Evidence-based analysis of odontoid fracture management

Management of fresh odontoid fractures using posterior C1-2 fixation without fusion: a long-term clinical follow-up study

OBJECTIVE

Posterior C1-2 fixation without fusion makes it possible to restore atlantoaxial motion after removing the implant, and it has been used as an alternative technique for odontoid fractures; however, the long-term efficacy of this technique remains uncertain. The purpose of the present study was to explore the long-term follow-up outcomes of patients with odontoid fractures who underwent posterior C1-2 fixation without fusion.

METHODS

A retrospective study was performed on 62 patients with type II/III fresh odontoid fractures who underwent posterior C1-2 fixation without fusion and were followed up for more than 5 years. The patients were divided into group A (23 patients with implant removal) and group B (39 patients without implant removal) based on whether they underwent a second surgery to remove the implant. The clinical outcomes were recorded and compared between the two groups. In group A, the range of motion (ROM) of C1-2 was calculated, and correlation analysis was performed to explore the factors that influence the ROM of C1-2.

RESULTS

A solid fracture fusion was found in all patients. At the final follow-up, no significant difference was found in visual analog scale score or American Spinal Injury Association Impairment Scale score between the two groups (p > 0.05), but patients in group A had a lower Neck Disability Index score and milder neck stiffness than did patients in group B (p < 0.05). In group A, 87.0% (20/23) of the patients had atlantoodontoid joint osteoarthritis at the final follow-up. In group A, the C1-2 ROM in rotation was 6.1° ± 4.5° at the final follow-up, whereas the C1-2 ROM in flexion-extension was 1.8° ± 1.2°. A negative correlation was found between the C1-2 ROM in rotation and the severity of tissue injury in the atlantoaxial region (r = -0.403, p = 0.024) and the degeneration of the atlantoodontoid joint (r = -0.586, p = 0.001).

CONCLUSIONS

Posterior C1-2 fixation without fusion can be used effectively for the management of fresh odontoid fractures. The removal of the implant can further improve the clinical efficacy, but satisfactory atlantoaxial motion cannot be maintained for a long time after implant removal. A surgeon should reconsider the contribution of posterior C1-2 fixation without fusion and secondary implant removal in preserving atlantoaxial mobility for patients with fresh odontoid fractures.

Successful Nonsurgical Management of a Traumatic Dens Fracture in a Cat with Clinical and Radiographic Resolution

An adult domestic shorthair presented with obtundation, vestibular ataxia, head tilt, and visible evidence of facial injury following motor vehicle trauma. Plain radiographs and computed tomography imaging revealed a complete minimally displaced transverse fracture of the caudal aspect of the dens of the C2 vertebra and multiple minimally displaced cranial fractures. The dens fracture was managed with 8 wk of strict rest, followed by 4 wk of supervised activity at home. No external immobilization was performed. Neurological examinations at 8 days, 10 wk, and 9 mo following initial presentation were normal. Repeat radiographic and computed tomography examinations at 10 wk and 9 mo following the traumatic event demonstrated progressive and eventual complete osseous union of the fractured dens. To the authors’ knowledge, this is the first report of successful nonsurgical management of a traumatic dens fracture in an adult cat with documented radiographic and clinical resolution. This report suggests that nonsurgical management can be considered in such cats and that complete resolution with osseous union is feasible.

Morbidity and Mortality in Patients over 90 Years of Age Following Posterior Stabilization for Acute Traumatic Odontoid Type II Fractures: A Retrospective Study with a Mean Follow-Up of Three Years

Odontoid type II fractures represent the most common cervical spine injuries in the elderly. The decision for surgical treatment in very elderly patients is still controversial. The aim of this study was to assess morbidity and mortality in patients over 90 years of age undergoing CT-guided posterior stabilization for unstable odontoid type II fractures. A total of 15 patients with an acute traumatic odontoid type II fracture who received surgical treatment for unstable odontoid type II fractures were retrospectively analyzed. Complications, morbidity, and mortality as well as length of ICU and hospital stay were determined. Clinical follow-up evaluation was based on outpatient presentation and information from family members and general practitioners. Finally, we conducted a comparison of complications rates between patients over 90 years of age and patients between 65 and 89 years old with a type II odontoid fracture after CT-guided posterior stabilization in our institution. The mean age was 91.4 years. Patients were predominately female (87%). In-hospital deaths did not occur. The average length of the hospital stay was 13.4 days and 1.9 days for the ICU. Blood transfusion was necessary in two patients (13%). Two patients (13%) developed urinary tract infection, one patient (7%) a delirium, and another epistaxis (7%). One patient (7%) developed pneumonic sepsis and fully recovered within several weeks. The mean follow-up was 36 months (range 9–72 months). Implant-related complications developed in one patient (7%). Five patients died during the follow-up period, with an average time to death of 26.6 months. Postoperative bracing was not needed in any of the patients. Posterior stabilization of unstable odontoid fractures type II using CT-guided navigation in patients over 90 years of age is a safe and effective procedure with low complications and mortality rates.

Halo vest immobilization - an institutional review of safety in acute cervical spine injury from 2013 to 2017

Objective: Halo vest immobilization (HVI) remains an important treatment option for occipital-cervical injuries. It provides the surgeon with a safe and effective medical treatment options for challenging patients. The aim of this study was to evaluate the safety of HVI in these patients.Methods: This retrospective study identified adult patients treated with Halo vests immobilization (HVI) for acute cervical spine injury at our metropolitan level 1 trauma center from 2013 to 2017. This heterogenous cohort included 67 consecutive patients with acute cervical spine injury secondary to trauma or iatrogenic injury following surgical intervention with a mean age of 52 and a mean injury severity score (ISS) of 18. Forty-six percent of patients were treated with HVI as an adjunct therapy to surgical fixation (both short- and long-term immobilization), 45% of patients were treated with HVI as a primary medical treatment, and 9% of patients were treated with HVI instead of failed conservative medical treatment, such as cervical braces. Results: Pneumonia during the initial hospital stay was the most common complication (25%), followed by the correction of loose pins (22%) and pin site infections (18%). Overall, 51% of patients experienced at least one of these complications. There were significant associations between low initial GCS scores and the development of pneumonia (p < 0.001), high ISS scores and the development of pneumonia (p < 0.01), and duration of HVI and the occurrence of loose pins (p < 0.05). Four patients initially treated with HVI as primary medical treatment was converted to surgical treatment due to an intolerance of HVI or non-healing injuries.Conclusions:The HVI is a safe and effective treatment modality in a subset of patients with complex cervical junction and subaxial cervical spine pathology.

