Modified Posterior C1 Lateral Mass Screw Insertion for Type II Odontoid Process Fractures Using Intraoperative Computed Tomography–Based Spinal Navigation to Minimize Postoperative Occipital Neuralgia

Morbidity and mortality related to type II odontoid fractures in octogenarians undergoing surgery: a retrospective study with 5 year follow up

Introduction

The prevalence of trauma is increasing in the geriatric population. The optimal therapy for type II odontoid fractures in the elderly is controversial. This study aims to assess the morbidity and mortality associated with odontoid fractures in octogenarians undergoing C1/C2 posterior screw fixation and describe the perioperative and post-operative complications and risk factors associated with mortality.

Materials and methods

Electronic medical records from a single institution pertaining to the period between September 2005 and December 2020 were retrieved. Data on patient demographics, neurological conditions, surgical characteristics, complications, hospital course, and 90-day mortality were collected.

Results

Over a 16-year period, 60 patients aged ≥80 years diagnosed with type II odontoid fractures were enrolled in the study. The mean age was 85.0 ± 1.9 years. The mean Charlson Comorbidity Index (CCI) was >6 indicating a poor baseline reserve (8.5 ± 1.9), while cardiovascular diseases were the most prevalent among comorbidities. The mean surgical duration was 217.5 ± 65.9 min, with a mean blood loss of 725.5 ± 275.7 mL. The in-hospital was 5-0% and the 90-day mortality rates increased at 10.0%. No revision surgery was needed in any of the cases. Intraoperative and post-operative X-ray and computed tomography (CT) imaging revealed correct screw placement. Proper alignment of the atlantoaxial spine and fusion could be achieved in all cases. The unique risk factors for mortality included the presence of comorbidities and the occurrence of post-operative complications.

Conclusion

The complication and mortality rates associated with odontoid fractures in octogenarians are relatively high. However, the therapeutic goals in this population also include bone union and preservation of neurological status. Despite the often-high comorbidity rate, we still recommend that surgery should be considered in patients over 80 years. However, it is necessary to evaluate several approaches when treating such frail patients.

Nuance in Craniovertebral Junction Surgical Approach for Posterior C1-C2 Harms Stabilization: "Window Transposition" of the External Vertebral Venous Plexus for Bloodless C1 Lateral Mass Screw Insertion: Anatomical Aspects and Technical Notes

Atlas and axis instrumentation may be necessary in cases of several craniocervical junction pathologies. According to the Harms technique, C1-C2 polyaxial screws are inserted respectively in the C1 lateral masses and in C2 pedicles. C1 lateral mass screw insertion requires the careful subperiosteal dissection of the posterior elements of C1, the identification of the screw entry point by the downward distraction of C2 nerve root, and the cautious sparing of the overlying posterior external vertebral venous plexus (peVVP), whose bleeding, obstructing the surgical field, is sometimes barely controlled by hemostatic agents and swabbing. The authors describe in detail the anatomical aspects of an alternative surgical technique developed for the microsurgical transposition of the C1-C2 interposed external vertebral venous plexus in the case of Harms C1-C2 screw stabilization. The longitudinal median incision of the atlantoaxial membrane, followed by bilateral subperiosteal dissection and microsurgical section respectively at the inferior borders of the C1 laminae and at the superior borders of the C2 laminae, allows, as a "window opening," the symmetrical mediolateral transposition of the peVVP. This procedure provides a faster and cleaner anatomical exposition of the posterior surface of the C1 lateral mass and the C2 isthmus, preventing troublesome intraoperative venous bleeding that hinders C1 lateral mass screw insertion.

Efficacy and Safety of Goel-Harms Technique in Upper Cervical Spine Surgery: A Systematic Review and Meta-Analysis

OBJECTIVE

The main purpose of this systematic review and meta-analysis was to estimate the incidence of implant-associated complications and fusion rates for the Goel-Harms technique (GHT) and to show potential factors affecting the complications and nonunion development.

METHODS

A systematic search of the PubMed database according to PRISMA guidance was performed. The main inclusion criteria comprised description of fusion rate and/or implant-associated complications rate.

RESULTS

This systematic review included 86 articles focused on the results of surgery in 4208 patients. The rate of screw-related complications was as follows: 1) vertebral artery (VA) injury, 2.8%; 2) screw malposition in the direction of the VA, 5.8%; and 3) C2 nerve root irritation, 6.1%. The nonunion rate was 4.2%. Transpedicular screw insertion to the C1 and C2 vertebrae were the safest regarding VA injury and correlated with lower blood loss. For C1-C2 fusion, there was no statistical difference for the different bone graft localization. C2 nerve root irritation rate did not depend on screw insertion technique. The use of a freehand technique did not correlate with a high rate of screw-related complications.

CONCLUSIONS

The Goel-Harms technique is a promising method of C1-C2 fusion, with a relatively low nonunion and VA injury rate. It can be performed safely without C-arm or navigation system assistance. Transpedicular screw insertion trajectories to the C1 and C2 vertebrae were safest regarding VA injury and blood loss volume. Further comparative studies of various C1-C2 stabilization methods with a high level of significance should be carried out to identify the optimal approach.

