Acute injuries of the axis vertebra

Traumatic irreducible non-Hangman's type bilateral C2-C3 high-grade facet dislocation: technical nuance

Majority of C2-C3 vertebral dislocations occur as in combination with bilateral pars fractures, also known as Hangman's fractures. Isolated C2-C3 facet dislocation without any associated C2 fracture is a very rare injury. One such case has been presented in this report. A 29-year male was involved in a road traffic accident (RTA) after which he developed midline neck pain. Following a minor neck manipulation at a hair salon 15 days after the RTA, his neck pain worsened and he developed quadriparesis. Imaging at the time of admission showed bilateral high-grade C2-C3 facet dislocations without any associated fracture of C2 vertebra. Due to non-reduction of the dislocation with skeletal traction, surgery was contemplated. Intraoperatively, the C2-C3 joint spaces were opened but only partial reduction could be achieved. Complete reduction was achieved only after opening of the C1-C2 joints was performed. Later, C2-C4 screw-rod constructs were placed. Patient achieved good outcome with resolution of symptoms. This report concludes that, in cases of delayed presentation of irreducible C2-C3 bilateral facet dislocations and non-reducibility by skeletal traction, opening of the C1-2 joints may need to be performed in addition to the C2-C3 joint spaces, in order to achieve complete reduction.

Proposal of New Radiological Classification and Treatment Strategy for Transverse Fractures of the C2 Axis Body

OBJECTIVE

To investigate the characteristics of transverse fractures of the C2 axis body diagnosed on sagittal computed tomography (CT) and to propose new classification and appropriate treatment strategies.

METHODS

A retrospective study was performed by enrolling 49 patients (26 men and 23 women) with transverse fractures of the C2 axis body who were treated at four national trauma centers of tertiary university hospitals from January 2000 to December 2017. The mean age of the patients was 60.8 years (ranging from 21 to 90 years). We classified 49 transverse fractures of the C2 body into three types based on fracture trajectories involving superior articular facet (SAF) and lateral cortex (LC) of the C2 body on coronal CT as follows: Type 1, involvement of C2 SAF on both sides; Type 2, unilateral involvement of C2 SAF on one side and LC on the other side; Type 3, involvement of LC on both sides. The characteristics, treatment methods, and results of 49 transverse fractures of the C2 body were analyzed. Mean follow-up was 12.6 months (ranging from 12 to 26 months).

RESULTS

Twenty-six (53.1%) patients were Type 1, 21 (42.9%) were Type 2, and 2 (4.0%) were Type 3. Correlation coefficients for intra-observer and inter-observer reliabilities of classification were 0.723 and 0.598 (both, P < 0.001), respectively. About 40.8% (7 Type 1 and 13 Type 2) of the patients had fracture displacement >3 mm; Incidence of fracture displacement >3 mm was higher in Type 2 than Type 1 (61.9% vs 26.9%, P < 0.05). About 79.6% (20 Type 1, 17 Type 2 and 2 Type 3) of the patients were treated conservatively, and 20.4% (6 Type 1 and 4 Type 2) underwent surgery. At last follow-up, 47 out of 49 patients achieved fusion; overall fusion rate was 95.9%. All conservatively treated Type 1 and Type 3 patients achieved fusion. Out of 17 conservatively treated Type 2 patients, 15 achieved fusion but two developed nonunion; however, two nonunion patients opted not to undergo surgery. Subgroup analysis showed that Philadelphia brace caused nonunion significantly in fracture displacement >3 mm compared to Minerva brace/Halovest (100% vs 0%, P < 0.05). All surgically treated Type 1 and 2 patients achieved fusion. In terms of clinical outcomes, neck pain visual analog scale and neck disability index were significantly improved (both, P < 0.01). According to Odom's criteria, 93.9% (46/49) of the patients achieved satisfactory outcomes. No major complications occurred.

CONCLUSIONS

The majority of transverse fractures of C2 body can be treated conservatively. However, surgery or rigid Minerva brace/Halovest should be considered for Type 2 transverse fractures of the C2 body with fracture displacement >3 mm.

Does fracture-extension into the pars interarticularis alter outcomes in odontoid failure? a technical note on pars interarticularis osteotomy and atlantoaxial distraction arthrodesis

PURPOSE

Odontoid process fractures can extend rostral into the C2 arch. We investigated the clinical impact of a concurrent fracture of the pars interarticularis on odontoid failure. To overcome the surgical challenges related to the morphology of these fractures, we describe a novel surgical strategy using atlantoaxial joint distraction arthrodesis.

