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Study design Systematic review. Objective To determine the difference in postoperative sagittal alignment when single level cervical radiculopathy or myelopathy is treated with an anterior cervical discectomy and fusion (ACDF) using a structural graft and plate, a stand-alone ACDF, or a total disc arthroplasty (TDR). We also wanted to determine if postoperative sagittal alignment impacted clinical outcomes in this patient population. Summary of background data Although there are several accepted techniques for interbody reconstruction during single level anterior cervical surgery, little is known on the impact of any of them on segmental and regional sagittal alignment. Methods A systematic review of the literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines of the PubMed, Embase, and Cochrane databases. Only studies which contained pre and postoperative C2-7 Cobb angles as well as Neck Disability Index (NDI) scores following single level traditional ACDF with plate and cage, stand-alone ACDF, or TDR with at least 1 year follow up were included. Results There were 12 publications that fulfilled the inclusion criteria with a total of 658 patients. Cluster regression analysis showed no difference between treatment arms at each respective time-point or in the overall change in NDI from preoperative to postoperative (P = 0.88). Cluster regression analysis showed no difference between treatment arms at each respective time point or in the overall change in lordosis from pre-op to post-op (P = 0.93). Conclusion This review provides evidence that while NDI scores improved across all devices, there was no significant difference in NDI improvement or C2-7 Cobb angle change between single level traditional ACDF, stand-alone ACDF, or TDR. Although TDR has not been considered a lordosis producing operation, our investigation shows it does not differ significantly in sagittal profile from other cervical fusion techniques. Moreover, we show that the NDI score improved, regardless of device implanted. Level of evidence 1.

Physical function is a critical aspect of patient outcomes. NDI is a widely validated outcome measure in cervical spine disease, yet to what extent its individual domains predict changes in physical function remains unknown.To examine the impact of individual NDI domains on changes in physical function in patients undergoing cervical spine surgery.Prospective Cohort Study.Adult patients undergoing cervical spine surgery, excluding those undergoing surgery for instability due to trauma.Absolute change in outcome measures (Patient Reported Outcomes Measurement Information System [PROMIS] Physical Function [PF], Short Form 36 [SF-36] Physical Component Score [PCS], and Neck Disability Index [NDI]) from pre- to postoperatively, correlation of NDI individual domains with PROMIS PF and SF-36 PCS (preoperatively, postoperatively, and change from pre- to postoperatively).Patients undergoing cervical spine surgery between 2016 and 2018 were prospectively enrolled. Patients completed questionnaires (NDI, SF-36 PCS, and PROMIS PF) preoperatively and at 6 months postoperatively. Patient demographics, including age, body mass index, Charlson Comorbidity Index, and underlying diagnoses were collected. Comparisons between NDI scores preoperatively versus postoperatively were conducted using Wilcoxon signed rank sum test. Correlations of NDI individual items and PROMIS/SF-36 were assessed using Pearson correlation. A stepwise linear regression analysis was performed to identify NDI items that are independently predictive of PROMIS PF and SF-36 PCS.A total of 137 patients were included in the study, with mean age 56.9 years (range 24.4-84.9). Each of the NDI domains as well as PROMIS PF and SF-36 PCS demonstrated significant improvement following cervical spine surgery (p.001). Changes in all NDI domains demonstrated significant negative correlation with changes in PROMIS PF, with recreation (R=-0.537, p.001), work (R=-0.514, p.001), and pain intensity (R=-0.488, p.001) having the greatest negative correlation. Changes in all NDI domains demonstrated significant negative correlation with changes in SF-36 PCS, with recreation (R=-0.451, p.001), work (R=-0.443, p.001), lifting (R=-0.373, p.001), and driving (R=-0.373, p.001) having the greatest negative correlation. For PROMIS PF, the NDI domains that were independently associated with changes in PF were work (R=-0.092, p=.001), pain intensity (R=-0.089, p=.003), and recreation (R=-0.067, p=.004). For SF-36 PCS, the NDI items that were independently associated with changes in PCS were work (R=-0.269, p=.003) and recreation (R=-0.215, p=.002).All NDI domains improve significantly after cervical spine surgery and demonstrate significant correlation with changes in PROMIS PF and SF-36 PCS. The work, recreation, and pain intensity domains were the only independent predictors of physical function changes postoperatively. Considering physical function, our findings highlight the importance of presenting changes in individual NDI domains in addition to the total score.

Objective Cervical disc replacement (CDR) is an effective long-term treatment for both cervical radiculopathy and myelopathy. However, there may be unique differences in the early postoperative clinical improvement for patients with and without myelopathy. In addition, previous studies using CDR to treat cervical myelopathy were underpowered to determine risk factors for relatively postoperative medical complications. Methods Two different cohorts were studied. A local cohort of patients undergoing CDR by a single surgeon was utilized to study the early postoperative course of clinical improvement. In addition, a national cohort of patients undergoing CDR in the 2015 and 2016 National Surgical Quality Improvement Program database was utilized to study differences in postoperative medical complications after CDR. Patients with a preoperative diagnosis of cervical myelopathy were identified in both cohorts, and perioperative outcomes and complications were compared to patients without myelopathy. Results A total of 43 patients undergoing CDR were included in the institutional cohort, of those 16 patients (37% of cohort) had a preoperative diagnosis of cervical myelopathy. A total of 3,023 patients undergoing CDR were included in the national cohort, of those 411 (13% of cohort) had a preoperative diagnosis of cervical myelopathy. In the institutional cohort, the nonmyelopathy group had a lower initial Neck Disability Index (NDI) and saw a faster improvement in NDI by 2 weeks postoperative. However, at 24 weeks there was no significant difference between groups in terms of NDI. Interestingly, only the nonmyelopathy cohort had a significant improvement in modified Japanese Orthopaedic Association score by 6 weeks (p0.05) between myelopathy and nonmyelopathy patients. Conclusion Significant improvements in NDI, visual analogue scale (VAS)-arm pain, and VAS-neck pain are seen in both myelopathy and nonmyelopathy populations undergoing CDR by 6 weeks postoperatively. However, nonmyelopathy populations improve faster by 2 weeks postoperatively. In the national cohort analysis, medical complications were similarly low in both myelopathy and nonmyelopathy groups.

