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As robotics in spine surgery has progressed over the past 2 decades, studies have shown mixed results on its clinical outcomes and economic impact. In this review, we highlight the evolution of robotic technology over the past 30 years, discussing early limitations and failures. We provide an overview of the history and evolution of currently available spinal robotic platforms and compare and contrast the available features of each. We conclude by summarizing the literature on robotic instrumentation accuracy in pedicle screw placement and clinical outcomes such as complication rates and briefly discuss the future of robotic spine surgery.

Background K-wireless robotic pedicle screw instrumentation with navigation is a new technology with large potential. Barriers to adoption are added registration time with robotic-navigated system and reliable screw positioning. Understanding the learning curve and limitations is crucial for successful implementation. The purpose of this study was to describe a learning curve of k-wireless robotic assisted pedicle screw placement with navigation and compare to conventional techniques. Methods A retrospective review of prospectively collected data of 65 consecutive adult patients underwent robotic-navigated posterior spinal fusion by a single spine surgeon. Registration, screw placement, and positioning times were recorded. All patients underwent intra-operative 3D fluoroscopy and screw trajectory was compared to pre-operative CT. Results A total of 364 instrumented pedicles were planned robotically, 311 (85.4%) were placed robotically; 17 screws (4.7%) converted to k-wire, 21 (5.8%) converted to freehand, and 15 (4.1%) planned freehand. Of the 311 robotically placed pedicle screws, three dimensional fluoroscopic imaging showed 291 (93.5%) to be GRS Grade A in the axial plane (fully contained within the pedicle) and 281 (90.4%) were GRS Grade A in the sagittal plane. All breached screw deviations from plan were identified on 3D fluoroscopy during surgery and repositioned and confirmed by additional 3d fluoroscopy scan. Reasons for conversion included morphology of starting point (n=18), soft tissue pressure (n=9), hypoplastic pedicles (n=6), obstructive reference pin placement (n=2), and robotic arm issues (n=1). Seventeen (5.5%) critical breaches (≥2-4 mm) were recorded in 11 patients, 9 (2.9%) critical breaches were due to soft tissue pressure causing skive. Two patients experienced 6 (1.9%) critical breaches from hypoplastic pedicles, and 3 (0.9%) unplanned lateral breaches were found in another patient. One patient (0.3%) experienced skive due to morphology and spinal instability from isthmic spondylolisthesis. Imaging showed 143 screws placed medially to plan (1.2±0.9 mm), 170 lateral (1.2±1.1 mm), 193 screws caudal (1.0±0.6 mm) and 117 cranial (0.6±0.5 mm). No adverse clinical sequelae occurred from implantation of any screw. Conclusions The learning curve showed improvement in screw times for the first several cases. Understanding the learning curve and situations where the robotic technique may be suboptimal can help guide the surgeon safe and effectively for adoption, as well as further refine these technologies.

Study design This is a prospective observational study. Objective The aim was to record daily opioid use and pain levels after 1-level or 2-level anterior cervical discectomy and fusion (ACDF) or cervical disc arthroplasty (CDA). Summary of background data Data to inform opioid prescription guidelines following ACDF or CDA is lacking. Understanding postoperative opioid consumption behaviors is critical to provide appropriate postdischarge prescriptions. Methods Patients undergoing 1-level or 2-level primary ACDF or CDA were consecutively enrolled at 2 participating institutions between March 2018 and March 2019. Patients with opioid dependence (defined as daily use ≥6 mo before surgery) were excluded. Starting postoperative day 1, daily opioid use and numeric pain rating scale pain levels were collected through a Health Insurance Portability and Accountability Act-compliant, automated text-messaging system. To facilitate clinical applications, opioid use was converted from oral morphine equivalents into "pills" (oxycodone 5 mg equivalents). After 6 weeks or upon patient-reported cessation of opioid use, final survey questions were asked. Refill data were verified from the state prescription registry. Risk factors for patients in top quartile of consumption were analyzed. Results Of 57 patients, 48 completed the daily queries (84.2%). Mean age of the patient sample was 50.2±10.9 years. Thirty-two patients (66.7%) underwent ACDF and 16 CDA (33.3%); 64.6% one level; 35.4% two levels. Median postdischarge use was 6.7 pills (range: 0-160). Cumulative opioid use did not vary between the 1-level and 2-level groups (median pill consumption, 10 interquartile range: 1.3-31.3 vs. 4 interquartile range: 0-18, respectively, P=0.085). Thirteen patients (27.1%) did not use any opioids after discharge. Of those patients that took opioids after discharge, half ceased opioids by postoperative day 8. Preoperative intermittent opioid use was associated with the top quartile of opioid consumption (9.1% vs. 50%, P=0.006). Conclusion Given that most patients use few opioids, patients could be offered the option of a 12 oxycodone 5 mg (90 oral morphine equivalents) discharge prescription, accompanied by education on appropriate opioid use and disposal.

Study design Longitudinal cohort. Objective The aims of this study were to measure concordance between patients' and surgeons' preoperative expectations of lumbar surgery, and determine which member of the dyad more closely predicted fulfillment of expectations, defined as patient-reported status postoperatively. Summary of background data Concordant patient-surgeon expectations reflect effective communication and should foster better outcomes. Methods Preoperatively patients and surgeons completed identical surveys measuring expectations for improvement in symptoms and physical/psychosocial function. Responses ranged from "complete improvement" to "do not have this expectation"; scores for each survey ranged from 0 to 100 (greatest expectations). Concordance between pairs of patient-surgeon scores was measured with the intraclass correlation coefficient (ICC). Postoperatively, fulfillment of expectations was measured from patient-reported amount of improvement received and was calculated as the proportion of patient-reported postoperative score relative to patient-reported preoperative score, and surgeon-reported preoperative score (range 0 [no expectations fulfilled] to >1.2 [expectations surpassed]). Clinical measures included patient-reported spine-related disability. Results For 402 patient-surgeon pairs, mean survey scores were 73 ± 19 (patients) and 57 ± 16 (surgeons); 84% of patients had higher scores than surgeons, mainly due to expecting complete improvement, whereas surgeons expected a lot/moderate/little improvement. The ICC for the entire sample was .31 (fair agreement); for subgroups, the greatest difference in ICC was for patients with more spine-related disability (ICC = .10, 95% confidence interval [CI]:0.00-0.23) versus less disability (ICC = .46, 95% CI: 0.34-0.56). 96% of patients were contacted ≥2.0 years postoperatively. Proportions of expectations fulfilled were 0.79 (0-3.00) (patients) and 1.01 (0-2.29) (surgeons). Thus patients were less likely to anticipate subsequent postoperative status (odds ratio [OR] 0.34, 95% CI 0.25-0.45) versus surgeons who were more likely to anticipate patient-reported postoperative status (OR 2.98, 95% CI: 2.22-4.00). Conclusion Concordance between patients' and surgeons' expectations was fair; due mostly to patients expecting complete improvement whereas surgeons expected a lot/moderate/little improvement. Compared to patients' expectations, surgeons' expectations more closely coincided with patient-reported fulfillment of expectations 2 years postoperatively.Level of Evidence: 1.

Study design This is a prospective observational study. Objective The aim of this study is to determine the rate of occult infection after instrumented spine surgery in presumed aseptic patients. Summary of background data The reported incidence rate of delayed/occult infection determined by positive culture swabs after instrumented spine surgery in prospective studies is 0.2%-6.9%. However, this rate may be higher as delayed infections are challenging to diagnose. Fever can be absent and inflammatory markers are often normal. If indolent organisms exist in low concentrations surrounding the instrumentation, these organisms can possibly avoid detection and disrupt bone formation leading to instrumentation loosening, pain generation, and/or failure of a solid fusion. Materials and methods This study included 50 consecutive presumed aseptic patients undergoing a posterior revision requiring removal of instrumentation at least 6 months following their index procedure. Common markers of infection were examined preoperatively. Multiple culture swabs were taken directly from the removed instrumentation and cultured for 14 days. Results Of the 50 patients, 19 (38%) were culture-positive (CP) for bacteria upon removal of their instrumentation, with 14 patients (28%) having ≥2 positive specimens of the same organism. The average length of time between the index procedure and the revision surgery was 4.55 years (range: 0.53-21 y). Polymicrobial infections were found in 26% (5/19) of CP patients. The most prevalent microorganism found was Propionibacterium acnes, in 63% (12/19) of CP patients. There was no significant difference between CP and culture-negative patients regarding preoperative markers for infection, age, or length between index and revision procedures. Conclusions The results of this study indicate a positive culture rate of 38% in presumed aseptic patients who had previously undergone instrumented spine surgery. These results are consistent with other retrospective studies and are >6 times greater than any previous prospective study utilizing culture swabs. Level of evidence Level-III.

STUDY DESIGN This was a prospective cohort study. OBJECTIVE The objective of this study was to establish minimal clinically important difference (MCID) and substantial clinical benefit (SCB) thresholds for Patient-Reported Outcomes Measurement Information System (PROMIS) in cervical spine pathology. SUMMARY OF BACKGROUND DATA PROMIS enables improved psychometric properties with reduced questionnaire burden through computer adaptive testing. Despite studies showing good correlation with "legacy" outcome measures, literature on the clinical significance of changes in PROMIS scores is scarce. MATERIALS AND METHODS Adult patients undergoing cervical spine surgery at a single institution between 2016 and 2018 were prospectively enrolled. Patients completed questionnaires [Short Form-36 (SF-36), Neck Disability Index (NDI), Visual Analogue Scale Arm/Neck, and PROMIS Pain Interference (PI) and Physical Function (PF)] preoperatively and at 6 months postoperatively. MCID was calculated using distribution-based and SCB using anchor-based methods. The SF-36 Health Transition Item was utilized as an anchor with the cutoff values chosen using receiver operating characteristic curve analysis. RESULTS There were 139 patients meeting inclusion criteria, with a mean age of 56.4 years and diagnoses of myelopathy (n=36), radiculopathy (n=48) and myeloradiculopathy (n=49). There were significant improvements in PROMIS PF, PROMIS PI, NDI, and SF-36 preoperatively to postoperatively (P

Background: Three-dimensional (3D) computer-assisted navigation (CAN) has emerged as a potential alternative to 2-dimensional (2D) fluoroscopy in the surgical placement of spinal instrumentation. Recently, 3D-CAN systems have improved significantly in their ability to provide real-time anatomical referencing while shortening the registration and set-up time. A novel system in navigation, Machine-Vision Image-Guided Surgery (MvIGS; 7D Surgical, Toronto, Canada) was cleared by the US Food and Drug Administration, but its potential benefits in reducing intra-operative radiation exposure to patients and enhancing surgical accuracy of pedicle screw placement are not fully known. Purpose: We sought to conduct a prospective, randomized, clinical study comparing the 3D-MvIGS spinal navigation system and 2D-fluoroscopy for pedicle screw insertion up to 3 levels (T10-S1) and for various measures of surgical efficacy. Methods: Sixty-two eligible patients were randomized to receive spine surgery using either the 3D-MvIGS group or the conventional 2D-fluoroscopy for pedicle screw fixation for the treatment of spinal stenosis and degenerative spondylolisthesis. Intra-operative parameters and procedure-related unintended protocol violations were recorded. Results: Operative time and estimated blood loss were not significantly different between groups. Radiation time and exposure to patients were significantly reduced in the 3D-MvIGS group. There was no difference between groups in pedicle screw placement accuracy (2D-fluoroscopy group, 96.6%; 3D-MvIGS group, 94.2%). There were no major complications or cases that required revision surgery. Conclusion: The 3D-MvIGS navigation system performed comparably with 2D-fluoroscopy in terms of pedicle screw placement accuracy and operative time. The 3D-MvIGS showed a significant reduction in radiation exposure to patients. In more complex cases or larger cohorts, the true value of greater anatomical visualization can be elucidated.