METHODS

We conducted a single centre cohort study of 13 consecutive patients with odontoid fractures extending into the pars treated between June 2016 and June 2018. Criteria for a stable fibrous non-union were: Atlanto-Dens Interval (ADI) < 3 mm, Posterior Atlanto-Dens Interval (PADI) > 14 mm and lack of symptomatic motion at the fracture site. Atlantoaxial instability was defined as greater than 50% subluxation across the C1-C2 joint. Return to pre-injury performance status was considered a satisfactory clinical outcome.

RESULTS

The mean age of the patient population was 77.2 years (SD 11.9). The mean follow-up time was 15 months (SD 5.2). 69% had an associated atlantoaxial instability (P-value 0.0005). Cervical orthosis treatment was associated with a high non-union rate (70%) (P-value 0.04) although it did not affect the overall clinical outcome. 2 cases presented with cord compression were treated surgically with pars interarticularis osteotomy and atlantoaxial distraction arthrodesis.

CONCLUSIONS

Odontoid fracture with extension into the pars interarticularis often present with atlantoaxial instability and may result in stable fibrous non-union if treated non-operatively. The C1-C2 segment can be stabilised with atlantoaxial distraction arthrodesis achieved through an osteotomy of the pars interarticularis.

Atypical hangman's fracture with concomitant subaxial fracture-dislocation treated with circumferential fusion of C2-C5-a case report

INTRODUCTION

Atypical hangman's fractures are coronally-oriented vertical fractures of the posterior body of C2. Though these are not uncommon injuries, there is a paucity of data investigating the management of these fractures, especially when they occur in association with subaxial fracture dislocations.

CASE PRESENTATION

A 50-year-old male suffered a cervical extension injury when he dove into a shallow swimming pool while intoxicated. Initial examination demonstrated 2/5 strength in the right deltoid and biceps and 3/5 strength in the left deltoid and biceps with no motor or sensory function distal to the C5 level. Cervical CT scan revealed a C2 atypical hangman's fracture and a C4 right-sided facet fracture with traumatic spondylolisthesis at C4/5. We performed C2-C5 anterior cervical discectomy and fusion followed by a C3-C5 posterior instrumented fusion. At the patient's two year postoperative visit, the patient has had minimal improvement in neurologic function with 4/5 strength in bilateral deltoids and biceps and 2/5 strength in right wrist extension. Radiographs show a solid arthrodesis on flexion-extension radiographs.

DISCUSSION

To our knowledge, this is the first case report discussing the operative management of an atypical hangman's fracture with a concomitant subaxial fracture-dislocation. This case report adds to our current knowledge by demonstrating a novel anterior-posterior approach for treating these complicated injuries.

Hangman's Fracture

STUDY DESIGN

Review article.

OBJECTIVE

A review and update of the treatment of Hangman's fractures including the indications for both nonoperative and operative treatment of typical and atypical fractures.

SUMMARY OF BACKGROUND DATA

Hangman's fractures are the second most common fracture pattern of the C2 vertebrae following odontoid fractures. Many of the stable extension type I and II fractures can be treated with external immobilization, whereas the predominant flexion type IIa and III fractures require surgical stabilization.

METHODS

A review of the literature.

RESULTS

The clinical and radiographic outcomes of the treatment of Hangman's fractures lend a good overall prognosis when the correct diagnosis is made. The nonoperative treatment of stable type I and II fractures with external immobilization leads to excellent long-term outcomes as does the operative treatment of the unstable type IIa and III fractures.

CONCLUSIONS

Hangman's fractures can be classified as stable (type I and most II) or unstable (type IIa and III) and the optimal treatment depends upon this distinction. Stable injuries do well with rigid immobilization and rarely require operative intervention. In contrast, unstable injuries do poorly if treated nonoperatively but do well with surgical intervention. When treating atypical Hangman's variants, great vigilance and close clinical observation is paramount if nonoperative treatment is indicated given the potential for neurological compression in this fracture pattern. Properly identifying and treating these injuries represents an opportunity for the spine surgeon to optimize patient outcomes.