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

Study design Prospective cohort study. Objective To examine preoperative urinary cross-linked n-telopeptide (uNTx) and assess for association with fusion rates in patients undergoing single and multi-level anterior cervical decompression and fusion (ACDF). Summary of background data Although high rates of fusion have been reported for ACDF, the risk of pseudarthrosis remains substantial. An established marker of bone turnover, uNTx may prove useful as a predictor of fusion. Methods Patients undergoing primary ACDF with allograft/plating technique from 2015 to 2017 by a single surgeon were consecutively enrolled and preoperative uNTx was collected. Patients undergoing revision, with creatinine >1.2, and with improperly-collected uNTx were excluded. Demographics, laboratory values, and fusion status were assessed at 6 months, 1 year, and 2 years postoperatively. Results Of the 97 patients enrolled, 69 met inclusion criteria. Of included cases, 41%, 33%, 18%, and 8% underwent 1-, 2-, 3-, and 4-level ACDF, respectively. Overall, fusion rates were 37.3%, 70.9%, and 95.3% at 6 months, 1 year, and 2 years, respectively. uNTx was higher in the fusion group (31.1 vs. 22.2, P = 0.001) at 6 months and 1 year (30.0 vs. 21.0, P = 0.006), with no difference at 2 years. No differences were identified in the proportion of smokers, immunomodulatory agents, corpectomies, or fusion levels between groups. Multivariate regression analysis demonstrated that uNTx is an independent predictor of fusion (odds ratio, OR, 1.124, P = 0.003). Both groups experienced improvements in NDI and VAS neck pain at 6 months with no significant differences noted between groups. Of 16 patients with pseudarthrosis at 1 year, 2 underwent posterior cervical fusion for symptoms. Conclusion Preoperative uNTx was greater in patients with successful ACDF fusion compared with patients with pseudarthrosis at 6 months and 1 year. A negative correlation was found between preoperative uNTx and motion on dynamic imaging. These results suggest that uNTx could serve to identify patients at risk for pseudarthrosis after ACDF. Level of evidence 3.

A retrospective cohort study of prospectively collected data.The aim of this study was to describe the development of and early experience with an evidence-based enhanced recovery after surgery (ERAS) pathway for lumbar decompression.ERAS protocols have been consistently associated with improved patient experience and outcomes, and reduced cost and length of hospital stay (LoS). Despite successes in other orthopedic subspecialties, ERAS has yet to be established in spine surgery. Here, we report the development of and initial experience with the first comprehensive ERAS pathway for MIS lumbar spine surgery.An evidence-based review of the literature was performed to select components of the ERAS pathway. The pathway was applied to 61 consecutive patients presenting for microdiscectomy or lumbar laminotomy/laminectomy between dates. Data collection was performed by review of the electronic medical record. We evaluated compliance with individual ERAS process measures, and adherence to the overall pathway. The primary outcome was LoS. Demographics, comorbidities, perioperative course, prevalence of opioid tolerance, and factors affecting LoS were also documented.The protocol included 15 standard ERAS elements. Overall pathway compliance was 85.03%. Median LoS was 279 minutes [interquartile range (IQR) 195-398 minutes] overall, 298 minutes (IQR 192-811) for lumbar decompression and 285 minutes (IQR 200-372) for microdiscectomy. There was no correlation between surgical subtype or duration and LoS. Overall, 37% of the cohort was opioid-tolerant at the time of surgery. There was no significant effect of baseline opioid use on LoS, or on the total amount of intraoperative or PACU opioid administration. There were four complications (6.5%) resulting in extended LoS (23 hours).This report comprises the first description of a comprehensive, evidence-based ERAS for spine pathway, tailored for lumbar decompression/microdiscectomy resulting in short LoS, minimal complications, and no readmissions within 90 days of surgery.3.

STUDY DESIGN Retrospective study of prospectively collected data. OBJECTIVE To determine the incidence, timing, risk factors, and clinical implications of postoperative hematoma requiring reoperation after anterior cervical discectomy and fusion (ACDF). SUMMARY OF BACKGROUND DATA Postoperative hematomas requiring reoperation are rare but potentially catastrophic complications after ACDF. However, there has been a lack of large cohort studies investigating these complications in the ACDF population despite increasing outpatient procedure volume. METHODS Patients who underwent ACDF in the 2012 to 2016 National Surgical Quality Improvement Program database were identified. The primary outcome was an occurrence of hematoma requiring reoperation within 30 days postoperatively. Risk factors for this outcome were identified using multivariate regression. Postoperative length of stay, subsequent complications, and mortality were compared between patients who did and did not develop a hematoma requiring reoperation. RESULTS A total of 37,261 ACDF patients were identified, of which 148 (0.40%) developed a hematoma requiring reoperation (95% confidence interval [CI], 0.33%-0.46%). Of the cases that developed this complication, 37% occurred after discharge. Risk factors for the development of hematoma requiring reoperation were multilevel procedures (most notably ≥3 levels, relative risk [RR] = 3.14, 95% CI = 1.86-5.32, P 1.2 (RR = 2.85, 95% CI = 1.42-5.71, P = 0.006), lower BMI (notably body mass index ≤24, RR = 2.11, 95% CI = 1.21-3.67, P = 0.008), American Society of Anesthesiologists classification ≥3 (RR = 2.07, 95% CI = 1.47-2.91, P