Background: Robotic-assisted and computer-assisted navigation (CAN) systems utilization has been rapidly increasing in recent years. Most existing data using these systems are performed in the thoracic, lumbar, and sacral spine. The unique anatomy of the cervical spine maybe where these technologies have the greatest potential. To date, the role of navigation-enabled robotics in the cervical spine remains in its early stages of development and study. Purpose: This review article describes the early experience, case descriptions and technical considerations with cervical spine screw fixation and decompression using CAN and robotic-assisted surgery. Methods: Representative cervical cases with early surgical experience with cervical and robotic assisted surgery with CAN. Surgical set up, technique considerations, instrumentation, screw accuracy and screw placement were elevated and recorded for each representative cervical case. Results: Existing robotic assisted spine surgical systems are reviewed as they pertain to the cervical spine. Method for cervical reference and positioning on radiolucent Mayfield tongs are presented. C1 lateral mass, odontoid fracture fixation, C2 pedicle, translaminar, subaxial lateral mass, mid cervical pedicle, navigated decompression and ACDF cases and techniques are presented. Conclusion: In conclusion, within the last several years, the use of CANs in spinal surgery has grown and the cervical spine shows the greatest potential. Several robotic systems have had FDA clearance for use in the spine, but such use requires simultaneous intraoperative fluoroscopic confirmation. In the coming years, this recommendation will likely be dropped as accuracy improves.

Background Surgical navigation improves pedicle screw insertion accuracy and reliability. Robotic-assisted spinal surgery and screw placement has not been fully assessed in pediatric patients with spine deformity undergoing posterior spinal fusion. The purpose of this study was to describe the learning curve for robotically assisted pedicle screw placement in pediatric patients. Methods A retrospective review on a consecutive series of the first 19 pediatric patients who underwent posterior spinal fusion by a single surgeon using robotic navigation was performed. Demographics, curve parameters, pedicle diameter, vertebral rotation, and additional outcome measures were recorded. Screw position was assessed with calibrated intraoperative 3-dimensional fluoroscopic images. All complications of planned and placed robotically placed screws were recorded. Results A total of 194 left-sided screws were planned as robot-assisted. One hundred sixty-eight of the robotically planned screws (86.6%) were placed with robot assistance; 29 robotically planned screws (15.0%) were abandoned or converted to freehand. The mean time per robotically placed screw was 3.6±2.4 minutes. Fifteen breaches (8.9%) and 1 anterior perforation occurred with 2 critical (>2 to 4 mm) breaches, 1 was associated with a durotomy, and both occurred in the first case. There were no intraoperative/postoperative neuromonitoring changes and no sequela from the durotomy. Six breaches occurred in the first case. The odds ratio of obtaining a breach in screws with a matched trajectory was 0.275 (95% confidence interval: 0.089-0.848). Conclusions Screw time and accuracy improved and the number of breaches decreased after 10 cases. This series had 2 critical breaches (between 2 and 4 mm) on the first case. Overall, excluding the 2 critical breaches, 98.8% of robotically executed screws were placed without a critical breach, which is comparable to previous pediatric deformity studies. Caution should be exercised during the initial training period to avoid complications as experience and training lead to an improved understanding of surgical planning, skive, and soft-tissue pressure on the end-effector all of which can impact accuracy of robotically assisted pedicle screw placement. Level of evidence Case Series, IV.

Study Design: Retrospective case series. Objective: To report contemporary rates of complications and subsequent surgery after spinal surgery in patients with skeletal dysplasia. Methods: A case series of 25 consecutive patients who underwent spinal surgery between 2007 and 2017 were identified from a single institution’s skeletal dysplasia registry. Patient demographics, medical history, surgical indication, complications, and subsequent surgeries (revisions, extension to adjacent levels, or for pathology at a non-contiguous level) were collected. Charlson comorbidity indices were calculated as a composite measure of overall health. Results: Achondroplasia was the most common skeletal dysplasia (76%) followed by spondyloepiphyseal dysplasia (20%); 1 patient had diastrophic dysplasia (4%). Average patient age was 53.2 ± 14.7 years and most patients were in excellent cardiovascular health (88% Charlson Comorbidity Index 0-4). Mean follow up after the index procedure was 57.4 ± 39.2 months (range). Indications for surgery were mostly for neurologic symptoms. The most commonly performed surgery was a multilevel thoracolumbar decompression without fusion (57%). Complications included durotomy (36%), neurologic complication (12%), and infection requiring irrigation and debridement (8%). Nine patients (36%) underwent a subsequent surgery. Three patients (12%) underwent a procedure at a non-contiguous anatomic zone, 3 (12%) underwent a revision of the previous surgery, and another 3 (12%) required extension of their previous decompression or fusion. Conclusions: Surgical complication rates remain high after spine surgery in patients with skeletal dysplasia, likely attributable to inherent characteristics of the disease. Patients should be counseled on their risk for complication and subsequent surgery.

Study design Randomized, double-blinded, controlled trial. Objective To investigate the effectiveness of local intraoperative corticosteroids at decreasing the severity of swallowing difficulty following multilevel anterior cervical discectomy and fusion (ACDF). Summary of background data Dysphagia is a common complication after ACDF, and while for most patients the symptoms are mild and transient, some patients can suffer from severe dysphagia resulting in significant postoperative morbidity. Previous studies investigating the local application of corticosteroids are limited. Methods This was a prospective, randomized, double-blinded, controlled trial of patients undergoing 2, 3, or 4 level ACDF for radiculopathy and/or myelopathy. Patients undergoing multilevel ACDF were randomized to receive local corticosteroid in the retropharyngeal space or placebo (no steroid). Dysphagia was assessed using validated outcomes including the Eating Assessment Tool-10 (Eat-10) and Swallowing Quality of Life (SWAL-QOL) Questionnaire both preoperatively and at 1 day (POD1), 2 days (POD2), and 1-month postoperatively. Results One-hundred nine patients had a complete dataset available for analysis. Eat-10 scores were significantly lower in the Steroid group on POD2 (8 vs. 16, P = 0.03) and 1-month postoperatively (2 vs. 5, P = 0.03). A comparison of the individual SWAL-QOL subscale scores demonstrated that patients in the Steroid group had better scores than the Control group in various subscales at all postoperative time points. Significant differences were noted (always in favor of the Steroid group) in 40% of subscales on POD1, 60% of subscales on POD2, and 50% of subscales at 1-month postoperatively. The Control group never had a better SWAL-QOL subscale score at any time point postoperatively. Conclusion Local administration of corticosteroid after multilevel ACDF can decrease postoperative severity and symptomatology of dysphagia during the immediate postoperative period to 1-month postoperatively. The long-term effects of local steroid administration on fusion and other complications will need to be established in future studies.Level of Evidence: 1.

Study DesignRetrospective case-control study.PurposeThe purpose of this study was to examine the effect of antidepressants on blood loss and transfusion requirements in spinal surgery patients.Overview of LiteratureSeveral studies have shown an increase in perioperative bleeding in orthopedic surgery patients on antidepressant drug therapy, yet no study has examined the impact of these agents on spinal surgery patients.MethodsCharts of patients who underwent single-level spinal fusion (posterior lumbar interbody fusion with posterior instrumentation) performed by five fellowship-trained surgeons at a tertiary spine center between 2008 and 2013, were retrospectively reviewed. Exclusion criteria included select medical comorbidities, select drug therapy, and Amercian Society of Anesthesiologists Physical Status Classification score of greater than 2. Serotonergic antidepressants were examined in multivariate analysis to assess their predictive value on estimated blood loss and risk of transfusion.ResultsA total of 235 patients, of which 52% were female, were included. Allogeneic blood was transfused in 7% of patients. The average estimated blood loss was 682±463 mL. Selective serotonin reuptake inhibitors were taken by 10% of all patients. Multivariable regression analysis showed that intake of selective serotonin reuptake inhibitors was a significant predictor for blood loss (average increase of 34%, p=0.015) and for the need of allogeneic blood transfusion (odds ratio, 4.550; p=0.029).ConclusionsThere was a statistically significant association between selective serotonin reuptake inhibitors and both increased blood loss and risk of allogeneic red blood cell transfusion. Surgeons and perioperative providers should take these findings into account when assessing patients' preoperative risk for blood loss and transfusion.

