Direct Fixation of C1 Jefferson Fracture Using C1 Lateral Mass Screws: A Case Report

Monoaxial Screws Versus Polyaxial Screws Osteosynthesis for Unstable Atlas Fractures: A Retrospective, Comparative Study With a Minimum Follow-Up of 3 years

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The study aimed to compare the radiological parameters, clinical outcomes, and long-term effects of the posterior osteosynthesis with polyaxial screw-rod system and the monoaxial screw-rod system in the treatment of unstable atlas fractures.

METHODS

We retrospectively analyzed the clinical data of 33 patients with posterior ORIF for unstable atlas fractures in our hospital from August 2013 to June 2020, with a minimum of 3 years of follow-up. Polyaxial screws (group A) were used in 12 patients and monoaxial screws (group B) in 21 patients. Perioperative data, radiological parameters, and clinical outcomes were collected and compared between the 2 surgical approaches.

RESULTS

The operative time, blood loss, time of screw-rod system placement, and hospital stay were significantly lower in group A than in group B. At the last follow-up, the visual analog scale (VAS) score and anterior arch reduction rate of the atlas in group A were lower than those in group B, while the lateral mass displacement (LMD) in group A was higher than that in group B. There was no significant difference between Group A and Group B in terms of the anterior atlantodental interval (AADI), posterior arch reduction rate of the atlas, range of motion (ROM), and neck disability index (NDI).

CONCLUSIONS

Monoaxial screws can achieve better reduction results for unstable atlas fractures, especially for the anterior arch of atlas. However, the surgical operation of monoaxial screws is more complicated than that of polyaxial screws and has more complications. Appropriate implants should be selected for the treatment of unstable atlas fractures based on the type of atlas fracture, the experience of surgeons, and the demands of patients.

Jefferson fracture as sport injury in weight-lifting athlete: A rare case report and literature review

INTRODUCTION AND IMPORTANCE

Cervical spine fractures are rare in sports, but their potentially grave consequences mean that they must be given special attention. The aim of this study was to present the case of a recreational athlete with a fracture of C1 resulting from weightlifting.

CASE PRESENTATION

Young, recreational athlete came with severe neck pain right after weightlifting. There was no neurologic deficits occurred. X ray and CT scan examination showed complete fracture of the right posterior and anterior arch of C1 and disruptions of the right transverse foramen and ligament. MRI revealed no sign of impingement or compromised canal. Patient was then treated conservatively with sternal occipital mandibular immobilizer (SOMI) brace for 4 weeks. Thereafter, the neck pain resolved gradually. No neurologic deterioration occurred. At time of brace removal, patient was free of pain with normal motoric and sensory function.

CLINICAL DISCUSSION

Our case was the first report of a Jefferson fracture caused by a direct injury mechanism due to the weightlifting sport. The type III Jefferson fracture produced by this contrary injury mechanism showed that with adequate force, another spectrum of injury mechanisms may be created.

CONCLUSION

With adequate assessment and proper patient selection, Jefferson fracture can be treated effectively by SOMI brace with excellent functional outcomes.

Direct osteosynthesis in the treatment of atlas burst fractures: a systematic review

PURPOSE

The treatment of unstable atlas fractures remains a controversial topic. The study aims at assessing the prognosis and efficacy of osteosynthesis for unstable atlas fractures through a review of the current literature and additionally aims to compare outcomes between the transoral and posterior approaches.

METHODS

A systematic review of databases including PubMed, EMBASE, Cochrane, Web of Science, CNKI, and Wanfang was conducted. Titles and abstracts were screened by two reviewers to identify studies meeting pre-defined inclusion criteria for comprehensive analysis.

RESULTS

The systematic review included 28 articles, 19 employing the posterior approach and 9 utilizing the transoral approach. It covered osteosynthesis in 297 patients with unstable atlas fractures, comprising 169 treated via the posterior approach and 128 via the transoral approach. Analysis revealed high healing rates and clinical improvement in both approaches, evidenced by improvements in the visual analog scale, range of motion, atlantodens interval, and lateral displacement distance post-surgery.

CONCLUSION

Osteosynthesis offers effective treatment for unstable atlas fractures. Both transoral and posterior approaches can achieve good clinical outcomes for fracture, and biomechanical studies have confirmed that osteosynthesis can maintain the stability of the occipitocervical region, preserve the motor function of the atlantoaxial and occipito-atlantoaxial joints, and greatly improve the quality of life of patients. However, variations exist in the indications and surgical risks associated with each method, necessitating their selection based on a thorough clinical evaluation of the patient's condition.

Design of a novel lateral mass screw-plate system for the treatment of unstable atlas fractures: a finite element analysis

BACKGROUND

Osteosynthesis of unstable atlas fractures preserves joint motion and therefore has a distinct advantage over a range of treatment procedures. To prevent the potential disadvantages associated with osteosynthesis, a new atlas lateral mass screw-plate (LMSP) system has been designed. However, the biomechanical role of using the LMSP system in atlas internal fixation is not known. The aim of this study was to compare the biomechanical stability of a new LMSP with traditional posterior screw and rod (PSR) fixation techniques on the occipitocervical junction (C0-C2) through finite element analysis.

METHODS

A nonlinear C0-C2 finite element model of the intact upper cervical spine was developed and validated. The unstable model using the PSR system was then compared with the model using the LMSP system for fixation. A vertical load of 40 N was applied to the C0 to simulate head weight, while a torque of 1.5 Nm was applied to the C0 to simulate flexion, extension, lateral bending, and axial rotation.

