Faculty Bibliography

Background/UNASSIGNED:The purpose of this study is to evaluate the knowledge and attitudes on osteoporosis among first-time spine surgery patients. Methods/UNASSIGNED:An electronic survey consisting of demographics, prior experience with osteoporosis, and the Facts on Osteoporosis Quiz (FOOQ) was sent via email to first-time spine surgery patients. Patients were then randomized into 2 groups: 1 received a brief osteoporosis information packet prior to beginning the FOOQ, and 1 proceeded directly to the survey. Results/UNASSIGNED:value of .068. Conclusions/UNASSIGNED:Our study demonstrates high FOOQ scores among all first-time spine patients as compared to historical scores in general at-risk populations. No statistical differences between FOOQ scores were noted between the group that received the information packet and the control group. This study demonstrates that patients new to spine care have a good understanding of osteoporosis and are thus willing to participate in osteoporosis treatment as part of their spine care.

Background/UNASSIGNED:Evaluate the current evidence in meta-analyses on posterior thoracolumbar minimally invasive surgery techniques and outcomes for degenerative conditions. Methods/UNASSIGNED:A systematic review of the literature from 1950 to 2015. Results/UNASSIGNED:The review of the literature yielded 34 meta-analysis studies evaluating posterior thoracolumbar minimally invasive techniques and outcomes for degenerative conditions. There were 11 studies included which investigated minimally invasive surgery (MIS) versus open posterior lumbar decompressions. There were 14 studies included which investigated MIS versus open posterior lumbar interbody fusions. Finally, there were 9 studies focused on navigation techniques and radiation safety within MIS procedures. Conclusions/UNASSIGNED:There are 34 meta-analysis studies evaluating minimally invasive to open thoracolumbar surgery for degenerative disease. The studies show a trend toward decreased estimated blood loss, decreased length of stay, decreased complications, similar fusion rates, improved accuracy, and decreased radiation when minimally invasive techniques are used.

Study Design/UNASSIGNED:Retrospective database study. Objectives/UNASSIGNED:Analysis of economic and demographic data concerning interspinous device (ID) placement throughout the United States to improve value-based care and health care utilization. Methods/UNASSIGNED:The National Inpatient Sample (NIS) database was queried for patients who underwent insertion of an interspinous process spinal stabilization device (ICD-9-CM 84.80) between 2008 and 2014 across 44 states. Demographic and economic data were obtained which included the annual number of surgeries, age, sex, insurance type, location, and frequency of routine discharge. The NIS database represents a 20% sample of discharges from US hospitals, which is weighted to provide national estimates. Results/UNASSIGNED:There was a 73% decrease in ID implanted from 2008 to 2014. The mean cost associated with insertion of the device increased 28% from $13 653 in 2008 to $17 515 in 2014. The mean length of stay (LOS) increased from 1.8 to 2.4 days. Patients aged 45 to 64 years increased from 14.1% to 34.3% while patients aged 65 to 84 years decreased from 74.4% to 60.6%. By region, 34% of ID placement occurred in the South followed by 19.7% that occured in the Northeast. When stratifying by median income for patient zip code, the procedure was performed more in cities designated as higher rather than lower income areas (74.2% and 19.5%, respectively). Conclusions/UNASSIGNED:Throughout the United States, there was a progressive decline in the insertion of interspinous spacers by 73% over the study period. The total costs for the procedure increased by 28% while the aggregate national charges decreased by 55.6% between 2008 and 2014.