Intervertebral disc herniation (IDH) can cause back pain and/or radiculopathy and accounts for a significant portion of patients having spinal surgery in the USA. One of the most impactful and well-executed randomized trials to study diagnosis, treatments, and outcomes in patients with three commonly treated spinal conditions was the Spine Patient Outcomes Research Trial (SPORT). This study and the subsequent data analyses have resulted in numerous publications related to IDH. The purpose of this review is to summarize SPORT publications with IDH results to better understand what we have learned from this important landmark trial. Publications utilizing SPORT data that reported findings related to IDH patients were identified from Medline, PubMed, and PubMed Central. The primary findings pertaining to IDH were summarized. There were 25 studies identified reporting findings related to IDH from the SPORT data published between 2004 and 2017. Publications in the following areas were summarized: epidemiology and baseline patient characteristics (1), treatment preferences and expectations (2), radiological and MRI (3), primary study objectives at two years (2), four years (1) and eight years (1), subgroup analyses (13), cost-effectiveness (1), and reherniation (1). This report reviewed the current state of SPORT publications related to IDH to identify and summarize what we have learned about diagnosis, patient characteristics, treatments, outcomes, and cost-effectiveness in patients with lumbar disc herniations. Many important findings are now published from this robust trial’s data. Clinicians should incorporate these results into their clinical decision-making and during counseling patients presenting with lumbar disc herniations.

As part of ongoing efforts to address the opioid crisis, on June 1, 2018, HSS Journal® convened a multidisciplinary panel of experts for a daylong discussion: Toward Opioid-Free Arthroplasty: A Leadership Forum. Each invited participant presented on a specific aspect of the opioid crisis and/or pain management as it relates to total hip or knee arthroplasty. Representing orthopedics, anesthesiology, psychiatry, bioethics, health information technology, and law, this group crafted a consensus statement on appropriate pain management for total hip or knee arthroplasty. Many have also contributed to this special issue of HSS Journal on “Opioid Prescribing and Pain Management” (February 2019) (Fig. 1). Open in a separate window Fig. 1 Participants in Toward Opioid-Free Arthroplasty: A Leadership Forum, June 1, 2018, at Hospital for Special Surgery (pictured left to right): Travis N. Rieder, PhD, Christopher Lee Wu, MD, Jonathan Avery, MD, Seth Waldman, MD, Charles N. Cornell, MD, Ellen M. Soffin, MD, PhD, William Schairer, MD, Mark Barnes, JD, LLM, Alex Rich, MPH, and Louis A. Shapiro, FACHE. (Not pictured: Todd J. Albert, MD, and E. Carlos Rodriguez-Merchan, MD, PhD.) Photograph by Robert Essel.

Our institution developed a 1-hour mandatory narcotics-prescribing education program as well as postoperative opioid-prescribing guidelines in response to the opioid epidemic. The purpose of this study was to evaluate the effect of this hospital-wide opioid education and subsequent institution of postoperative opioid guidelines on opioid-prescribing practices after ambulatory surgery.This retrospective study was performed at 1 academic orthopaedic hospital. In November 2016, a 1-hour mandatory opioid education program was completed by all hospital prescribers. Postoperative opioid guidelines were then developed and were disseminated in February 2017. All postoperative narcotic prescriptions after ambulatory procedures performed by 3 separate services (hand, sports, and foot and ankle services) were evaluated over 4 months prior to and after the mandatory opioid education and subsequent release of service-specific guidelines.Overall, there was a significant decrease in pills and total oral morphine equivalents prescribed after dissemination of guidelines compared with the pre-intervention cohort procedures (p0.001) performed by the sports and hand services. With regard to the sports medicine service, the mean difference in pills prescribed was 6.47 pills (95% confidence interval [CI], 5.4 to 7.5 pills) for knee arthroscopy, 5.6 pills (95% CI, 2.5 to 8.7 pills) for shoulder arthroscopy, and 16.3 pills (95% CI, 13.6 to 19.1 pills) for hip arthroscopy. With regard to the hand service, the mean difference in pills prescribed was 13.0 pills (95% CI, 10.2 to 15.8 pills) for level-1 procedures, 12.4 pills (95% CI, 9.9 to 15.0 pills) for carpal tunnel release, and 21.7 pills (95% CI, 18.0 to 25.3 pills) for distal radial fractures. The decrease in pills prescribed in the post-intervention cohort amounts to almost 30,000 fewer opioid pills prescribed per year after these 6 procedures alone. There was no significant change (p0.05) in either the number of pills or the oral morphine equivalents prescribed after any of the 3 procedures performed by the foot and ankle service (ankle arthroscopy, bunion surgery, and Achilles tendon repair).We developed a prescriber education program and followed up with consensus-based guidelines for postoperative opioid prescriptions. These interventions caused a significant decrease in excessive opioid-prescribing practices after ambulatory orthopaedic surgery at our hospital. We urge initiatives by national orthopaedic organizations to develop and promote education programs and procedure and disease-specific opioid-prescribing guidelines.

Retrospective cohort comparison study.The aim was to compare perioperative complications and 30-day readmission between ambulatory and inpatient posterior cervical foraminotomy (PCF) in the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database.Single-level PCF for cervical radiculopathy is increasingly being performed as an ambulatory procedure. Despite this increase, there is a lack of published literature documenting the safety of ambulatory PCF.Patients who underwent PCF (through laminotomy or laminectomy) were identified in the 2005-2018 NSQIP database. Ambulatory procedures were defined as cases that had hospital length of stay=0 days. Inpatient procedures were defined as cases that had length of stay=1-4 days. Patient characteristics, comorbidities, and procedural variables (laminotomy or laminectomy performed) were compared between the 2 cohorts. Propensity score matched comparisons were then performed for postoperative complications and 30-day readmissions between the 2 groups.In total, 795 ambulatory and 1789 inpatient single-level PCF cases were identified. After matching, there were 795 ambulatory and 795 inpatient cases. Statistical analysis after propensity score matching revealed no significant difference in individual complications including 30-day readmission, thromboembolic events, wound complications, and reoperation, or aggregated complications between ambulatory versus matched inpatient procedures. Overall 30-day readmissions after ambulatory single-level PCF were noted for 2.46% of the study population, and the most common reasons were surgical site infections (46%) and pain control (15%).The perioperative outcomes assessed in this study support the conclusion that single-level PCF for cervical radiculopathy can be performed for correctly selected patients in the ambulatory setting without increased rates of 30-day perioperative complications or readmissions compared with inpatient procedures.Level III.

