Posterior atlantoaxial dislocation without fracture or neurological symptoms treated by transoral-posterior approach surgery: a case report and literature review. Eur Spine J. 2019;28:37-40. [PMID: 30448988 DOI: 10.1007/s00586-018-5823-6]

Clinical epidemiology, management and outcomes of traumatic cervical spinal-cord and spine injuries: a systematic review of 1645 pooled cases

INTRODUCTION

Cervical spine (mostly atlanto-axial) accounts for over half of the acute traumatic disruptions of the spinal cord and its coverings; alongside its persisting neurological deficits. Two-thirds of the etiology were fairly evenly distributed between traffic crashes, falls, assault and other occupation-related injuries. We described the etiological mechanisms, neuro-anatomical level, severity, treatment and outcomes of traumatic cervical spinal-cord and spine injuries (C-SCI+SI).

EVIDENCE ACQUISITION

We systematically reviewed PubMed and Cochrane CENTRAL on 16th May 2023, using a prospectively registered protocol (CRD42023417530). The search strategy combined search words (from the keywords; "cervical spinal cord injury," "conservative" and "operative" "treatment") using Boolean operators. These yielded 787 and 55 records from PubMed (then 223 after delimiting to 10 years) and CENTRAL respectively; after records screening, 106 and 1 record were relevant respectively. Seventy-six reports were recruited for the quasi-quantitative synthesis following full-text review and methodological quality/bias assessment (using Joanna Briggs Institute critical appraisal tools).

EVIDENCE SYNTHESIS

Seventy-six reports yielded 1645 pooled cases. Weighted-mean age (N.=1512) was 46.3 years, with male (70.2%; gender N.=1525) preponderance. C-SCI+SI were mostly caused (N.=1079) by falls (42.1%) and road traffic crashes (42.2%); presenting(N.=178) with neck pain (71.4%) mostly and under one-fifth had neurological deficits (-plegias or -paresis, 11.8%; radiculopathy, 6.2%). The commonest vertebral levels (N.=1525) were 23.9% for the second cervical vertebra (c2), c5(20.4%) and c6(20.0%). Treatment (N.=1297) was combined pre-operative non-operative [skull traction (72.0%/842), cervical collar (13.9%/163)] in 90.2%, with solely non-operative (33.9%/439) options also used. Operative implant-based arthrodeses (66.2%/858) were done, using anterior (68.5%), posterior (20.2%/173) and combined (10.4%/89) approaches. Good bony fusion (89.0%) and clinical improvements (43.2%) were reported.

CONCLUSIONS

Mostly low-level evidence showed C-SCI+SI occurring more amongst the middle-aged and men; following falls or road traffic crashes. The second, fifth and sixth cervical levels are mostly affected; with excellent post-intervention bony-union, with neurological improvements in two-fifths. Better international reporting standards are advocated.

Traumatic posterior atlantoaxial dislocation without an associated fracture: a PRISMA-compliant case-based systematic review and meta-analysis

Traumatic posterior atlantoaxial dislocation (TPAD) without an associated fracture is a rare and challenging spinal injury. This PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses)-compliant case-based systematic review and meta-analysis aimed to comprehensively explore TPAD, covering clinical presentation, diagnosis, treatment, and clinical and radiological outcomes. Following the presentation of a case of TPAD without an associated fracture, we conducted a systematic search of electronic databases, including Scopus, PubMed, and Web of Science, from inception through October 2023, without language restrictions. Cases involving dislocations due to congenital anomalies or inflammatory processes were excluded. The search yielded 31 eligible cases of TPAD without an associated fracture. The majority (81%) of the cases were males, with traffic accidents being the leading cause (87%). Notably, 52% of the cases presented without any neurological deficits. Regarding treatment approaches, 23% of the cases were managed through closed reduction alone, 32% required fusion following closed reduction, and 45% underwent open reduction and fusion. A time delay exceeding 7.5 days was associated with a significantly higher risk of closed reduction failure (odds ratio, 56.463; p =0.011). This review identified key management strategies for TRAD without fracture, informed by the available evidence. Optimal management entails prompt closed reduction under C-arm while monitoring neurological status once hemodynamic stability is achieved. Surgical fusion is indicated for cases with magnetic resonance imaging-confirmed transverse ligament rupture or residual instability. If closed reduction fails, open reduction and fusion should be carried out. Posterior C1-C2 screws fixation is the preferred fusion technique, providing high levels of safety and biomechanical stability.