Curious Case of Atypical Hangman’s Fracture: C2–C3 Listhesis without Pars Fracture

Traumatic spondylolisthesis of axis or hangman’s fracture is the second most common C2 vertebra injury. We present a report of a young man presenting with a history of fall from height with C2 to C3 spondylolisthesis without any evidence of injury to pars interarticularis but with associated injury to capsular ligament of facet joint along with posterior spinous ligamentous injury. The patient underwent intraoperative reduction in listhesis with posterior screw fixation. The patient showed uneventful postoperative course with neurological improvement at 6-week follow-up. Hangman’s fracture refers to a diverse group of injury in which the soft tissue injury has an equally important part to play as the bone fracture.

Direct trans-pedicular screw fixation for atypical hangman's fracture: A minimally invasive technique using the tubular retractor system

The ideal treatment strategy of atypical hangman's fracture (AHF) is debatable. If surgical treatment is needed, direct trans-pedicular fixation technique is advantageous in that it stabilizes the fracture site and spares adjacent motion segments. The authors describe relatively simple and minimally invasive technique using the tubular retractor system (TRS) for surgical treatment of AHF. Trans-pedicular screw fixation using the TRS was performed in seven patients with AHF. This technique was facilitated by using intraoperative fluoroscopy and a surgical microscope. Rigid cervical collar was used for 4 weeks, postoperatively. To evaluate postoperative radiological outcomes, cervical computed tomography (CT) was performed at postoperative 6 months. The clinical outcomes, including visual analog scale and neck motion, were evaluated. In surgical outcomes, no intraoperative neuro-vascular injury or postoperative complications occurred. For all patients, dynamic radiographs and CT images demonstrated a stable construct. Clinical examination also showed satisfactory pain relief and restoration of the full range of motion in the neck. Direct trans-pedicular screw fixation using the TRS for AHF appears to be safe and effective. This technique permits less skin incision and muscle dissection with good postoperative recovery. This report serves as a preliminary study and may be a surgical option for minimally invasive direct repair.

Zero-Profile Implantation Combined with Miniscrew Fixation via Anterior Approach for Huge Teardrop Fracture of Axis

BACKGROUND

We present 3 case reports to share our experience and explore the safety and efficacy of treating huge teardrop fracture of the axis (HTDFA).

CASE DESCRIPTION

Case 1: A 47-year-old man suffered from generalized pain after falling from a height. Case 2: A 39-year-old woman suffered facial contusions and lacerations during a car accident, and her neck was sore. Case 3: A 51-year-old woman was hit in the face during a car accident, and her neck was sore. These 3 patients had limited neck movement and no nerve injury, and their radiographs showed HTDFA. The patients were treated with Zero-Profile (Zero-P) implant placement combined with miniscrew fixation.

CONCLUSIONS

The treatment of HTDFA by Zero-P implant placement combined with miniscrew fixation is effective and stable. The last follow-up examination of the patients showed that fusion had been achieved, and their neck pain had disappeared. Anterior reduction, diskectomy, and Zero-P implantation combined with miniscrew fixation can be used to treat HTDFA. Both avulsed teardrop fragment removal and C2-3 bone grafting lead to bone healing. This method is effective, safe, and simple for the treatment of HTDFA.

Individual Surgical Strategy Using Posterior Lag Screw-Rod Technique for Unstable Atypical Hangman's Fracture Based on Different Fracture Patterns

OBJECTIVE

The literature on surgical management of atypical hangman's fracture (AHF) is sparse. The aim of this study was to describe an individual surgical strategy using a lag screw-rod technique for treatment of unstable AHF based on different fracture patterns.

METHODS

A retrospective analysis of 23 patients with unstable AHF was performed. Fractures were classified into 3 patterns: A, 1 fracture line through 1 side of C2 body obliquely and another through pars interarticularis on the other side; B, 1 fracture line through 1 side of C2 body obliquely and another through contralateral lamina; C, bilateral oblique fracture lines through posterior cortex of C2 on different sides. Posterior C2-C3 pedicle screw fixation and fusion using a lag screw-rod technique with different surgical strategies for each fracture pattern was used for all patients. Complications, neck pain, neurologic status, reduction of anterior translation and angulation between C2 and C3, and fusion rate were evaluated.

RESULTS

No technique-related complications (e.g., spinal cord or nerve injury caused by malposition of screws) occurred. Mean follow-up time was 37 months. Satisfactory reduction and bony union were demonstrated on postoperative radiographs. Neck pain and neurologic deficits caused by C2 injury improved significantly in all patients after operation. No graft or implant-related complications were observed in patients during the entire follow-up period.

CONCLUSIONS

Using individual surgical strategies based on different fracture patterns, the posterior C2-C3 lag screw-rod technique may be an effective and reliable option for unstable AHF.