Odontoid Type II fractures in elderly: what are the real management goals and how to best achieve them? A multicenter European study on functional outcome

Odontoid fractures constitute the most common cervical fractures in elderly. External immobilization is the treatment of choice for Type I and III; there is still no wide consensus about the best management of Type II fractures. Observational multicenter study was conducted on a prospectively built database on elderly patients (> 75 years) with Type II odontoid fracture managed conservatively during the last 10 years. All patients underwent CT scan on admission and at 3 months; if indicated, selected patient had CT scan at 6 and 12 months. All patients were clinically evaluated by Neck Disability Index (NDI), Charlson Comorbidity Index (CCI), and American Society of Anaesthesiologists classification (ASA) on admission; NDI was assessed also at 6 weeks, 3, 6, 12, and 24 months; furthermore, a quality of life (QoL) assessment with the SF-12 form was performed at 3 and 12 months. Among the 260 patients enrolled, 177 (68%) were women and 83 (32%) men, with a median age of 83 years. Patients were followed up for a minimum of 24 months: 247 (95%) showed an excellent functional outcome within 6 weeks, among them 117 (45%) showed a good bony healing, whereas 130 (50%) healed in pseudo-arthrosis. The residual 5% were still variably symptomatic at 12 weeks; however, only 5 out of 13 (2% of the total cohort) required delayed surgery. This study showed that a conservative approach to odontoid Type II fracture in elderly is an effective and valid option, resulting in an excellent functional outcome (regardless of bony fusion) in the majority of cases. Failure of conservative treatment can be safely addressed with surgical fixation at a later stage.

Anterior Odontoid Screw Fixation for Pediatric and Adolescent Odontoid Fractures: Single-Center Experience Over a Decade

OBJECTIVE

Management of pediatric odontoid fractures is tricky and controversial. This study will enrich world literature with intricacies of anterior odontoid screw (OS) fixation in the pediatric population learned over the last decade.

METHODS

In this retrospective study, all patients with pediatric odontoid fracture who underwent anterior odontoid screw fixation from January 2010 to December 2019 were included and evaluated for surgical outcome.

RESULTS

Thirteen patients were included in this study (mean age, 15 years; range, 6-18 years; male/female, 11:2; type II, 10; type IIA, 1; type III, 2). Common causes of injury were motor vehicle accidents (61.5%) followed by fall from height (38.5%) and all were acute fractures (2-30 days). Five patients had neurologic deficits. Accurate placement of screw was achieved in 92.3% of patients, including all 9 patients who used intraoperative O-arm. K wire migration during bicortical drilling resulted in neurovascular injury, with 1 mortality (7.7%). The remaining 12 patients were available for follow-up (mean, 36 months; range, 20-72 months) and all had preservation of neck movements. Successful OS fixation was achieved in 84.6% of patients, including 1 patient (7.7%) who had a fibrous union. One patient (8.3%) had nonunion because of migration of the screw head in the C2 body.

CONCLUSIONS

Anterior odontoid screw fixation in the pediatric population provides good functional outcomes with instant fixation by direct osteosynthesis. However, the surgeon should be meticulous in the surgical approach and should achieve a lag effect. The surgeon should stop after engaging the outer cortex of the odontoid peg with K wire to avoid cranial migration. Intraoperative O-arm guidance is useful.

Development and first application testing of a new protocol for CT-based stability evaluation of the injured upper cervical spine

PURPOSE

For trauma surgeons, the evaluation of the stability of the upper cervical spine may be demanding. The aim of this study was to develop a protocol for decision-making on upper cervical spine stability in trauma patients based on established parameters obtained by CT imaging as well as testing the protocol by having it applied by trauma surgeons.

METHODS

A structured literature search on upper cervical spine stability was performed. The best evaluated instability criteria in CT imaging were determined. Based on these parameters a protocol for stability evaluation of the injured upper cervical spine was developed. A first application testing was performed. In addition to the assessment of instability, the time required for the assessment was analyzed.

RESULTS

A protocol for CT-based stability evaluation of the injured upper cervical spine based on the current literature was developed and displayed in a flow chart. Testing of the protocol found the stability of the cervical spine was correctly assessed in 55 of 56 evaluations (98.2%). In one test run, a stable upper cervical spine was judged to be unstable. Further analysis showed that this case was based on a measurement error. The assessment time of CT-images decreased significantly during repeat application of the protocol (p < 0.0001), from 336 ± 108 s (first case) to 180 ± 30 s (fourth case).

CONCLUSION

The protocol can be applied quickly and safely by non-specialized trauma surgeons. Thus, the protocol can support the decision-making process in CT-based evaluation of the stability of the injured upper cervical spine.

C1-C2 Wiring With Timed Self-Obsolescence for Complex C2 Body Fracture

BACKGROUND AND IMPORTANCE

Fractures of C2 are typically managed nonoperatively with good rates of healing. Management decisions are complicated, however, when there are additional fractures in the axis possibly leading to increased instability. Additionally, the techniques used for treating these unstable axis fractures can have either significant complications or permanent loss of range of motion. Here, we present a novel technique for the reduction and stabilization of complex C2 body fracture.

CLINICAL PRESENTATION

A 34-yr-old woman with a complex C2 body fracture, which included a right pars and left lateral mass fracture, presented after a water slide accident. It was felt that this fracture was both unstable and would not heal in an anatomically acceptable way so an open surgical reduction was needed. After consideration of more traditional fusion and osteosynthesis techniques, we chose to perform a C1-C2 internal stabilization with C1 sublaminar and C2 spinous process wiring. The patient was then instructed to wear a Miami J collar for 3 mo.

CONCLUSION

The outcome was favorable with good approximation and healing with preserved range of motion.

Identifying factors influencing mortality in patients aged over 65 following an acute type II odontoid process fracture. A retrospective cohort study

OBJECTIVE

Compare short-term mortality rates following operative and nonoperative management of geriatric patients following an acute type II odontoid process fracture.

METHODS

One hundred forty-one patients with a type II odontoid fracture were identified from a single centre between 2002 and 2018. Patient demographics, details of injury and management, plus mortality data were collected. The incidence of mortality at 3 and 12 months was calculated, and a multivariate model built which included the treatment modality variable and allowed adjustment for six individual confounders.

RESULTS

Of the 141 patients with a type II odontoid process fracture, 39 were managed operatively, while 102 were managed nonoperatively. Relative to the nonoperative group, the operative group was younger (79.0 ± 7.0 vs. 83.7 ± 7.6), more likely to have odontoid angulation > 15^° (74.4% vs. 43.1%, p < 0.01), and a greater proportion having fracture displacement > 2 mm (74.4% vs. 31.4%, p < 0.01). Both groups were comparable for gender, comorbidities, and associated injuries. On univariate analysis of treatment modality, the odds ratio of 3-month mortality with nonoperative management was 2.55 (95% CI: 0.82-7.92; p = 0.08), whilst at 12-months it was 3.12 (95% CI: 1.11-8.69; p = 0.02). On multivariate analysis of 12-month mortality, however, treatment modality was not found to be significant. This multivariate analysis suggested that increasing age, male gender, and injury severity were significant predictors of 12-month mortality.

CONCLUSION

In contrast to the findings of a number of previous studies, operative management may not influence survival at 3- and 12-months.

Current updates on various treatment approaches in the early management of acute spinal cord injury

Spinal cord injury (SCI) is a debilitating condition which often leads to a severe disability and ultimately impact patient's physical, psychological, and social well-being. The management of acute SCI has evolved over the couple of decades due to improved understanding of injury mechanisms and increasing knowledge of disease. Currently, the early management of acute SCI patient includes pharmacological agents, surgical intervention and newly experimental neuroprotective strategies. However, many controversial areas are still surrounding in the current treatment strategies for acute SCI, including the optimal timing of surgical intervention, early versus delayed decompression outcome benefits, the use of methylprednisolone. Due to the lack of consensus, the optimal standard of care has been varied across treatment centres. The authors have shed a light on the current updates on early treatment approaches and neuroprotective strategies in the initial management of acute SCI in order to protect the early neurologic injury and reduce the future disability.

