Jamal N. Shillingford

Accuracy of S2 Alar-Iliac Screw Placement Under Robotic Guidance

STUDY DESIGN Case series. OBJECTIVES To determine the safety and feasibility of S2 alar-iliac (S2AI) screw placement under robotic guidance. SUMMARY OF BACKGROUND DATA Similar to standard iliac fixation, S2AI screws aid in achieving fixation across the sacropelvic junction and decreasing S1 screw strain. Fortunately, the S2AI technique minimizes prominent instrumentation and the need for offset connectors to the fusion construct. Herein, we present an analysis of the largest series of robotic-guided S2AI screws in the literature without any significant author conflicts of interest with the robotics industry. METHODS Twenty-three consecutive patients who underwent spinopelvic fixation with 46 S2AI screws under robotic guidance were analyzed from 2015 to 2016. Screws were placed by two senior spine surgeons, along with various fellow or resident surgical assistants, using a proprietary robotic guidance system (Renaissance; Mazor Robotics Ltd., Caesara, Israel). Screw position and accuracy was assessed on intraoperative CT O-arm scans and analyzed using three-dimensional interactive viewing and manipulation of the images. RESULTS The average caudal angle in the sagittal plane was 31.0° ± 10.0°. The average horizontal angle in the axial plane using the posterior superior iliac spine as a reference was 42.8° ± 6.6°. The average S1 screw to S2AI screw angle was 11.3° ± 9.9°. Two violations of the iliac cortex were noted, with an average breach distance of 7.9 ± 4.8 mm. One breach was posterior (2.2%) and one was anterior (2.2%). The overall robotic S2AI screw accuracy rate was 95.7%. There were no intraoperative neurologic, vascular, or visceral complications related to the placement of the S2AI screws. CONCLUSIONS Spinopelvic fixation achieved using a bone-mounted miniature robotic-guided S2AI screw insertion technique is safe and reliable. Despite two breaches, no complications related to the placement of the S2AI screws occurred in this series. LEVEL OF EVIDENCE Level IV, therapeutic.STUDY DESIGN Case series. OBJECTIVES To determine the safety and feasibility of S2 alar-iliac (S2AI) screw placement under robotic guidance. Similar to standard iliac fixation, S2AI screws aid in achieving fixation across the sacropelvic junction and decreasing S1 screw strain. Fortunately, the S2AI technique minimizes prominent instrumentation and the need for offset connectors to the fusion construct. Herein, we present an analysis of the largest series of robotic-guided S2AI screws in the literature without any significant author conflicts of interest with the robotics industry. METHODS Twenty-three consecutive patients who underwent spinopelvic fixation with 46 S2AI screws under robotic guidance were analyzed from 2015 to 2016. Screws were placed by two senior spine surgeons, along with various fellow or resident surgical assistants, using a proprietary robotic guidance system (Renaissance; Mazor Robotics Ltd., Caesara, Israel). Screw position and accuracy was assessed on intraoperative CT O-arm scans and analyzed using three-dimensional interactive viewing and manipulation of the images. RESULTS The average caudal angle in the sagittal plane was 31.0° ± 10.0°. The average horizontal angle in the axial plane using the posterior superior iliac spine as a reference was 42.8° ± 6.6°. The average S1 screw to S2AI screw angle was 11.3° ± 9.9°. Two violations of the iliac cortex were noted, with an average breach distance of 7.9 ± 4.8 mm. One breach was posterior (2.2%) and one was anterior (2.2%). The overall robotic S2AI screw accuracy rate was 95.7%. There were no intraoperative neurologic, vascular, or visceral complications related to the placement of the S2AI screws. CONCLUSIONS Spinopelvic fixation achieved using a bone-mounted miniature robotic-guided S2AI screw insertion technique is safe and reliable. Despite two breaches, no complications related to the placement of the S2AI screws occurred in this series. LEVEL OF EVIDENCE Level IV, therapeutic.