Background/UNASSIGNED:Controversy exists over the ability of various lumbar interbody fusion techniques to realign global and regional balance and their effect on patient outcomes. This is a retrospective cohort study to compare thirty-day postoperative outcomes between anterior and posterior interbody fusion techniques within a large national database. Methods/UNASSIGNED:A retrospective cohort study utilizing the National Surgical Quality Improvement Program (NSQIP) database included 2,372 (29.9%) single-level anterior/direct lateral interbody fusions (ALIF/DLIF) and 5,563 (70.1%) single-level posterior/transforaminal lateral interbody fusions (PLIF/TLIF) between 2013 and 2014. Emergent cases, fracture cases, and preoperative compromised wounds were not analyzed. Primary thirty-day outcomes included mortality, return to operating room, readmission, length of stay, and other major complications. Minor outcomes included urinary tract infection, superficial incisional site infection, and perioperative blood transfusion within 72 hours. Results/UNASSIGNED:0.6%, P=0.025), which persisted in the multivariate analysis (OR =2.03; 95% CI, 1.13-3.65; P=0.017). Conclusions/UNASSIGNED:Although numerous techniques can be utilized in the treatment approach to various lumbar pathologies, anterior approaches have an increased risk of developing a perioperative DVT and early mortality. Transfusion risk is more strongly associated with elevated American Society of Anesthesiologists (ASA) class, increased age, preoperative anemia, and patients with bleeding disorders.

STUDY DESIGN/METHODS:Retrospective cohort chart review. OBJECTIVE:To determine the optimal lowest instrumented vertebra (LIV) following posterior segmental spinal instrumented fusion (PSSIF) of thoracic adolescent idiopathic scoliosis (AIS) with LIV at L2 or above. SUMMARY OF BACKGROUND DATA/BACKGROUND:Few studies evaluate the optimal LIV based on rotation or center sacral vertical line (CSVL). METHODS:A radiographic assessment of 544 thoracic major AIS patients (average age 14.7 years) with minimum 2 years' follow-up (average 4.1 years) after PSSIF was performed. The LIV was divided by CSVL: stable vertebra 1 (SV-1) if the CSVL fell between the medial walls of the LIV pedicles; SV-2 if between stable vertebra 1 and 3; and SV-3 if the CSVL did not touch the LIV. LIV was divided by rotation into: neutral vertebra 0 (NV-0) if the LIV was at or distal to the neutral vertebra; NV-1 if one vertebra proximal to the NV; NV-2 if two vertebrae proximal; and NV-3 if three vertebrae proximal to the NV. RESULTS:The prevalence of adding-on (AO) or distal junctional kyphosis (DJK) at ultimate follow-up was 13.6%. Patients with AO or DJK had a higher rate of open triradiate cartilage, LIV not touching the CSVL, and more proximal to the NV (p < .05). Risk factors were SV-3 (39% vs. SV-2 14%, SV-1 9%, p < .05), NV-3 (35% vs. NV-2 9%, NV-1 6%, NV-0 12%, p = .000), open triradiate cartilage (43% vs. closed 13%, p < .05), lumbar C modifier (22% vs. B modifier 8%, A modifier 13%, p < .05), and Risser stage 0 (19% vs. 12% Risser 1-5, p < .05). CONCLUSION/CONCLUSIONS:The prevalence of AO or DJK at ultimate follow-up of PSSIF for AIS with LIV at L2 or above was 13.6%. Risk factors included the CSVL outside the LIV, LIV 3 or more proximal to the NV, open triradiate cartilage, lumbar C modifier, and Risser stage 0. LEVEL OF EVIDENCE/METHODS:Level IV.

