Occipitocervical Fusion via Cervical Pedicle Fixation Assisted with O-arm Navigation

Surgical outcomes of intraoperative O-arm versus C-arm fluoroscopy in occipitocervical fixation: a retrospective analysis

PURPOSE

This study aims to compare the effect of using O-arm and C-arm fluoroscopy on the surgical outcomes of occipitocervical fixation.

METHODS

The study included patients who underwent occipitocervical fixation using O-arm or C-arm between 2005 and 2021. Of 56 patients, 34 underwent O-arm-assisted surgery (O-group) and 22 underwent C-arm-assisted surgery (C-group). We assessed surgical outcomes, including operative time, intraoperative blood loss, perioperative complications, and bone union.

RESULTS

Almost half of the patients had rheumatoid arthritis-related disorders in both groups. Sixteen cases (47.1%) in the O-group and 12 cases (54.5%) in the C-group were fixed from occipito (Oc) to C3, 12 cases (38.2%) in the O-group and 7 cases (31.8%) in the C-group from Oc to C4-7, 5 cases (14.7%) in the O-group, and 3 cases (13.6%) in the C-group from Oc to T2 (p = 0.929). There was no significant difference in operative time (p = 0.239) and intraoperative blood loss (p = 0.595) between the two groups. Dysphagia was the most common complication in both groups (O-group vs. C-group, 11.7% vs. 9.1%). Regarding implant-related complications, occipital plate dislodgement was observed in four cases (18.2%) in the C-group (p = 0.02). The bone union rate was 96.3% in the O-group and 93.3% in the C-group (P = 1).

CONCLUSIONS

O-arm use is associated with a reduced rate of occipital plate dislodgment and has a similar complication incidence compared with C-arm-assisted surgery and does not prolong operative time despite the time needed for setting and scanning. Accordingly, an O-arm is safe and useful for occipitocervical fixation surgery.

Accuracy and Safety Assessment of Subaxial Cervical Pedicle Screw Instrumentation: A Systematic Review

BACKGROUND CONTEXT

Given increasing use of both cervical pedicle screw (CPS) fixation in the subaxial cervical spine (C3-C7) and emerging navigation technologies, a quantitative profile of safety and accuracy remains wanting. Compared with lateral mass instrumentation of this region, CPS fixation shows superior biomechanical properties but poses higher risk of complications because of the narrow cervical pedicle width and proximity to neurovascular structures.

PURPOSE

This systematic review quantifies the accuracy and safety of all types of subaxial CPS insertion, with or without navigation or template-based methods, to weigh the strengths and limitations of each technique.

STUDY DESIGN

Systematic review according to PRISMA guidelines.

PATIENT SAMPLE

Patients who underwent CPS instrumentation since its introduction.

OUTCOME MEASURES

Primary and secondary outcomes in our review included pedicle screw breach in the subaxial cervical spine determined on intra- or postoperative imaging, and screw-related operative complications, respectively.

METHODS

Following the PRISMA guidelines, our literature search of PubMed, Cochrane, and Scopus databases identified 3,312 clinical studies (1980-2024) using subaxial CPS that assessed for screw accuracy. After full-text analysis, data extracted included number of CPS, level of placement, number of patients, indications, insertion techniques, accuracy assessment method, classification of accuracy, breach rate, complication rate, and study origin.

RESULTS

The 73 studies included in final analysis from Asia (80%), Europe (12%) and North America (8%) yielded 14,118 CPS in 3,342 patients (1999-2024). Accuracy rates were 85.3% for 10,108 CPS placed with non-navigated techniques (free-hand and fluoroscopy), 82.7% for 3,067 with navigation techniques, and 96.3% for 943 CPS placed using 3D templates. Complication rates were 1.1%, 2.1%, and zero, respectively.

CONCLUSION

Our comprehensive review of more than 14,000 subaxial CPSs inserted found rates of high 84% overall accuracy and low 1.2% perioperative complications (i.e., attributed to a misplaced screw). With biomechanical advantages superior to lateral mass screws, our quantitative findings support consideration for CPS instrumentation in select patients by experienced surgeons.

