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AimsThe aim of this study was to assess the accuracy of pedicle screw placement, as well as intraoperative factors, radiation exposure, and complication rates in adult patients with degenerative disorders of the thoracic and lumbar spines who have undergone robotic-navigated spinal surgery using a contemporary system.MethodsThe authors reviewed the prospectively collected data on 196 adult patients who had pedicle screws implanted with robot-navigated assistance (RNA) using the Mazor X Stealth system between June 2019 and March 2022. Pedicle screws were implanted by one experienced spinal surgeon after completion of a learning period. The accuracy of pedicle screw placement was determined using intraoperative 3D fluoroscopy.ResultsA total of 1,123 pedicle screws were implanted: 1,001 screws (89%) were placed robotically, 63 (6%) were converted from robotic placement to a freehand technique, and 59 (5%) were planned to be implanted freehand. Of the robotically placed screws, 942 screws (94%) were determined to be Gertzbein and Robbins grade A with median deviation of 0.8 mm (interquartile range 0.4 to 1.6). Skive events were noted with 20 pedicle screws (1.8%). No adverse clinical sequelae were noted in the 90-day follow-up. The mean fluoroscopic exposure per screw was 4.9 seconds (SD 3.8).ConclusionRNA is highly accurate and reliable, with a low rate of abandonment once mastered. No adverse clinical sequelae occurred after implanting a large series of pedicle screws using the latest generation of RNA. Understanding of patient-specific anatomical features and the real-time intraoperative identification of risk factors for suboptimal screw placement have the potential to improve accuracy further.Cite this article: Bone Joint J 2023;105-B(5):543–550.

Background: Assessing the impact of spine disorders such as lumbar degenerative spondylolisthesis (LDS) on overall health is a component of quality of care that may not be comprehensively captured by spine-specific and single-attribute patient-reported outcome measures (PROMs). Purpose: We sought to compare PROMs to the Lumbar Surgery Expectations Survey (“Expectations Survey”), which addresses multiple aspects of health and well-being, and to compare the relevance of surgeon-selected versus survey-selected Patient-Reported Outcomes Measurement Information System (PROMIS) items to LDS. Methods: In a cross-sectional study, 379 patients with LDS preoperatively completed the Expectations Survey, Numerical Rating Pain Scales, Oswestry Disability Index (ODI), and PROMIS computer-adaptive physical function, pain, and mental health surveys. Expectations Survey scores were compared to PROMs with correlation coefficients (indicating strengths of relationships) and probability values (indicating associations by chance). Surgeons reviewed physical function questions to identify those particularly relevant to LDS. Results: Patients’ mean age was 67 years, 64% were women, and 83% had single-level and 17% had multiple-level LDS. Probability values between the Expectations Survey and PROMs were reliable, but strengths of relationships were only mild to moderate, indicating PROMs did not comprehensively capture the impact of LDS. None of the surgeon-selected PROMIS physical function questions were posed to patients. Conclusion: This cross-sectional study found PROMs to be reliably associated but not strongly correlated with the Expectations Survey, which addresses the whole-patient impact of LDS. New measures that complement PROMIS and ODI should be developed to capture the whole-person effects of LDS and permit attribution of LDS treatments to overall health.