Comparison of robot-assisted versus fluoroscopically guided treatment of atlantoaxial dislocation in combination with high-riding vertebral artery: a preliminary study

BACKGROUND

Robotic-assisted surgery has emerged as an innovative approach widely adopted in the field of orthopedics. However, its application specifically for managing atlantoaxial dislocation with a high-riding vertebral artery (AAD-HVA) remains underreported in the existing literature.

OBJECTIVE

To compare the perioperative outcomes of robotic-assisted (RA) and fluoroscopic-guided free-hand (FH) techniques for atlantoaxial dislocation in combination with a high-riding vertebral artery (AAD-HVA).

STUDY DESIGN

This was a retrospective study.

SETTING

This research was performed at a single department of spine surgery.

METHODS

Data from patients who underwent atlantoaxial internal fixation between July 2018 and January 2022 at our hospital were retrospectively analyzed. Among the cases, 14 were performed using free-hand (FH) techniques and 11 utilized robotic-assisted (RA) techniques. Data collected included case notes, imaging records, and follow-up data. The reliability of screw placement was evaluated based on the Gertzbein and Robbins scores, while treatment outcomes were assessed using the Japanese Orthopaedic Association (JOA) score, visual analog scale (VAS), neck disability index (NDI), and postoperative complication rate.

RESULTS

Baseline patient characteristics were comparable between the FH and RA groups. The mean blood loss was markedly lower in the RA group (157.3 ± 49.7 ml) compared to the FH group (290.0 ± 110.3 ml) (p = 0.03). Although the average operative time was slightly higher in FH group than in RA group, this disparity did not achieve statistical significance (p = 0.7588). Moreover, the radiation exposure dose was remarkably higher in FH group (32.7 ± 4.4 mGy) than in RA group (23.0 ± 3.2 mGy) (p < 0.0001). The percentage of clinically acceptable screw placement was slightly lower in FH group (87.5%) than in RA group (97.8%), but the observed variance was not statistically meaningful (p = 0.3669). Furthermore, the differences in JOA, VAS, and NDI scores between the FH and RA groups were not statistically significant. Additionally, no obvious differences were found in clinical outcomes or complications related to screw implantation between the two groups.

LIMITATIONS

This study has inherent limitations as it was retrospective in nature and conducted at a single center.

CONCLUSION

Robotic-assisted surgery for AAD-HVA patients offers a minimally invasive approach, reduced bleeding and lower radiation exposure compared with traditional free-hand surgery.

Navigated Anterior Full-Endoscopic Transcervical Approach Odontoidectomy for Traumatic Posterior Atlantoaxial Dislocation Without Odontoid Fracture

BACKGROUND AND IMPORTANCE

Complete posterior atlantoaxial dislocation (PAAD) with an unfractured odontoid process is a rare condition where a dislocated but intact odontoid process is positioned ventrally to the anterior arch of C1. This lesion is related to transverse and alar ligament rupture secondary to hyperextension and rotatory traumatic injury and is often associated with neurological deficit. The treatment strategy remains controversial, and in many cases, odontoidectomy is required. Traditional approaches for odontoidectomy (transnasal and transoral) are technically demanding and are related to several complications. This article describes a 360° reduction and stabilization technique through a navigated anterior full-endoscopic transcervical approach (nAFETA) as a novel technique for odontoidectomy and C1-C2 anterior transarticular fixation supplemented with posterior fusion.

CLINICAL PRESENTATION

A 21-year-old man presented to the emergency room by ambulance after a motorcycle accident. On evaluation, incomplete ASIA B spinal cord injury was documented. Imaging revealed a complete PAAD. We performed a two-staged procedure, a nAFETA odontoidectomy plus C1-C2 anterior transarticular fixation followed by posterior C1-C2 wired fusion. At a 2-year follow-up, the patient had a 10-point Oswestry Disability Index score and neurological improvement to ASIA E.

CONCLUSION

PAAD can be successfully treated through minimally invasive nAFETA. Noteworthy, the risks of the transoral and endonasal routes were avoided through this approach. In addition, nAFETA allows anterior transarticular fixation during the same procedure providing spinal stability. Further studies are required to expand the use of nAFETA in this field.