Importance Cervical spondylotic myelopathy is the most common cause of spinal cord dysfunction worldwide. It remains unknown whether a ventral or dorsal surgical approach provides the best results. Objective To determine whether a ventral surgical approach compared with a dorsal surgical approach for treatment of cervical spondylotic myelopathy improves patient-reported physical functioning at 1 year. Design, Setting, and Participants Randomized clinical trial of patients aged 45 to 80 years with multilevel cervical spondylotic myelopathy enrolled at 15 large North American hospitals from April 1, 2014, to March 30, 2018; final follow-up was April 15, 2020. Interventions Patients were randomized to undergo ventral surgery (n = 63) or dorsal surgery (n = 100). Ventral surgery involved anterior cervical disk removal and instrumented fusion. Dorsal surgery involved laminectomy with instrumented fusion or open-door laminoplasty. Type of dorsal surgery (fusion or laminoplasty) was at surgeon’s discretion. Main Outcomes and Measures The primary outcome was 1-year change in the Short Form 36 physical component summary (SF-36 PCS) score (range, 0 [worst] to 100 [best]; minimum clinically important difference = 5). Secondary outcomes included 1-year change in modified Japanese Orthopaedic Association scale score, complications, work status, sagittal vertical axis, health resource utilization, and 1- and 2-year changes in the Neck Disability Index and the EuroQol 5 Dimensions score. Results Among 163 patients who were randomized (mean age, 62 years; 80 [49%] women), 155 (95%) completed the trial at 1 year (80% at 2 years). All patients had surgery, but 5 patients did not receive their allocated surgery (ventral: n = 1; dorsal: n = 4). One-year SF-36 PCS mean improvement was not significantly different between ventral surgery (5.9 points) and dorsal surgery (6.2 points) (estimated mean difference, 0.3; 95% CI, −2.6 to 3.1;P = .86). Of 7 prespecified secondary outcomes, 6 showed no significant difference. Rates of complications in the ventral and dorsal surgery groups, respectively, were 48% vs 24% (difference, 24%; 95% CI, 8.7%-38.5%;P = .002) and included dysphagia (41% vs 0%), new neurological deficit (2% vs 9%), reoperations (6% vs 4%), and readmissions within 30 days (0% vs 7%). Conclusions and Relevance Among patients with cervical spondylotic myelopathy undergoing cervical spinal surgery, a ventral surgical approach did not significantly improve patient-reported physical functioning at 1 year compared with outcomes after a dorsal surgical approach. Trial Registration ClinicalTrials.gov Identifier:NCT02076113

BACKGROUND: A recent randomized controlled trial (RCT), performed by the authors, comparing early surgical microdiscectomy with 6 months of nonoperative care for chronic lumbar radiculopathy showed that early surgery resulted in improved outcomes. However, estimates of the incremental cost-utility ratio (ICUR), which is often expressed as the cost of gaining one quality-adjusted life year (QALY), of microdiscectomy versus nonsurgical management have varied. Radiculopathy lasting more than 4 months is less likely to improve without surgical intervention and may have a more favorable ICUR than previously reported for acute radiculopathy. QUESTION/PURPOSE: In the setting of chronic radiculopathy caused by lumbar disc herniation, defined as symptoms and/or signs of 4 to 12 months duration, is surgical management more cost-effective than 6 months of nonoperative care from the third-party payer perspective based on a willingness to pay of less than CAD 50,000/QALY? METHODS: A decision analysis model served as the vehicle for the cost-utility analysis. A decision tree was parameterized using data from our single-center RCT that was augmented with institutional microcost data from the Ontario Case Costing Initiative. Bottom-up case costing methodology generates more accurate cost estimates, although institutional costs are known to vary. There were no major surgical cost drivers such as implants or bone graft substitutes, and therefore, the jurisdictional variance would be minimal for tertiary care centers. QALYs derived from the EuroQoL-5D were the health outcome and were derived exclusively from the RCT data, given the paucity of studies evaluating the surgical treatment of lumbar radiculopathy lasting 4 to 12 months. Cost-effectiveness was assessed using the ICUR and a threshold of willingness to pay CAD 50,000 (USD 41,220) per QALY in the base case. Sensitivity analyses were performed to account for the uncertainties within the estimate of cost utility, using both a probabilistic sensitivity analysis and two one-way sensitivity analyses with varying crossover rates after the 6-month nonsurgical treatment had concluded. RESULTS: Early surgical treatment of patients with chronic lumbar radiculopathy (defined as symptoms of 4 to 12 months duration) was cost-effective, in that the cost of one QALY was lower than the CAD 50,000 threshold (note: the purchasing power parity conversion factor between the Canadian dollar (CAD) and the US dollar (USD) for 2019 was 1 USD = 1.213 CAD; therefore, our threshold was USD 41,220). Patients in the early surgical treatment group had higher expected costs (CAD 4118 [95% CI 3429 to 4867]) than those with nonsurgical treatment (CAD 2377 [95% CI 1622 to 3518]), but they had better expected health outcomes (1.48 QALYs [95% CI 1.39 to 1.57] versus 1.30 [95% CI 1.22 to 1.37]). The ICUR was CAD 5822 per QALY gained (95% CI 3029 to 30,461). The 2-year probabilistic sensitivity analysis demonstrated that the likelihood that early surgical treatment was cost-effective was 0.99 at the willingness-to-pay threshold, as did the one-way sensitivity analyses. CONCLUSION: Early surgery is cost-effective compared with nonoperative care in patients who have had chronic sciatica for 4 to 12 months. Decision-makers should ensure adequate funding to allow timely access to surgical care given that it is highly likely that early surgical intervention is potentially cost-effective in single-payer systems. Future work should focus on both the clinical effectiveness of the treatment of chronic radiculopathy and the costs of these treatments from a societal perspective to account for occupational absences and lost patient productivity. Parallel cost-utility analyses are critical so that appropriate decisions about resource allocation can be made. LEVEL OF EVIDENCE: Level III, economic and decision analysis.