Fractures of C2 (Axis) Vertebra: Clinical Presentation and Management

BACKGROUND

Injuries of the upper cervical spine are a major cause of morbidity and mortality due to associated spinal cord and head injuries. The injury patterns of the upper cervical spine are numerous, and the neurologic sequelae are diverse. The axis (C2) is the most commonly fractured vertebra in the upper cervical spine; its unique anatomy and architecture pose difficulties in the diagnosis and the management of its fractures.

METHODS

All cases of acute spinal injuries at Prince Mohammed Bin Abdulaziz Hospital in Riyadh, Saudi Arabia, were screened for fractures of C2 vertebrae. These patients underwent computerized tomography (CT) imaging of the cervical spine with special attention paid to the cranio-cervical junction. Magnetic resonance imaging (MRI) and angiography of the neck were performed to exclude ligamentous tears and vascular injuries. Unstable fractures were fixed surgically. In the remaining cases, a conservative trial was given. All patients were followed up once every 3 months for a period of 1 year. During follow-up, some patients underwent additional CT imaging of the cervical spine to monitor the healing of fractures.

RESULTS

Out of 230 spinal trauma patients, 43.5% suffered from cervical spine injury. C2 fractures were recorded in 26% cases, and fractures of the C2 vertebral body, including pedicles, laminae, lateral masses, and articular processes, were found in many cases, followed by odontoid fractures (50%). No case of atlanto-axial or atlanto-occipital dislocation was recorded. Road traffic accidents were found to be responsible for 92% of cases. The majority of patients were young males, and 96% of patients had no neurological deficit. Only 15% of the patients required surgery for their unstable fractures. Half of the patients attended outpatient follow -up appointments, all of whom underwent CT scanning of the cervical spine 9 months after the accident or operation.

CONCLUSIONS

The axis (C2) is the most commonly affected vertebra in cervical spine trauma, and odontoid fractures make up 50% of all C2 fractures. C2 fractures rarely cause any neurological deficit or vascular injury, and the majority of affected patients can be managed conservatively; only a small proportion requires surgical intervention. Surgical intervention leads to early and complete healing.

Outcomes of Patients Undergoing Anterior Screw Fixation for Odontoid Fracture and Analysis of the Predictive Factors for Surgical Failure

Objective

Anterior odontoid screw fixation (AOSF) is a safe and effective treatment for type II and rostral type III odontoid fracture. This study aimed to report the outcomes of the AOSF surgery and evaluate the potential risk factors of surgical failure.

Methods

We enrolled 63 patients who underwent AOSF. Follow-up computed tomography was performed 6 months after the surgery and once a year thereafter to evaluate the union. Clinical data including the age, sex, presenting symptoms, cause of injury, fracture gaps, dislocation position, degree of displacement, screw direction angle, and time interval from injury to operation were collected.

Results

Successful fusion was achieved in 55 patients (87.3%) and surgical failure occurred in 8 patients (12.7%). Variables such as age, sex, dislocation position, degree of displacement, screw direction angle, and time interval from injury to operation were not significantly associated with the surgical failure. However, surgical failure was statistically significantly associated with the fracture gap. The overall mean fracture gap at the time of injury was 1.29 mm (range, 0–3.11 mm), and the incidence of surgical failure was 8.3 times higher when the fracture gap at the time of injury was > 2 mm (p=0.019).

Conclusion

When performing AOSF in patients with type II or rostral shallow type III odontoid fractures, the displacement of the odontoid fracture fragment should be appropriately reduced to the aligning position before screw insertion and downward reduction should be achieved by perforation of the apical cortex of the odontoid during screw fixation, even if the surgery is delayed.

The Anterior Transarticular Fixation of C1/C2 in the Elderly With Dens Fractures

Background

Anterior transarticular screw fixation (ATSF) of C1/C2 can be used for the treatment of unstable dens fractures. Here, we evaluated the feasibility of an anterior C1/C2 fixation in elderly patients with unstable dens fractures. Furthermore, we tried to analyze safe entry zones for ATSF surgery.

Methods

A consecutive cohort of 13 patients with unstable dens fractures were treated with ATSF of C1/C2 between January 2015 and October 2016. If necessary, an additional screw was placed into the odontoid process. The placement was radiographically analyzed using the 3D Arcadis Orbic (Siemens, Erlangen, Germany). Additionally, computed tomography scans of the cervical spine from 50 trauma patients were analyzed to evaluate safe entry zones for anterior odontoid screw fixation and for ATSF.

Results

ATSF was performed in 13 cases (7 female, 6 male; mean age 81.80 years). One screw had to be corrected intraoperatively due to initial malplacement. Neurological deficits or an injury of the vertebral artery were not observed. All patients suffered from swallowing difficulties during the postoperative course, without lesions of the esophagus or the trachea. In 4 patients (30.8%), an additional posterior fixation was offered to the patients due to progressive loosening of the screws.The anatomical-radiographic analyzes revealed a significantly shallower angle of trajectory for anterior odontoid screw fixation (24.9° ± 5.85°) than for ATSF (39.1° ± 6.44° (left); 40.5° ± 6.79° (right) P = 0.02).

Conclusions

The ATSF of C1/C2 might be a valuable option in the treatment of instable C1/C2 fractures, especially in the elderly or in patients with short necks and/or high body mass index due to the steeper trajectory compared with odontoid screw placement. Yet available screws seem to be of inferior resistance compared with the biomechanical properties of a dorsal fixation. Further studies should focus on screws with better mechanical properties and probably additional cement augmentation.

Level of Evidence

4.

Use of simultaneous traction over a halo ring to achieve reduction of a type 2 odontoid fracture for anterior odontoid screw fixation

Introduction

Odontoid fractures are common. They represent 20% of all cervical trauma. There is a trend towards surgical stabilization. Fracture fixation with 1 or 2 anterior screws is standard operative treatment in younger population.

Presentation of case

A case of type 2 odontoid fracture. The fracture was fixed initially with a halo vest temporarily. The patient was later treated operatively with anterior odontoid screw fixation. Reduction of the fracture was achieved using a bivector traction over a halo ring. The patient achieved an anatomical reduction and a rigid fixation.

Discussion

Type 2 odontoid fracture is very controversial to treat. Several methods of fracture reduction have been described in the literature including Gardner-Wells Tongs and Mayfield head clamp. To our knowledge, fracture reduction with biverctor traction over a halo frame hasn’t been described before in the literature.

Conclusion

Bivector traction over a halo ring can be used for intraoperative reduction of odontoid fracture.