[Traumatic posterior atlantoaxial dislocation without fracture of the upper cervical spine in a female geriatric patient : Case report and literature search]

Traumatic posterior atlantoaxial dislocation (PAAD) without detection of a fracture of the upper cervical spine is a very rare injury that usually occurs in younger patients and in most cases leads to immediate death due to distraction of the spinal cord. In contrast, the present case describes this injury in a female geriatric patient at the age of 75 years. In the literature there are also clinical case reports, where traumatic PAAD without a fracture did not result in neurological deficits and where initially existing neurological deficits were completely reversible through closed or open reduction and internal fixation.

Traumatic posterior atlantoaxial dislocation without fracture of the odontoid process: illustrative case

BACKGROUND

Traumatic posterior atlantoaxial dislocation without fracture of the odontoid process is extremely rare. Only 24 cases have been documented since the first patient was reported by Haralson and Boyd in 1969. Although various treatment strategies are reported, no consensus has been yielded.

OBSERVATIONS

A 58-year-old man experienced loss of consciousness and breathing difficulties after being struck by a car from behind. An immediate computed tomography scan showed subarachnoid hemorrhage, a posterior atlantoaxial dislocation without C1-2 fracture, and a right tibiofibular fracture. After the patient's respiration and hemodynamics were stabilized, closed reduction was attempted. However, this strategy failed due to unbearable neck pain and quadriplegia, resulting in surgical intervention with transoral odontoidectomy and posterior occipitocervical fusion. The patient developed postoperative central nervous system infection. After anti-infective and drainage treatment, the infection was controlled. At 1-year follow-up, the patient did not complain of special discomfort and was generally in good condition.

LESSONS

The authors report their experience with transoral odontoidectomy and concomitant posterior occipitocervical fusion in a case of posterior atlantoaxial dislocation without related fracture. Although these procedures are highly feasible and effective, particular attention should be paid to their complications, such as postoperative infection.

Retropharyngeal Reduction Plate for Atlantoaxial Dislocation: A Cadaveric Test and Morphometric Trajectory Analysis

Objective

To evaluate the placement feasibility and safety of the newly designed retropharyngeal reduction plate by cadaveric test and to perform morphometric trajectory analysis.

Methods

The five cadaveric specimens with intact atlantoaxial joint were enrolled in this study. They were used for simulating the placement process and evaluating the placement feasibility of the retropharyngeal reduction plate. The atlantoaxial dislocation (AAD) of five cadaveric specimens were obtained by proper external force after dissecting ligaments. The retropharyngeal reduction plate was placed on atlantoaxial joint of cadaveric specimens. The X‐ray and three‐dimensional (3D) spiral CT were used for evaluating the placement safety of retropharyngeal reduction plate. The DICOM data was obtained after 3D spiral CT scanning for the morphometric trajectory analysis.

Results

The reduction plates were successfully placed on the atlantoaxial joint of five cadaveric specimens through the retropharyngeal approach, respectively. The X‐ray and 3D spiral CT showed the accurate screw implantation and satisfying plate placement. The length of the left/right atlas screw trajectory (L/RAT) was, respectively, 1.73 ± 0.01 cm (LAT) and 1.71 ± 0.02 cm (RAT). The length of odontoid screw trajectory (OST) was 1.38 ± 0.02 cm. The length of the left/right axis screw trajectory (L/RAXT) was, respectively, 1.67 ± 0.02 cm (LAXT) and 1.67 ± 0.01 cm (RAXT). There was no statistical significance between left side and right side in terms of AT and AXT (P > 0.05). The angles of atlas screw trajectory angle (ASTA), axis screw trajectory angle (AXSTA), and odontoid screw trajectory angle (OSTA) were 38.04° ± 2.03°, 56.92° ± 2.66°, and 34.78° ± 2.87°, respectively.

Conclusion

The cadaveric test showed that the retropharyngeal reduction plate is feasible to place on the atlantoaxial joint, which is also a safe treatment choice for atlantoaxial dislocation. The meticulous preoperative planning of screw trajectory based on individual differences was also vital to using this technique.