BACKGROUND CONTEXT Bone density in the lumbar spine is variable by level and can impact surgical strategy. In the cervical spine, low Hounsfield units (HU) have been associated with cage subsidence. The distribution of HU in the cervical spine has not been established. PURPOSE To define level-specific cervical HU reference values and the relationship between cervical bone density, age, BMI, comorbidities and alignment. STUDY DESIGN/SETTING Retrospective review at a single center from May 2015 to December 2019. PATIENT SAMPLE A total of 224 patients, 18 excluded for previous hardware and 5 for known osteoporosis. OUTCOME MEASURES Hounsfield units. METHODS Patients who presented with neck symptoms and had a cervical spine CT for evaluation of pathology or surgical planning were included. Exclusions were hardware on CT, osteoporosis, or cervical deformity. Measurements were performed in 5 regions of each vertebral body (VB) (C2-T1; mid-axial, anterior-axial, posterior-axial, mid-coronal, and mid-sagittal) and 2 regions of the lateral masses (LMs) (C3-C6; mid-cor, mid-sag). The VB measurements were averaged at each level to obtain a composite value of each vertebral body (TotalVB), similarly the mid-cor and mid-sag values were averaged at each LM (TotalLatM). Outliers were excluded pairwise. To evaluate reliability, 6 observers each measured 355 HU values (71 over 5 patients), inter-relater reliability assessed with intraclass correlation coefficients (ICCs). Correlations of composite HU with age, BMI, Charlston Comorbidity Index (CCI) and cervical alignment were evaluated. RESULTS Average age 57±12 years, mean BMI 28±6 kg/m2, 63.5% male, 90.1% white. Diagnoses included radiculopathy (45.8%), myelopathy (37.9%) and facet arthropathy (46.3%). ICC for HU measurements were as follows: VB, 0.82 mid-axial, 0.59 ant-axial, 0.77 post-axial, 0.88 mid-cor, 0.88 mid-sag; LM, 0.46 mid-sag, 0.61 mid-cor. C4 VB and C4 LM had the highest HU (383.6±71.9 and 480.0±103, respectively) while T1 VB and C6 LM had the lowest (232.3±46.5 and 398.3±98.2, respectively). No significant correlations were found between LM HU and age, BMI, CCI, or alignment. Increased kyphosis was weakly correlated with VB HU at all levels (except C2) strongest correlations at C7 (0.25) and weakest correlation at C3 (0.16). Age and CCI showed weak-moderate correlations with VB HU at all levels (age, r= -0.20 to -0.35; CCI r= -0.28 [C2, C7, T1] to -0.17 [C4]). CONCLUSIONS Our level-specific cervical HU values may be referenced when evaluating cervical BMD. The most reliable measurement technique is on the mid-sag or mid-cor VB, measurement of LMs is less reliable. Bone is least dense in the lower cervical spine, which may influence instrumentation strategies. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Study design Retrospective cross-sectional cohort. Objective The aim of this sudy was to determine whether muscle health measurements are associated with health-related quality of life scores (HRQOLs) for patients with lumbar spine pathology. Summary of background data Poor muscle health has been implicated as a source of pain/dysfunction for patients with lumbar spine pathology. Our aim was to quantify the relationship using muscle health measurements and HRQOLs. Methods Three hundred and eight patients were included (mean age 57.7 ± standard deviation 18.2 years' old). We randomly selected patients into a derivation cohort (200) and validation cohort (108) to create our muscle health grade. We measured muscle health by the lumbar indentation value (LIV), goutallier classification (GC), and ratio of paralumbar muscle cross-sectional area over body mass index (PL-CSA/BMI). A muscle health grade was derived based on whether a measurement showed a statistically significant impact on visual analog scale back and leg pain (VAS-leg and VAS-leg), Oswestry Disability Index (ODI), short-form 12 physical health score (SF-12 PHS), short-form 12 mental health score (SF-12 MHS) and Patient-reported Outcomes Measurement Information System (PROMIS). A variety of statistical tools were used to determine whether there was a relationship between a measurement and HRQOLs. Results In the derivation cohort, a muscle health grade was created based on the GC and PL-CSA/BMI ratio. For patients with a GC ≤2, one point was given. For patients with a PL-CSA/BMI ≥130, one point was given. Patients with 2 points were graded as "A" and 0 or 1 point were graded "B." Within the validation cohort of patients, there was a statistically significant higher PROMIS (mean 34.5 ± standard deviation 12.6 vs. 27.6 ± 14.0, P = 0.002), ODI (38.8 ± 18.3 vs. 45.8 ± 18.1, P = 0.05) and SF-12 PHS (34.7 ± 11.3 vs. 29.1 ± 6.3, P = 0.002) for patients with a good muscle health grade of "A." Conclusion This study offers an objective measurement of muscle health that correlates with HRQOLs for patients with lumbar spine pathology.Level of Evidence: 3.