Background: Quantitative computed tomography (qCT) efficiently measures 3-dimensional vertebral bone mineral density (BMD), but its utility in measuring BMD at various vertebral levels in patients with lumbar degenerative spondylolisthesis (LDS) is unclear. Purpose: We sought to determine whether qCT could differentiate BMD at different levels of LDS, particularly at L4-L5, the most common single level for LDS. In addition, we sought to describe patterns of BMD for single-level and multiple-level LDS. Methods: We conducted a study of patients undergoing surgery for LDS who were part of a larger longitudinal study comparing preoperative and intraoperative images. Preoperative patients were grouped as single-level or multiple-level LDS, and qCT BMD was obtained for L1-S1 vertebrae. Mean BMD was compared with literature reports; in multivariable analyses, BMD of each vertebra was assessed according to the level of LDS, controlling for covariates and for BMD of other vertebrae. Results: Of 250 patients (mean age: 67 years, 64% women), 22 had LDS at L3-L4 only, 170 at L4-L5 only, 13 at L5-S1 only, and 45 at multiple levels. Compared with other disorders reported in the literature, BMD in our sample similarly decreased from L1 to L3 then increased from L4 to S1, but mean BMD per vertebra in our sample was lower. Nearly half of our sample met criteria for osteopenia. In multivariable analysis controlling for BMD at other vertebrae, lower L4 BMD was associated with LDS at L4-L5, greater pelvic incidence minus lumbar lordosis, and not having diabetes. In contrast, in similar multivariable analysis, greater L4 BMD was associated with LDS at L3-L4. Bone mineral density of L3 and L5 was not associated with LDS levels. Conclusion: In our sample of preoperative patients with LDS, we observed lower BMD for LDS than for other lumbar disorders. L4 BMD varied according to the level of LDS after controlling for covariates and BMD of other vertebrae. Given that BMD can be obtained from routine imaging, our findings suggest that qCT data may be useful in the comprehensive assessment of and strategy for LDS surgery. More research is needed to elucidate the cause-effect relationships among spinopelvic alignment, LDS, and BMD.

ContextMany individuals at high risk for fracture are never evaluated for osteoporosis and subsequently do not receive necessary treatment. Utilization of magnetic resonance imaging (MRI) is burgeoning, providing an ideal opportunity to use MRI to identify individuals with skeletal deficits. We previously reported that MRI-based bone texture was more heterogeneous in postmenopausal women with a history of fracture compared to controls.ObjectiveThe present study aimed to identify the microstructural characteristics that underlie trabecular texture features.MethodsIn a prospective cohort, we measured spine volumetric bone mineral density (vBMD) by quantitative computed tomography (QCT), peripheral vBMD and microarchitecture by high-resolution peripheral QCT (HRpQCT), and areal BMD (aBMD) by dual-energy x-ray absorptiometry. Vertebral trabecular bone texture was analyzed using T1-weighted MRIs. A gray level co-occurrence matrix was used to characterize the distribution and spatial organization of voxelar intensities and derive the following texture features: contrast (variability), entropy (disorder), angular second moment (ASM; uniformity), and inverse difference moment (IDM; local homogeneity).ResultsAmong 46 patients (mean age 64, 54% women), lower peripheral vBMD and worse trabecular microarchitecture by HRpQCT were associated with greater texture heterogeneity by MRI—higher contrast and entropy (r ∼ −0.3 to 0.4, P < .05), lower ASM and IDM (r ∼ +0.3 to 0.4, P < .05). Lower spine vBMD by QCT was associated with higher contrast and entropy (r ∼ −0.5, P < .001), lower ASM and IDM (r ∼ +0.5, P < .001). Relationships with aBMD were less pronounced.ConclusionMRI-based measurements of trabecular bone texture relate to vBMD and microarchitecture, suggesting that this method reflects underlying microstructural properties of trabecular bone. Further investigation is required to validate this methodology, which could greatly improve identification of patients with skeletal fragility.

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.

Retrospective cohort analysis.To elucidate trends in the utilization of intraoperative neuromonitoring (IONM) during elective anterior cervical decompression and fusion (ACDF) procedures in New York State using the Statewide Planning and Research Cooperative System (SPARCS) and to determine if utilization of IONM resulted in a reduction in postoperative neurologic deficits.IONM has been available to spinal surgeons for several decades. It has become increasingly prevalent in all facets of spinal surgery including elective ACDF procedures. The utility of IONM for preventing neurologic deficit in elective spine procedures has recently been called into question.The SPARCS database was accessed to perform a retrospective cohort study comparing monitored versus unmonitored ACDF procedures between 2007 to 2018 as defined by International Classification of Disease-9 and 10 Procedural Coding System (ICD-9 PCS, ICD-10 PCS) codes. Patient demographics, medical history, surgical intervention, pertinent in-hospital events, and urban versus rural medical center (as defined by the US Office of Management and Budget) were recorded. Propensity-score-matched (PSM) comparisons were used to identify factors related to the utilization of IONM and risk factors for neurologic deficits following elective ACDF.A total of 70,838 (15,092 monitored [21.3%] and 55,746 [78.7%] unmonitored) patients' data were extracted. The utilization of IONM since 2007 has increased in a linear fashion from 0.9% of cases in 2007 to 36.7% by 2018. Overall, baseline characteristics of patients who were monitored during cases differed significantly from unmonitored patients in age, race/ethnicity, insurance type, presence of myelopathy or radiculopathy, and Charlson Comorbidity Index (CCI); however, only race/ethnicity was statistically significant when analyzed using PSM. When comparing urban and rural medical centers, there is a significant lag in adoption of the technology with no monitored cases in rural centers until 2012 with significant fluctuations in utilization compared to steadily increasing utilization among urban centers. During 2017-2018 reporting of neurologic deficit after surgery resembled literature-established norms. Pooled analysis of these years revealed that incidence of neurological complication occurred more frequently in monitored cases than unmonitored (3.0% vs. 1.4%, P0.001).The utility of IONM for elective ACDF remains uncertain; however, it continues to gain popularity for routine cases. For medical centers that lack similar resources to centers in more densely populated regions of New York State, reliable access to this technology is not a certainty. In our analysis of intraoperative neurological complications, it appears that IONM is not protective against neurologic injury.