Transoral digital reduction of complete anterior odontoid dislocation followed by fiducial-based navigated transcondylar screw fixation: illustrative case

BACKGROUND

Posterior atlantoaxial dislocations (i.e., complete anterior odontoid dislocation) without C1 arch fractures are a rare hyperextension injury most often found in high-velocity trauma patients. Treatment options include either closed or open reduction and optional spinal fusion to address atlantoaxial instability due to ligamentous injury.

OBSERVATIONS

A 60-year-old male was struck while on his bicycle by a truck and sustained an odontoid dislocation without C1 arch fracture. Imaging findings additionally delineated a high suspicion for craniocervical instability. The patient had neurological issues due to both a head injury and ischemia secondary to an injured vertebral artery. He was stabilized and transferred to our facility for definitive neurosurgical care.

LESSONS

The patient underwent a successful transoral digital closed reduction and posterior occipital spinal fusion via a fiducial-based transcondylar, C1 lateral mass, C2 pedicle, and C3 lateral mass construct. This unique reduction technique has not been recorded in the literature before and avoided potential complications of overdistraction and the need for odontoidectomy. Furthermore, the use of bone fiducials for navigated screw fixation at the craniocervical junction is a novel technique and recommended particularly for placement of technically demanding transcondylar screws and C2 pedicle screws where pars anatomy is potentially unfavorable.

Surgical Management for Posterior Atlantoaxial Dislocation without Fracture and Atlantoaxial Dynamic Test to Confirm the Integrity of the Transverse Ligament: A Case Report

Background

Traumatic posterior atlantoaxial dislocation (PAAD) without fracture of the odontoid process is a rare injury. Closed reduction by skull traction under C‐arm fluoroscopic guidance and open reduction have been reported previously for the treatment of PAAD.

Objective

To report a rare case of PAAD without fracture treated by closed manual reduction and posterior fixation. To provide a new method—atlantoaxial dynamic test—for confirming the integrity of the transverse ligament after reduction and evaluate the ideal treatment strategy for traumatic PAAD without fracture of the odontoid process or rupture of the transverse ligament.

Method

A 54‐year‐old woman was riding in the passenger seat when her vehicle was rear‐ended by a car. X‐ray and computed tomography (CT) scans were used to diagnose PAAD without a related fracture. Closed manual reduction under C‐arm fluoroscopy was performed after applying general anesthesia via sober intubation, and the integrity of the transverse ligament was confirmed by the atlantoaxial dynamic test with C‐arm fluoroscopy. Then, pedicle screw internal fixation via the posterior approach was applied to maintain atlantoaxial stability.

Results

The procedure was performed uneventfully, and the patient was able to move out of bed on the first day after surgery with Philadelphia cervical gear. During a 2‐year follow‐up period, imaging data demonstrated no instability of the atlantoaxial complex.

Conclusion

Closed manual reduction under C‐arm fluoroscopy is an easy and effective method for PAAD. The integrity of the transverse ligament can be confirmed by C‐arm fluoroscopy through the atlantoaxial dynamic test after reduction. Pedicle screw internal fixation via the posterior approach can provide sufficient stability.

Single door laminoplasty plus posterior fusion for posterior atlantoaxial dislocation with congenital malformation: A case report and review of literature

BACKGROUND

Posterior atlantoaxial dislocation (PAD) is a rare type of upper cervical spine disease. We sought to describe a unreported case of old PAD with os odontoideum (OO) and atlas hypoplasia (AH) and our unique treatment approach consisting of C1 single door laminoplasty with C1-3 posterior fixation and fusion.

CASE SUMMARY

A 70-year-old male patient who suffered from progressive aggravating numbness and limb weakness for 4 years without trauma, was diagnosed with old PAD with OO and AH. The patient underwent closed reduction and C1 single door laminoplasty with C1-3 posterior fixation and fusion instead of C1 laminectomy with occipitocervical fusion. During the 3-year follow-up, he was able to walk by himself instead of using a wheelchair and with a ± 25° range of head rotation as well as a ± 10° range of flexion-extension. Three-year follow-up images showed satisfactory reduction and fusion.

CONCLUSION

C1 single door laminoplasty with cervical fusion in PAD combined with spinal cord compression could be a suitable and effective surgical option. Compared with laminectomy and occipitocervical fusion, it retains more cervical range of motion, has a smaller incision and provides an adequate bone grafting space for atlantoaxial fusion.