RESULTS

The range of motion of both systems was close to the intact model. Compared with the LMSP system model, the PSR system model increased flexion, extension, lateral bending, and axial rotation by 4.9%, 3.0%, 5.0%, and 29.5% in the C0-C1 segments, and 4.9%, 2.7%, 2.4%, and 22.6% in the C1-C2, respectively. In flexion, extension, and lateral bending motion, the LMSP system model exhibited similar stress to the PSR system model, while in axial rotation, the PSR system model exhibited higher stress.

CONCLUSIONS

The findings of our study indicate that the two tested system models provide comparable stability. However, better stability was achieved during axial rotation with the LMSP system, and in this system, the maximum von Mises stress was less than that of the PSR one. As the atlantoaxial joint functions primarily as a rotational joint, the use of the LMSP system may provide a more stable environment for the joint that has become unstable due to fracture.

Temporary posterior C1-2 instrumentation without fusion for treatment of displaced atlantoaxial fractures

OBJECTIVE

We describe open reduction internal fixation (ORIF) with posterior C1-2 instrumentation without fusion to treat displaced atlantoaxial fractures with later instrumentation removal. Potential benefits are improved fracture healing while maintaining C1-2 mobility and avoiding complications of halo vest immobilization (HVI).

METHODS

A retrospective review identified 14 patients (mean age 44 years) with displaced atlantoaxial fractures treated with ORIF without fusion. Patient demographics, fracture morphology, trauma etiology, instrumentation levels, timing of hardware removal, and complications were collected. Patients were maintained in a cervical collar, and healing was confirmed via imaging prior to instrumentation removal.

RESULTS

Fractures included Type III odontoid, C2 pars, C1 ring, and complex C1 or C2 fractures. All cases utilized C1 lateral mass screws and C2 pars or pedicle screws with a C1 crosslink. Two patients had C3 lateral mass screws. All patients showed fracture healing on imaging within 4 months after ORIF. Thirteen patients underwent instrumentation removal. No complications were noted.

CONCLUSION

Displaced atlantoaxial fractures have been traditionally managed with HVI closed reduction or ORIF with fusion. We described a technique of ORIF without fusion and subsequent hardware removal as an alternative. This strategy preserves mobility at C1-2 and avoids HVI, and appears to be a safe option for the treatment of atlantoaxial fractures.

Hemiparesis resulting from an unusual C1 fracture: A case report and literature review

Background:

Jefferson fractures are burst fractures involving both the anterior and posterior arches of C1. They typically result from axial compression or hyperextension injuries. Most are stable, and neurological deficits are rare. They are often successfully treated with external immobilization, but require surgery (e.g., fusion/ stabilization).

Case Description:

An 89-year-old male presented with a left-sided hemiplegia following a trivial fall. The cervical computed tomography scan revealed a left-sided displaced comminuted C1 fracture involving the arch and lateral mass. The MR revealed posterior cord compression and focal myelomalacia. Six months following an emergent C1–C3 decompression with occiput to C4 instrumented fusion, the patient was neurologically intact and pain-free.

Conclusion:

An 89-year-old male presented with a left-sided hemiplegia due to a Type 3/4 C1 Jefferson fracture. Following posterior C1–C3 surgical decompression with C0–C4 instrumented fusion, the patient sustained a complete bilateral motor recovery.

Traumatic Atlanto-occipital Dislocation: Analysis of 15 Survival Cases With Emphasis on Associated Upper Cervical Spine Injuries

STUDY DESIGN

Retrospective case analyses.

OBJECTIVE

The aim of this study was to investigate the incidence and characteristics of associated upper cervical spine injuries in 15 survival cases of traumatic atlanto-occipital dislocation (AOD).

SUMMARY OF BACKGROUND DATA

Traumatic AOD is a rare and generally fatal injury. Information regarding associated upper cervical spine injuries that may affect treatment methods, outcomes, and prognosis is limited.

METHODS

Fifteen patients (11 patients with posterior-type AOD and four patients with vertical-type AOD) who survived traumatic AOD were included in this study. Plain radiographs, computed tomography, magnetic resonance imaging, and medical records were reviewed. The incidence and characteristics of associated upper and lower cervical spine and thoracolumbar spine injuries and brain injuries were evaluated.

RESULTS

Thirteen patients with traumatic AOD (11 patients with posterior-type AOD and two patients with vertical-type AOD) showed associated upper cervical spine injuries; the overall incidence was 87% (100% in posterior-type AOD and 50% in vertical-type AOD). In posterior-type AOD, eight (72.7%) patients had C1 fractures (four patients had three-part fracture, three patients had two-part fracture, and one patient had four-part fracture), four (36.4%) patients had C1 lateral mass fractures, two (18.2%) patients had transverse atlantal ligament injuries. In vertical-type AOD, two (50%) patients had C1-C2 vertical subluxation with C1 anterior arch horizontal and sagittal split fractures. In posterior-type AOD, two (18%) patients had lower cervical spine injuries and one (9%) patient had brain injury. In vertical-type AOD, one (25%) patient had thoracic spine injury, and three (75%) patients had brain injuries additionally.

CONCLUSION

Survival cases with traumatic AOD showed a high incidence of associated upper cervical spine injuries and brain injuries. High index of suspicion and careful radiologic examination are needed to investigate the presence of associated upper cervical spine injuries and brain injuries in traumatic AOD, which affects treatment, outcome, and prognosis.

LEVEL OF EVIDENCE

4.