Thinking beyond pannus: a review of retro-odontoid pseudotumor due to rheumatoid and non-rheumatoid etiologies

Retro-odontoid pseudotumor, or mass-like retro-odontoid soft tissue thickening, is an uncommon but important imaging finding that may be associated with rheumatoid arthritis, crystal deposition diseases, as well as non-inflammatory conditions such as cervical degenerative changes and mechanical alterations. Retro-odontoid pseudotumor is commonly associated with atlantoaxial microinstability or subluxation. MRI and CT have an important role in the detection and diagnosis of retro-odontoid pseudotumor. However, due to a wide range of imaging characteristics and ambiguous etiology, it is a frequently misunderstood entity. The purpose of this article is to review relevant anatomy of the craniocervical junction; describe various imaging appearances, pathophysiology and histology in both rheumatoid and non-rheumatoid etiologies; and discuss differential diagnosis of retro-odontoid pseudotumor in order to help guide clinical management.

Outcomes of Halo Immobilization for Cervical Spine Fractures

STUDY DESIGN

Retrospective.

OBJECTIVES

To evaluate complications and outcomes of halo immobilization in patients with cervical spine fractures treated at a level I trauma center.

METHODS

A retrospective evaluation of patients treated at a single institution with halo immobilization from August 2000 to February 2016 was performed. Demographic information, mechanism of injury, level and type of spine fracture, length of halo immobilization, complications associated with halo immobilization, and length of patient follow-up were collected.

RESULTS

A total of 189 patients treated with halos were identified. Of the 189 patients, 121 (64%) received halos for the management of cervical spine fractures and were included in the study. A total of 49.6% were males and 50.4% were females. The average age was 50.8 years (range 1-89 years). Overall, 10.7% sustained C1 fractures, 71.1% C2 fractures, and 18.2% subaxial spine (C3-C7) fractures. In all, 47.1% of the upper cervical fractures were either odontoid or hangman-type fractures. A total of 25.1% of patients had multiple cervical fractures. At latest follow-up, 81% had healed fractures with good alignment, minimal pain, and return to normal activities. There was an 8.3% mortality rate. The mortality group had an average age of 64.7 years (range 19-84 years). A total of 10.7% of patients failed halo immobilization and 46.3% of patients had complications such as pin site infections (5.8%), loose pins (1.7%), neck pain (20.7%), decreased range of motion (14%), thoracic skin ulcers (2.4%), and dysphagia (1.7%).

CONCLUSIONS

The use of halo immobilization for cervical spine fractures resulted in clinical success in 81% of patients. Complication rates in geriatric patients were lower than previously reported in the literature.

Range of motion in the cervical spine after odontoid fracture treated with anterior screw fixation

BACKGROUND

It is believed that direct odontoid screw fixation preserves the physiological cervical range of motion following surgery. However, there are no clinical studies confirming the motion sparing value of this technique. This study aims to (1) to assess active cervical range of motion following types II and III odontoid fracture, successfully treated with anterior odontoid screw fixation, and (2) to examine the relationship between the range of motion of the head and duration of collar usage, neck pain, quality of life, and patients' age.

METHODS

The study involved 41 patients subjected to a procedure of direct osteosynthesis of the dens with lag screw. Following the operation all the patients had to wear a cervical collar to protect the osteosynthesis. The control group consisted of 41 individuals with no clinical diagnosis of any cervical spine disorders. The spinal motion was assessed using multi-cervical unit, taking into account bending/extension, left and right lateral flexion, and left and right axial rotation.

RESULTS

In the study group, spine mobility correlated with the duration of hard collar usage following the operation, with a longer duration corresponding to poorer spine mobility at the end of the treatment. Statistically significant correlation was observed in the case of extension (p < 0.021) and axial rotation (p < 0.007). In the study group, there was a negative correlation between the range of motion and the patients' age, i.e., the older the patient the poorer his/her spinal mobility (p < 0.001).

CONCLUSIONS

Active cervical range of motion in patients following direct osteosynthesis of the dens, augmented with a hard collar, was significantly lower than in the control population, and it correlated negatively with the duration of collar usage, the patients' age, and intensity of spinal pain.

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 Type II Fractures in Octogenarians: Balancing Two Different Treatment Strategies

OBJECTIVE

Demographic changes have led to a higher incidence of C-2 fractures, especially in elderly patients. For patients with type II fractures, treatment remains controversial, as discussed by Anderson and D'Alonzo, due to the rising morbidity and mortality rates for any treatment. The aim of this study was to compare conservative and surgical management in patients with type II C-2 fractures regarding outcomes, complications, and the mortality rate.

METHODS

A retrospective analysis was performed of the medical records, X-rays, and/or computed tomography scans of patients ≥80 years of age with type II fractures who were admitted to our Department of Neurosurgery between January 1990 and December 2017. The success of treatment was evaluated 3 months after surgery.

RESULTS

In total, 125 patients were included, of whom 98 were treated surgically and 27 were treated conservatively. Surgical treatment was successful in 90.8% of cases, while conservative treatment was successful in 70.0%. The in-hospital mortality was 14.29% and the 3-month mortality was 27.8% in the surgical group, compared to 3.7% and 20% in the conservatively treated group. The in-hospital complication rate was 22.4% in the surgically treated patients and 7.4% in the conservatively treated patients.

CONCLUSION

Surgical treatment of type II fractures seemed to be associated with higher success and complication rates than conservative treatment. Nevertheless, 3-month mortality was comparable in both groups. Therefore, we conclude that surgical treatment for type II fractures in elderly patients is superior to conservative management, although conservative treatment remains a valuable option in elderly patients with severe comorbidities.

Type II Odontoid Fracture: a case series highlighting the treatment strategies

BACKGROUND

A type II odontoid fracture, if unstable, can cause spinal cord damage. In this case, it is essential to choose the correct treatment-but the issues of what the correct treatment is and which of the different surgical options is best are quite controversial. In this paper we present strategies for treatment of type II odontoid fracture.

MATERIALS AND METHODS

Thirty consecutive cases of type II odontoid fracture were treated at the Division of Neurosurgery at Villa Sofia Hospital in Palermo (23 cases) and at the Neurosurgical Clinic, University Hospital of Palermo (seven cases), from January 2011 to August 2016. Four patients were treated with external immobilization. Twenty-six patients underwent a surgical procedure.

RESULTS

There was no mortality related to the surgical procedure. One patient had a pre- and postoperative neurological deficit, and remained tetraparetic. Follow-up radiological studies in the surgically treated group showed bone union in 21 patients and stable fibrous union in one.

CONCLUSION

In our and other authors' experience, when the direction of the fracture line is down and forward, external immobilization can be sufficient for healing. Anterior odontoid screw fixation can be considered the treatment of choice for unstable odontoid fractures (with a horizontal, down and back, or comminuted fracture line) without dislocation or with dislocation less than 7 mm.When the odontoid fracture is associated with a Jefferson fracture or dislocation greater than 7 mm, stabilization of C1-C2 may be necessary. In this case, placement of screws in the dens and in the joints through a single approach represents the most valid technique.In the case of an inveterate fracture of the dens with severe C1-C2 dislocation, the surgical operation that offers the best prospects is posterior stabilization, utilizing the Guo technique.

Odontoid fracture with missed diagnosis of Transverse Atlantal Ligament (TAL) injury resulting in late-onset instability

Background:

Concurrent injuries to both the odontoid and transverse atlantal ligament are rare and can be easily missed. Failure to diagnose both lesions potentially leads to the late onset of sagittal plane instability and acute myelopathy. Here, we present a patient with an odontoid fracture whose transverse atlantal ligament (TAL) injury was originally missed on magnetic resonance imaging (MRI) and computed tomography (CT) scans. He later developed atlantoaxial instability requiring surgery.