BACKGROUND CONTEXT Agreement between patients and surgeons regarding expectations of lumbar surgery may vary depending on whether expectations are for improvement in physical or mental health. Focusing patient-surgeon communication on health domains where there is more disagreement should be a priority before surgery. PURPOSE To compare agreement within the patient-surgeon pair for expected improvement in domains of physical and mental health, STUDY DESIGN/SETTING Cross-sectional, tertiary spine. PATIENT SAMPLE This study included 402 lumbar surgery patient-surgeon pairs. OUTCOME MEASURES HSS Lumbar Spine Surgery Expectations Survey. METHODS Patients of five spine surgeons were interviewed preop and completed the ODI and the valid 20-item Expectations Survey, which is composed of four domains: personal activities (eg, sit); complex function (eg, exercise, stop condition from getting worse); psychological well-being (eg emotional stress); and skeletal function (eg, balance). The survey asks how much improvement is expected for each item with response options of complete to no improvement, and a total score and four domain scores are generated (possible score range 0-100, higher is greater expectations). Surgeons completed an identical survey asking them to rate expected improvement for each item for each patient, yielding similar total and domain scores. Agreement within the patient-surgeon pair was measured with the intraclass correlation coefficient (ICC), range 0-1.0 (0-.20 poor; .21-.40 fair; .41-60 moderate; .61-.80 good; .81-1.0 excellent agreement). Differences between patients’ and surgeons’ scores were then assessed in multivariable models controlling for psychosocial and surgical characteristics. RESULTS Mean age was 55, 55% were men, 21% were non-white race/ethnicity, 79% had degenerative conditions, and mean ODI score was 53 (range 4-84). Patients and surgeons independently completed the survey within 10 days preop. Patients’ mean survey scores were greater than surgeons’ scores for each domain: personal activities 65 vs 50; complex function 84 vs 66; psychological well-being 74 vs 58; and skeletal function 69 vs 51 (p CONCLUSIONS Agreement between patients’ and surgeons’ expectations was poor-to-good with patients expecting greater improvement in all domains. Agreement was similar for physical and mental health expectations, but was markedly worse for complex functions. Greater disability was most consistently associated with less agreement for all domains, indicating that disability impacts perceptions of all aspects of health. Thus preop discussions should consider disability when addressing expectations for both physical and mental health. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Since 2000, the annual death toll from opioid associated overdose has increased by over 300%. To reduce the opioid consumption, physicians have used alternative approaches, which have proven to not only be effective, but also reduce the side effects such as nausea, constipation, and addiction. IV acetaminophen has been shown to successfully accomplish the reduction in opioid use, however, it is an expensive alternative. Testing the efficacy of IV acetaminophen vs its oral formulation will likely modify future postoperative pain management regimens while also addressing cost-effectiveness. PURPOSE To prospectively evaluate clinical outcomes and determine the cost effectiveness of IV vs oral (PO) acetaminophen following lumbar circumferential spine surgery. We hypothesize that IV acetaminophen will perform better than PO in terms of length of stay, morphine equivalence, and change in VAS scores from baseline. STUDY DESIGN/SETTING A prospective, single-center, randomized control trial. PATIENT SAMPLE Patients between the ages of 18-85 who underwent circumferential lumbar fusion surgery, while failing conservative treatment for more than 6 months were included in the study. Patients were excluded if they had already undergone lumbar surgery at the index level(s), were diagnosed with osteoporosis, had dysphagia prohibiting oral administration, or had a history of substance abuse. OUTCOME MEASURES Outcome measures included opioid equivalence, length of hospital stay, VAS measurements, and Oswestry Disability Index (ODI) scores. METHODS Once enrolled, patients were randomized to either the IV or PO acetaminophen treatment groups. Preoperatively, patients completed a baseline analgesic regimen questionnaire, surveys including VAS, SF-12, and ODI, and were administered their first acetaminophen dose within three hours of first incision. Postoperatively, patients received seven subsequent doses of their assigned acetaminophen, with access to supplemental analgesics if needed. Analgesic usage and VAS scores were monitored until discharge. Surveys were completed at six weeks and six months follow-up. RESULTS Average daily opioid consumption for the IV group was significantly lower than the PO group during the immediate postoperative period. Average length of stay was similar between groups, 3.3 days for PO and 3.7 days for IV. VAS back and leg scores were not statistically different between groups, however, both groups experienced a decrease by more than the minimally clinically important difference (MCID) of 12 points from baseline. ODI also decreased by the MCID at the 6-month follow-up, which was defined as 12.8% for ODI. CONCLUSIONS Along with an overall reduction in opioid usage, patient-reported outcomes depict successful improvement of pain management with the use of IV acetaminophen following circumferential spinal fusion surgery. Furthermore, despite the large discrepancy between the two formulations in cost-to-perceived-benefit ratio, the significant reduction of opioid usage and, therefore, its associated costs, provides a far less dramatic divergence. The continued testing of the efficacy of IV acetaminophen vs its oral formulation will likely modify future postoperative pain management regimens while also addressing the opioid epidemic plaguing communities across the US. FDA DEVICE/DRUG STATUS OFIRMEV (Approved for this indication).

BACKGROUND CONTEXT Patients undergo cervical spine surgery because they expect improvement in physical and psychological symptoms and function. Patients and surgeons need to share an understanding of what are possible, probable and realistic expectations so they can work toward the same goals. PURPOSE To compare concordance (agreement) within the patient-surgeon pair regarding expectations of cervical spine surgery. STUDY DESIGN/SETTING Cross-sectional, tertiary spine center. PATIENT SAMPLE This study included106 patients scheduled for cervical spine surgery and their surgeons. OUTCOME MEASURES Hospital for Special Surgery Cervical Spine Surgery Expectations Survey. METHODS Patients scheduled for cervical spine surgery were recruited from the practices of 5 spine surgeons and interviewed in person several days before surgery with several patient-centered questionnaires including the Neck Disability Index (NDI) (score range 0-100, higher is worse), the PHQ8 for depressive symptoms (score range 0-24, ≥10 is a positive screen for depression), and the valid Cervical Spine Surgery Expectations Survey. The 20-item Expectations Survey addresses symptoms, physical function, and psychological well-being, and asks how much improvement is expected with response options of “complete” (=4 points), “a lot” (=3 points), “a moderate amount” (=2 points), “a little” (=1 point), or “no improvement/this expectation does not apply to me” (=0 points). An overall score is calculated as the sum of all responses (range 0-100, higher is greater expectations). Before surgery, surgeons completed an identical survey asking them to rate how much improvement they expected for each item for each of their patients. The surgeon's survey is scored similarly to generate an overall score (range 0-100). Concordance between scores for each patient-surgeon pair was measured with the intraclass correlation coefficient (ICC) for continuous data (range 0-1.0: 0-.20 poor; .21-.40 fair; .41-60 moderate; .61-.80 good; .81-1.0 excellent agreement). RESULTS Patients completed the Expectations Survey a mean of 9 days before surgery, mean age was 57 years, 50% were women, mean NDI score was 42±20, 26% had a positive screen for depression, 32% had a diagnosis of myelopathy, and 68% had a diagnosis of radiculopathy. The 5 surgeons were age 41-63 years, in practice for 8-31 years, and all had completed a spine fellowship. The mean Expectations Survey score was 65±22 for patients and 57±19 for surgeons (p CONCLUSIONS Overall concordance between patients’ and surgeons’ expectations was moderate, but varied from fair to excellent based on major demographic, diagnostic, and clinical characteristics. Because patients and surgeons may not be aware of differences in expectations, discussions about expectations should be part of comprehensive preoperative evaluations. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT While fusion in the context of anterior cervical discectomy and fusion (ACDF) has been reported to be as high as 97% at 4 years postop, little is known about the bridging of trabecular bone, radiolucency and interspinous motion (ISM) as definitive criterion for assessing fusion on radiographic X-ray imaging. While there is no conclusive method for quantifying interbody fusion (IBF), there is curiosity about whether these parameters can prove a spacer type to have a higher fusion rate than another. PURPOSE To determine whether the use of interbody cages (IC) promotes higher fusion rates in ACDF using plain X-ray studies. STUDY DESIGN/SETTING Single-center retrospective analysis of prospective consecutive database of multilevel ACDF. PATIENT SAMPLE This study included 94 patients and 232 levels were evaluated with 1-year postop images from August 2015 to November 2018. OUTCOME MEASURES Interspinous motion, bridging trabecular bone, fusion grade. METHODS A total of 32 published papers were reviewed to select the three best parameters for assessing cervical fusion: the passage of trabecula through the implant, the presence of a radiolucent line interfacing implant and vertebral plate, and the range of motion between two adjacent spinous processes. Radiolucency and bridging trabecular bone (BTB) parameters were combined to categorize each ACDF level as fused (≥75% BTB present) or not fused ( RESULTS A total of 234 surgical levels from 92 patients were included (age: 62.5, 42.4% F, BMI: 29.87). Median number of levels fused by patient was 2 (IQR: 1). Overall, 28.2% of the patients had at least 1 level with incomplete fusion. Patients with incomplete fusion (by BTM or ISM method) had longer ACDF than those with complete fusion (median=3 vs 2, p=0.022). No associations were found between demographic, smoking status and fusion rate (all p > 0.1). When investigating fusion level by level, using the BTB and ISM methods respectively, no significant differences were found based on IC type (bone graft vs cage; p=.867 and .585), iliac bone vs local (p =.869, .796) or allograft. Lower fusion rate was noticed for C6-C7 (58.1%) compared to more proximal disc spaces (71.4% to 78.7%, p = 0.049). Combination of IC and graft material revealed no significant difference (bonegraft + local=71.8% vs cage + iliac=66.7%, p = 0.517). Multivariate analysis, controlling for demographic and smoking status, demonstrated that only location of the fusion was an independent predictor of incomplete fusion. CONCLUSIONS There was no superiority within the allograft and autograft respective groups or between spacers, using the ISM or BTB techniques. More than 2mm of motion on dynamic X-ray studies, BTB and radiolucent interface between implant and endplates are efficient quantifiable methods to measure fusion on X-ray studies, as they are easily accessible and affordable within the health care field. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Prospective observational study OBJECTIVE.: The aim of this study was to record daily opioid use and pain levels after 1-level lumbar decompression or microdiscectomy.The standardization of opioid-prescribing practices through guidelines can decrease the risk of misuse and lower the number of pills available for diversion in this high-risk patient population. However, there is a paucity of quantitative data on the "minimum necessary amount" of opioid appropriate for post-discharge prescriptions.At two institutions between September 2017 and 2018, we prospectively enrolled 85 consecutive adult patients who underwent one-level lumbar decompression or microdiscectomy. Patients with a history of opioid dependence were excluded. Daily opioid consumption and pain scores were collected using an automated text-messaging-based platform for 6 weeks or until consumption ceased. Refills during the study period were monitored. Patients were asked for the number of pills left over and the method of disposal. Opioid use was converted to oral morphine equivalents (OMEs). Results are also reported in terms of "pills" (oxycodone 5 mg equivalents) to facilitate clinical applications. Risk factors were compared between patients in the top and bottom half of opioid consumption.Total opioid consumption ranged from 0 to 118 pills, with a median consumption of 32 pills (236.3 OME). Seventy-five percent of patients consumed ≤57 pills (431.3 OME). Mean Numeric Rating Scale pain scores declined steadily over the first 2 weeks. By postoperative day 7 half of the study population had ceased taking opioids altogether. Only 22.4% of patients finished their initial prescription, and only 9.4% of patients obtained a refill.These data may be used to formulate evidence-based opioid prescription guidelines, establish benchmarks, and identify patients at the higher end of the opioid use spectrum.2.