Opioid use following cervical spine surgery: trends and factors associated with long-term use

BACKGROUND CONTEXT Limited or no data exist evaluating risk factors associated with prolonged opioid use following cervical arthrodesis. PURPOSE The objectives of this study were to assess trends in postoperative narcotic use among preoperative opioid users (OUs) versus non-opioid users (NOUs) and to identify factors associated with postoperative narcotic use at 1 year following cervical arthrodesis. STUDY DESIGN/SETTING This is a retrospective observational study. PATIENT SAMPLE The patient sample included 17,391 patients (OU: 52.4%) registered in the Humana Inc claims dataset who underwent anterior cervical fusion (ACF) or posterior cervical fusion (PCF) between 2007 and 2015. OUTCOME MEASURES Prolonged opioid usage was defined as narcotic prescription filling at 1 year following cervical arthrodesis. METHODS Based on preoperative opioid use, patients were identified as an OU (history of narcotic prescription filled within 3 months before surgery) or a NOU (no preoperative prescription). Rates of opioid use were evaluated preoperatively for OU and trended for 1 year postoperatively for both OU and NOU. Multivariable regression techniques investigated factors associated with the use of narcotics at 1 year following ACF and PCF. Based on the model findings, a web-based interactive app was developed to estimate 1-year postoperative risk of using narcotics following cervical arthrodesis (http://neuro-risk.com/opiod-use/ or https://www.neurosurgerycost.com/opioid/opioid_use). RESULTS Overall, 87.4% of the patients (n=15,204) underwent ACF, whereas 12.6% (n=2187) underwent PCF. At 1 month following surgery, 47.7% of NOUs and 82% of OUs had a filled opioid prescription. Rates of prescription opioids declined significantly to 7.8% in NOUs versus 50.5% in OUs at 3 months, but plateaued at the 6- to 12-month postoperative period (NOU: 5.7%-6.7%, OU: 44.9%-46.9%). At 1 year, significantly higher narcotic prescription filling rates were observed in OUs compared with NOUs (45.3% vs. 6.3%, p<.001). Preoperative opioid use was a significant driver of 1-year narcotic use following ACF (odds ratio [OR]: 7.02, p<.001) and PCF (OR: 6.98, p<.001), along with younger age (≤50 years), history of drug dependence, and lower back pain. CONCLUSIONS Over 50% of the patients used opioids before cervical arthrodesis. Postoperative opioid use fell dramatically during the first 3 months in NOU, but nearly half of the preoperative OUs will remain on narcotics at 1 year postoperatively. Our findings serve as a baseline in identifying patients at risk of chronic use and encourage discontinuation of opioids before cervical spine surgery.

Restoration of Sagittal Balance in Spinal Deformity Surgery

The prevalence of patients with adult spinal deformity (ASD) has been reported as high as 68%. ASD often leads to significant pain and disability. Recent emphasis has been placed on sagittal plane balance and restoring normal sagittal alignment with regards to the three dimensional deformity of ASD. Optimal sagittal alignment has been known to increase spinal biomechanical efficiency, reduce energy expenditure by maintaining a stable posture with improved load absorption, influence better bony union, and help to decelerate adjacent segment deterioration. Increasingly positive sagittal imbalance has been shown to correlate with poor functional outcome and poor self-image along with poor psychological function. Compensatory mechanisms attempt to maintain sagittal balance through pelvic rotation, alterations in lumbar lordosis as well as knee and ankle flexion at the cost of increased energy expenditure. Restoring normal spinopelvic alignment is paramount to the treatment of complex spinal deformity with sagittal imbalance. Posterior osteotomies including posterior column osteotomies, pedicle subtraction osteotomies, and posterior vertebral column resection, as well anterior column support are well known to improve sagittal alignment. Understanding of whole spinal alignment and dynamics of spinopelvic alignment is essential to restore sagittal balance while minimizing the risk of developing sagittal decompensation after surgical intervention.