Case Description:

A 17-year-old male presented with neck pain, restricted cervical range of motion, but a normal neurological exam following a motor vehicle accident. The original X-rays showed a moderately displaced type-3 odontoid fracture. Additional MRI and CT scans excluded ligamentous injury, and he was initially treated with 13 weeks of halo vest immobilization. Radiographs 5 months later showed an enlarged atlanto-dens interval (e.g., >3 mm); the diagnosis of an odontoid fracture with an accompanying TAL injury was established, following which the patient successfully underwent a posterior C1–C2 fusion.

Conclusion:

Odontoid fractures require strict clinical and radiographic (X-ray, MRI, CT) surveillance to help rule out accompanying TAL injuries that may warrant surgical intervention.

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.

Nonoperative management of C-2 dens fractures: Single center experience and review of the literature

OBJECTIVE

The demographic change in the population leads to a rising number of patients presenting with fractures of the cervical spine, especially C-2, due to falls. With an increase of co-morbidities in these elder patients, the risk for intra- and postoperative complications is increased likewise. Thus, an alternative strategy instead of operative management of these fractures should be taken into account whenever possible. Conservative management of dens fractures in the elderly is still a subject of great controversy despite numerous studies on this topic. The aim of this study was to analyze the rate of successful osseous consolidation of C-2 fractures with conservative treatment by wearing a semi-rigid collar or halo thoracic vest without further surgical intervention.

PATIENTS AND METHODS

We analyzed the medical records and CT-scan of the cervical spine of 254 patients with C-2 fractures retrospectively, who were admitted to our department between January 1990 and September 2015. Fractures were diagnosed by CT-scan of the cervical spine and classified according to the Anderson - D`Alonzo classification. 183 patients were submitted to surgery as treatment of choice. In 71 patients a conservative management with external immobilization was chosen. The latter group was subjected to study analysis.

RESULTS

71 patients (mean age 74.08 years ± 16.06 years) were diagnosed with C-2 fractures (Typ I: 4; Typ II 36; Typ III: 31) and treated conservatively using a Philadelphia collar (n = 57), or a halo-thoracic vest (n = 14), respectively. 12 patients were lost to follow up and excluded from further analysis. Conservative treatment of the fractures was deemed successful when a bony consolidation of the fracture in follow-up CT scans was seen (45 of 59 patients; 76.3%). 20 patients with a Type II fracture (20/28, 71.4%) showed a successful ossification. In 14 patients (overall 23.7%; Typ I: 1 (7.14%), Typ II: 8 (57.14%), Typ III: 5 (35.71%)) external immobilization failed to achieve primary stability. These patients were submitted to consecutive surgery.

CONCLUSION

From our data it can be concluded that elderly patients, presenting with non-dislocated Type II fractures of the axis without accompaining neurological deficits, will have a more than 70% chance for a bony consolidation by conservative management. Consolidation rates may be estimated even higher in Type I and III fractures. Therefore, we suggest that external immobilization might be a valuable option to treat elderly patients with these fractures under certain circumstances.

Short-Term Complications of Anterior Fixation of Odontoid Fractures

STUDY DESIGN

Retrospective study.

OBJECTIVE

Anterior fixation of odontoid fracture has been associated with high morbidity and mortality in small, single institution series. Identifying risk factors may improve risk stratification and highlight factors that could be optimized preoperatively. The objective of this study was to determine the 30-day complication rate following anterior fixation of odontoid fractures and to identify associated risk factors among patients in a large national database.

METHODS

Patients who underwent anterior fixation were identified in the American College of Surgeons National Quality Improvement Program database (ACS NSQIP) from 2007 to 2012. Patient demographics, medical comorbidities, perioperative complications, and postoperative complications up to 30 days were analyzed by univariate and multivariate analysis.

RESULTS

Overall, 103 patients met criteria for the study. The average age was 73.9 years and patients were predominantly white (85.4%). Cardiac comorbidity was common (66.0%), as were dependent functional status (14.6%) and bleeding disorders (13.6%). Complications occurred in 37.9% of patients, and mortality was high (6.8%). Age, white race, and history of bleeding disorders were independently predictive of complications in the multivariate analysis. The postoperative hospital stay was >5 days for 45.6% of patients.

CONCLUSION

In a large, multicenter database study, anterior fixation of odontoid fracture was associated with high morbidity and mortality. Although advanced age was associated with increased risk of complications, patients undergoing anterior fixation were older, on average, than in prior studies. Bleeding disorder was a potentially modifiable risk factor for complications that could be optimized prior to surgery.

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.

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.

Controversies in the Management of Geriatric Odontoid Fractures

Fractures of the odontoid process of C2 have become increasingly prevalent in the aging population and are typically associated with a high incidence of morbidity. Dens fractures comprise the majority of all cervical fractures in patients older than 80 years and remain the most common cervical fracture pattern in all geriatric patients. Type II odontoid fractures have been associated with limited healing potential, and both nonoperative and operative management are associated with high mortality rates. Historically, there has been some debate in the literature with regards to optimal management strategies to maximize outcomes in geriatric patients. Recent, high-quality evidence has indicated that surgical treatment of type II odontoid fractures in elderly patients is associated with improvements in both short- and long-term mortality. Additionally, surgical intervention has been shown to improve functional outcomes when compared with nonsurgical treatment. Factors to consider before surgery for geriatric type II odontoid fractures include associated comorbidities and the safety of general anesthesia administration. With appropriate measures of patient selection, surgery can provide an efficacious option for geriatric patients with type II odontoid fractures. We recommend surgical intervention via a posterior C1-C2 arthrodesis for geriatric type II odontoid fractures, provided that the surgery itself does not represent an unreasonable risk for mortality.

"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.

Patient-reported outcome following nonsurgical management of type II odontoid process fractures in adults

Background:

Transverse (type II) odontoid process fracture is among the most commonly encountered cervical spine fractures. Nonsurgical management through external immobilization is occasionally preferred to surgical management but is criticized for its higher rates of failure and lower patient satisfaction. Our aim is to analyze patient-reported outcomes in patients who underwent nonsurgical treatment for type II odontoid fractures.

Methods:

We identified patients >18-year-old who underwent external immobilization as a treatment for isolated type II odontoid fracture between 2007 and 2012. We collected demographic parameters, clinical presentation, mode of injury, imaging studies and modality and duration of treatment (soft collar, halo-vest, or both). Patients were contacted by telephone to participate in a 15-min survey addressing their recovery including their subjective rate of return to preinjury level of functioning.

Results:

Fifteen patients met the inclusion/exclusion criteria and participated in our survey. Patients were followed up for an average of 19 months after injury. Overall mean age was 61 years. Injury followed a mechanical fall or a road traffic accident in 11 and 4 cases, respectively. External immobilization was achieved by halo vest only in nine patients, soft collar only in two patients (13%), and through a sequential combination in the remaining 4 (27%). This was deployed for a mean of 7.8 months. Radiological studies at the last follow-up showed bony healing (27%), fibrous nonunion (60%), and persistent instability (13%). Patients reported gradual recovery of function throughout the 1^st year after injury with levels above 70% of preinjury functioning achieved by 13% of patients at 6 months, 33% at 9 months, and 47% at 12 months. Overall satisfaction with nonsurgical management was 68%.