BACKGROUND CONTEXT There is a lack of data informing opioid prescription quantities after ACDF or CDA. PURPOSE To record daily opioid use and pain levels after one- or two-level ACDF or CDA using an automated text-messaging based data collection system. STUDY DESIGN/SETTING Dual-institutional prospective observational study. PATIENT SAMPLE This study included 57 patients who underwent ACDF or CDA at one of two institutions (66.7% ACDF, 33.3% CDA; 64.6% one level, 35.4% two levels). OUTCOME MEASURES Daily opioid consumption, daily pain scores (NRS scale), initial prescription amount and type, number of pills left over, method of disposal, refill rate. METHODS All adult patients undergoing one- or two-level primary ACDF or CDA were enrolled at two high-volume institutions. Patients with daily opioid dependence were excluded, while those patients who utilized opioids on a non-daily basis in the 6 months before surgery were categorized as “intermittent opioid users.” Starting POD1, daily opioid use and pain scores were collected through a HIPAA-compliant, automated text-messaging system. To facilitate clinical applications, opioid use was converted from oral morphine equivalents (OME) into “pills” (oxycodone 5 mg equivalents). After 6 weeks or upon patient-reported cessation of opioid use, final survey questions were asked. Refill and prescription data were verified from the state registry. Risk factors for patients in top 25% of opioid use were analyzed. RESULTS A total of 48 patients completed the daily queries (84.2%). Average age of the patient sample was 50.2±10.9 years, with a BMI of 27.4±4.2 kg/m2. Thirty-two patients (66.7%) underwent ACDF and 10 CDA (33.3%); 64.6% one level and 35.4% two levels. In the six months before surgery, 18.8% used opioids on a non-daily basis. Total postdischarge opioid use ranged from 0-160 “pills” (oxycodone 5mg equivalents), median of 6.7 pills (IQR 0-30). Use did not vary between the one- and two-level groups (10 IQR [1.3-31.3] vs 4 pills IQR [0-18], respectively, p=0.085). Thirteen patients (27.1%) used no opioids after discharge. Out of those patients who took opioids, use dropped from median 2.6 pills POD1 to 1 pill POD5. By POD12, 91.4% stopped opioids. Only 6 patients (14.2%) obtained a refill. Preoperative intermittent opioid use was associated with the top 25% of opioid consumption (9.1% vs 50%, p=0.006). In all patients, pain scores declined from a median 6 on POD1 to 4 on POD7. CONCLUSIONS Most patients fall at the low end of the opioid-use spectrum, with a quarter taking no opioids postdischarge. A prescription equivalent to 10 oxycodone 5 mg pills (75 OME) would allow for pain relief while minimizing the number of leftover pills. Prescribing guidelines must reflect these numbers to avoid excess leftover pills in the home. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

STUDY DESIGN A cross-sectional, mixed methods analysis of sources of expectations of lumbar surgery. OBJECTIVE The aim of this study was to ascertain sources of expectations and compare them to clinical characteristics. SUMMARY OF BACKGROUND DATA Understanding where patients obtain expectations of lumbar surgery is necessary in order to develop interventions to foster appropriate expectations. METHODS This was a qualitative-quantitative study of 428 patients interviewed preoperatively with a 20-item validated survey, which asks patients how much improvement they expect per item. Patients then were asked open-ended questions about how they came to have these expectations and, using qualitative analysis, responses were grouped into themes representing different sources of expectations. The likelihood of citing various sources was then assessed with odds ratios (ORs) based on demographic and clinical characteristics. RESULTS Patients' mean age was 55 years, 80% had degenerative diagnoses and 24% had prior lumbar surgery. Patients volunteered multiple sources; most prevalent were current surgeon (83%), internet resources (55%), social network contacts (26%), other physicians (22%); and previous experience (65%) for the subgroup who had prior lumbar surgery. Patients were more likely to cite their surgeon if they had less disability [OR 2.8, confidence interval (CI) 1.3-5.8, P = 0.007], were treated with conservative care, such as physical therapy (OR 2.7, CI 1.6-4.7, P = 0.0003), and had symptoms for ≤12 months (OR 1.8, CI 1.1-3.0, P = 0.03). Patients who cited the internet were employed (OR 2.2; CI 1.5-3.3; P

BACKGROUND CONTEXT Concordance, or agreement, between patients and surgeons regarding expectations of lumbar surgery is a preoperative goal. Understanding what demographic and clinical characteristics contribute to differences in expectations, particularly unrealistically high expectations, would help direct preoperative communication. PURPOSE To compare concordance within the patient-surgeon pair regarding expectations of surgery, and to assess differences in expectations by demographic and clinical characteristics STUDY DESIGN/SETTING Cross-sectional, tertiary spine center. PATIENT SAMPLE A total of 402 lumbar surgery patient-surgeon pairs. OUTCOME MEASURES HSS Lumbar Spine Surgery Expectations Survey. METHODS Patients of 5 spine surgeons were interviewed preoperatively and completed the ODI and the valid 20-item Expectations Survey. The Survey asks how much improvement is expected for each item with response options of complete to no improvement, and a total and 4 domain scores (ie, personal activities, daily function, psychological well-being and skeletal function) are generated (range 0-100, higher is greater expectations). Surgeons completed an identical survey asking them to rate expected improvement for each item for each patient, yielding similar 0-100 total and domain scores. Concordance within the patient-surgeon pair was measured with the intraclass correlation coefficient (ICC) (range 0 [agreement no better than chance] to 1 [perfect agreement]). Differences between patients’ and surgeons’ total and domain scores were then assessed in multivariable models. RESULTS Mean age was 55, 55% were men, 21% were self-described as non-white race/ethnicity, 79% had degenerative conditions, and mean ODI score was 53 (range 4-84). Patients and surgeons independently completed the Survey within 10 days preoperatively. The mean total survey score was 73±19 for patients, 57±16 for surgeons (p CONCLUSIONS There was fair agreement between patients and surgeons regarding expectations with patients having greater expectations, especially if they were more disabled. Although it seems logical that patients with the most disability would have the most to expect, the essential issue is whether such high expectations (ie, complete improvement) are realistic; according to surgeons, a lot/moderate improvement is more appropriate. Thus preoperative discussions should not be centered on what items to expect, but instead should emphasis how much improvement to expect for each item. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Generic and spine-specific surveys are used before surgery for lumbar degenerative spondylolisthesis (LDS) to measure pain. While both types of surveys can discern various aspects of pain, such as pain intensity and pain-associated disability, their ability to capture how pain impacts other outcomes, such as fulfillment of expectations, is not known. PURPOSE To determine which pain surveys are most closely associated with fulfillment of expectations after surgery for LDS. STUDY DESIGN/SETTING Prospective 2-year longitudinal study, tertiary spine center. PATIENT SAMPLE A total of 146 patients undergoing surgery for LDS. OUTCOME MEASURES HSS Lumbar Spine Surgery Expectations Survey. METHODS Patients were interviewed several days before surgery with the valid 20-item Expectations Survey addressing symptoms, physical function, and psychological well-being. Patients rated how much improvement they expected for each item with response options of complete to no improvement. To measure pain, patients completed back-specific measures of global pain with a numeric rating scale (0-10) and the modified Oswestry Disability index (ODI) (0-100), and generic PROMIS measures of Pain Intensity and Pain Interference with computer adapted tests (T scores 50). Medical records were reviewed for surgeon-reported pain on flexion/extension and surgical complexity according to the Invasiveness Index (max 10 points/vertebral level). Two-year postop patients again completed the Expectations Survey rating how much improvement they actually received. A proportion of expectations fulfilled was calculated as total improvement received divided by total improvement expected (range 0 (no improvement), 1 (improved as expected), >1 (improved more than expected). In multivariable linear regression analyses controlling for complexity, the proportion was the dependent variable and various pain measures were independent variables, expressed as estimates with desired 95% confidence intervals (CI) not to cross 0. RESULTS Mean age was 68, 61% were women, 82% had LDS at only one level (69% L45), mean pelvic incidence was 61° (30-84), mean pelvic incidence minus lumbar lordosis was 10° ((-16)-50), and the median surgical complexity was 7 (1-22). With respect to pain, 60% of patients had pain with extension, 25% with flexion. The median global back pain was 6 (0-10), and mean values were: ODI 50 (6-88), PROMIS Intensity 55 (31-72), and PROMIS Interference 63 (3-100). The mean time to follow-up was 2.1 years. The mean Expectations Survey proportion of expectations fulfilled was .99 (0-3.53); 42% of patients had low, 21% had equivalent, and 36% had high proportions (ie, greater expectations fulfilled). Controlling for surgical complexity, higher proportions were associated with less ODI pain (1.1, CI 0.5-1.6, p=.0001), less global back pain (4.5, CI 1.6-7.3, p=002) and, to lesser extents, less generic PROMIS Pain Intensity (1.5, 0.3-2.6, p=.01) and Pain Interference (0.8, -0.1-1.6, p=.08). There were no associations between surgeon-reported pain on extension/flexion and proportions of expectations fulfilled (p>.10). CONCLUSIONS Compared to generic pain surveys, preop pain measured by spine-specific pain surveys were more closely associated with the outcome of fulfillment of expectations. Whether generic pain surveys, such as PROMIS, are sufficiently sensitive to explain other outcomes of LDS needs to be assessed further. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Patients are instructed to restrict activity for several months after lumbar surgery to safely recuperate. However, after recuperation many patients continue sedentary lifestyles because of fear of spine injury, persistent pain, deconditioning, and habit. Lack of activity has serious long-term adverse consequences for spine health and other physical and mental diagnoses (ie, Sedentary Death Syndrome). Because surgeons comprehensively understand the spine condition and extent of surgery, they and their surgical team are uniquely positioned to address apprehensions and advise/encourage prudent activity. Thus programs to foster physical activity that can be integrated into the busy postop spine care setting are needed. PURPOSE To determine whether an intervention encompassing major psychosocial tenets of behavior change would be effective in increasing prudent physical activity, primarily walking, after 4-6 months. STUDY DESIGN/SETTING Randomized controlled trial, tertiary spine center. PATIENT SAMPLE A total of 225 patients 3 months after complex lumbar surgery, cleared by surgeons to increase physical activity. OUTCOME MEASURES Paffenbarger Physical Activity and Exercise Index (PAEI). METHODS During routine 3-month postop visits, 111 intervention patients received (1) a booklet about benefits of physical activity and national activity guidelines, (2) instruction on how to increase lifestyle walking, (3) a pedometer calibrated to stride length, (4) made a self-contract specifying walking goals, and (5) received interval telephone contract-directed encouragement from study personnel. A total of 114 controls received information about safe physical activity. At enrollment, all patients completed the valid 3-domain PAEI measuring number of blocks walked and stairs climbed daily, and sports during the past week. Kcal/week were calculated for each domain and for an overall total. The national recommended threshold overall total is ≥2000 Kcal/week. Operative records were reviewed and a Surgical Invasiveness Index (SII) value was calculated (maximum 10 points per vertebral level); higher is greater complexity. The primary outcome was change in Kcal/week in the PAEI walking domain at 4-6 months post enrollment; a secondary outcome was change in overall total Kcal/week. RESULTS At enrollment, intervention and control groups were similar in mean age (64 vs 64), women (44% vs 50%), median SII value (11 vs 10), PAEI walking Kcal/week (1447 vs 1246), PAEI overall total Kcal/week (1826 vs 1631), and percent meeting the recommended activity threshold total (37% vs 30%) (all p>.05). Mean post-enrollment follow-up was 4.2±0.6 months. The within-patient mean increase in PAEI walking was 1132 vs 582 Kcal/week (p=.03) and the mean increase in PAEI overall total was 1713 vs 1067 Kcal/week (p=.04). In multivariable analysis with change in PAEI walking as the dependent variable, intervention group (p=.02), younger age (p=.01), and female sex (p=.05) were associated, but more complex surgery was not (p=.24). Similar results were found for the PAEI overall total as the dependent variable. At the follow-up more patients in the intervention group met the ≥2000 Kcal/week threshold (63% vs 46%) (OR 2.0, CI 1.2-3.5, p=.009). CONCLUSIONS A psychosocial intervention in the spine care setting was successful in increasing physical activity after recuperation from lumbar surgery. Our study highlights the need to guide patients in regaining prudent activity that will promote subsequent spine and overall health. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Dysphagia is a common complication in the setting of ACDF surgery. There is controversy in the literature regarding the effectiveness of Local Intraoperative Corticosteroids (LIC) in reducing postoperative dysphagia. This study aims to evaluate the effectiveness of LIC in decreasing the severity of swallowing difficulty following ACDF. PURPOSE To determine if the application of local intraoperative corticosteroids (LIC) during multilevels ACDF surgery impacts early postoperative dysphagia severity STUDY DESIGN/SETTING Double blinded randomized clinical trial early postoperative results. PATIENT SAMPLE A total of 106 adult patients undergoing primary multilevel ACDF (2-4 levels) at a single institution. OUTCOME MEASURES SWAL-QOL, Eat-10 (standard and modified). METHODS Patients who sustained a multilevel ACDF were enrolled and randomized in a double blinded fashion. Arm S (steroid) received 1ml (40mg) of methylprednisolone delivered with an absorbable hemostatic matrix (vehicle) to the retro-esophageal space prior to closure. The control arm (C) only received the vehicle prior to closure. Dysphagia specific instruments (EAT-10 and the SWAL-QOL) were collected preoperatively, and at day 1 (POD1), day 2 (POD2), and 1 month (M1) postoperatively. Potential randomization biases were assessed by comparing the preoperative characteristics and surgical treatment of the 2 arms. A Friedman test was used to investigate change over time in patient-reported outcomes (PRO); a Mann-Whitney U test was performed to compare the median PRO scores (S vs C) at each time points. RESULTS Out of the 106 enrolled patients, 95 (90%) had complete dataset and were included in the analysis. The overall mean age was 57.6 year-old, for a BMI of 29.4kg/m2, and 48.4% of female patients. The most common diagnoses were cervical spondylosis (63.2%), radiculopathy (48.4%), myeloradiculopathy (30.5%) and myelopathy (24.2%). The comparison of the C arm (n=47) and S arm (n=48) revealed no significant difference in demographics, diagnosis, or surgical information in terms of number of levels fused (1.5±0.6 vs 1.4±0.6, p = 0.521), Op time (150min±37 vs 136min±33 p = 0.065), or EBL (100cc±43 vs 91cc±52 p = 0.358). Preoperatively, there was also no significant difference in PRO, with the exception of the Eat-Desire domain (p=0.049, but similar median, 25th and 75th percentile). Overall and for each randomized arm, significant change in dysphagia scores were observed from pre- to postop. The comparison of postoperative PRO across the study arms revealed that the S arm had significantly better dysphagia scores than the control arm. At POD1, the S arm had better SWALL-QOL in ood selection (p=0.049, 87.5 [50-100] vs 75 [37.5-100]), and Fear (p=0.027, 100 [89-100] vs 93.7 [75-100]); at POD2 the S arm had better dysphagia scores in Burden (p=0.02), Eat Duration (p=0.008), Fear (p = 0.017), Fatigue (p=0.047), and modified Eat-10 (p=0.013). Finally, better dysphagia scores were maintained at M1 in terms of Eat Desire (p = 0.015), East duration (p=0.046), Fear Swallow (p=0.016), and Fatigue (p=0.003) CONCLUSIONS Both arms demonstrated similar preoperative characteristics and underwent similar surgical procedure. Our study demonstrated the benefit of LIC with this delivery method to prophylactically reduce dysphagia following ACDFs. Early postop results were superior for treatment group, especially postop days 2, and maintained at 1 month. FDA DEVICE/DRUG STATUS Unavailable from authors at time of publication.