Advancements in occipitocervical fusion: Biomechanical insights, surgical techniques, and clinical outcomes

Background

Occipitocervical fusion (OCF) has been performed for over 70 years to address craniocervical instability caused by trauma, tumors, or congenital anomalies. Despite technological advances, challenges persist due to the unique anatomy, high mobility, and complex pathological processes at the occipitocervical junction. This study aimed to evaluate clinical, radiographic, and surgical outcomes of OCF in patients with craniocervical instability.

Methods

A 2-year cohort study was conducted at Dr. Saad Alwitry's Neurosciences Hospital (April 2021- March 2023) involving 45 patients aged 17-53 (mean age 35.6). Inclusion criteria required radiologically confirmed instability, psychological fitness, and a normal coagulation profile. Patients with advanced rheumatoid arthritis or prior posterior fossa surgery were excluded. OCF procedures were performed using modern rigid instrumentation, including plates and rods, and outcomes were monitored using radiographic fusion assessments and clinical evaluations.

Results

All patients achieved solid fusion (100%) within a mean of 7.06 months (range 5-9 months). Myelopathy and neurological deficits were present in all patients preoperatively, while neck pain affected 73.3%. Postoperatively, 73.3% of patients showed improvement in myelopathic symptoms, and all patients reported resolution of neck pain. Complications included one transient neurological deterioration, one wound infection, and one cerebrospinal fluid leak, all managed successfully. No operative mortalities or vascular injuries occurred.

Conclusion

Rigid occipitocervical fixation stabilizes the craniocervical junction, achieving high fusion rates and symptom resolution with minimal complications. Thorough preoperative planning, precise surgical technique, and an understanding of craniocervical anatomy are crucial for optimal outcomes.

Cutting Edge Developments in Spine Surgery at the University of Missouri

The treatment of spinal pathologies has evolved significantly from the times of Hippocrates and Galen to the current era. This evolution has led to the development of cutting-edge technologies to improve surgical techniques and patient outcomes. The University of Missouri Health System is a high-volume, tertiary care academic medical center that serves a large catchment area in central Missouri and beyond. The Department of Neurosurgery has sought to integrate the best available technologies to serve their spine patients. These technological advancements include intra-operative image guidance, robotic spine surgery, minimally invasive techniques, motion preservation surgery, and interdisciplinary care of metastatic disease to the spine. These advances have resulted in safer surgeries with enhanced outcomes at the University of Missouri. This integration of innovation demonstrates our tireless commitment to ensuring excellence in the comprehensive care of a diverse range of patients with complex spinal pathologies.

[TiRobot-assisted surgery by O-arm navigation system for percutaneous minimally invasive treatment of posterior pelvic ring injury]

Objective

To evaluate the effectiveness of TiRobot-assisted surgery by O-arm navigation system for percutaneous minimally invasive treatment of posterior pelvic ring injury.

Methods

The clinical data of 76 patients with posterior pelvic ring injury between January 2016 and June 2021 were retrospectively analyzed. Among them, 45 cases were treated with minimally invasive percutaneous sacroiliac screw fixation assisted by TiRobot and O-arm navigation system (study group), 31 cases were treated with minimally invasive percutaneous sacroiliac screw fixation under the guidance of C-arm X-ray machine (control group). There was no significant difference in gender, age, cause of injury, Tile classification, time from injury to operation between the two groups ( P>0.05). The operation time, intraoperative blood loss, the times of nail track adjustment, and intraoperative fluoroscopy times were recorded. The quality of fracture reduction was evaluated by Matta score. At last follow-up, Majeed score was used to evaluate the recovery of pelvic function.

