Use of the Scan-and-Plan Workflow in Next-Generation Robot-Assisted Pedicle Screw Insertion: Retrospective Cohort Study and Literature Review.

OBJECTIVE: To report our experience using the scan-and-plan workflow and review current literature on surgical efficiency, safety, and accuracy of next-generation robot-assisted (RA) spine surgery. METHODS: The records of patients who underwent RA pedicle screw fixation were reviewed. The accuracy of pedicle screw placement was determined based on the Ravi classification system. To evaluate workflow efficiency, 3 demographically matched cohorts were created to analyze differences in time per screw placement (defined as operating room [OR] time divided by number of screws placed). Group A had <4 screws placed, Group B had 4 screws placed, and Group C had >4 screws placed. Intraoperative errors and postoperative complications were collected to elucidate safety. RESULTS: Eighty-four RA cases (306 pedicle screws) were included for analysis. The mean number of screws placed was 2.1 ± 0.3 in Group A and 6.4 ± 1.2 in Group C; 4 screws were placed in Group B patients. The accuracy rate (Ravi grade I) was 98.4%. Screw placement time was significantly longer in Group A (101 ± 37.7 minutes) than Group B (50.5 ± 25.4 minutes) or C (43.6 ± 14.7 minutes). There were no intraoperative complications, robot failures, or in-hospital complications requiring a return to the OR. CONCLUSIONS: The scan-and-plan workflow allowed for a high degree of accuracy. It was a safe method that provided a smooth and efficient OR workflow without registration errors or robotic failures. After the placement of 4 pedicle screws, the per-screw time remained constant. Further studies regarding efficiency and utility in multilevel procedures are necessary.

Evaluation of Benefit and Cost Utility of Immediate Postanesthesia Care Unit Radiographs to Predict Airway Compromise After Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: Retrospective review. OBJECTIVE: Anterior cervical discectomy and fusion (ACDF) is a commonly performed procedure that may be complicated by airway compromise postoperatively. This life-threatening complication may necessitate reintubation and reoperation. We evaluated the cost utility of conventional postoperative x-ray. SUMMARY OF BACKGROUND DATA: Studies have demonstrated minimal benefit in obtaining an x-ray on postoperative day 1, but there is some utility of postanesthesia care unit (PACU) x-rays for predicting the likelihood of reoperation. METHODS: We retrospectively reviewed the records of consecutive patients who underwent ACDF between September 2013 and February 2017. Patients were dichotomized into those who received PACU x-rays and those who did not (control group). Primary outcomes were reoperation, reintubation, mortality, and health care costs. RESULTS: Eight-hundred and fifteen patients were included in our analysis: 558 had PACU x-rays; 257 did not. In those who received PACU x-rays, mean age was 53.7 ±â€Š11.3 years, mean levels operated on were 2.0 ±â€Š0.79, and mean body mass index (BMI) was 30.3 ±â€Š6.9. In those who did not, mean age was 51.8 ±â€Š10.9 years, mean levels operated on were 1.48 ±â€Š0.65, and mean BMI was 29.9 ±â€Š6.3. Complications in the PACU x-ray group were reintubation-0.4%, reoperation-0.7%, and death-0.3% (due to prevertebral swelling causing airway compromise). Complications in the control group were reintubation-0.4%, reoperation-0.8%, and death-0. There were no differences between groups with respect to reoperation (P = 0.92), reintubation (P = 0.94), or mortality (P = 0.49). The mean per-patient cost was significantly higher (P = 0.009) in those who received PACU x-rays, $1031.76 ±â€Š948.67, versus those in the control group, $700.26 ±â€Š634.48. Mean length of stay was significantly longer in those who had PACU x-rays (P = 0.01). CONCLUSION: Although there were no differences in reoperation, reintubation, or mortality, there was a significantly higher cost for care and hospitalization in those who received PACU x-rays. Further studies are warranted to validate the results of the presented study.Level of Evidence: 3.

Navigation-Guided Subaxial Cervical Pedicle Screws in Revision Spine Surgery: 2-Dimensional Operative Video.