Study design Observational study. Objective To demonstrate use of magnetic resonance (MR) neurography to visualize the course of the lumbar plexus at the L4-L5 disc space. Summary of background data Risk of injury to the lumbar plexus during lateral transpsoas approach for lumbar interbody fusion (LLIF) is significant. We describe a new technique for preoperative mapping using magnetic resonance neurography to directly visualize the course of the plexus relative to the L4-L5 disc space. Methods Consecutive lumbar plexus MR neurograms (n=35 patients, 70 sides) were studied. Scans were obtained on a Siemens 3-Tesla Skyra magnetic resonance imaging scanner. T1- and T2-color-coded fusion maps were generated along with 3-dimensional models of the lumbosacral plexus with attention to the L4-L5 interspace. The position of the plexus and the shape of the psoas muscle at the L4-L5 interspace were evaluated and recorded. Results Direct imaging of the lumbar plexus using MR neurography revealed a substantial variability in the position of the lumbar plexus relative to the L4-L5 disc space. The left-side plexus was identified in zone 2 (5.7%), zone 3 (54.3%), and zone 4 (40%) (P = 0.0014); on the right, zone 2 (8.6%), zone 3 (42.9%) or zone 4 (45.7%), and zone 5 (2.9%) (P = 0.01). Right-left symmetry was found in 18 of 35 subjects (51.4%) (P = 0.865). There was no association between the position of the plexus and the shape of the overlying psoas muscle identified. In patients with an elevated psoas (n = 12), the lumbar plexus was identified in zone 3 in 75% and 66% (left and right) compared with patients without psoas elevation (n = 23), 30.4% and 43.5% (left and right). Conclusion The course of the lumbosacral plexus traversing the L4-L5 disc space may be more variable than has been suggested by previous studies. Magnetic resonance neurography may provide a more reliable means of preoperatively identifying the plexus when compared with current methods. Level of evidence 3.

STUDY DESIGN Retrospective case series. OBJECTIVE To determine the clinical and radiographic outcomes of patients undergoing minimally invasive lateral lumbar interbody fusion (LLIF) with a minimum 2-year follow-up. SUMMARY OF BACKGROUND DATA Minimally invasive LLIF is performed through a lateral, retroperitoneal, transpsoas approach. This procedure is characterized by the use of a tubular retractor to minimize tissue damage and real-time neuromonitoring to ensure safe passage through the psoas muscle. To date, advantages of minimal invasive LLIF, compared with open procedures, has been limited to early postoperative outcomes and complications, with the longest mean follow-up duration of 22 months. METHODS A total of 118 patients who underwent minimally invasive LLIF with a minimum of 2 years follow-up were included in this study. Clinical outcomes were determined by using Visual Analog Score for the degree of pain (trunk or lower extremity), and Oswestry Disability Index and Short Form-12 scoring methods for patient function. Radiographic evaluations included (i) disk height; (ii) segmental coronal angulation; (iii) segmental lordotic angulation; (iv) Cobb angle; (v) cage subsidence; and (vi) fusion status. Data were statistically tested using either paired Students t test or Wilcoxon matched-pair test. Significance level was set at P

Study Design: Narrative review. Objectives: The etiology of adjacent segment degeneration (ASDeg) and adjacent segment disease (ASDz) after lumbar interbody fusion (LIF) remains controversial. The aim of this narrative review was to provide an evidence-based analysis of the peer-reviewed literature on clinical studies of ASDeg and ASDz after LIF. Methods: A review was performed utilizing Medline, Embase, and Cochrane databases. Two reviewers independently extracted relevant data from each included study. Statistical comparisons were made when appropriate. Results: Nine articles that matched the inclusion and exclusion criteria were included. All the studies were Level III and retrospective. MINORS scores ranged from 9.5 to 13. Clinical outcomes were assessed in all 9 studies, but only 6 studies used validated outcomes measures. Only 6 studies reported values for both ASDeg and ASDz. ASDeg alone was reported in 3 studies. Due to the variability in the criteria for designation as ASDz (different radiographic modalities) and ASDeg (different outcomes measures), we were unable to calculate frequency-weighted mean values or compare the various surgical techniques. Conclusions: This review highlights the various limitations of the current literature on ASDeg and ASDz after lumbar fusion, specifically the absence of a rigorous definition and classification system and an extraordinary heterogeneity in methodology. There needs to be a fundamental shift in the current ASDeg and ASDz research landscape, toward a consensus, so that the high-level clinical research that is essential for treatment of spinal pathology may become available.

Preoperative psychological symptoms predict surgical outcomes. The impact of surgical outcomes on psychological well-being, however, has not been delineated.This study aimed to compare pre- with postoperative depressive and anxiety symptoms based on success of surgery, defined as fulfilled expectations and improvement in disability and pain.A prospective 2-year longitudinal study in a tertiary care center was carried out.The sample consisted of 276 patients who underwent lumbar surgery.The Geriatric Depression Scale (GDS) and the Spielberger State-Trait Anxiety Inventory (STAI) were the outcome measures.Patients completed the following validated surveys several days before and again 2 years after surgery: the GDS with a set threshold for a positive screen for depression; the STAI with population norms used as threshold values; the Oswestry Disability Index (ODI); a numerical pain rating; and the Expectations Survey measuring amount of improvement expected. Dependent variables were pre- to postoperative within-patient change in GDS and STAI scores. Independent variables were three outcomes of surgery: proportion of expectations fulfilled, and changes in ODI scores and pain ratings. Analyses were conducted with GDS and STAI scores as continuous variables and according to threshold values, and for expectations, ODI and pain according to minimum clinically important differences (MCIDs).Mean age was 55, 56% were men, and 78% had degenerative diagnoses. For depressive symptoms, 41% screened positive preoperatively and 16% screened positive postoperatively; 72% had some improvement. In multivariable analysis adjusted for age, gender, comorbidity, diagnosis, and surgical invasiveness, depressive symptoms improved more for more expectations fulfilled (p.0001), more ODI improvement (p.0001), and more pain improvement (p=.001). For anxiety symptoms: 59% were worse than population norms preoperatively and 26% were worse postoperatively; 73% had some improvement. In adjusted multivariable analyses, anxiety symptoms improved more for more expectations fulfilled (p=.0002), more ODI improvement (p.0001), and more pain improvement (p=.03). Similar results were obtained according to threshold values and MCIDs.Substantial improvements in psychological well-being resulted after surgery among patients with favorable spine-specific outcomes.