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 Design Retrospective cohort study Objective Given changes in bone density induced by degenerative disease, general measures of bone health (ie DEXA) are inadequate to evaluate bone density in surgical areas of interest. Regional differences in HU in the cervical spine may influence surgical strategies. The purposes of our study were to determine whether cervical Hounsfield units (HU) vary by level, examine their relationship with age, comorbidities, and alignment, and propose a technique to measure HU in the lateral masses. Methods Two hundred twenty-four patients with degenerative spine pathology with a cervical computed tomography were included (2015-2019). Measurements were performed in each vertebral body (C2-T1; mid-axial, anterior-axial, posterior-axial, mid-coronal, and mid-sagittal) and 2 regions of the lateral masses (C3-C6; mid-cor, mid-sag). To evaluate reliability, 6 observers each measured 355 HU values, inter-relater reliability assessed with intraclass correlation coefficients Correlations of HU with age, BMI, comorbidities, and cervical alignment were evaluated. Results Bone density differed by level, with the lowest HU scores in the lower cervical spine (C6-T1) ( P < .001). No correlations were found between LM HU and age, BMI, CCI, or alignment ( P > .05). Increased kyphosis was weakly correlated with VB HU, while age and CCI showed moderate correlations with VB HU at all levels (PConclusion Bone is least dense in the lower cervical spine. HU scoring is not reliable in the lateral masses. We recommend that a level-specific approach to bone density is considered in surgical planning.

This is a critical analysis of a study by Hoernschemeyer et al, “Anterior Vertebral Body Tethering for Adolescent Scoliosis with Growth Remaining: A Retrospective Review of 2 to 5-Year Postoperative Results” ( J Bone Joint Surg Am, 2020;102[13]:1169–1176), that assessed the clinical and radiographic outcomes of vertebral body tethering (VBT) in the treatment of adolescent scoliosis. The authors demonstrated successful treatment in 74% of patients, based on radiographic outcomes and avoidance of subsequent posterior spinal fusion. Nearly a quarter of patients required revision surgery. Almost half suffered a broken tether, although the effects of such complications are not fully understood. The study provided valuable information for determining which patients are reasonable candidates for VBT and emphasizes several questions surrounding this novel technology that remain unanswered. This analysis discusses the study’s strengths and weaknesses, suggests potential directions of future research, and examines the potential indications for VBT.

Design This was a narrative review. Purpose Summarize artificial intelligence (AI) fundamentals as well as current and potential future uses in spine surgery. Summary of background data Although considered futuristic, the field of AI has already had a profound impact on many industries, including health care. Its ability to recognize patterns and self-correct to improve over time mimics human cognitive function, but on a much larger scale. Methods Review of literature on AI fundamentals and uses in spine pathology. Results Machine learning (ML), a subset of AI, increases in hierarchy of complexity from classic ML to unsupervised ML to deep leaning, where Language Processing and Computer Vision are possible. AI-based tools have been developed to segment spinal structures, acquire basic spinal measurements, and even identify pathology such as tumor or degeneration. AI algorithms could have use in guiding clinical management through treatment selection, patient-specific prognostication, and even has the potential to power neuroprosthetic devices after spinal cord injury. Conclusion While the use of AI has pitfalls and should be adopted with caution, future use is promising in the field of spine surgery and medicine as a whole. Level of evidence Level IV.

BACKGROUND CONTEXT Surgical site infections (SSIs) are medically devastating and financially costly complications after posterior spinal fusion (PSF) for neuromuscular scoliosis (NMS). Many strategies exist to reduce their occurrence. The efficacy of intraoperative antibiotics in the wound or bone graft is gaining in popularity, but this practice has not been well-studied in the PSF NMS population. PURPOSE To assess the potential utility of intraoperative local antibiotics in patients with NMS undergoing PSF. STUDY DESIGN/SETTING Retrospective review of prospectively collected data. PATIENT SAMPLE Pediatric patients who underwent PSF for NMS were identified from the 2016–2018 National Surgical Quality Improvement Program (NSQIP) pediatric spinal fusion datasets. OUTCOME MEASURES Perioperative adverse outcome variables assed included the occurrence of SSI, renal complications, and adverse hospital metrics. METHODS Patient demographic factors, comorbidities, and the use of intraoperative antibiotics in the wound were recorded (a specifically assessed variable in the dataset). The association between the use of intraoperative antibiotics and the occurrence of adverse outcomes/infection was assessed for the entire study population and higher risk sub-populations. RESULTS In total, 1,990 patients met the inclusion criteria, of which 87% received local antibiotics. Higher risk patients were more likely to receive local antibiotics in the wound as part of their procedure. When controlling for potentially confounding factors, the use of local antibiotics was not statistically significantly associated with any of the studied adverse outcomes for the overall study population. Subgroup analysis of higher risk patient populations (≥13 levels fused, osteotomy performed, prior deformity surgery, nonasthma lung condition) revealed a significantly decreased risk of SSI in patients undergoing ≥13 level fusions (relative risk: 0.48, 95% confidence interval: 0.25–0.91). CONCLUSIONS With no increased overall risks and reduced SSIs in higher risk NMS patients undergoing PSF, the use of intrawound antibiotics appears to be supported by this dataset.

Aging is a major risk factor for numerous painful, inflammatory, and degenerative diseases including disc degeneration. A better understanding of how the somatosensory nervous system adapts to the changing physiology of the aging body will be of great significance for our expanding aging population. Previously, we reported that chronological aging of mouse lumbar discs is pathological and associated with behavioral changes related to pain. It is established that with age and degeneration the lumbar discs become inflammatory and innervated. Here we analyze the aging lumbar dorsal root ganglia (DRGs) and spinal cord dorsal horn (SCDH) in mice between 3 and 24 months of age for age‐related somatosensory adaptations. We observe that as mice age there are signs of peripheral sensitization, and response to inflammation at the molecular and cellular level in the DRGs. From 12 months onwards the mRNA expression of vasodilator and neurotransmitter, Calca (CGRP); stress (and survival) marker, Atf3; and neurotrophic factor, Bdnf, increases linearly with age in the DRGs. Further, while the mRNA expression of neuropeptide, Tac1, precursor of Substance P, did not change at the transcriptional level, TAC1 protein expression increased in 24‐month‐old DRGs. Additionally, elevated expression of NFκB subunits, Nfkb1 and Rela, but not inflammatory mediators, Tnf, Il6, Il1b, or Cox2, in the DRGs suggest peripheral nerves are responding to inflammation, but do not increase the expression of inflammatory mediators at the transcriptional level. These results identify a progressive, age‐related shift in the molecular profile of the mouse somatosensory nervous system and implicates nociceptive sensitization and inflammatory response., Age‐related degeneration including disc degeneration induces Atf3 expression in the DRGs, possibly through the Npy, Bdnf and TRPA1 pathways. Intact small‐diameter nerves respond by inducing Calca expression in DRGs, its transport to the SCDH, and increased Calca expression by the SCDH neurons, leading to central sensitization. Expression of TNFalpha in aging degenerative tissues or the circulatory system induces NFκB pathway, causing increased expression of nociceptive sodium channels, NaV1.8 and NaV1.9, which further stimulates SCDH neuron.