Conservative Treatment of Hangman Variant Fractures

STUDY DESIGN

This is retrospective cohort study.

OBJECTIVE

Investigate the stability of patients with hangman variant fractures and outcomes of treatment with external immobilization.

SUMMARY OF BACKGROUND DATA

Traumatic spondylolisthesis of the axis (C2) with the fracture extending into the vertebral body has been incompletely characterized. Small case series have showed high rates of neurological injury and cite difficulty treating closed due to greater instability secondary to extensive ligamentous injury.

MATERIALS AND METHODS

Retrospectively, all patients admitted to a level 1 trauma center from 2004 to 2015 with acute C2 fractures were identified and classified based on computed tomographic imaging. Study cohort included patients with anterior translation <5 mm and C2-3 angulation <15 degrees that were followed to conclusion of treatment.

RESULTS

In total, 107 hangman's variant fractures (14.5%) were identified from a database of 735 acute C2 fractures. In total, 106 of the 107 patients displayed no neurological injury related to the cervical spine at the time of presentation. A total of 63 patients met the inclusion criteria and were followed as outpatients until collar or halo vest removal. All fractures progressed to union without progressive displacement or late neurological injury. No difference was observed in radiographic outcome between patients treated in a hard collar versus halo orthosis.

CONCLUSIONS

Although widely considered a difficult fracture to treat with closed means, hangman variants are relatively neurologically benign injuries with low incidence of ligamentous injury. Fractures with <5 mm of horizontal translation and 15 degrees of angulation can be treated with external immobilization. Our results suggest no advantage of halo immobilization versus hard collar orthosis.

TRAUMATIC INJURIES OF THE CERVICAL SPINE: CURRENT EPIDEMIOLOGICAL PANORAMA

Objective:

To collect data from patients with cervical fracture who were treated surgically in a tertiary health service, in order to better understand the current scenario of this kind of injury in our population.

Methods:

This retrospective survey examined consecutive cases of patients with cervical spine trauma who received surgical treatment during 2013 and 2014. The data were subjected to descriptive statistical analysis.

Results:

Fifty-two patients were treated with surgery during 2013 and 2014. All patients classified as Frankel A and B developed respiratory failure. Patients classified as Frankel A, B, and C had significantly higher rates for postoperative complications (p < 0.01) than patients classified as Frankel D and E, except for the rate of postoperative infections (p = 0.717). Hospitalization time was also longer in the first group (p < 0.01).

Conclusion:

Patients with cervical trauma who present with neurological deficit at hospital admission should receive special attention, since the rate of postoperative complications is higher and hospital stays are lengthier in this group. In addition, patients with Frankel A and B classification should be monitored in an intensive care unit. Level of Evidence III; Retrospective comparative study.

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.

A novel classification for atypical Hangman fractures and its application: A retrospective observational study

Atypical Hangman fractures (AHF) were first formally reported and considered to be more often associated with neurologic deficit in 1993. However, there is a paucity of literature focusing on these fractures. The purpose of the retrospective study was to introduce a new classification scheme for AHF and its application.Sixty-two patients with Hangman fractures were identified. There were 46 (74.2%, 46/62) AHF patients, including 29 type I, 9 type II, 5 type IIa, and 3 type III fractures (Levine-Edwards classification). Based on fracture patterns, incidence, and their impact on neurologic status, a primary classification for AHF was devised. The clinical features of AHF were observed, and a new classification was introduced. The appropriate treatment strategy of AHF was discussed.Of 46 AHF patients, 27 underwent surgical treatment (24 with posterior approach with screw-rod fixation and fusion, 1 with anterior approach by C2/3 discectomy and fusion, and 2 with anterior and posterior approach), and the remaining 19 patients underwent nonoperative treatment. No patient complained severe neck pain at final follow-up. Neurologic status improved 1 to 2 grade in 12 cases with neurologic deficit. All patients achieved bony fusion within the follow-up period.AHF should be recognized as a distinct fracture subtype. The new classification for AHF is based on the feature of fracture patterns, injury mechanism, incidence, and their impact on neurologic deficit. And the new classification is complementary to Levine-Edwards.

Burst C2 Fractures Combined with Traumatic Spondylolisthesis: Can Atlantoaxial Motion Be Preserved? Including Some Technical Tips for Reduction and Fixation

STUDY DESIGN

Retrospective comparative clinical case series.