Traditionally, lateral mass screws (LMSs) have been the mainstay of posterior fixation in the subaxial spine. Although LMSs provide adequate fixation, cervical pedicle screws (CPSs) facilitate high fusion rates (90.5%) and provide for greater bone purchase, better reduction, lower rates of screw loosening or pull out, 2 times greater biomechanical advantage, superior stabilization, decreased development of pseudarthrosis, and decreased revision surgeries compared to LMSs.1-4 In addition, CPSs can be a powerful bail-out option after lateral mass construct failure. Navigation-guided CPS placement has been reported to have an accuracy of 90.3%.5 Navigation has the added advantage of mitigating screw malposition for the placement of CPS because of the smaller pedicle sizes and variability in cervical anatomy.1,3,6 The potential risks of subaxial CPS placement include the risks of vertebral artery injury, spinal cord injury, and injury to adjacent neurovasculature.2 The overall radiographic breach rate with intraoperative imaging is reported to range from 2.9% of 22.9%, with the majority of breaches occurring in the lateral direction.7,8 Despite radiographic breaches, the occurrence of nerve root injury (0.31% per screw), vertebral artery injury (0.15% per screw), and spinal cord injury (0% per screw) is rare.3,7 Here, we demonstrate navigation-assisted C1-C2 posterior fusion, with combined C1 LMSs and C2 pedicle screws with subaxial pedicle screw revision of prior failed instrumentation.3 The patient gave informed consent for surgery and video recording. Institutional review board approval was deemed unnecessary.

Comparing Cortical Bone Trajectories for Pedicle Screw Insertion using Robotic Guidance and Three-Dimensional Computed Tomography Navigation.

BACKGROUND: Cortical bone trajectories (CBTs) for pedicle screw insertion can be used to stabilize the spine. Surgeons often rely on fluoroscopy or computed tomography (CT)-navigation technologies to guide screw placement. Robotic technology has potential to increase accuracy. We report our initial experience with robotic guidance for pedicle screw insertion utilizing CBTs in patients with degenerative disc disease. METHODS: A retrospective chart review was conducted using data for consecutive patients who underwent spinal stabilization using a posterior approach for CBTs. The newest robotic platform (Mazor X) was used in these cases. Accuracy was determined by applying the Ravi Scale: grade I (no breach or deviation), II (breach <2 mm), III (breach 2-4 mm), or IV (breach >4 mm). The results were compared with those for a historical cohort of patients who underwent CT navigation-guided pedicle screw insertion using CBTs. RESULTS: Twenty-two patients underwent robot-assisted pedicle screw placement using CBTs. A total of 92 screws were inserted across 24 spinal levels with grade I accuracy and without complications in the robotic group. Eighteen patients underwent CT-navigation for CBT pedicle screw insertion. A total of 74 screws were inserted across 19 levels, 69 of which were grade I accuracy and 5 were grade II accuracy. When comparing operative time (P = 0.97), fluoroscopy time (P = 0.8), and radiation dose (P = 0.4), no significant differences were observed between cohorts. CONCLUSIONS: Robotic technology and CT-navigation technology for CBT pedicle screw insertion were safe and accurate.

Robot-Assisted Cortical Bone Trajectory Insertion of Pedicle Screws: 2-Dimensional Operative Video.

Robot-assisted pedicle screw insertion has been slowly gaining popularity in the spine surgery community. In previous studies, robotics has been shown to increase accuracy and reduce complication rates compared to other navigation technologies, although those studies have been conducted using traditional trajectories for pedicle screw insertion. We present a surgical video in which a robotics system (Mazor X; Mazor Robotics Ltd, Caesarea, Israel) was used to create cortical bone trajectories for the insertion of the screws. The patient in this case is a 52-yr-old woman with severe L4-5 disc herniation requiring a transforaminal interbody fusion with the insertion of pedicle screws. The robotic system's scan-and-plan technique was utilized, in which an intraoperative computed tomography (CT) scan generates a real-time operative plan. Other techniques for inserting pedicle screws using cortical bone trajectories include CT navigation and fluoroscopic guidance. These techniques allow the surgeon to manually direct the screw under precise guidance in multiple planes, although the surgeon is still using all 6 degrees of freedom the human hand provides. With robotic guidance, a pilot hole is drilled, which eliminates 4 of 6 degrees of freedom, which can potentially reduce the risk of misplaced screws. To our knowledge, this is the first video demonstrating pedicle screw insertion through cortical bone trajectories using robotic guidance. Future studies are warranted to compare cortical bone trajectory insertion using different navigation techniques to determine the long-term efficacy of each technique. The patient gave informed consent for surgery and video recording. Institutional review board approval was deemed unnecessary.