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.

Can anatomical feasibility studies drive neurosurgical procedures and reach patients faster than traditional translational research?

Often, surgical techniques are practiced and studied in the anatomy laboratory. Occasionally, new surgical methods are developed with cadaveric anatomical studies. Some cadaveric feasibility studies, if published, might go on to be used by surgeons from around the world for improved patient care. Herein, we review our experience with 37 published anatomical feasibility studies over an 18-year period (2002-2020) and analyze the literature for published examples of surgical application of these same anatomical studies. We found that, for cadaveric anatomical feasibility studies within 7 years of their publication date, approximately 22% will be used in neurosurgery with the clinical applications published. Of these studies awarded clinical citation within 7 years of publication, the median time to that citation was approximately 3.4 years. As the average time for translational research to reach patient care is 17 years, cadaveric anatomical studies in this series reached patient care much sooner than traditional translational research. Cadaveric anatomical studies, based on our experience, can drive neurosurgical procedures.

Cirq® Robotic Assistance for Minimally Invasive C1-C2 Posterior Instrumentation: Report on Feasibility and Safety

BACKGROUND

Accurate screw placement remains very challenging especially in the upper cervical spine.

OBJECTIVE

To present our first experience of a percutaneous posterior C1-C2 fixation for a traumatic fracture.

METHODS

This is a case report of a non-neurological patient, harboring a type II odontoid fracture. She underwent a posterior percutaneous fixation using Cirq® Robotic Assistance coupled to the AIRO® intraoperative computed tomography (iCT)-scan and BrainLab® navigation system (all by BrainLab AG). Routine CT was performed on postoperative day 2 to evaluate pedicle screw placement. The effective dose was calculated.

RESULTS

The C1-C2 posterior percutaneous fixation was performed with cannulated VERTEX® Reconstruction System (Medtronic). Overall, 4 screws were placed. All of them were rated as acceptable (100%). Radiation dose received by the patient was 4.13 mSv. Radiation dose received by the surgical staff was 0 mSv. Postoperative course was excellent.

CONCLUSION

Posterior percutaneous fixation using Cirq® Robotic Assistance coupled with iCT navigation system is a major innovation that can improve pedicle screw positioning's accuracy with acceptable patient radiation and reduced surgical team exposure.

3-Dimensional printing templates guiding versus free hand technique for cervical lateral mass screw fixation: A prospective study

OBJECTIVE

In this randomized, single blind and controlled study, the feasibility and precision of 3-dimensional printing templates for cervical lateral mass screw insertion was evaluated.

METHODS

A total of 6 patients (72 screws), who were diagnosed with cervical spondylotic myelopathy (CSM) and developmental cervical spinal stenosis, were randomly divided into A and B two groups. All subjects underwent modified posterior surgery with using cervical lateral mass screws insertion (C4-C6). Group A underwent surgeries with screw insertion assisted by the guidance of 3-dimensional printing templates and Group B underwent surgeries with screw insertion by freehand. The criteria of the accuracy of screw placement were set as the main evaluation indicators.

RESULTS

There was no significant difference between the 2 groups in age, improvement rate of JOA, operation time and blood loss. According to Bayard's criteria, 32 screws (88.9%) were described as "acceptable" in group A and 22 screws (61.1%) were described as "acceptable" in Group B (P < 0.05). Based on our criteria, the "excellent and good" rate of screws was 83.3% in group A and 47.2% in Group B, respectively (P < 0.05). The precision of screws' location in Group A was superior to that in Group B.

CONCLUSIONS

3-Dimensional printing screw insertion templates may achieve (1) comprehensive visualization of the cervical vertebrae and lateral mass and the individual surgical planning using the 3-dimensional model preoperatively. (2) increasing the accuracy of cervical lateral mass screw insertion.

Safety and performance of a novel articulating cage for transforaminal lumbar interbody fusion in the setting of intraoperative spinal navigation

OBJECTIVE

Transforaminal lumbar interbody fusion (TLIF) has been described as safe and effective procedure for the treatment of low back pain. However, only a few retrospective articles describing articulating cages exist in literature. The aim of this study was to assess the clinical and radiological results, as well as patient safety and complications by using a novel articulating TLIF cage.

PATIENTS AND METHODS

Out of 50 patients, 49 were included in this prospective study. Under computer tomography (CT) guided spinal navigation the TLIF procedure was performed. Clinical outcome scores visual analog scale (VAS), Oswestry disability index (ODI) and short form-36 health survey questionnaire (SF-36) were obtained preoperatively, 6 and 12 months after surgery. Radiological data were acquired preoperatively, after 6 weeks, as well as 6 and 12 postoperatively and included measurements for disc height (anterior/posterior), foraminal height, segmental and global lumbar lordosis.