STUDY DESIGN Multivariate analysis. OBJECTIVE The purpose of this study was to investigate risk factors for incidental durotomy (ID) in modern spine surgery techniques. SUMMARY OF BACKGROUND DATA ID, a relatively common complication of spine surgery, has been associated with postoperative complications such as durocutaneous fistulas, pseudomeningoceles, and arachnoiditis. Revision surgery may be necessary if the dural tear is not recognized and repaired during the initial procedure. METHODS ID was prospectively documented in patients who underwent spine surgery at a single institution during a 2-year period (n=4822). Patients with ID (n=182) from lumbar or thoracolumbar cases were matched 1:1 to a control cohort without ID. Demographic, diagnostic, and surgical procedure data were retrospectively collected and analyzed. RESULTS Multivariate analysis identified revision spine surgery (adjusted odds ratio [aOR]: 4.78, 95% confidence interval [CI]: 2.84-8.06, P

Background context Lateral lumbar interbody fusion (LLIF) has become an increasingly common minimally invasive procedure for selective degenerative deformity correction, reduction of low-grade spondylolisthesis, and indirect foraminal decompression. Concerns remain about the safety of the transpsoas approach to the spine due to proximity of the lumbosacral plexus. Purpose To address risk factors for iatrogenic nerve injury in a large cohort of patients undergoing LLIF. Study design Retrospective analysis of 919 LLIF procedures to identify risk factors for lumbosacral plexus injuries. Methods The medical charts of patients who underwent transpsoas interbody fusion with or without supplemental posterior fusion for degenerative spinal conditions over a 6-year period were retrospectively reviewed. Patients with prior lumbar spine surgery or follow-up of less than 6 months were excluded. Factors that may affect the neurologic outcome were investigated in a subset of patients who underwent stand-alone LLIF. Results Four hundred fifty-one patients (males/females: 179/272) met the inclusion criteria and were followed for a mean of 15 months (range, 6–53 months). Average age at the time of surgery was 63 years (range, 24–90 years). Average body mass index was 29 kg/m2 (range, 17–65 kg/m2). A total of 919 levels were treated (mean, 2 levels per patient). Immediately after surgery, 38.5% of the patients reported anterior thigh/groin pain, whereas sensory and motor deficits were recorded in 38% and 23.9% of the patients, respectively. At the last follow-up, 4.8% of the patients reported anterior thigh/groin pain, whereas sensory and motor deficits were recorded in 24.1% and 17.3% of the patients, respectively. When patients with neural deficits present before surgery were excluded, persistent surgery-related sensory and motor deficits were identified in 9.3% and 3.2% of the patients, respectively. Among 87 patients with minimum follow-up of 18 months, persistent surgery-related sensory and motor deficits were recorded in 9.6% and 2.3% of the patients, respectively. Among patients with stand-alone LLIF, the level treated was identified as a risk factor for postoperative lumbosacral plexus injury. The use of recombinant human bone morphogenetic protein 2 was associated with persistent motor deficits. Conclusions Although LLIF is associated with an increased prevalence of anterior thigh/groin pain as well as motor and sensory deficits immediately after surgery, our results support that pain and neurologic deficits decrease over time. The level treated appears to be a risk factor for lumbosacral plexus injury.

STUDY DESIGN Retrospective cohort study. OBJECTIVE To assess the association between vertebral body Hounsfield unit (HU) measurements on quantitative computed tomography and the risk for incidental durotomy (ID). SUMMARY OF BACKGROUND DATA ID during spine surgery has been associated with adverse postoperative sequelae that may require prolonged hospital stay and reoperation. Previously identified independent risk factors include age, revision surgery, and lumbar surgery. METHODS ID was prospectively documented in spine surgery patients at a single institution during a 2-year period (incidence: 4%, 191/4,822). Patients with ID were matched 1:1 to a control cohort without ID based on age and sex. Inclusion criteria for both cohorts were primary lumbar surgery and quantitative computed tomographic scans within 1 year of date of surgery. Demographic, radiographical, and intraoperative data, along with dual x-ray absorptiometry t scores, were collected and analyzed. RESULTS A total of 71 patients with ID met the inclusion criteria (38 male, 33 female). Average age of patients with ID was 63.8 ± 12.9 years (range: 34-85 yr). Computed tomographic scans were acquired 1.5 ± 2.2 months away from date of surgery (range: 0-12 mo). Inter-rater reliability for HU measurements between a fellowship-trained spine surgeon and a research fellow was strong (r = 0.901, P < 0.001). HU values were significantly lower in patients with ID than controls (149.2 ± 60.7 [range: 44.5-301.5] versus 177.0 ± 81.4, [range: 62.0-524.0], respectively; P = 0.023). The area under the receiver operating characteristic curve was 0.603 (P = 0.034). A threshold of 169 HU optimized sensitivity (0.718) and specificity (0.451), and patients with HU value 169 or less were found to be at increased risk for ID (odds ratio: 2.092, 95% confidence interval: 1.042-4.201, P = 0.037). CONCLUSION Lower HU value is an accessible clinical marker for increased risk of ID. A threshold value of HU was defined (≤169) that may be used clinically to identify patients at elevated risk for ID, which may improve the informed decision making process prior to spinal surgery. LEVEL OF EVIDENCE 3.

BACKGROUND CONTEXT Lumbar spine fusions are rated amongst the most painful surgical procedures. Adequately controlling post-operative pain while minimizing opioid use is an important public health objective PURPOSE The purpose of this study was to examine the effect of intravenous ketorolac (IV-K) on hospital opioid use compared to IV placebo (IV-P) and IV Acetaminophen (IV-A). STUDY DESIGN/SETTING Prospective, randomized, double-blind trial. PATIENT SAMPLE Patients aged 18-75 undergoing 1-2 level posterior lumbar fusion without history of long-term opioid use. Smokers and those with contraindications to IV-A or IV-K were excluded OUTCOME MEASURES The primary outcome was in-hospital opioid use up to post-operative day 3 (POD3). The secondary outcomes were opioid related adverse events (ORAE) and length of stay (LOS). METHODS Patients (Pts) were randomized to receive IV-K, IV-P or IV-A. IV-K pts received 15mg (age > 65) or 30mg (age RESULTS A total of 115 patients met the inclusion criteria (39 IV-K, 39 IV-A, 37 IV-P). There was no difference between patients with regards to demographic or surgical variables. The IV-K group had substantially lower opioid use at 72h (181±156mg) compared to IV-A (268± 176mg) and IV-P (315±183mg) (p=0.003). IV-K was superior to IV-A (p=0.030) and IV-P (0.001). IV-A was not superior to IV-P (p=0.234). Similar trends were observed for opioid use per hour (IV-K: 3.0±2.4mg/hr; IV-A: 4.1±2.3mg/hr; IV-P: 4.7±2.5mg/hr, p=0.009). IV-K pts reported improved pain control on POD1 (p=0.050). IV-K pts trended toward shorter LOS (IV-K: 75±44hr; IV-A: 93±60hr; IV-P:88±35hr, p=0.231). There were no differences in ORAE, drain output, hematocrit levels, serum creatinine and transfusion rates. CONCLUSIONS IV-K results in a substantial reduction in opioid use (>40% vs IV-P, >30% vs IV-A) and improved pain control on POD1. There is a trend toward decreased LOS; there appears to be no increase in in-hospital complications. Longer term follow-up is planned to assess the impact of IV-K on pseudarthrosis. FDA DEVICE/DRUG STATUS Unavailable from authors at time of publication.

BACKGROUND CONTEXT Major goals of lumbar surgery are pain relief and safe and timely restoration of functional status with return to desired roles and responsibilities. In addition to increasing mobility, prudent physical activities, such as walking more in the near-term postop period, may facilitate return to functional status in diverse domains of daily life. PURPOSE To determine if increased physical activity after recuperation from lumbar surgery is associated with improvement in a composite measure of overall functional status STUDY DESIGN/SETTING Secondary analysis, longitudinal cohort, tertiary spine center. PATIENT SAMPLE Pooled sample of 220 patients enrolled during routine 3-month postop visits into a trial to increase physical activity; subsequently followed for an additional 4-6 months. OUTCOME MEASURES RAND-12 composite score, encompassing subscales for daily activities, work and social roles, pain, and mental health. METHODS At enrollment patients completed the RAND-12 (composite score=50 for the general population) and the 3-domain Paffenbarger Physical Activity and Exercise Index (PAEI) measuring number of blocks walked, stairs climbed daily and sports during the past week. Kcal/week were calculated for an overall total. Patients also rated global change in pain since surgery on a 7-point scale. Patients were then assigned into groups receiving different amounts of information about safely increasing physical activity, primarily walking, and follow-ups were conducted at varying time intervals. After 4-6 months, patients again completed the RAND-12 and PAEI. Operative records were reviewed and a surgical invasiveness index value was calculated (maximum 10 points/vertebral level); higher is greater complexity. In multivariable analysis the dependent variable was change in RAND-12 scores, the main independent variable was change in overall PAEI Kcal/week, and analyses were controlled for covariates. RESULTS Group assignments did not affect RAND-12 scores, thus all patients were pooled for this analysis. The mean age was 64, 52% were men, 40% had major comorbidity. The mean time from surgery to enrollment was 2.9±0.4 months, and since surgery, 64% reported a lot of improvement in pain: 25% moderate-little, 11% same-worse. The mean time from enrollment to follow-up was 4.2±0.6 months; at the follow-up, patients reported improvement for both the RAND-12 and PAEI, with enrollment, follow-up and within-patient change mean scores for the RAND-12 of 37±10, 43±10, and 6±10 (paired ttest p CONCLUSIONS Improvement in physical activity, primarily walking more, was associated with improvement in diverse subscales of functional status. Our study showed that in addition to preserving mobility, increased physical activity in the near-term postop period is a gateway behavior with beneficial downstream effects on diverse domains of physical and mental health. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Patients and surgeons may not have the same preop expectations of lumbar surgery. Whose expectations more closely coincide with patient-reported fulfillment of expectations has implications for preoperative surgeon-patient communication. PURPOSE To determine if patient-reported fulfilment of expectations measured postop more closely matched patients’ or surgeons’ expectations measured preop. STUDY DESIGN/SETTING Prospective 2-year longitudinal study, tertiary spine center. PATIENT SAMPLE A total of 402 lumbar surgery patient-surgeon pairs. OUTCOME MEASURES HSS Lumbar Spine Surgery Expectations Survey METHODS Patients of 5 spine surgeons were interviewed preop with the valid 20-item Expectations Survey addressing symptoms, physical function and psychological well-being. The survey asks how much improvement is expected for each item with response options of complete to no improvement and a total score is generated (range 0-100). Surgeons completed an identical survey asking them to rate expected improvement for each patient for each item, yielding a similar 0-100 score. Two years postoperatively, patients completed the survey again asking how much improvement they actually received for each item with options ranging from complete to no improvement. A “patient proportion” reflecting expectations fulfilled was calculated as the improvement received (numerator) divided by the improvement expected (denominator); range 0 (no improvement) to 1 (improved as expected) to >1 (improved more than expected). A similar “surgeon proportion” was calculated using patient-reported improvement received (numerator) divided by surgeons’ improvement expected (denominator). Patients’ and surgeons’ proportions were compared and then assessed in multivariable analysis. RESULTS Mean age was 55, 55% were men, 21% were self-described as non-white race/ethnicity and 79% had degenerative spine conditions. Surveys were independently completed within 10 days preoperative. Patients completed the postop survey after 2.1 years; during this period 11% had a spine-related rehospitalization. The mean proportion of expectations fulfilled was .79±.34 for patients and 1.01±.43 for surgeons (p CONCLUSIONS Compared to patients’ preoperative expectations, surgeons’ preoperative expectations more often corresponded to patient-reported fulfillment of expectations two years after lumbar surgery. These findings have potential implications for clinical practice including ensuring surgeons impart and patients acknowledge realistic expectations, and whether surgeons’ predictions of patient-reported outcome is a potential metric for quality of care. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Lumbar spine fusions are rated among the most painful surgical procedures. Adequately controlling postoperative pain while minimizing opioid use is an important public health objective. SUMMARY Early results of this double-blind, randomized, placebo-controlled trial show that intravenous ketorolac (IV-K) results in a substantial reduction in opioid use and improved pain control compared to placebo (IV-P) and IV acetaminophen (IV-A). IV-K did not increase rates of hematoma, drain output, transfusions or serum creatinine. There was a trend toward decreased length of stay (LOS) with IV-K. HYPOTHESIS IV-K would decrease in hospital opioid use compared to IV Placebo (IV-P) and Intravenous Acetaminophen (IV-A). DESIGN Randomized, double-blind trial. METHODS Patients (Pts) were randomized to receive IV-K, IV-P or IV-A. The inclusion criteria were: age 18-75, 1-2 level lumbar fusion and no history of long-term opioid use. Smokers and pts with contraindications to IV-A or IV-K were excluded. IV-K pts received 15mg (age >65) or 30mg (age RESULTS A total of 115 pts met inclusion criteria (39 IV-K, 39 IV-A, 37 IV-P). There was no difference between pts with regard to demographic or surgical variables. IV-K group had substantially lower opioid use at 72h (181±156mg) compared to IV-A (268±176mg) and IV-P (315±183mg) (p=0.003). IV-K was superior to IV-A (p=0.030) and IV-P (0.001). IV-A was not superior to IV-P (p=0.234). Similar trends were observed for opioid use per-hour (IV-K: 3.0±2.4mg/h; IV-A: 4.1±2.3mg/h; IV-P: 4.7±2.5mg/h, p=0.009). IV-K pts reported improved pain control on POD1 (p=0.050). IV-K pts trended toward shorter LOS (IV-K: 75±44h; IV-A: 93±60h; IV-P:88±35h, p=0.231). There were no differences in ORAE, drain output, hematocrit levels, serum creatinine and transfusion rates. CONCLUSION IV-K results in a substantial reduction in opioid use (>40% vs IV-P, >30% vs IV-A) and improved pain control on POD1. There is a trend toward decreased LOS; there appears to be no increase in in-hospital complications. Longer term follow-up will assess impact of IV-K on pseudarthrosis. IV-K reduces opioid use after spinal fusion by >40% compared to placebo and >30% compared to IV acetaminophen. There is a trend toward decreased LOS with IV-K. FDA DEVICE/DRUG STATUS Intravenous ketorolac and intravenous acetaminophen are FDA app

