoaxial joint was stable, and computed tomography (CT) scans confirmed odontoid fracture fusion. The screw was found to be movable during endoscopy. The screw could be removed by using a transpharyngeal endoscopic approach under general anesthesia. The failure of the screw was considered to be due in part to malpositioning of the screw and in part to local infection. A transoropharyngeal endoscopic approach to remove the loose anterior odontoid screw was feasible.

Physician-industry conflict of interest: public opinion regarding industry-sponsored research

Object

The nature of physician-industry conflict of interest (COI) has become a source of considerable concern, but is often not discussed in the research setting. With reduced funding available from government and nonprofit sources, industry support has enthusiastically grown, but along with this comes the potential for COI that must be regulated. In this era of shared decision making in health care, society must have input into this regulation. The purpose of this study was to assess the opinions of a North American population sample on COI regarding industry-funded research and to analyze population subgroups for trends.

Methods

A survey was developed for face and content validity, underwent focus group evaluation for clarity and bias reduction, and was administered via the World Wide Web. Demographic and general survey results were summarized as a percentage for each answer, and subgroup analysis was done using logistic regression. Generalizability of the sample to the US population was also assessed.

Results

Of 541 surveys, 40 were excluded due to missing information, leaving 501 surveys for analysis. The sample population was composed of more females, was older, and was more educated than a representative cross-section of the American population. Respondents support multidisciplinary surgeon-industry COI regulation and trust doctors and their professional societies the most to head this effort. Respondents trust government officials and company representatives the least with respect to regulation of COI. Most respondents feel that industry-sponsored research can involve physicians and be both objective and beneficial to patients.

Conclusions

Most respondents in this study felt that surgeons should be involved in industry-sponsored research and that more research, regardless of funding source, will ultimately benefit patients. The majority of respondents distrust government or industry to regulate COI. The development of evidence-based treatment recommendations requires the inclusion of patient preference. The authors encourage regulatory bodies to follow suit and include society's perspective on regulation of COI in research.

Inception of an Australian spine trauma registry: the minimum dataset

Background The establishment of a spine trauma registry collecting both spine column and spinal cord data should improve the evidential basis for clinical decisions. This is a report on the pilot of a spine trauma registry including development of a minimum dataset. Methods A minimum dataset consisting of 56 data items was created using the modified Delphi technique. A pilot study was performed on 104 consecutive spine trauma patients recruited by the Victorian Orthopaedic Trauma Outcomes Registry (VOTOR). Data analysis and collection methodology were reviewed to determine its feasibility. Results Minimum dataset collection aided by a dataset dictionary was uncomplicated (average of 5 minutes per patient). Data analysis revealed three significant findings: (1) a peak in the 40 to 60 years age group; (2) premorbid functional independence in the majority of patients; and (3) significant proportion being on antiplatelet or anticoagulation medications. Of the 141 traumatic spine fractures, the thoracolumbar segment was the most frequent site of injury. Most were neurologically intact (89%). Our study group had satisfactory 6-month patient-reported outcomes. Conclusion The minimum dataset had high completion rates, was practical and feasible to collect. This pilot study is the basis for the development of a spine trauma registry at the Level 1 trauma center.

Do concomitant cranium and axis injuries predict worse outcome? A trauma database quantitative analysis

We performed a trauma database analysis to identify the effect of concomitant cranial injuries on outcome in patients with fractures of the axis. We identified patients with axis fractures over a 14-year period. A binary outcome measure was used. Univariate and multiple logistic regression analysis were performed. There were 259 cases with axis fractures. Closed head injury was noted in 57% and skull base trauma in 14%. Death occurred in 17 cases (6%). Seventy-two percent had good outcome. Presence of abnormal computed tomography head findings, skull base fractures, and visceral injury was significantly associated with poor outcome. Skull base injury in association with fractures of the axis is a significant independent predictor of worse outcomes, irrespective of the severity of the head injury. We propose that presence of concomitant cranial and upper vertebral injuries require careful evaluation in view of the associated poor prognosis.