OBJECTIVE

Burst C2 fractures are very rare. Treatment options include conservative treatment or fusion (anterior, posterior, or anterior and posterior). Anterior fusion addresses mainly hangman component. The bursting body usually needs posterior or combined anterior-posterior fusion, but both permanently sacrifice atlantoaxial motion. Can anterior-"first" approach preserve C1-C2 motion and restore function?

METHODS

We report nine cases of burst C2 combined with C2-C3 spondylolisthesis and an odontoid fracture. The surgical group included six patients treated initially with an anterior approach, moving to a posterior one when necessary. All were treated with anterior diskectomy fusion using one session and one incision. The halo group included three patients treated conservatively using halo traction followed by rigid collar. Assessments included self-reported, physiologic, and functional measures. Reduction was assessed using Roy-Camille's criteria and improvement of canal compression ratio. Clinical outcome was graded excellent, very good, good, or poor according to pain, range of motion, and work status.

RESULTS

Mean follow-up was 44.5 ± 8.3 (range 36.0 to 62.0) weeks. Results in the surgical group were judged to be excellent in four and good in two. One patient developed atlantoaxial osteoarthritis. Results were good in one patient and poor in two patients in the halo group. Two patients developed atlantoaxial osteoarthritis. All three cases had work limitations.

CONCLUSION

A single anterior approach achieved union and preserved C1-C2 motion and function in some cases. Conservative treatment achieved union but failed to achieve good reduction or good clinical outcome in grossly instable fractures. However, we believe that the ideal management is yet to evolve.

Management of Typical and Atypical Hangman's Fractures

Study Design Retrospective study of a prospectively maintained database. Objective Our aim was to retrospectively review management and outcomes of patients with low-grade hangman's fractures, specifically looking at differences in outcomes between collars and halo immobilization. We also studied fracture patterns and their treatment outcomes. Methods Forty-one patients with hangman's fractures were identified from 105 patients with axis fractures between 2007 and 2013. Typical hangman's fractures were defined as traumatic spondylolisthesis of the axis causing a bilateral pars interarticularis fracture. Fractures involving the posterior cortex of C2 on one or both sides or an asymmetrical pattern were defined as atypical. Results There were 41 patients with a mean age of 59 years, with 13 (31.7%) typical and 28 (68.2%) atypical fractures. There were 22 (53.6%) type 1 fractures, 7 (41.4%) type 2 fractures, and 2 (4.9%) type 2a fractures in this series. Cervical collars were used to manage 11 patients (27% of all patients with hangman's fractures) and halo orthosis was used in 27 (65.8%). Three (7.3%) patients underwent surgical fixation of the fracture. Bony union was achieved in all patients on radiologic follow-up. Permanent neurologic deficit occurred in one patient due to associated injuries. Neck pain and stiffness were reported more commonly in the atypical group, but this finding was not statistically significant. Conclusions The majority of hangman type fractures can be treated nonoperatively. We found no difference in outcomes between a rigid collar or halo immobilization for treatment of low-grade fractures. Radiologic follow-up is essential to identify cases of nonunion.

Conservative and Operative Treatment in Extension Teardrop Fractures of the Axis

STUDY DESIGN

A retrospective case series describing teardrop fracture of the axis.

OBJECT

The purpose of the study was to clarify the clinical features, the mechanism of injury, and the potential instability of extension teardrop fractures of the axis, so as to emphasize the importance of recognizing this injury as a separate entity.

SUMMARY OF BACKGROUND DATA

Teardrop fractures of the axis are rare spinal fractures, comprising only a small percentage of all injuries of the cervical spine. The stability of this fracture pattern has been a matter of debate leading to controversy regarding treatment strategies and the need for stabilization.

METHODS

We retrospectively reviewed data collected from 16 patients to document the mechanism of injury, neurological deficit, treatment and clinical outcome, and imaging findings.

RESULTS

Extension teardrop fractures accounted for approximately 8.9% of the upper cervical spinal injuries and 12.7% of axis fractures at the authors' institution over the same period. Six patients (4 males and 2 females) underwent surgery (4 by an anterior approach, 2 by a posterior approach). Ten cases underwent Halo-vest immobilization for a period between 6 and 12 weeks. At final follow-up, 14 cases achieved excellent results, whereas 2 patients complained of mild residual neck pain. Maximum cranial-caudal dimensions of the fragments were between 5 and 24 mm (average, 12.9 mm), and the transverse dimensions were between 5 and 22 mm (average, 11.1 mm). Fragment displacement ranged from 1 to 9 mm (average, 3.5 mm), whereas fragment rotation ranged from 10 to 52 degrees (average, 24.4 degrees) in the sagittal plane.