Conclusion:

In selected patients with type II odontoid fractures, external immobilization represents a good option with acceptable course of recovery.

Retrospective analysis of a case series of patients with traumatic injuries to the craniocervical junction

Objective

To evaluate the correlation between the treatment, the characteristics of the lesions and the clinical outcome of patients with traumatic injuries to the craniocervical junction.

Methods

This was a retrospective study of patients treated conservatively or surgically between 2010 and 2013 with complete data sets.

Results

We analyzed 37 patients, 73% were men with mean age of 41.7 years. Of these, 32% were submitted to initial surgical treatment and 68% received conservative treatment. Seven (29%) underwent surgery subsequently. In the surgical group, there were seven cases of odontoid type II fractures, two cases of fracture of posterior elements of the axis, one case of C1-C2 dislocation with associated fractured C2, one case of occipitocervical dislocation, and one case of combined C1 and C2 fractures, and facet dislocation. Only one patient had neurological déficit that improved after treatment. Two surgical complications were seen: a liquoric fistula and one surgical wound infection (reaproached). In the group treated conservatively, odontoid fractures (eight cases) and fractures of the posterior elements of C2 (five cases) were more frequent. In two cases, in addition to the injuries of the craniocervical junction, there were fractures in other segments of the spine. None of the patients who underwent conservative treatment presented neurological deterioration.

Conclusion

Although injuries of craniocervical junction are relatively rare, they usually involve fractures of the odontoid and the posterior elements of the axis. Our results recommend early surgical treatment for type II odontoid fractures and ligament injuries, the conservative treatment for other injuries.

Objetivo

Avaliar a correlação entre o tratamento, as características das lesões e o resultado clínico em pacientes com lesões traumáticas na junção craniocervical.

Métodos

Estudo retrospectivo de pacientes maiores de 18 anos tratados de forma conservadora ou cirúrgica, entre 2010 e 2013.

Resultados

Foram analisados 37 pacientes, 73% eram do sexo masculino e a média de idade foi de 41,7 anos. Inicialmente 32% dos pacientes foram submetidos a tratamento cirúrgico, e 68% foram submetidos a tratamento conservador. Sete pacientes (29%) do grupo conservador foram submetidos posteriormente à cirurgia. No grupo cirúrgico, houve sete casos de fratura de odontóide tipo II, dois casos de fratura de elementos posteriores do áxis, um caso de luxação C1-C2, um caso de deslocamento occipito-cervical e um caso de fraturas de C1 e C2 e luxação facetária. Um paciente apresentava déficit neurológico, melhorando após o tratamento. Houve duas complicações pós-cirúrgicas, uma fístula liquórica e uma infecção de ferida operatória (reabordada). No grupo conservador, predominaram as fraturas do odontóide (oito) e dos elementos posteriores de C2 (cinco). Em dois casos, havia também fraturas em outros segmentos da coluna. Nenhum dos pacientes deste grupo apresentou deterioração neurológica.

Conclusão

As lesões da junção craniocervical são raras, sendo mais frequentes as fraturas do odontóide e dos elementos posteriores do áxis. Nossos resultados recomendam o tratamento cirúrgico precoce para os pacientes com fraturas do odontóide tipo II e lesões ligamentares, e tratamento conservador para os demais pacientes.

A Systematic Review of the Treatment of Geriatric Type II Odontoid Fractures

BACKGROUND

Odontoid fractures are the most common cervical spine fracture in the geriatric population; however, the treatment of type II odontoid fractures in this age group is controversial.

OBJECTIVE

To compare the short-term (<3 months) mortality, long-term (≥12 months) mortality, and complication rates of patients >60 years of age with a type II odontoid fracture managed either operatively or nonoperatively.

METHODS

We performed a systematic review of literature published between January 1, 2000, and February 1, 2015, related to the treatment of type II odontoid fractures in patients >60 years of age. An analysis of short-term mortality, long-term mortality, and the occurrence of complications was performed.

RESULTS

A total of 452 articles were identified, of which 21 articles with 1233 patients met the inclusion criteria. Short-term mortality (odds ratio, 0.43; 95% confidence interval, 0.30-0.63) and long-term mortality (odds ratio, 0.47; 95% confidence interval, 0.34-0.64) were lower in patients who underwent surgical treatment than in those who had nonsurgical treatment, and there were no significant differences in the rate of complications (odds ratio, 1.01; 95% confidence interval, 0.63-1.63). Surgical approach (posterior vs anterior) showed no significant difference in mortality or complication rate. Similarly, no difference in mortality or complication rate was identified with hard collar or a halo orthosis immobilization.

CONCLUSION

The current literature suggests that well-selected patients >60 years of age undergoing surgical treatment for a type II odontoid fracture have a decreased risk of short-term and long-term mortality without an increase in the risk of complications.

The Feasibility of Two Screws Anterior Fixation for Type II Odontoid Fracture Among Arabs

STUDY DESIGN

Retrospective, cross-sectional study.

OBJECTIVE

To evaluate the feasibility of two screws anterior fixation of the odontoid process among Arab adults.

SUMMARY OF BACKGROUND DATA

Anterior screw fixation is the treatment of choice for type II odontoid fractures. In order to perform the procedure safely, the diameter of the odontoid process should be wide enough to allow for the placement of one or two screws.

METHODS

A retrospective review of 156 computed tomography scans of the cervical spine was done. The included patients were Arabs, adults (at least 18 years old), and had no evidence of upper cervical spine trauma, deformity, infection, tumor, or surgery. The minimum external transverse diameter (METD), minimum internal transverse diameter (MITD), minimum external anteroposterior diameter (MEAD), and minimum internal anteroposterior diameter (MIAD) of the odontoid process were measured. A P value of ≤0.05 was considered as the cutoff level of statistical significance.

RESULTS

Our study included 94 (60.3%) males and 62 (39.7%) females. The mean age of the subjects was 37.8 ± 16.9 years (range 18-85). The mean values of the METD, MITD, MEAD, and MIAD were 8.7 ± 1.0 mm, 6.0 ± 1.1 mm, 10.3 ± 1.0 mm, and 7.4 ± 1.1 mm, respectively. Men had larger diameters compared to women. This was statistically significant for METD (P = 0.035) and MEAD (P < 0.001). The METD was <9.0 mm in 95 (60.9%) subjects, while the MITD was <8.0 mm in 153 (98.1%) subjects. These findings were not significantly different between males and females.

CONCLUSION

Two screws anterior fixation of type II odontoid fracture is not feasible among the majority of Arabs.

LEVEL OF EVIDENCE

3.

Advantages of Direct Insertion of a Straight Probe Without a Guide Tube During Anterior Odontoid Screw Fixation of Odontoid Fractures

STUDY DESIGN

A retrospective cohort study.

OBJECTIVE

The aim of this study was to compare the anterior odontoid screw fixation (AOSF) with a guide tube or with a straight probe.

SUMMARY OF BACKGROUND DATA

AOSF associates with several complications, including malpositioning, fixation loss, and screw breakage. Screw pull-out from the C2 body is the most common complication.