Comparing Next-Generation Robotic Technology with 3-Dimensional Computed Tomography Navigation Technology for the Insertion of Posterior Pedicle Screws.

OBJECTIVE: To study the differences between robot-guided (Mazor X, Mazor Robotics Ltd., Caesarea, Israel) and 3-dimensional (3D) computed tomography (CT) navigation (O-arm Surgical Imaging System, Medtronic, Minneapolis, Minnesota, USA) for the insertion of pedicle screws. METHODS: We reviewed the charts of 50 patients who underwent robot-guided pedicle screw insertion (between May 2017-October 2017), and 49 patients who underwent 3D-CT navigation pedicle screw insertion (between September 2015-August 2016). Variables included were age, sex, body mass index, blood loss, length of stay, lumbar level(s), operation time, fluoroscopy time, radiation dose, accuracy, and time-per-screw placement. RESULTS: Mean ages were 59.3 years in the robotic group and 58.2 years in the 3D-CT navigation group. Mean was 30.7 kg/m2 in the robotic group and 32.1 kg/m2 in the 3D-CT navigation group. Mean time-per-screw placement was 3.7 minutes for the robotic group and 6.8 minutes for the 3D-CT navigation group, P < 0.001. In the robotic group, 189 of 190 screws were placed with Ravi grade I accuracy, and 1 was grade II. In the 3D-CT navigation group, 157 of 165 screws were Ravi grade I, and 8 were grade II (P = 0.11). Fluoroscopy time (P < 0.001), time-per-screw placement (P < 0.001), and length of stay (P < 0.001) were significantly lower in the robotic group. CONCLUSIONS: Both technologies are safe and accurate. Robotic technology exposed patients to less fluoroscopy time, decreased time-per-screw placement and shorter hospital stay than 3D-CT navigation. Further studies are warranted to verify our results.

Next-Generation Robotic Spine Surgery: First Report on Feasibility, Safety, and Learning Curve.

BACKGROUND: Pedicle screw placement is a commonly performed procedure. Robot-guided screw placement is a recent technological advance that has shown accuracy and reliability with first-generation platforms. OBJECTIVE: To report our initial experience with the safety, feasibility, and learning curve associated with pedicle screw placement utilizing next-generation robotic guidance. METHODS: A retrospective chart review was conducted to obtain data for 20 patients who underwent lumbar pedicle screw placement under robotic guidance after undergoing interbody fusion for lumbar spinal stabilization for degenerative disc disease with or without spondylolisthesis. The newest generation Mazor X (Mazor Robotics Ltd, Caesarea, Israel) was used. Accuracy of screw placement was determined to be grade I to IV. Grade I was in the pedicle (no breach/deviation), grade II was breach < 2 mm, grade III was breach 2 to 4 mm, and grade IV was breach >4 mm; breach direction (superior, lateral, inferior, or medial) was also recorded. RESULTS: Twenty patients underwent robotically assisted pedicle screw placement of 75 screws at 24 levels. Seventy-four screw placements (98.7%) were grade I; 1 (1.3%) was grade II (medial). No complications occurred. Mean time for screw insertion was 3.6 min. Mean fluoroscopy time was 13.1 s and mean radiation dose was 29.9 mGy. CONCLUSION: We found that next-generation robotic spine surgery was safe and feasible with reliable and precise accuracy and a minimal learning curve. As this technology improves, further novel applications are expected to develop. Further research is needed to determine long-term efficacy.

Robotic Guidance for the Insertion of Posterior Pedicle Screws: 2-Dimensional Operative Video.