CONCLUSIONS

Most patients with an extension teardrop fracture of the axis can be treated conservatively. On the basis of this case series, the authors suggest that large fragment size, displacement or angulation, intervertebral disk injury, neurologic deficit, or signs of instability are reasonable indications for surgical treatment.

Clinical features of the extension teardrop fracture of the axis: review of 13 cases

Object

Extension teardrop fracture of the axis is an extremely rare cervical spinal injury. The classic clinical features, which have mainly been described by radiologists rather than spine surgeons, include its occurrence in elderly patients with osteoporosis, an association with minimal or no prevertebral soft-tissue swelling, and an absence of associated neurological deficit. However, recent case studies indicate notable exceptions to these clinical features, although few studies have investigated osteoporosis in these patients. The purpose of the present study was to clarify the clinical features of extension teardrop fracture of the axis.

Methods

The authors retrospectively reviewed data obtained in 13 patients with regard to their injury etiology, neurological deficit, treatment and outcome (residual neck pain), and imaging findings (size and displacement of the fragment, C2–3 subluxation, disc injury, and osteoporosis of the axis).

Results

Extension teardrop fracture of the axis constituted 11.6% of upper cervical spinal injuries at the authors' institute. The mean age of the patients was 49.5 years and distinct osteoporosis was identified in only 1 patient. A C2–3 subluxation was observed in 2 patients, in whom the displacement of the fragment was significant, although its size did not appear to have an effect. Magnetic resonance imaging, undertaken in 7 patients within 48 hours of injury, showed no disc injuries. Instability of the cervical spine was absent in all patient at follow-up. Only one patient underwent surgery for the presenting symptoms of dysphagia. The other patients were treated conservatively. The authors examined 9 patients directly; these patients had bony fusion and did not complain of neck pain, except for a patient with traumatic spondylolisthesis.

Conclusions

Extension teardrop fracture of the axis is generally caused by hyperextension of the cervical spine caused by a direct high-energy blow to the forehead or mandible. Based on the present case study, the authors believe that osteopenia and older age should not be considered risk factors. Most patients with an extension teardrop fracture of the axis can be treated conservatively, and surgical intervention may only be indicated for specific cases, such as those in which a patient presents with dysphagia or with other complicated fractures.

Conservative treatment of neural arch fractures of the axis: computed tomography scan and X-ray study on consolidation time

BACKGROUND

Computed tomography (CT) scan and X-ray study on consolidation time of C2 neural arch fractures treated conservatively were examined.

METHODS

A prospective study was undertaken: 28 conservatively treated fractures of the neural arch of the axis (11 hanged-man type I, 5 type II, and 12 miscellaneous fractures) were monitored during the period of orthosis by means of CT scan and plain X-rays performed on admission, and then at intervals between 2 and 120 days afterward. In patients treated with a halo vest (20 cases), a CT scan of the skull was performed to make sure that the pins were correctly positioned and to evaluate the osteolytic processes at the pin-bone interface.

RESULTS

Two patients died as a result of other severe brain or thoracoabdominal injuries, and the remaining 26 fractures healed in an average time of 109 days (range 90-120). The process of bone consolidation was documented in detail by CT, which showed how the newly formed osteofibrous tissue (iso-hypodense) progressively filled the interfragmentary space. In 2 cases of cranial pin loosening, CT demonstrated an osteolytic rim at the interface, which prompted early removal of the halo system. At clinical follow-up (mean 32 months; range 24-84), functional status was evaluated: all of the patients were neurologically intact with the exception of one, who presented with persistent paresthesias. The most frequent disturbance was cervical pain (12 cases, 46%).

CONCLUSIONS

CT with two- and three-dimensional reconstructed images has been shown to be the most reliable method for clarifying the evolution of bone consolidation and to show any osteolytic processes at the pin-bone interface during halo vest immobilization. Follow-up results of our series suggest that surgical treatment would not have improved the quality of life in these patients.

Axis fractures

BACKGROUND

Traumatic fractures of the second cervical vertebra are common, representing nearly 20% of all acute cervical spinal fracture-dislocation injuries. They are divided into 3 distinct injury patterns: odontoid fractures, hangman's fracture injuries, and fractures of the axis body, involving all other fracture injuries to the C2 vertebra.