BACKGROUND CONTEXT A worldwide survey conducted in 2013 reported that 78% of surgeons utilize 2D fluoroscopy during spine surgery. By comparison, and despite improved accuracy, computer-assisted spine navigation systems have lagged behind, largely due to increased costs, prolonged operative times and cumbersome surgical equipment. However, in recent years, computer-assisted spine navigation systems have grown in popularity as a result of decreasing costs and advancements in their user friendliness, thus improving integration into the surgical workflow. In an effort to address the growing concerns of current computer-assisted spine navigation systems, an emergent technology has been developed that does not require intraoperative ionizing radiation exposure. In addition to sparing the patient and surgeon to radiation exposure, this new spine navigation system, named the Machine-vision Image Guided Surgery (MvIGS) (7D Surgical, Toronto, Canada) system, is also projected to seamlessly integrate and therefore not contribute to prolonged operative times. By use of proprietary technology, localizing reference images are generated in a matter of seconds, as opposed to minutes, thus mitigating the disturbance to normal surgeon-defined workflow while maintaining accuracy. PURPOSE The purpose of this study is to prospectively compare clinical outcomes between the MvIGS spine navigation system to conventional 2D fluoroscopy in patients requiring posterior instrumentation in spine surgery. STUDY DESIGN/SETTING Prospective, single-center consecutive series. PATIENT SAMPLE Patients undergoing single- and multilevel posterior spine fusion surgery with pedicle screw instrumentation. OUTCOME MEASURES Our primary outcome measure is operative time. Secondary outcomes include demographic characteristics, intraoperative parameters and radiographic measurements including total exposure time (TET) and cumulative radiation dose (mGy). METHODS Radiographic and intraoperative data were collected from the first 26 patients enrolled in a large single-center, randomized prospective study comparatively evaluating 2D fluoroscopy to 3D MvIGS spine navigation in single and multilevel posterior spine fusion surgery. Intraoperative parameters assessed include mean operative time, estimated blood loss (EBL), total exposure time (TET) as measured in time (secs), and cumulative radiation dose (mGy) emitted by 2D fluoroscopy. Incidence of intraoperative complications, including dural tears or perioperative new/worsening neurological deficits, as well as mean length of hospital stay (LOS), were also collected. In patients undergoing circumferential spine surgery, only data pertaining to posterior instrumentation were collected. RESULTS Over 100 screws were implanted into 26 patients, 12 male and 14 female, with a mean age and BMI of 60.4 years and 29.8, respectively. Mean operative time between 3D and 2D imaging was 236 and 251 minutes, respectively. No significant difference in total exposure time (seconds) and cumulative radiation dose (mGy) were recorded with 3D navigation exhibiting an average of 27.4 and 14.3 respectively, compared to 2D's 28.8 and 16.1, respectively (p=1.0). Fifty-six percent (56%) of cases were multilevel fusion procedures, with nearly 90% involving the L4-5 vertebral segment. Mean intraoperative EBL and length of hospital stay were 390 mL and 3.5 days, respectively, with no significant difference between treatment groups. No new neurological deficits or complications were recorded. CONCLUSIONS Use of navigation systems in spine surgery is often cumbersome and time consuming, frequently disrupting surgeon workflow and prolonging operative times. Results from our cohort analysis demonstrate no significant difference in operative times between groups, indicating minimal workflow disruption. We believe two predominant theories as to why the MvIGS spine navigation system has resulted in minimal workflow disturbance. The integration of the navigation camera into the surgical light eliminates the need to stop surgery, drape and position supplemental surgical equipment, thereby allowing for continuous access to the surgical field. Secondly, and unique to the MvIGS system, the reference clamp can be repositioned and re-registration images completed within 20 seconds. This combination allows for seamless clinical applicability and reverses many of the well-documented drawbacks of preceding navigation systems. We believe we are the first to report on the clinical application of this radiation-free MvIGS technology in spine surgery. FDA DEVICE/DRUG STATUS Machine-Vision Image Guided Surgery (MvIGS) (Approved for this indication).

Background context Traumatic fractures of the spine are most common at the thoracolumbar junction and can be a source of great disability. Purpose To review the most current information regarding the pathophysiology, injury pattern, treatment options, and outcomes. Study design Literature review. Methods Relevant articles, textbook chapters, and abstracts covering thoracolumbar spine fractures with and without neurologic deficit from 1960 to the present were reviewed. Results The thoracolumbar spine represents a unique system from a skeletal as well as neurological standpoint. The rigid rib-bearing thoracic spine articulates with the more mobile lumbar spine at the thoracolumbar junction (T10 - L2), the site of most fractures. A complete examination includes a careful neurologic examination of both motor and sensory systems. CT scans best describe bony detail while MRI is most efficient at describing soft tissues and neurological structures. The most recent classification system is that of the new Thoracolumbar Injury Classification and Severity Score. The different fracture types include compression fractures, burst fractures - both stable and unstable -, flexion-distraction injuries and fracture dislocations. Their treatment, both operative and non-operative depends on the degree of bony compromise, neurological involvement, and the integrity of the posterior ligamentous complex. Minimally invasive approaches to the care of thoracolumbar injuries have become more popular, thus, the evidence regarding their efficacy is presented. Finally, the treatment of osteoporotic fractures of the thoracolumbar spine is reviewed, including vertebroplasty and kyphoplasty, their risks and controversies, and senile burst fractures, as well. Conclusions Thoracolumbar spine fractures remain a significant source of potential morbidity. Advances in treatment have minimized the invasiveness of our surgery and in certain stable situations, eliminated it all together.

Study design Retrospective case series. Objective To report on the rare finding of motor deficits contralateral to the transpsoas approach in patients who underwent lateral lumbar interbody fusion (LLIF). Summary of background data Although sensorimotor deficits occurring ipsilaterally to a transpsoas approach have more fully been elucidated, there seems to be a paucity of data on motor deficits contralateral to an LLIF approach. Methods The electronic medical records and radiographical studies of 244 patients who underwent LLIF at a single institution between 2006 and 2009 were retrospectively reviewed for reports on motor deficits contralateral to the surgical approach. Results Of the patients reviewed, 2.9% (7/244) presented with a postoperative contralateral motor deficit, the most severe of which was a 1/5 weakness of the quadriceps muscle. An average of 3 levels (range: 2-4) was fused in 7 patients who developed a contralateral motor deficit, and in 3 of the 7 patients, an anterior lumbar interbody fusion (ALIF) was performed in addition to the LLIF. At 1 year follow-up, 3 patients presented with complete resolution of their muscle weakness, 1 patient still had mild weakness, 1 patient had decreased range of motion in the affected joint, and 1 patient had a 2/5 foot drop. One patient was lost to follow-up. Conclusion These data are among the largest reports of contralateral motor deficits after LLIF. Among possible underlying mechanisms are entrapment of the contralateral nerve root through translational correction of spondylolisthesis, front-to-back misalignment of the cage resulting in contralateral nerve root impingement, pressure on the contralateral peroneal nerve during positioning, and overdistraction neurapraxia when using ALIF at L5-S1 concomitantly. Awareness of the possibility of this rare complication can play an important role in surgical consideration and preoperative patient counseling. Level of evidence 4.