Recent years have shown an increase in implementing robotics in surgical procedures. Utilizing robotic technology in spine surgery remains limited in comparison to other surgical fields. We present a surgical video of minimally invasive robotic-assisted insertion of posterior pedicle screws using the newest generation robotic technology (Mazor X, Mazor Robotics Ltd, Caesarea, Israel), in a 29-yr-old man who suffers from Grade I degenerative spondylolisthesis at L5-S1 levels and severe, right-sided foraminal stenosis. The plan was to perform anterior fusion at L5-S1 using robotic guidance with posterior pedicle screw supplementation due to his extensive smoking history. This technology has two distinct registration methods: (1) using a preoperative thin-cut computed tomography (CT) scan to create a surgical plan for screw placement; and (2) scan-and-plan using intraoperative 3-dimensional (3D) imaging to create a plan in real-time intraoperatively. We present the scan-and-plan technique. The widely used freehand technique allows the surgeon to manually direct tools and implants relying on the 6-degrees-of-freedom of the human arm. When Mazor X robotic technology is utilized, a pilot hole is drilled through a cannula docked to the bone above the entry point, which provides the surgeon with a planned trajectory and eliminates 4 of 6-degrees-of-freedom (up/down and yaw remain). This provides increased multidimensional control and reduces reliance on hand-eye coordination with simultaneous concentration on the imaging, potentially leading to increased rates of accuracy and reduction in severe complications of misplaced screws. Further prospective clinical studies are needed to determine the long-term effectiveness of this technology. Patient consent was obtained prior to performing the procedure. Institutional board review approval is not required for the report of a single case at the University at Buffalo.

Bowel injury in lumbar spine surgery: a review of the literature.

Although rarely documented in the medical literature, bowel perforation injury can be a severe complication of spine surgery. Our goal was to review current literature regarding this complication and study possible methods of avoidance. We conducted a literature search in the PubMed database between January 1960 and March 2016 using the terms abrasion, bowels, bowel, complication, injury, intestine, intra-abdominal sepsis/shock, perforation, lumbar, spine, surgery, visceral. Diagnostic criteria, outcomes, risk factors, surgical approach, and treatment strategy were the parameters extracted from the search results and used for review. Thirty-one patients with bowel injury were recognized in the literature. Bowel injury was more frequent in patients who underwent lumbar discectomy and microdiscectomy (18 of 31 patients, 58.1%). Minimally invasive surgery and lateral techniques involving fusions accounted for 10 of the reported cases (32.3%). Finally, 2 cases (6.5%) were reported in conjunction with sacrectomies and 1 case (3.2%) with posterior fusion plus anterior longitudinal ligament (ALL) release. Diagnosis was made mostly by clinical signs/symptoms of acute abdominal pain, post-surgical wound infection, and abscess or enterocutaneous fistulas. Significant risk factors for postoperative bowel injury were complex surgical anatomy, medical history of previous abdominal surgeries or infections, irradiation before surgery, errors related to surgical technique, lack of surgical experience, and instrumentation failure. The overall mortality rate from bowel injury was 12.9% (4 of 31 patients). The overall morbidity rate was 87.1% (27 of 31 patients). According to our review of the literature, bowel injury is linked to significant morbidity and mortality. It can be prevented with meticulous pre-surgical planning. When it occurs, timely treatment reduces the risks of morbidity and mortality.

Trends in Physician Reimbursement for Spinal Procedures Since 2010.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To identify trends in spinal procedure reimbursement in our practice since 2010. SUMMARY OF BACKGROUND DATA: In an uncertain healthcare climate with continuous reform, trends in physician reimbursement are unclear. Market forces of supply and demand, legislation imposing penalties for quality measures, local competition, and geographic location have the potential to affect reimbursement. An emphasis on quality-of-care and cost reduction is placed on providers and insurers. In a high-cost area such as spine surgery, it is unknown what the reimbursement trends have been over the last 7 years of major healthcare reforms. METHODS: We collected payments received data for the 20 most commonly billed Current Procedural Terminology (CPT) codes for spinal surgery from January 2010 to December 2016. Payments were adjusted for inflation using the Consumer Price Index for Medical Care in the Northeastern United States. Insurers were separated into four groups: Medicare, Medicaid, Private Insurance, and Workers Compensation and No Fault (WC/NF). Using a weighted average to adjust for variation in procedures performed, average payments were trended over time. Average payments were trended by insurance group averaged by CPT code. RESULTS: After adjusting for inflation, average overall payments for spinal claims from 2010 to 2016 increased 13.6%. Average reimbursement declined 1.9% from 2010 to 2013 and rose 16.8% from 2014 to 2016. Average Medicaid payments increased 150.1% since 2010 whereas average Medicare payments rose 4.9%. Average reimbursement from private insurers and WC/NF claims decreased 16.2% and 8.5%, respectively, from 2010 to 2013; increasing 14.2% and 12.5%, respectively, from 2014 to 2016. From 2010 to 2016, reimbursement for private insurance decreased 9.3% and increased 8.2% for WC/NF claims. CONCLUSION: Since 2010, inflation-adjusted reimbursement for spinal procedures increased in our practice. There was a decline from 2010 to 2013. Increases occurred from 2014 to 2016 across all insurers. Medicaid payments more than doubled since 2010. LEVEL OF EVIDENCE: 3.