National Trends for Primary and Revision Lumbar Disc Arthroplasty Throughout the United States

Study Design: Retrospective database study. Objectives: Analysis of economic and demographic data concerning lumbar disc arthroplasty (LDA) throughout the United States to improve value-based care and health care utilization. Methods: The National Inpatient Sample database was queried for patients who underwent primary or revision LDA between 2005 and 2013. Demographic and economic data included total surgeries, costs, length of stay, and frequency of routine discharge. The National Inpatient Sample database represents a 20% sample of discharges from US hospitals weighted to provide national estimates. Results: Primary LDA decreased 86% from 3059 to 420 from 2005 to 2013. The mean total cost of LDA increased 33% from

Neuromonitoring in Spinal Deformity Surgery: A Multimodality Approach:

17 747 to

Vertebral Column Resection for Rigid Spinal Deformity

23 804. The mean length of stay decreased from 2.8 to 2.4 days. The mean routine discharge (home discharge without visiting nursing care) remained constant at 91%. Revision procedures (removal, supplemental fixation, or reoperation at the treated level) declined 30% from 194 to 135 cases over the study period. The mean revision burden, defined as the ratio of revision procedures to the sum of primary and revision procedures, was 12% (range 6% to 24%). The mean total cost of revisions ranged from

Permanent implantation of antibiotic cement over exposed instrumentation eradicates deep spinal infection

12 752 to

Utilization of intraoperative neuromonitoring throughout the United States over a recent decade: an analysis of the nationwide inpatient sample

22 282. Conclusions: From 2005 to 2013, primary LDA significantly declined in the United States by 86% despite several studies pointing to improved efficacy and cost-efficiency. This disparity may be related to a lack of surgeon reimbursement from insurance companies. Congruently, the number of revision LDA cases has declined 30%, while revision burden has risen from 6% to 24%.

Complications following single-level interbody fusion procedures: an ACS-NSQIP study

Study Design: Literature review. Objective: The aim of this study was to provide an overview of the available intraoperative monitoring techniques and the evidence around their efficacy in vertebral column resection. Methods: The history of neuromonitoring and evolution of the modalities are reviewed and discussed. The authors’ specific surgical techniques and preferred methods are outlined in detail. In addition, the authors’ experience and the literature regarding vertebral column resection and surgical mitigation of neurologic alarms are discussed at length. Results: Risk factors for signal changes have been identified, including preoperative neurologic deficit, severe kyphosis, increased curve magnitude, and significant cord shortening. Even though no evidence-based treatment algorithm exist for signal changes, strategies are discussed that can help prevent alarms and address them appropriately. Conclusion: Through implementation of multimodal intraoperative monitoring techniques, potential neurologic injuries are localized and managed in real time. Intraoperative monitoring is a valuable tool for improving the safety and outcome of spinal deformity surgery.

Robotic versus freehand S2 alar iliac fixation: in-depth technical considerations

Study Design: Broad narrative review. Objective: To review the evolution, operative technique, outcomes, and complications associated with posterior vertebral column resection. Methods: A literature review of posterior vertebral column resection was performed. The authors’ surgical technique is outlined in detail. The authors’ experience and the literature regarding vertebral column resection are discussed at length. Results: Treatment of severe, rigid coronal and/or sagittal malalignment with posterior vertebral column resection results in approximately 50–70% correction depending on the type of deformity. Surgical site infection rates range from 2.9% to 9.7%. Transient and permanent neurologic injury rates range from 0% to 13.8% and 0% to 6.3%, respectively. Although there are significant variations in EBL throughout the literature, it can be minimized by utilizing tranexamic acid intraoperatively. Conclusion: The ability to correct a rigid deformity in the spine relies on osteotomies. Each osteotomy is associated with a particular magnitude of correction at a single level. Posterior vertebral column resection is the most powerful posterior osteotomy method providing a successful correction of fixed complex deformities. Despite meticulous surgical technique and precision, this robust osteotomy technique can be associated with significant morbidity even in the most experienced hands.