Study design A retrospective cohort study. Objective To present the technique, radiographic, and clinical outcomes of a series of patients who underwent a novel method for revision L5-S1 interbody fusion. Summary of background data Pseudoarthrosis at L5-S1 is a relatively common problem after long fusion to the sacrum. Revision approach to L5-S1 for cage or graft removal by anterior lumbar interbody fusion, posterior lumbar interbody fusion, or transforaminal interbody fusion is challenging and potentially dangerous which makes salvage by a posterior reamed transacral technique appealing. Methods Consecutive patients with symptomatic pseudoarthrosis at L5-S1, who underwent posterior reamed fluoroscopically guided fusion were identified over a 3-year period. Operative notes, medical records, preoperative and postoperative plain radiographs, computed tomography scans, Visual Analog Scores (VAS) (lower extremity and low back) preoperatively, and at most recent follow-up were studied. Results Ten patients (age, 53±2.8 y) with prior lumbar spinal operations (mean, 3.5±0.6) met the inclusion criteria. Prior procedures at L5-S1 were anterior lumbar interbody fusion (n=4), posterior lumbar interbody fusion (n=3), and posterolateral fusion (n=3). Mean Meyerding grade was 1.41 (range, 0-4). Reaming was performed between the S1 and S2 (n=9) or S2 and S3 (n=1) nerve roots and allowed fragmentation/removal of polyetheretherketone interbody grafts (n=3) or femoral ring allografts (n=3). Transacral Harms cage (n=8) or autograft (n=1) was passed through the reamed channel or a carbon fiber-reinforced polyetheretherketone directly into the interspace (n=1). VAS scores lower extremity (P=0.003) and low back (P=0.001) were improved at a mean follow-up of 13.5±3.6 months. No neurologic sequelae occurred and solid fusion was achieved in 9/10 (90%). Conclusions We report a series of patients who underwent a novel revision technique for symptomatic lumbosacral pseudoarthrosis. Despite the small numbers in this cohort, a salvage technique is presented that permitted fusion as confirmed by computed tomography scan and improved VAS scores in the majority of patients. The data suggest that this technique should be considered as an alternative to the revision anterior or posterior approaches to L5-S1 and merits further investigation.

Pathologies of the atlantoaxial motion segment may result in sequelae ranging from severe pain to life-threatening neurologic injury. Instrumentation and fusion of the atlantoaxial segment may be indicated when clinical or biomechanical instability exists. An evolution of posterior techniques has provided multiple options for instrumentation through a routine midline posterior approach. Anterior transoral ventral plating techniques raise concerns of transoral contamination and associated infection. Anterior lag-screw fixation and grafting for C1–C2 fusion of the anterior atlantoaxial articulation through the more commonly performed Smith–Robinson approach provides an alternative method. Early experience with an anterior surgical technique for C1–C2 fusion and key considerations are presented here.

Background context The lateral transpsoas approach to interbody fusion of the lumbar spine (lateral lumbar interbody fusion [LLIF]) with recombinant human bone morphogenetic protein-2 (BMP-2) augmentation has been increasingly performed in recent years. Potential side effects and adverse sequelae of BMP-2 in the acute setting remain to be fully elucidated. Purpose To review the literature for reports of complications related to BMP-2 implantation in lumbar spinal surgery and present a case of a contralateral psoas muscle seroma after LLIF with BMP-2 implantation. Study design Case report and literature review. Methods The PubMed database was searched for articles related to adverse events to BMP-2 in lumbar spinal surgery. We report the case of a 57-year-old woman who underwent routine right-sided transpsoas approach for LLIF with the use of BMP-2 at our institution and developed a left-sided psoas muscle fluid accumulation 2 weeks postoperatively. Results No reports of complications contralateral to an LLIF approach attributable to an inflammatory response to BMP-2 were identified in the English literature. In the presented patient, a large (4.2×6.5×2.7 cm) left-sided sterile intramuscular psoas fluid collection was seen on a magnetic resonance imaging study obtained on postoperative day 14. At a 6-month follow-up, left-sided L5 radiculopathy resulting in 4/5 foot drop was confirmed by electromyography. The patient reported here represents the only case of a contralateral psoas seroma with suspected association to BMP-2 utilization in LLIF encountered at our institution. Conclusions A serous psoas muscle fluid accumulation after BMP-2 implantation may rarely occur contralateral to the surgical approach for LLIF. Further characterization of complications related to BMP-2 implantation after lumbar spinal surgery will help guide preoperative informed decision making and the management of this unusual postoperative adverse event.

The sequelae of atlantoaxial instability (AAI) range from axial neck pain to life-threatening neurologic injury. Instrumentation and fusion of the C1-2 joint is often indicated in the setting of clinical or biomechanical instability. This is the first clinical report of anterior Smith-Robinson C1-2 transarticular screw (TAS) fixation for AAI. The first patient presented with ischemic brain tissue secondary to post-traumatic C1-2 segment instability from a MVC 7 years prior to presentation. The second patient presented with a 3 year history of persistent right-sided neck and upper scalp pain. Both were treated with transarticular C1-2 fusion through decortication of the atlantoaxial facet joints and TAS fixation via the anterior Smith-Robinson approach. At 16 months follow-up, the first patient maintained painless range of motion of the cervical spine and denied sensorimotor deficits. The second patient reported 90% improvement in her pre-operative symptoms of neck pain and paresthesia. Anterior Smith-Robinson C1-2 TAS fixation provides a useful alternative to the posterior Goel and Magerl techniques for C1-2 stabilization and fusion.

STUDY DESIGN Prospective retrieval analysis of Prodisc-C cervical total disc replacements (CTDRs) from 24 explanting surgeons during a 6-year period. OBJECTIVE To determine the in vivo mechanical performance and fixation to bone of explanted Prodisc-C CTDRs. SUMMARY OF BACKGROUND DATA The nature and quantity of damage sustained by an implanted device has proven to be important in the prediction of clinical longevity. We hypothesized that retrieval analysis of the Prodisc-C will display characteristic modes of wear consistent with increased posterior angulation and translation of the functional spinal unit after resection of the discoligamentous anatomy. METHODS Thirty CTDRs from 29 patients (mean age, 45.1 ± 1.9; range, 31-57 yr) after a mean length of implantation of 1.0 ± 0.2 years (range, 2 d-3.5 yr) were studied. Operative level was C4-C5 in 20% (6 of 30), C5-C6 in 47% (14 of 30), C6-C7 in 20% (6 of 30), and unknown in 13% (4 of 30). Polyethylene and metallic (cobalt chrome molybdenum [CoCrMo]) components were examined using light stereo-microscopy (6X-31X), scanning electron microscopy, and energy dispersive x-ray analysis. RESULTS CTDRs were explanted for indications of axial pain (n = 9), radicular symptoms (n = 6), atraumatic loosening (n = 6), trauma (n = 5), metal allergy (n = 1), myelopathy (n = 1), hypermobility (n = 1), and unknown (n = 1). Surface area of ongrowth (mean = 7.2 ± 1.4%) was not associated with operative level (P = 0.37), surgeon-reported axial pain (P = 0.56), or atraumatic loosening (P = 0.93). Burnishing consistent with metallic endplate impingement was present in 80% (24 of 30) of retrieved CTDRs, most commonly in the posterior quadrant (P < 0.001). There was no association between implant height (P = 0.19) or depth (P = 0.17) and posterior impingement. Backside wear was not observed on any of the disassembled implants (0 of 16). Third-body wear occurred in 23% (7 of 30) and the donor site was confirmed by scanning electron microscope/energy dispersive x-ray analysis to be the porous-coated surface of the CTDR. CONCLUSION Early clinical failures of Prodisc-C CTDRs display surface damage evidence of metal endplate-endplate impingement, most commonly posteriorly. Backside wear was not evident; however, third-body wear was found. Future studies will determine the clinical impact of these predominant modes of wear on long-term metal-on-polyethylene semiconstrained CTDR performance.

STUDY DESIGN A retrieval analysis of wear modes and fixation of lumbar total disc replacements (TDRs). Explanted Prodisc-L TDRs were prospectively collected during a 7-year period (2005-2011) and analyzed. OBJECTIVE To assess the in vivo modes of wear and fixation of lumbar TDR with the Prodisc-L device. SUMMARY OF BACKGROUND DATA Inferior clinical outcomes and failure of lumbar TDR may occur because of suboptimal component fixation, wear properties, and impingement in a subset of patients. Posterior component TDR impingement has been demonstrated radiographically; however, despite its widespread use, the in vivo mechanical performance and fixation of the Prodisc-L device remain unknown. METHODS Explanted polyethylene and metallic (CoCrMo) components of Prodisc-L devices were examined by light stereo-microscopy (6X-31X), scanning electron microscopy, and energy-dispersive x-ray analysis from an international retrieval registry, with 13 participating surgeons. RESULTS Nineteen ProDisc-L devices from 18 patients (age, 44.7 ± 2.9 yr) following an index TDR at L4-L5 (n = 6), L5-S1 (n = 11), and unknown level (n = 2) were explanted for pain (n = 8), prosthesis subluxation/migration (n = 4), end plate collapse/subsidence (n = 3), polyethylene dislodgement (n = 3), and unknown (n = 2) after a mean length of implantation of 13.0 ± 3.9 months. Surface area of bony ongrowth was 9.6 ± 2.9% (range, 0%-52.5%). TDR burnishing was observed posteriorly consistent with component impingement in extension in 53% (8/15) (P < 0.02), more commonly than anterior 20% (3/15) lateral 20% (n = 3) (3/15) patterns. Circumferential burnishing was not observed. Posterior impingement was associated with 6° lordotic implants (P < 0.05) and 10-mm polyethylene size (P < 0.05). Backside wear occurred in 75% (9 of 12) of the disassembled implants and third-body wear was observed in 33% (5 of 15). CONCLUSION Metallic end plate burnishing was evident in a large percentage of clinically failed Prodisc-L TDR devices, most commonly posteriorly, consistent with impingement in extension. Long-term follow-up studies will evaluate the effects of the observed backside wear, third-body wear, and end plate impingement on clinical outcomes.

Age-related changes in the spinal column result in a degenerative cascade known as spondylosis. Genetic, environmental, and occupational influences may play a role. These spondylotic changes may result in direct compressive and ischemic dysfunction of the spinal cord known as cervical spondylotic myelopathy (CSM). Both static and dynamic factors contribute to the pathogenesis. CSM may present as subclinical stenosis or may follow a more pernicious and progressive course. Most reports of the natural history of CSM involve periods of quiescent disease with intermittent episodes of neurologic decline. If conservative treatment is chosen for mild CSM, close clinical and radiographic follow-up should be undertaken in addition to precautions for trauma-related neurologic sequelae. Operative treatment remains the standard of care for moderate to severe CSM and is most effective in preventing the progression of disease. Anterior surgery is often beneficial in patients with stenotic disease limited to a few segments or in cases in which correction of a kyphotic deformity is desired. Posterior procedures allow decompression of multiple segments simultaneously provided that adequate posterior drift of the cord is attainable from areas of anterior compression. Distinct risks exist with both anterior and posterior surgery and should be considered in clinical decision-making.