Steinmann Pins for C1 Lateral Mass Screw Placement During Atlantoaxial Stabilization.

OBJECTIVE: The authors describe a modified technique for placement of the C1 lateral mass screw using a Steinmann pin as a guide. This technique minimizes dissection and provides atlantoaxial stabilization during arthrodesis. METHODS: In our technique, a nonthreaded 1.6-mm spade-tip Steinmann pin is placed into the lateral mass of C1 to serve as a guide over which a powered drill is used for screw insertion. Perioperative data were collected for consecutive patients who underwent a C1-2 arthrodesis that involved the modified technique between March 2010 and July 2016. Data included blood loss, operative times, and C2 nerve root injury. RESULTS: The data for 93 patients were reviewed. Most (91.4%) patients presented with a fracture from an acute trauma. A mean of 1.97 levels was fused in these patients, with a mean blood loss of 76 mL and a mean operative time of 144 minutes. The overall morbidity and mortality rate was 10.7%. The morbidity rate of 7.5% included 30-day postoperative complications of respiratory failure and dysphasia. There were no postoperative vertebral artery injuries, hardware failures, or instances of occipital neuralgia. CONCLUSIONS: The use of Steinmann pins to guide the placement of C1 lateral mass screws is safe and effective in C1-2 arthrodesis. Limiting dissection minimizes blood loss and injury, maintains efficient operative time, and assists in accurate placement of the screws. Furthermore, with less manipulation and retraction of the C2 nerve root, postoperative occipital neuralgia and the need for C2 root transection are avoided.

Carotid body tumor imitator: An interesting case of Castleman's disease.

BACKGROUND: There are very few reports in the literature of Castleman's disease affecting the carotid artery and a single previous report of a case of Castleman's disease of the neck originally mistaken as a carotid body tumor. CASE DESCRIPTION: We describe a rare case of Castleman's disease, manifesting with classic radiographic hallmarks of a carotid body tumor. The postoperative pathologic examination identified the resected mass as Castleman's lymphadenopathy. The management of this particular case is discussed, and the findings are highlighted. CONCLUSIONS: We present a unique case of a tumor initially and incorrectly diagnosed as a carotid body tumor. However, after comprehensive treatment with endovascular and surgical modalities and subsequent pathologic examination, the diagnosis of this rare entity was made.

Carotid cutdown for surgical retrieval of a guidewire introducer: an unusual complication after mitral valve repair.

With the use of endovascular techniques and indwelling catheters, potential complications can include embolization of fragments or components of various systems. The authors describe the surgical retrieval of a guidewire introducer from the right common carotid artery (CCA). A 64-year-old man was found to have a foreign body within the right CCA on CT angiography after he had presented with a transient ischemic attack. He had undergone a complex mitral valve repair several months before presenting to the authors' facility. That procedure involved a femoral artery cutdown and the insertion of an endovascular aortic balloon for cardiac bypass. As in most endovascular procedures, guidewire introducers were probably used to facilitate the introduction of the guidewire into the system during the procedure. Although rare, iatrogenic embolization of the introducer probably occurred during use of the guidewire. The guidewire introducer was successfully retrieved without complication by using a standard carotid cutdown approach. It is extraordinarily unusual for an extracorporeal part of an implantable system to embolize to the carotid circulation. To the authors' knowledge, this is the only reported case of an embolized guidewire introducer and the use of a carotid exposure to retrieve an intraluminal foreign body. This case demonstrates that a carotid cutdown approach can be used successfully for the retrieval of intraluminal extracranial carotid artery foreign bodies.