BACKGROUND:Spinopelvic fixation is an integral part of achieving solid fusion across the lumbosacral junction, especially in deformity procedures requiring substantial correction or long-segment constructs. Traditional S2-alar-iliac (S2AI) screw-placement techniques utilize fluoroscopy, increasing operative time and radiation exposure to the patient and surgeon. We describe a novel free-hand technique for S2AI screw placement in patients with adult spinal deformity. METHODS:We reviewed the records of 45 consecutive patients who underwent spinopelvic fixation performed with use of S2AI screws by the senior surgeon and various fellows or residents over a 12-month period (2015 to 2016). In each case, the S2AI screws were placed utilizing a free-hand technique without fluoroscopic or image guidance. Screw position and accuracy were assessed by intraoperative O-arm imaging and analyzed using 3-dimensional interactive manipulation of computed tomography images. RESULTS:A total of 100 screws were placed, 51 by the senior surgeon and 49 by trainees. The mean patient age was 57.4 ± 12.7 years at the time of surgery; 37 (82.2%) of the patients were female. Preoperative diagnoses included adult idiopathic scoliosis (n = 19), adult degenerative scoliosis (n = 15), flatback syndrome (n = 2), fixed sagittal imbalance (n = 6), and distal junctional kyphosis (n = 3). Five (5%) of the screws were placed with moderate to severe cortical breaches, all of which perforated the pelvis posteriorly, with no clinically notable neurovascular or visceral complications. The breach rate did not differ significantly between the senior surgeon and trainees. CONCLUSIONS:The free-hand technique for S2AI screw placement, when performed in a standardized manner, was demonstrated to be safe and reliable in constructs requiring spinopelvic fixation. The accuracy of screw placement relies on visible and palpable anatomic landmarks that obviate the need for intraoperative fluoroscopy or image guidance, potentially reducing operative time and radiation exposure. LEVEL OF EVIDENCE/METHODS:Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

STUDY DESIGN/METHODS:Consensus-building using the Delphi and nominal group technique. OBJECTIVE:To establish best practice guidelines using formal techniques of consensus building among a group of experienced spinal deformity surgeons to avert wrong-level spinal deformity surgery. SUMMARY OF BACKGROUND DATA/BACKGROUND:Numerous previous studies have demonstrated that wrong-level spinal deformity occurs at a substantial rate, with more than half of all spine surgeons reporting direct or indirect experience operating on the wrong levels. Nevertheless, currently, guidelines to avert wrong-level spinal deformity surgery have not been developed. METHODS:The Delphi process and nominal group technique were used to formally derive consensus among 16 fellowship-trained spine surgeons. Surgeons were surveyed for current practices, presented with the results of a systematic review, and asked to vote anonymously for or against item inclusion during three iterative rounds. Agreement of 80% or higher was considered consensus. Items near consensus (70% to 80% agreement) were probed in detail using the nominal group technique in a facilitated group meeting. RESULTS:Participants had a mean of 13.4 years of practice (range: 2-32 years) and 103.1 (range: 50-250) annual spinal deformity surgeries, with a combined total of 24,200 procedures. Consensus was reached for the creation of best practice guidelines (BPGs) consisting of 17 interventions to avert wrong-level surgery. A final checklist consisting of preoperative and intraoperative methods, including standardized vertebral-level counting and optimal imaging criteria, was supported by 100% of participants. CONCLUSION/CONCLUSIONS:We developed consensus-based best practice guidelines for the prevention of wrong-vertebral-level surgery. This can serve as a tool to reduce the variability in preoperative and intraoperative practices and guide research regarding the effectiveness of such interventions on the incidence of wrong-level surgery. LEVEL OF EVIDENCE/METHODS:Level V.