RESULTS

71% of the included patients have undergone previous lumbar surgery. In total, 80 SYNCHRO® cages have been implanted. The clinical results revealed a highly significant improvement of VAS, ODI and SF-36 after 6 and 12 months, compared to baseline levels (p < 0.05). Radiological analysis revealed a significant increase in anterior and posterior disc height, foraminal height, segmental and global lumbar lordosis postoperatively (p < 0.05). 47 out 49 patients (96%) showed evidence for fusion at the 12 months follow-up. Cage dislocation was found in 1 of 80 implanted cages (1%), which required revision surgery. Two dural tears occurred intraoperatively, which have been fixed. Another two patients needed surgical revision due to infection. The overall complication rate was 10% (n = 5/49).

CONCLUSIONS

The current study delineates satisfactory clinical and radiological results by using a novel articulating TLIF-cage. The implant-related complication rate was acceptable with low revision rate.

Finding the "Sweet Spot" for C2 Root Transection in C1 Lateral Mass Exposure

BACKGROUND

Atlantoaxial fusion often requires C2 nerve transection for complete C1 lateral mass exposure. Nerve transection is made ideally at the preganglionic segment proximal to the dorsal root ganglion to minimize the risk of postoperative dysesthesias. If the nerve is transected too proximally, cerebrospinal fluid leak may be encountered by violation of the dura and arachnoid where the sensory and motor nerve rootlets exit the subarachnoid space. In this study we aimed to quantify the length of the C2 nerve preganglionic segment using cadaveric specimens and develop a method for reliable intraoperative localization for sectioning during C1-2 arthrodesis.

METHODS

Using microsurgical techniques, 16 C2 nerves from 8 frozen and injected cadaveric cervical spine specimens were dissected. Two key measurements were taken to establish a reliable method of preganglionic segment identification. The "sweet spot" for nerve transection was based on the approximate location of the midpoint of the preganglionic segment.

RESULTS

The final determination of the ideal spot for C2 nerve transection using these calculations was 3 mm lateral to the medial border of the lateral mass.

CONCLUSIONS

This anatomic study found remarkable consistency in the preganglionic segment length. The medial border of the lateral mass appeared to be a consistently reliable landmark for identification of the preganglionic segment of the C2 nerve root. By using relationships between known anatomic structures intraoperatively, safety of atlantoaxial fixation can be optimized to maximize complication avoidance and satisfactory patient outcomes.

Comparison of clinical and radiological outcomes between modified Gallie graft fusion-wiring technique and posterior cervical screw constructs for Type II odontoid fractures

The aim of this study was to compare clinical and radiological outcomes between modified Gallie graft fusion-wiring technique and posterior cervical screw constructs for Type II odontoid fractures, and hope to provide references in decision making and surgical planning for both spinal surgeons and surgically treated patients.This is a retrospective study. By retrieving the medical records from January 2005 to July 2015 in our hospital, 53 Type II odontoid fracture patients were reviewed. According to the instrumentation type, patients were divided into 2 groups: Wiring group and Screw group. Three categorized factors were analyzed statistically: patient characteristics: age, body mass index, preoperative neurological status, duration, complicated injuries; surgical variables: surgery time, blood loss, vertebral artery injury, spinal cord or nerve root injury, major systemic complications, wound infection, pain at the bone donor area, instrumentation failure, revision rate; and radiographic parameters: preoperative and final follow-up data of C0-2 curvature, C2-7 curvature, C2-C7 sagittal vertical axis, C7 slope, fracture classification, separation, and displacement of odontoid fracture, fusion rate. An additional comparison of surgical outcomes was done, including patient satisfaction, visual analog scale score for neck pain, neck stiffness, medical expense.There was no statistically significant difference between the 2 groups in patient characteristics of age, sex, body mass index, preoperative neurological status, duration, and complicated injuries. No statistically significant difference was noted in surgical variables of blood loss, vertebral artery injury, spinal cord or nerve root injury, major systemic complications, wound infection, bone harvested zone pain, instrumentation failure, revision rate. The surgery time was shorter in Wiring group than that in Screw group, with a statistically significant difference. We noted no significant difference between the 2 groups when comparing radiographic parameters of preoperative and final follow-up data of C0-2 curvature, C2-C7 sagittal vertical axis, fracture classification, the separation and displacement of odontoid fracture, and fusion rate. Although we noted no significant difference in preoperative C2-7 curvature and C7 slope, the final follow-up data showed that C2-7 curvature and C7 slope were smaller in Wiring group than that in Screw group. We noted no significant difference in visual analog scale score, neck stiffness, and neurological status at final follow-up. The medical expense was less in Wiring group; the patient satisfaction was lower in the Wiring group than that in the Screw group.The modified Gallie graft fusion-wiring technique provided solid fusion and stabilization for patients with Type II odontoid fractures, Gallie graft fusion-wiring resulted in less surgery time, less medical expense, but lower patient satisfaction when compared with the posterior cervical screw constructs.