METHODS

All consecutive patients with type II or rostral shallow type III odontoid fractures who underwent AOSFs during the study period were enrolled retrospectively. The guide-tube AOSF method followed the standard published method except C3 body and C2-3 disc annulus rimming was omitted to prevent disc injury; instead, the guide tube was anchored at the anterior inferior C2 vertebra corner. After 2 screw pull-outs, the guide-tube cohort was analyzed to identify the cause of instrument failure. Thereafter, the straight-probe method was developed. A guide tube was not used. A small pilot hole was made on the most anterior side of the inferior endplate, followed by insertion of a 2.5 mm straight probe through the C2 body. Non-union and instrument failure rates and screw-direction angles of the guide-tube and straight-probe groups were recorded.

RESULTS

The guide-tube group (n = 13) had 2 screw pull-outs and 1 non-union. The straight-probe group (n = 8) had no complications and significantly larger screw-direction angles than the guide-tube group (60.5 ± 4.63 vs. 54.8 ± 3.82 degrees; P = 0.047).

CONCLUSION

Straight-probe AOSF yielded larger direction angles without injuring bone and disc. Complications were absent. The procedure was easier than guide-tube AOSF and assured sufficient engagement, even in horizontal fracture orientation cases.

LEVEL OF EVIDENCE

3.

Retrospective analysis of a case series of patients with traumatic injuries to the craniocervical junction

OBJECTIVE

To evaluate the correlation between the treatment, the characteristics of the lesions and the clinical outcome of patients with traumatic injuries to the craniocervical junction.

METHODS

This was a retrospective study of patients treated conservatively or surgically between 2010 and 2013 with complete data sets.

RESULTS

We analyzed 37 patients, 73% were men with mean age of 41.7 years. Of these, 32% were submitted to initial surgical treatment and 68% received conservative treatment. Seven (29%) underwent surgery subsequently. In the surgical group, there were seven cases of odontoid type II fractures, two cases of fracture of posterior elements of the axis, one case of C1-C2 dislocation with associated fractured C2, one case of occipitocervical dislocation, and one case of combined C1 and C2 fractures, and facet dislocation. Only one patient had neurological déficit that improved after treatment. Two surgical complications were seen: a liquoric fistula and one surgical wound infection (reaproached). In the group treated conservatively, odontoid fractures (eight cases) and fractures of the posterior elements of C2 (five cases) were more frequent. In two cases, in addition to the injuries of the craniocervical junction, there were fractures in other segments of the spine. None of the patients who underwent conservative treatment presented neurological deterioration.

CONCLUSION

Although injuries of craniocervical junction are relatively rare, they usually involve fractures of the odontoid and the posterior elements of the axis. Our results recommend early surgical treatment for type II odontoid fractures and ligament injuries, the conservative treatment for other injuries.

OBJETIVO

Avaliar a correlação entre o tratamento, as características das lesões e o resultado clínico em pacientes com lesões traumáticas na junção craniocervical.

MÉTODOS

Estudo retrospectivo de pacientes maiores de 18 anos tratados de forma conservadora ou cirúrgica, entre 2010 e 2013.

RESULTADOS

Foram analisados 37 pacientes, 73% eram do sexo masculino e a média de idade foi de 41,7 anos. Inicialmente 32% dos pacientes foram submetidos a tratamento cirúrgico, e 68% foram submetidos a tratamento conservador. Sete pacientes (29%) do grupo conservador foram submetidos posteriormente à cirurgia. No grupo cirúrgico, houve sete casos de fratura de odontóide tipo II, dois casos de fratura de elementos posteriores do áxis, um caso de luxação C1-C2, um caso de deslocamento occipito-cervical e um caso de fraturas de C1 e C2 e luxação facetária. Um paciente apresentava déficit neurológico, melhorando após o tratamento. Houve duas complicações pós-cirúrgicas, uma fístula liquórica e uma infecção de ferida operatória (reabordada). No grupo conservador, predominaram as fraturas do odontóide (oito) e dos elementos posteriores de C2 (cinco). Em dois casos, havia também fraturas em outros segmentos da coluna. Nenhum dos pacientes deste grupo apresentou deterioração neurológica.

CONCLUSÃO

As lesões da junção craniocervical são raras, sendo mais frequentes as fraturas do odontóide e dos elementos posteriores do áxis. Nossos resultados recomendam o tratamento cirúrgico precoce para os pacientes com fraturas do odontóide tipo II e lesões ligamentares, e tratamento conservador para os demais pacientes.

Complete Remodeling After Conservative Treatment of a Severely Angulated Odontoid Fracture in a Patient With Osteogenesis Imperfecta: A Case Report

STUDY DESIGN

Case report.

OBJECTIVE

This is the first case report describing successful healing and remodeling of a traumatic odontoid fracture that was dislocated and severely angulated in a patient with osteogenesis imperfecta who was treated conservatively.

SUMMARY OF BACKGROUND DATA

Osteogenesis imperfecta (OI) is a rare genetic disorder resulting in a low bone mass and bone fragility, predisposing these patients to fractures that often occur at a young age. Although any bone in the body may be involved, odontoid fractures are uncommon in this population. Because of a very high fusion rate, conservative management is accepted as a safe and efficient treatment of fractures of the odontoid in children. Several authors, however, recommend surgical treatment of patients who have failure of conservative treatment and have severe angulation or displacement of the odontoid.

METHODS

A 5-year-old female, diagnosed with OI type I, presented with neck pain without any neurological deficits after falling out of a rocking chair backward, with her head landing first on the ground. Computed tomography confirmed a type III odontoid fracture without dislocation and she was initially treated with a rigid cervical orthosis. At 1 and 2 months of follow-up, progressive severe angulation of the odontoid was observed but conservative treatment was maintained as the space available for the spinal cord was sufficient and also considering the patient's history of OI.

RESULTS

Eight months postinjury, she had no clinical symptoms and there was osseous healing of the fracture with remodeling of the odontoid to normal morphology.

CONCLUSION

Even in patients with OI, severely angulated odontoid fractures might have the capacity for osseous healing and complete remodeling under conservative treatment.

LEVEL OF EVIDENCE

5.

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.

Odontoid process fractures: the role of the ligaments in maintaining stability. A biomechanical, cadaveric study

Aims: We wished to investigate the role of the cervical ligaments in maintaining atlantoaxial stability after fracture of the odontoid process.

Methods: We dissected eight fresh-frozen cadaveric cervical spines to prepare the C1 and C2 vertebrae for biomechanical analysis. The C1 and C2 blocks were mounted and biomechanical analysis was performed to test the stability of the C1-C2 complex after cutting the odontoid process to create an Anderson and D’Alonzo type II fracture then successive division of the atlantoaxial ligaments. Biomechanical analysis of stiffness, expressed as Young’s modulus, was performed under right rotation, left rotation and anterior displacement.

Results: The mean Young’s modulus in anterior displacement decreased by 37% when the odontoid process was fractured (p = 0.038, 95% confidence interval 0.04–1.07). The mean Young’s modulus in anterior displacement decreased proportionally (compared to the previous dissection) by the following percentages when the structures were divided: facet joint capsules (bilateral) 16%, ligamentum flavum 27%, anterior longitudinal ligament 10%. These differences did not reach statistical significance (p > 0.05).