STUDY DESIGN/METHODS:A retrospective review of the Scoliosis Research Society (SRS) morbidity and mortality (M&M) database. OBJECTIVE:The aim of this study was to investigate visual related complications in spinal deformity patients undergoing spine surgery. SUMMARY OF BACKGROUND DATA/BACKGROUND:The SRS compiles surgeon-reported complications into an M&M database, tracking postoperative complications including visual loss, neurological deficits, infections, and death. Limited literature exists on postoperative visual complications, a rare but devastating complication following spine surgery. METHODS:We utilized the SRS M&M database to determine demographics, perioperative risk factors, and prognosis for visual related complications in spinal deformity patients undergoing corrective spine surgery from 2009 to 2012. RESULTS:A total of 167,972 spinal deformity patients from 2009 to 2012 were identified with a visual acuity complication (VAC) rate of 0.01%, or 12.5 per 100,000 patients. VAC rates for patients with kyphosis were significantly higher than patients with scoliosis (0.049% vs. 0.010%, P = 0.002) and spondylolisthesis (0.049% vs. 0.005%, P = 0.001). Postoperative visual loss rates significantly decreased from 2010 to 2012 (0.022% vs. 0.004%, P = 0.029). Twenty-one patients identified with VACs had a mean age of 34.8 ± 24.3 years. Two (9.5%) patients had preoperative vision changes, two (9.5%) were diabetic, two (9.5%) had vascular disease, one (4.8%) had a history of thromboembolic disease, and five (23.8%) had hypertension. Extent of VAC was bilateral-partial in four (19.0%), bilateral-total in five (23.8%), unilateral-partial in eight (38.1%), and unilateral-total in three (14.3%) patients. Four (19.0%) patients developed anterior ischemic optic neuropathy, four (19.0%) had posterior ischemic optic neuropathy (PION), five (23.8%) had central retinal artery occlusion, and five (23.8%) developed cortical blindness (CB). Greater than 50% of the VACs occurred on, or before, the first postoperative day. Ten (47.6%) patients recovered complete vision and four (19.0%) improved. All patients with CB and 50% with posterior ischemic optic neuropathy experienced complete resolution. CONCLUSION/CONCLUSIONS:VACs occur in approximately 12.5 per 100,000 deformity patients, with a rate five times higher in patients with kyphosis. More than 50% of these complications occur within 24 hours postoperatively. Nearly half of these complications resolve completely, and another 19% improve postoperatively. LEVEL OF EVIDENCE/METHODS:4.

STUDY DESIGN/METHODS:Retrospective review of high-dose tranexamic acid (TXA) use in consecutive patients. OBJECTIVE:To determine the safety profile of a high-dose TXA protocol in complex adult spinal deformity patients. SUMMARY OF BACKGROUND DATA/BACKGROUND:Adult spinal deformity (ASD) surgery may involve significant amounts of blood loss, especially when various osteotomy techniques are used. Antifibrinolytic agents such as TXA have been used to reduce intraoperative blood loss. However, there is no universally accepted dosing protocol for its use during complex ASD surgery. METHODS:Consecutive patients undergoing spinal deformity correction over a 14-month period at a single institution were identified. Inclusion criteria were adults (age ≥18 years) who underwent posterior spinal fusion of at least 5 levels and use of our standard TXA protocol of 50 mg/kg intravenous loading dose followed by a 5-mg/kg/h infusion until skin closure. Patient demographics, estimated blood loss (EBL), operative time, transfusion rates, complications, and other procedure-specific information were recorded. RESULTS:A total of 100 adult patients were included. All operative procedures were performed by the senior surgeon. The mean age was 47.3 years, and 71% of patients were female. Average body mass index was 24.9. The average fusion length was 14 levels; 33/100 patients had fusion constructs of 17 levels or more. Pedicle subtraction osteotomy was performed in 9 patients and vertebral column resections were performed in 14 patients. There were 45/100 patients who had a primary procedure, whereas the rest were revisions. Mean EBL was 1,336 mL (98 mL/level, 31% estimated blood volume). There were three thromboembolic complications, including one pulmonary embolism and two deep vein thromboses (DVTs), which were all treated successfully with anticoagulation. There were no cases of myocardial infarction, seizure, stroke, or acute renal failure. CONCLUSIONS:This is the first study to demonstrate the use of high-dose TXA in a complex ASD population. Larger prospective studies are needed to assess the efficacy and safety of high-dose TXA in ASD. LEVEL OF EVIDENCE/METHODS:Level IV, therapeutic.

STUDY DESIGN/METHODS:Case series. OBJECTIVES/OBJECTIVE:To determine the safety and feasibility of S2 alar-iliac (S2AI) screw placement under robotic guidance. SUMMARY OF BACKGROUND DATA/BACKGROUND: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/METHODS:Level IV, therapeutic.