OBJECTIVE

An evidence-based overview of the medical and surgical treatment strategies for each axis fracture injury sub-type.

RESULTS

Current medical and surgical management of traumatic fractures of the axis.

Simultaneous Anterior Arthrodesis C2-3 and Anterior Odontoid Screw Fixation for Stabilization of a 4-Part Fracture of the Axis—A Technical Description

Multiple fractures of the axis are rare and present challenging patterns of instability in cervical spine surgery. Once a surgeon is faced with a combination of fractures in the axis vertebra, including stable and unstable components, a sound treatment concept must be worked out to achieve primary stability, early mobilization, and superior outcome. We demonstrate an operative technique for the stabilization of a 4-part fracture of the axis. Utilizing anterior odontoid screw fixation and C2-3 arthrodesis, an unstable traumatic spondylolisthesis with fracture of the odontoid type IIA, and lateral mass of C2 was successfully stabilized at once. The technique enabled early postoperative mobilization of our patient, who, after 1 year, showed a favorable outcome with a pain-free range of motion. The basic thoughts guiding to treatment options in multiple fractures of the axis are discussed and our therapy concept is presented.

Spectrum of imaging findings in hyperextension injuries of the neck

Nonphysiologic hyperextension and lateral forces acting on the cervical spine and soft-tissue structures of the neck can result in a wide spectrum of injury patterns. Multiple factors (eg, patient age; the underlying morphologic features of the cervical spine; the magnitude, vector, and maximal focus of the force) all influence the observed patterns and the severity of injury. A review of the 5-year trauma database in two trauma centers revealed various injury patterns that were frequently recognized in patients with clinical evidence or historical documentation of a predominant hyperextension mechanism. Injuries included anterior arch avulsion and posterior arch compression fractures of the atlas, odontoid fractures, traumatic spondylolisthesis and teardrop fracture of C2, laminar and articular pillar fractures, and hyperextension dislocation injuries. More severe injuries were observed in patients with underlying predisposing conditions (eg, degenerative spondylosis, ankylosing spondylitis, diffuse idiopathic skeletal hyperostosis). Knowledge of the involved biomechanical factors provides a framework for understanding these injury patterns. Diagnostic imaging, especially computed tomography and magnetic resonance imaging, plays a fundamental role in the assessment of patients with suspected cervical injury. Furthermore, cross-sectional imaging facilitates the recognition of accompanying injuries to the face, the head, and the vascular structures of the neck.

Nonoperative Management of Vertical C2 Body Fractures

OBJECTIVE:

To estimate the incidence and to describe the clinical results of the nonoperative management of vertical C2 body fractures.

METHODS:

An 8-year retrospective review of upper cervical spine injuries from the registry of a level I trauma center identified 21 patients with a vertical C2 body fracture.

RESULTS:

Sixteen coronally oriented Type 1 vertical C2 body fractures and 5 sagittally oriented Type 2 vertical C2 body fractures were identified. These fractures account for approximately 10% of the upper cervical spine fractures identified over this period of time. One elderly patient with a Type 1 fracture died as a result of pneumonia, and two patients with Type 2 fractures died from severe closed-head injuries. One patient had evidence of spinal cord injury. This was not related to the C2 body fracture but rather to a subaxial cervical spine injury. Of the surviving 18 patients, all were managed nonoperatively (with external orthoses) and showed evidence of fusion (union of fracture fragments) at the time of the last follow-up.

CONCLUSION:

Vertical C2 body fractures are not rare injuries and can account for up to 10% of upper cervical spine injuries. In general, vertical C2 body fractures are amenable to nonoperative treatment with external orthoses.

Multiple fractures of the axis

Multiple fractures of the axis are not common lesions. A retrospective study was performed to identify the different fracture patterns and to analyze the incidence of these injuries and their long-term behavior. The medical records of 674 consecutive patients with fractures of the cervical spine were reviewed. Nine (1%) of 674 patients (6 men and 3 women) had multiple fractures of the axis. Mean patient age was 48 years. The most common lesion was a combination of traumatic spondylolisthesis with either an odontoid process or a teardrop fracture of the axis body. All patients were treated conservatively with an excellent or good outcome at mean 12-year follow-up (range: 2-18 years). Computed tomography was the imaging modality of choice for the correct diagnosis of these rare lesions.