Oblique axis body fracture--pitfalls in management

BACKGROUND

Transverse fractures through the body of the axis, rather than at the base of the odontoid are uncommon and management with an external orthosis is usually recommended. Oblique fractures through the body of the axis accompanying a hangman's fracture have not been reported and are not described as part of any classification system. Such fractures may be at high risk for treatment failure in an external orthosis.

CASE DESCRIPTION

We report on a case of an oblique axis fracture that failed treatment with external orthosis. Posterior instrumented fusion was employed successfully using a C1-C3 and C4 poly axial screw rod construct. Frameless stereotaxy and a biomodel were useful surgical adjuncts. Twelve month follow up revealed bony union in an asymptomatic patient.

CONCLUSIONS

Oblique fractures of the body of the axis can displace in a halo-thoracic orthosis. Serial radiological review is required to detect displacement prior to fracture union. Oblique fractures of the body of the axis can be managed surgically with preservation of atlanto-occipital motion, resulting in satisfactory clinical and radiological outcomes.

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.

Atlanto-axial deformity secondary to a neglected odontoid fracture: a report of six cases

We reviewed 6 patients with atlanto-axial (C1-2) deformities secondary to neglected odontoid fractures. All patients (except one with recent injury) were asymptomatic for a long period before development of neck pain or myelopathy, despite obvious subluxation and kyphotic deformities at the C1-2 joint complex. Patients were treated conservatively, except for one who underwent posterior spinal fusion and occiput-to-C2 decompression for progressive myelopathy. The reactive new bone formation around the odontoid fracture may play a role in preventing further movement and development of myelopathy. Conservative treatment should be considered for neglected odontoid fractures in elderly patients with stable non-progressive C1-2 deformity.

Teriparatide may accelerate healing in delayed unions of type III odontoid fractures: a report of 3 cases

STUDY DESIGN

Case Report.

OBJECTIVE

To report on the treatment of 3 cases of painful delayed unions of type III odontoid fractures with teriparatide.

SUMMARY OF BACKGROUND DATA

Fractures of the C2 vertebra, also known as odontoid fractures, are an important subset of cervical spine fractures. Type III odontoid fractures pass through predominately cancellous bone of C2. Generally accepted treatment is external immobilization with either a rigid collar or a halo vest for 8 to 12 weeks. We report 3 patients who, despite external immobilization, developed painful delayed unions of type III odontoid fractures. Teriparatide is a novel anabolic drug therapy for osteoporosis. It has been shown to stimulate osteoblasts, enhance bone connectivity, increase endosteal cortical thickness, and improve bone mineral content. The drug is given through subcutaneous injection of 20 microg/d for between 6 weeks and 2 years. We treated these 3 patients with teriparatide. Each was informed that details of their case would be submitted for publication.

METHODS

Retrospective case analysis.

RESULTS

All 3 patients experienced both rapid clinical improvement and computed tomography evidence of fracture union.

CONCLUSION

These 3 cases represent relatively uncommon clinical scenarios in which type III odontoid fractures in osteoporotic women failed to unite with external immobilization over several months. The patients presented for follow-up with substantial, activity-limiting neck pain. All 3 were begun on teriparatide doses therapeutic for osteoporosis, and all 3 experienced both remarkable resolution of chronic neck pain and computed tomography-confirmed union of the fractures.

Brown-Sèquard syndrome caused by type III odontoid fracture: a case report and review of the literature

STUDY DESIGN

Case report.

OBJECTIVE

To present the second case of Brown-Sèquard syndrome (BSS) produced by type III odontoid fracture managed by conservative treatment.

SUMMARY OF BACKGROUND DATA

The occurrence of BSS due to odontoid fracture is scarce. So far 6 cases have been reported, and only 1 is produced by type III odontoid fracture. The possible pathophysiology, clinical course and treatment outcome have been rarely discussed.