INTRODUCTION Although the Patient-reported Outcomes Measurement Information System (PROMIS) is increasingly being used, there are few studies assessing the psychometric properties of PROMIS in minimally invasive spine (MIS) surgery. Thus, the purpose of this study was to perform a psychometric evaluation of PROMIS Physical Function Computer Adaptive Testing (PROMIS-PF CAT) in MIS lumbar surgery. METHODS The patient-reported outcome measures collected preoperatively and postoperatively of patients undergoing MIS lumbar surgery were retrospectively analyzed to assess responsiveness, coverage, discriminant validity, and concurrent validity of PROMIS-PF CAT. RESULTS Four hundred twenty-one patients were included. The responsiveness of PROMIS Physical Function (PROMIS-PF) was lower than that of the Oswestry Disability Index (ODI) in the decompression subgroup. Although the ODI had a ceiling effect of 16.7% at 1 year, the Short-Form 12 physical health score and PROMIS-PF did not show floor or ceiling effects. PROMIS-PF demonstrated discriminant validity preoperatively and postoperatively and convergent validity with the ODI, as evidenced by a significant strong negative correlation but not with the Short-Form 12 Physical Health Score, as evidenced by the variability in strength of correlation. CONCLUSIONS Although the PROMIS-PF showed lower responsiveness than the ODI, particularly in the decompression subgroup, it demonstrated discriminant validity preoperatively and postoperatively, convergent validity with ODI, and better coverage than ODI. These findings suggest that the PROMIS-PF CAT demonstrates reasonable psychometric properties and may be a good surrogate for the ODI.

Study Design: Retrospective cohort study. Objective: To determine the rate of early failures (readmission or reoperation for new or recurrent pain/neurological symptoms) within 30 days after lumbar discectomy and identify associated risk factors. Methods: A retrospective cohort study was conducted of patients undergoing lumbar discectomy in the National Surgical Quality Improvement Program database between 2013 and 2017. Rates of readmission for new or recurrent symptoms or reoperation for revision discectomy or fusion within 30 days postoperatively were measured and correlated with risk factors. Results: In total 62 690 patients were identified; overall rate of readmission within 30 days was 3.3%, including 1.2% for pain or neurological symptoms. Populations at increased risk of readmission were those with 3 or more levels of treatment (2.0%, odds ratio [OR] 2.8%, P < .01), age >70 years (1.8%, OR 1.6, P < .01), class 3 obesity (1.5%, OR 1.4, P = .04), and female gender (1.4%, OR 1.2, P = .02). The overall rate of reoperation within 30 days was 2.2%, including 1.2% for revision decompression or lumbar fusion surgery. Populations at increased risk of reoperation were revision discectomies (1.4%, OR 1.7, P < .01) and females (1.1%, OR 1.4, P < 0.01). Extraforaminal discectomies were associated with lower rates of readmission (0.7%, OR 0.6, P = 0.02) and reoperation (0.4%, OR 0.4, P = .01). Conclusions: Early failures after lumbar discectomy surgery are rare. However, certain subpopulations are associated with increased rates of early failure: obesity, multilevel surgery, females, and revision discectomies.

The purpose of this study is to provide a morphometric description of the bony margins of the interlaminar spaces by level in the cervical spine for guidance of safe posterior cervical surgical dissection and decompression. We also aim to describe the impact of increasing static cervical lordosis on the overlap between the lamina.Morphometric measurements of the interlaminar space were performed on 100 consecutive cervical spine CT scans of patients ranging in age from 18 to 50 years were selected. Three raters performed measurements of the interlaminar height measured using two techniques (true interlaminar height and surgical interlaminar height), and interlaminar width from C2-C3 to C7-T1.In total, 100 patients were included. The true interlaminar height was greatest at C2-3, C3-4, C4-5 (5.2 ± 1.4-1.8 mm) and smallest at C6-7 (4.4 ± 1.3 mm). Surgical interlaminar height was greatest at C3-4 (4.2 ± 1.7) and smallest at C6-7 (3.0 ± 1.3 mm). The widest interlaminar space was observed at C3-4 (27.1 ± 2.1 mm) and most narrow at C7-T1 (20.9 ± 2.4 mm). Following multivariate regression, male gender was associated with greater interlaminar widths at each cervical level between C4 and T1 (Table 2). While greater patient height was associated with larger interlaminar height (true and surgical) and width at C2-3 and C4-5, weight was not independently associated with the interlaminar measurements. Increasing C2-C7 lordosis was significantly associated with decreasing true and surgical interlaminar heights at all levels except C7-T1, but was not associated with differences between interlaminar width.The study provides a morphometric analysis of interlaminar anatomy in the cervical spine. Surgeons can apply this information in their pre-operative plan to safely approach the posterior cervical spine.