Discussion: We have found that the odontoid process itself may account for up to 37% of the stiffness of the C1-C2 complex and that soft tissue structures account for further resistance to movement. We suggest magnetic resonance imaging (MRI) of the soft tissues in the acute setting of a minimally displaced odontoid process fracture to plan management of the injury. If the MRI determines that there is associated ligament injury it is likely that the fracture is unstable and we would suggest operative management.

Odontoid fracture biomechanics

STUDY DESIGN

In vitro biomechanical study.

OBJECTIVES

To investigate mechanisms of odontoid fracture.

SUMMARY OF BACKGROUND DATA

Odontoid fractures in younger adults occur most often due to high-energy trauma including motor vehicle crashes and in older adults due to fall from standing height.

METHODS

Horizontally aligned head impacts into a padded barrier were simulated using a human upper cervical spine specimen (occiput through C3) mounted to a surrogate torso mass on a sled and carrying a surrogate head. We divided 13 specimens into 3 groups on the basis of head impact location: upper forehead in the midline, upper lateral side of the forehead, and upper lateral side of the head. Post-impact fluoroscopy and anatomical dissection documented the injuries. Time-history biomechanical responses were determined.

RESULTS

Four of the 5 specimens subjected to impact to the upper forehead in the midline sustained type II or high type III odontoid fractures due to abrupt deceleration of the head and continued forward torso momentum. Average peak force reached 1787.1 N at the neck at 50.3 milliseconds. Subsequently, the motion peaks occurred for the head relative to C3 reaching 15.2° for extension, 2.1 cm for upward translation, and 5.3 cm for horizontal compression, between 62 and 68 milliseconds.

CONCLUSION

We identified impact to the upper forehead in the midline as a mechanism that produced odontoid fracture and associated atlas and ligamentous injuries similar to those observed in real-life trauma. We were not able to create odontoid fractures during impacts to the upper lateral side of the forehead or upper lateral side of the head. Dynamic odontoid fracture was caused by rapid deceleration of the head, which transferred load inferiorly combined with continued torso momentum, which caused spinal compression and anterior shear force and forward displacement of the axis relative to the atlas.

Case-control studies in neurosurgery

OBJECT

Observational studies, such as cohort and case-control studies, are valuable instruments in evidence-based medicine. Case-control studies, in particular, are becoming increasingly popular in the neurosurgical literature due to their low cost and relative ease of execution; however, no one has yet systematically assessed these types of studies for quality in methodology and reporting.

METHODS

The authors performed a literature search using PubMed/MEDLINE to identify all studies that explicitly identified themselves as "case-control" and were published in the JNS Publishing Group journals (Journal of Neurosurgery, Journal of Neurosurgery: Pediatrics, Journal of Neurosurgery: Spine, and Neurosurgical Focus) or Neurosurgery. Each paper was evaluated for 22 descriptive variables and then categorized as having either met or missed the basic definition of a case-control study. All studies that evaluated risk factors for a well-defined outcome were considered true case-control studies. The authors sought to identify key features or phrases that were or were not predictive of a true case-control study. Those papers that satisfied the definition were further evaluated using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist.

RESULTS

The search detected 67 papers that met the inclusion criteria, of which 32 (48%) represented true case-control studies. The frequency of true case-control studies has not changed with time. Use of odds ratios (ORs) and logistic regression (LR) analysis were strong positive predictors of true case-control studies (for odds ratios, OR 15.33 and 95% CI 4.52-51.97; for logistic regression analysis, OR 8.77 and 95% CI 2.69-28.56). Conversely, negative predictors included focus on a procedure/intervention (OR 0.35, 95% CI 0.13-0.998) and use of the word "outcome" in the Results section (OR 0.23, 95% CI 0.082-0.65). After exclusion of nested case-control studies, the negative correlation between focus on a procedure/intervention and true case-control studies was strengthened (OR 0.053, 95% CI 0.0064-0.44). There was a trend toward a negative association between the use of survival analysis or Kaplan-Meier curves and true case-control studies (OR 0.13, 95% CI 0.015-1.12). True case-control studies were no more likely than their counterparts to use a potential study design "expert" (OR 1.50, 95% CI 0.57-3.95). The overall average STROBE score was 72% (range 50-86%). Examples of reporting deficiencies were reporting of bias (28%), missing data (55%), and funding (44%).

CONCLUSIONS

The results of this analysis show that the majority of studies in the neurosurgical literature that identify themselves as "case-control" studies are, in fact, labeled incorrectly. Positive and negative predictors were identified. The authors provide several recommendations that may reverse the incorrect and inappropriate use of the term "case-control" and improve the quality of design and reporting of true case-control studies in neurosurgery.

Anterior Screw Fixation of Anteriorly Displaced Type III Odontoid Fracture Corrected by Transoral Digital Manipulation

Type III odontoid fractures have been treated by several methods. In case of anteriorly displaced type III odontoid fracture which is not corrected by closed reduction, anterior screw fixation cannot be used. We report the first case of anterior screw fixation of anteriorly displaced type III odontoid fracture corrected by transoral digital manipulation.

Comparative analysis of isocentric 3-dimensional C-arm fluoroscopy and biplanar fluoroscopy for anterior screw fixation in odontoid fractures

STUDY DESIGN

Retrospective clinical study.

OBJECTIVE

To compare long-term radiographic and clinical outcomes of patients undergoing anterior odontoid screw placement using traditional biplanar fluoroscopy or isocentric 3-dimensional C-arm (iso-C) fluoroscopy-assisted techniques.

SUMMARY OF BACKGROUND DATA

Anterior screw fixation of odontoid fractures preserves motion at the C1-C2 joint, but accurate screw positioning is essential for successful outcomes. Biplanar fluoroscopy image guidance is most often used; however, iso-C imaging improves the ease and accuracy of screw placement with less radiation exposure.

METHODS

Fifty-one patients underwent anterior odontoid screw fixation for type II (48 patients) and rostral type III fractures (3 patients). Procedures were guided by biplanar fluoroscopy in 25 (49%) patients, and with iso-C assistance in 26 (51%). Length of surgery, complications, and clinical outcomes based on the Smiley-Webster score were evaluated. Computed tomography confirmed adequate screw placement. Follow-up ranged from 3 to 9 months.

RESULTS

At 3-month follow-up, screw position and fusion across the fracture were evident in 87% of the cases treated with biplanar fluoroscopy and in 100% treated by iso-C. The average outcome score in the iso-C group was superior to that of the biplanar group (1.08 vs. 1.33, respectively), although not statistically significant. At last follow-up, the rate of successful fusion was 88% in the biplanar group and 95% in the iso-C group. Length of surgery was significantly lower in the iso-C group compared with the biplanar group (P=0.05). The significantly longer preparation time in the iso-C group (P=0.04) accounted for no overall difference in total operating room occupancy time between the 2 groups.

CONCLUSIONS

Iso-C significantly decreased surgical time. At last follow-up iso-C assistance was associated with improved rates of radiographic fusion with comparable outcome and complication profiles. This series represents the largest cohort of patients treated with intraoperative real-time navigation assistance for odontoid fractures.