METHODS

A 39-year-old man presented with weakness of his left arm and leg, mild neck pain, and impaired proprioceptive and light touch sensations below the left C2 dermatome. There were decreased pain and temperature sensations below the right C4 dermatome too. Computerized tomography showed odontoid type III fracture with posterior displacement at that level. Magnetic resonance imaging presented focal hyperintensity around the C2 vertebral level. High dose of prednisolone, close reduction with Gardner-Wells tong skull traction, following external stabilization by Halo-Vest and rehabilitation therapy were applied.

RESULTS

Complete resolution of neck pain and significant improvement of motor and sensory functions, i.e., light touch and proprioception, were shown 2 months after spinal injury. Impaired temperature discrimination persisted, however.

CONCLUSION

BSS is rarely caused by type III odontoid fracture and this is the second report. Conservative intervention is advantageous for both type III odontoid fracture and BSS which is consistent with previous results.

Operative versus nonoperative management of acute odontoid Type II fractures: a meta-analysis

Object

The purpose of this study was to evaluate the feasibility of the criteria described in the literature as the indications for surgery for acute Type II odontoid fractures.

Methods

The authors searched the PubMed database for studies in which the fusion rate of acute Type II odontoid fractures following external immobilization (halo vest or collar) or surgery (posterior C1–2 fusion or anterior screw fixation) was reported. The only studies included reported the fusion rate for either 1) groups of patients whose age was either more or less than a certain age range (45–55 years); or 2) groups of patients with a fracture displacement of either more or less than a certain odontoid fracture displacement (4–6 mm) or the direction of displacement (see Methods section of text for more details). A meta-analysis in which the random effect model was used was conducted to analyze the data.

Results

There was a statistically significantly higher fusion rate for operative management compared with external immobilization (85 vs 60%, p = 0.01) for the patients > 45–55 years. However, the overall fusion rate was > 80% for the patients whose age was < 45–55 years, regardless of treatment modality, and no significant differences were observed between surgically and nonsurgically treated patients (89 and 81%, respectively; p = 0.29). The result of operation (overall fusion rate 89%) was superior to external immobilization (44%) when the fracture was posteriorly displaced (p < 0.001), but for anteriorly displaced fractures, the results of operative and nonoperative management were identical (p = 0.15). The overall fusion rate of operative management of both anteriorly and posteriorly displaced fractures proved to be > 85%, and no statistically significant difference was observed (p = 0.50). For all degrees of displacement (either > or < 4–6 mm) the operation proved to provide significantly better results than conservative treatment. The fusion rate of conservatively treated fractures with < 4–6 mm displacement was significantly better than in fractures with > 4–6 mm displacement (76 vs 41%, p = 0.002).

Conclusions

Operative treatment (posterior C1–2 fixation or anterior screw fixation) provides a better fusion rate than external immobilization for acute odontoid Type II fractures, although in certain situations, such as anterior displacement of the fracture and for younger (< 45–55 years of age) patients, conservative management (halo vest or collar immobilization) can be as effective as surgery. Operative management is recommended in older patients, in cases of posterior displacement of the fracture, and when there is displacement of > 4–6 mm.

Traumatic spondylolisthesis of the axis: a biomechanical comparison of clinically relevant anterior and posterior fusion techniques

Object

Surgical management of unstable traumatic spondylolisthesis of the axis includes both posterior and anterior fusion methods. The authors performed a biomechanical study to evaluate the relative stability of anterior fixation at C2–3 and posterior fixation of C-1 through C-3 in hangman's fractures.

Methods

Fresh-frozen cadaveric spine specimens (occipital level to T-2) were subjected to stepwise destabilization of the C1–2 complex, replicating a Type II hangman's fracture. Intact specimens, fractured specimens, and fractured specimens with either anterior screw and plate or posterior screw and rod fixation were each tested for stability. Each spine was subjected to separate right and left rotation, bending, flexion, and extension testing.

Results

Anterior fixation restored stiffness in flexion and extension movements to values greater than those for intact specimens. For other movement parameters, the values approximated those for intact specimens. Posterior fixation increased the stiffness to above those values seen for anterior fixation specimens.