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 Medical vignettes. Objectives Lumbar spinal stenosis (LSS) is a degenerative condition with a high prevalence in the elderly population, that is associated with a significant economic burden and often requires spinal surgery. Prior authorization of surgical candidates is required before patients can be covered by a health plan and must be approved by medical directors (MDs), which is often subjective and clinician specific. In this study, we hypothesized that the prediction accuracy of machine learning (ML) methods regarding surgical candidates is comparable to that of a panel of MDs. Methods Based on patient demographic factors, previous therapeutic history, symptoms and physical examinations and imaging findings, we propose an ML which computes the probability of spinal surgical recommendations for LSS. The model implements a random forest model trained from medical vignette data reviewed by MDs. Sets of 400 and 100 medical vignettes reviewed by MDs were used for training and testing. Results The predictive accuracy of the machine learning model was with a root mean square error (RMSE) between model predictions and ground truth of .1123, while the average RMSE between individual MD’s recommendations and ground truth was .2661. For binary classification, the AUROC and Cohen’s kappa were .959 and .801, while the corresponding average metrics based on individual MD’s recommendations were .844 and .564, respectively. Conclusions Our results suggest that ML can be used to automate prior authorization approval of surgery for LSS with performance comparable to a panel of MDs.

Summary: Background: Lumbar intervertebral disc (IVD) herniations are associated with significant disability. Discectomy is the conventional treatment option for IVD herniations but causes a defect in the IVD, which has low self-repair ability, thereby representing a risk of further IVD degeneration. An acellular, bioresorbable, and good manufacturing practice (GMP)-compliant in situ-forming gel, which corrects discectomy-associated IVD defects and prevents further IVD degeneration had been developed. However, this acellular matrix-based strategy has certain limitations, particularly in elderly patients, whose tissues have low self-repair ability. The aim of this study was to investigate the therapeutic efficacy of using a combination of newly-developed, ultra-purified, GMP-compliant, human bone marrow mesenchymal stem cells (rapidly expanding clones; RECs) and the gel for IVD regeneration after discectomy in a sheep model of severe IVD degeneration. Methods: RECs and nucleus pulposus cells (NPCs) were co-cultured in the gel. In addition, RECs combined with the gel were implanted into IVDs following discectomy in sheep with degenerated IVDs. Findings: Gene expression of NPC markers, growth factors, and extracellular matrix increased significantly in the co-culture compared to that in each mono-culture. The REC and gel combination enhanced IVD regeneration after discectomy (up to 24 weeks) in the severe IVD degeneration sheep model. Interpretation: These findings demonstrate the translational potential of the combination of RECs with an in situ-forming gel for the treatment of herniations in degenerative human IVDs. Funding: Ministry of Education, Culture, Sports, Science, and Technology of Japan, Japan Agency for Medical Research and Development, and the Mochida Pharmaceutical Co., Ltd.

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.

Longitudinal cohort.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.Concordant patient-surgeon expectations reflect effective communication and should foster better outcomes.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] to1.2 [expectations surpassed]). Clinical measures included patient-reported spine-related disability.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).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.

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.