Results

A total of 72 screws were implanted in the study group, with a median of 1 (1, 2) screws per patient. In the control group, 47 screws were implanted, with a median of 1 (1, 2) screws per patient. There was no significant difference in the number of screws between the two groups ( Z=-0.392, P=0.695). The operation time, intraoperative blood loss, times of nail track adjustment, and intraoperative fluoroscopy times in the study group were significantly less than those in the control group ( P<0.05). All patients were followed up 6-24 months (mean, 14 months). No serious complications was found after operation and during follow-up. Matta score was used to evaluate the quality of fracture reduction at 1 week after operation, and there was no significant difference between the two groups ( Z=-1.135, P=0.256). At last follow-up, there was no significant difference of Majeed score between the two groups ( Z=-1.279, P=0.201).

Conclusion

TiRobot-assisted surgery by O-arm navigation system is a reliable surgical method for the treatment of posterior pelvic ring injury, which can reduce the operation time and fluoroscopy times when compared with the traditional operation under the guidance of C-arm X-ray machine. The safety, accuracy, and efficiency of the operation were improved.

Navigation for surgical treatment of disorders of the cervical spine - A systematic review

INTRODUCTION

Computer-assisted navigation (CAN) is a well-established tool in spinal instrumentation surgery. Different techniques - each with specific advantages and disadvantages - are used in the cervical spine.

METHODS

A structured summary of different spinal navigation techniques and a review of the literature were done to discuss the advantages and disadvantages of specific navigation tools in the cervical spine.

RESULTS

In cervical spine surgery, CAN increases the accuracy of pedicle screw placement, reduces screw mispositioning and leads to fewer revision surgeries. Due to the mobility of the cervical spine, preoperative CT followed by region matching or intraoperative CT are recommended.

CONCLUSIONS

CAN increases pedicle screw placement accuracy and should be used in spinal instrumentation for the cervical spine whenever possible.

3D-Printed Screw-Rod Auxiliary System for Unstable Atlas Fractures: A Retrospective Analysis

Objective

To develop and validate the efficacy of a 3D‐printed screw‐rod auxiliary system for unstable atlas fractures.

Methods

This research is a retrospective analysis, and a total of 14 patients, including 11 males and three females, were enrolled in our hospital from January 2017 to March 2019 who underwent occipitocervical fusion assisted by the 3D‐printed screw‐rod auxiliary system were reviewed, and with an average age of 53.21 ± 14.81 years, an average body mass index (BMI) of 23.61 ± 1.93 kg/m². The operation time, blood loss and radiation times during the operation were recorded. The maximum fracture displacement values of pre‐ and post‐operation were measured based on CT imaging. All screw grades were evaluated after surgery. The occipital‐cervical 2 (O‐C₂) angle and occipitocervical inclination (OCI) angle of pre‐operation, post‐operation and the last following‐up were measured. The dysphagia scale 3 months after surgery and at the last follow‐up, the Neck Disability Index (NDI) 3 months after surgery and at the last follow‐up were assessed.

Results

All patients were completed the surgery successfully. There was no patient with severe dysphagia or aggravation of nerve injury. The follow‐up was from 12 to 14 months, and with an average of 12.5 months. The average surgery time, average blood loss and average radiation times for the 14 patients were 112.14 min, 171.43 mL and 5.07 times, respectively. There was a significant difference in maximum fracture displacement between pre‐ and post‐operation values (P < 0.05). A total of 56 screws were inserted in 14 patients, among them, three screws were classified as grade 1, and the other screws were classified as grade 0. There was a significant difference in the O‐C₂ between pre‐operation and 3 days after operation (P = 0.002); There was a significant difference in OCI angles between pre‐operation and 3 days after operation (P < 0.05); there was no significant difference in the O‐C₂ or OCI angle between 3 days after the operation and the last follow‐up (P = 0.079; P = 0.201). The dysphagia scales of two patients were assessed as mild at 3 months after surgery, and the others were assessed as normal at 3 months after surgery. All patients' dysphagia scores returned to normal at the last follow‐up. The average NDI and average neck Visual Analogue Scale (VAS) scores at the last follow‐up were 2.53 and 8.41, respectively.

Conclusion

It can objectively restore the OCI to normal with few post‐operative complications under the assistance of a screw‐rod auxiliary system to perform occipitocervical fusion for unstable atlas fractures and atlantooccipital joint instability.