Conclusions

In cadaveric spine specimens subjected to a Type II hangman's fracture, both anterior fixation at C2–3 and posterior fixation with C-1 lateral mass screws and C-2 and C-3 pedicle screws resulted in a consistent increase in stiffness, and hence in stability, over intact specimens.

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.

Surgical treatment of C2 fractures in the elderly: a multicenter retrospective analysis

STUDY DESIGN

Multicenter retrospective analysis.

OBJECTIVES

To review the results of surgical treatment during the last 6 years of C2 fractures in patients over the age of 70.

SUMMARY OF BACKGROUND DATA

Little information exists about the clinical outcome of surgical treatment of elderly patients with C2 fractures, their ability to return to their previous environment, and their postoperative level of independence.

METHODS

The medical records and radiographs of 29 patients who had undergone surgical treatment for C2 fractures were reviewed. The type of C2 fracture, neurologic examination at presentation, type of surgical treatment, perioperative morbidity and mortality, presence of osseous union, and stability of alignment were recorded. Long-term disposition was determined from office visits or by telephone interview.

RESULTS

Twenty-four of 29 patients had type II dens fractures alone. The remaining 5 had associated C1 fractures. All patients were neurologically intact at presentation except for 2 patients with signs and symptoms of central cord syndrome. Perioperative complications occurred in 3 patients (10.3%). One patient died on postoperative day 6 from a myocardial infarction. Mean+/-SD radiographic follow-up was 9+/-3.2 months (range, 3 to 24). Of the 16 patients who underwent odontoid screw fixation, 6 (37.5%) had osseous union, and 9 (56.2%) were stable on radiographs. An additional patient who had odontoid screw initially required a posterior approach reoperation. Of the 13 posterior fusions, 4 (30.7%) had osseous unions and 9 (69.2%) were stable on flexion extension radiographs. Mean+/-SD clinical follow-up was 18+/-2.2 months (range, 3 to 72 mo). Twenty-five of 29 patients (86.2%) returned to their previous environment. Two patients died of unrelated etiology.

CONCLUSIONS

C2 fractures in the elderly can be treated surgically with both anterior and posterior approaches with acceptable morbidity and mortality rates. The majority of patients can be mobilized early and return to their previous levels of independence.

Single anterior procedure for stabilization of a three-part fracture of the axis (odontoid dens and hangman fracture): case report

STUDY DESIGN

A case of a 3-part fracture of the axis combining an odontoid dens and a hangman fracture is reported.

OBJECTIVE

To describe a single anterior procedure allowing stabilization with an odontoid screw fixation and a C2-C3 fusion in a case of complex fracture of the axis.

SUMMARY OF BACKGROUND DATA

Even if fractures of the axis are common, multiples fractures of the axis are rare and their management is still challenging for surgeons who have to achieve primary stability, early mobilization, preserved cervical range of motion, and favorable outcome.

METHODS

A 79-year-old man was referred in our neurosurgical department 3 weeks after a bicycle accident. He had persistent neck pain without radicular pain. Neurologic examination was normal. The initial CT scan showed a rare and complex fracture of the axis consisting of a fracture of the dens and a traumatic spondylolisthesis of C2-C3.

RESULTS

The surgical procedure was performed using an anterior cervical approach under fluoroscopic guidance. First, a C2-C3 fusion was performed using an iliac crest graft. Then an anterior odontoid screw was placed under fluoroscopic guidance. Finally, an anterior plating of C2-C3 covering the odontoid screw was achieved. Postoperative course was uneventful and patient was discharged at day 6.

CONCLUSION

This single time procedure was able to achieve primary stability of the fractures of the axis and offers the possibility of an early mobilization of the patient with a good outcome. This approach allowed a better preservation of the cervical range of motion compared with a classic posterior fusion.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Posterior atlanto-axial arthrodesis for fixation of odontoid nonunions

STUDY DESIGN

A retrospective case series.

OBJECTIVE

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

SUMMARY OF BACKGROUND DATA

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.