Fracture « tear-drop » en extension de l’axis

Tear-drop fracture of the axis is an exceptional spinal fracture which generally occurs after high-energy trauma with hyper-extension of the cervical spine. Purely anterior fracture can occur with no real impact on stability. Orthopedic treatment provides good results in this situation. If the fracture is posterior, it continues into the C2-C3 intervertebral disc and the common posterior vertebral ligament, leading to C2C3 instability and possible retrolisthesis of C2 over C3 and neurological involvement. We report a case of tear-drop fracture of C2 with C3 instability without neurological involvement. This patient underwent posterior fixation with C2C3 arthrodesis which provided good quality bone fusion without secondary displacement or clinical aggravation.

Isolated fractures of the axis in adults

FRACTURES OF THE ODONTOID:

STANDARDS

There is insufficient evidence to support treatment standards.

GUIDELINES

Type II odontoid fractures in patients 50 years and older should be considered for surgical stabilization and fusion.

OPTIONS

Type I, Type II, and Type III fractures may be managed initially with external cervical immobilization. Type II and Type III odontoid fractures should be considered for surgical fixation in cases of dens displacement of 5 mm or more, comminution of the odontoid fracture (Type IIA), and/or inability to achieve or maintain fracture alignment with external immobilization. TRAUMATIC SPONDYLOLISTHESIS OF THE AXIS (HANGMAN'S FRACTURE):

STANDARDS

There is insufficient evidence to support treatment standards.

GUIDELINES

There is insufficient evidence to support treatment guidelines.

OPTIONS

Traumatic spondylolisthesis of the axis may be managed initially with external immobilization in most cases. Surgical stabilization should be considered in cases of severe angulation of C2 on C3 (Francis Grade II and IV, Effendi Type II), disruption of the C2--C3 disc space (Francis Grade V, Effendi Type III), or inability to establish or maintain alignment with external immobilization. FRACTURES OF THE AXIS BODY (MISCELLANEOUS FRACTURES):

STANDARDS

There is insufficient evidence to support treatment standards.

GUIDELINES

There is insufficient evidence to support treatment guidelines.

OPTIONS

External immobilization is recommended for treatment of isolated fractures of the axis body.

Classification and treatment of axis body fractures

We have classified 31 cases of axis body fracture by the type of bony injury depicted in radiographic images into the following four types: avulsion, transverse, burst, and sagittal fractures. The results of treatment in these types were retrospectively analyzed. In all of nine cases of avulsion fracture and two cases of transverse fracture, bone union was obtained by nonoperative treatment. All three cases of burst fracture healed, one by nonoperative treatment, and the remaining two by C2/3 anterior interbody fusion. Bone union was also obtained in all of the 17 cases of sagittal fracture, which included nonoperative treatment in 15 cases, and transoral atlanto-axial fusion in the remaining two cases. because many axis body fractures are inherently stable injuries, the authors normally select nonoperative treatment as initial therapy. However, in sagittal fractures, eight patients had sequelae of nuchal pain caused by osteoarthrosis of the atlanto-axial joint. As a result of these findings, the authors deem it appropriate to utilize atlanto-axial fusion when severe malalignment of the atlanto-axial joint is recognized.

Fractures of the C-2 vertebral body

Vertical C-2 body fractures are presented in 15 patients with clinical and imaging correlations that suggest the existence of a variety of mechanisms of injury. In these patients, clinical and imaging correlations were derived by: 1) defining the point of impact by clinical examination; 2) defining the point of impact by soft-tissue changes on cranial magnetic resonance (MR) imaging or computerized tomography (CT); 3) obtaining an accurate history of the mechanism of injury; and 4) spine imaging (x-ray studies, CT, and MR imaging) of the C-2 body fracture and surrounding bone and soft tissue. The cases presented involve the region located between the dens and the pars interarticularis of the axis. Although these fractures are rarely reported, they are not uncommon. An elucidation of their pathological anatomy helps to further the understanding of the mechanistic etiology of upper cervical spine trauma. A spectrum of mechanisms of injury causing upper cervical spine fractures was observed. The type of injury incurred is determined predominantly by the force vector applied during impact and the intrinsic strength and anatomy of C-2 and its surrounding spinal elements. From this clinical experience, two types of vertical C-2 body fractures are defined and presented: coronally oriented (Type 1) and sagittally oriented (Type 2). A third type of C-2 body fracture, the horizontal rostral C-2 fracture (Type 3), is added for completeness; this Type 3 fracture is the previously described Type III odontoid process fracture described by Anderson and D'Alonzo.