Background Context Various designs of total disc replacement (TDR) devices have been compared to ACDF with favorable outcomes in FDA-approved investigational device exemption (IDE) trials. The design of M6-C with a compressible viscoelastic nuclear core and an annular structure is substantially different than prior designs and has previously demonstrated favorable kinematics and clinical outcomes in small case series. Purpose To evaluate the safety and effectiveness of the novel M6-C compressible artificial cervical disc compared with anterior cervical discectomy and fusion (ACDF) for subjects with single level degenerative cervical radiculopathy. Study Design/Setting Prospective, multicenter, concurrently- and historically-controlled, FDA-approved investigational device exemption (IDE) clinical trial. Patient Sample Subjects with one-level symptomatic degenerative cervical radiculopathy were enrolled and assigned to receive M6-C or ACDF. Outcome Measures Pain and function (NDI, VAS), quality of life (SF-36), safety, neurological and radiographic assessments of motion (both flexion extension and lateral bending) were performed. The primary clinical endpoint was composite clinical success (CCS) at 24 months. Methods Using propensity score subclassification to control for selection bias, 160 M6-C subjects were compared to a matched subset of 189 ACDF controls (46 concurrent and 143 historical controls). Results Both ACDF AND M6-C subjects reported significant improvements in patient reported outcomes at all time points over baseline. Overall SF-36 Physical Component Score and neck and arm pain scores were significantly improved for M6-C as compared to ACDF treatment. CCS and mean NDI improvements were similar between M6-C and ACDF. Correspondingly, there were significantly fewer subjects that utilized pain medication or opioids following M6-C treatment at 24 months relative to baseline. Range of motion was maintained in subjects treated with M6-C. Subsequent surgical interventions, dysphagia rates, and serious adverse events were comparable between groups. Conclusions M6-C treatment demonstrated both safety and effectiveness for the treatment of degenerative cervical radiculopathy. Treatment with M6-C demonstrated non-inferiority for the primary endpoint, indicating a similar ability to achieve Composite Clinical Success (CCS) at 24 months. However, for the secondary endpoints, M6-C subjects demonstrated significantly improved pain and function compared to ACDF subjects, while maintaining range of motion, improving quality of life and decreasing analgesic and opioid usage at 2 years postoperatively relative to baseline.

STUDY DESIGN Follow-up study. OBJECTIVE To determine whether minimally invasive lumbar spine surgery outcomes are different between those who are lost to follow-up and those who are not. SUMMARY OF BACKGROUND DATA Lost to follow-up patients are a common source of selection bias for clinical outcomes research. Currently, there are no US based studies that evaluate the differences in outcomes of lost to follow-up patients after spine surgeries. METHODS A retrospective review of prospectively collected data of 289 patients who underwent minimally invasive lumbar surgery and were at least 1 year postsurgery was performed. Patients were divided into two groups: (1) lost to follow-up (LTF), defined as patients who had missed more than two consecutive follow-up visits and had not attended their 1-year follow-up appointment; and (2) not lost to follow-up. For the not-LTF cohort, patient response outcome measures (PROMs) (oswestry disability index (ODI), visual analog scale (VAS) back/leg, Short Form-12 (SF-12) Physical/Mental, PROMIS) and return to activities data were collected prospectively at each follow-up. For LTF patients, data were collected through emailed surveys or telephone interviews. PROMs and return to activities data of the two groups were compared. Sub-group analysis by type of surgery (decompression or fusion) was also performed. RESULTS For the entire cohort, independent t test analysis showed LTF patients had greater improvement in PROMIS Physical Function scores than those who were not-LTF (15.08 vs. 10.38, P = 0.026). For fusion surgeries, LTF patients showed a greater improvement in ODI (-30.94 vs. -16.23, P = 0.003) VAS back (-4.92 vs. -2.99, P = 0.044), and PROMIS-PF (16.09 vs. 10.38, P = 0.049). There were no significant differences in complication rates between LTF and not LTF patients. CONCLUSION Patients undergoing minimally invasive lumbar surgery-in particular lumbar fusions-who are lost to follow-up and responded to subsequent email and phone interviews showed greater improvements in self-reported outcomes than those who continued to follow-up. Thus, our results suggest that a substantial subset of patients who are lost to follow-up do not fare worse than those who do follow-up. However, an opposite response cannot be excluded in those who did not respond to email and phone interviews. LEVEL OF EVIDENCE 3.

Peak performance is the ability to achieve optimal outcomes or performance of a given task in a consistent manner. Commonly studied in athletes and musicians, this topic is less often studied in medicine and rarely broached for trainees. However, residency is a crucial period of training where foundations for future success are sewn into habit and daily practice. As educators, we should aim to equip trainees with the tools necessary to achieve peak performance. Studies in athletes and musicians focus on achieving peak performance by setting goals, mastering skills through deliberate practice, perseverance, grit, and discipline. Mentorship is also an important element to streamline efforts for the trainee and help them to focus. In the following article, we review the current literature on applying these principles to surgical trainees to achieve peak performance.

Retrospective cohort.To describe our technique for and evaluate the time demand, radiation exposure and outcomes of skin-anchored intraoperative three-dimensional navigation (ION) in minimally invasive (MIS) lumbar surgery, and to compare these parameters to 2D fluoroscopy for MI-TLIF.Limited visualization of anatomic landmarks and narrow access corridor in MIS procedures result in greater reliance on image guidance. Although two-dimensional fluoroscopy has historically been used, ION is gaining traction.Patients who underwent MIS lumbar microdiscectomy, laminectomy, or MI-TLIF using skin-anchored ION and MI-TLIF by the same surgeon using 2D fluoroscopy were selected. Operative variables, radiation exposure, and short-term outcomes of all procedures were summarized. Time-demand and radiation exposure of fluoroscopy and ION for MI-TLIF were compared.Of the 326 patients included, 232 were in the ION cohort (92 microdiscectomies, 65 laminectomies, and 75 MI-TLIFs) and 94 in the MI-TLIF using 2D fluoroscopy cohort. Time for ION setup and image acquisition was a median of 22 to 24 minutes. Total fluoroscopy time was a median of 10 seconds for microdiscectomy, 9 for laminectomy, and 26 for MI-TLIF. Radiation dose was a median of 15.2 mGy for microdiscectomy, 16.6 for laminectomy, and 44.6 for MI-TLIF, of this, 93%, 95%, and 37% for microdiscectomy, laminectomy, and MI-TLIF, respectively were for ION image acquisition, with the rest attributable to the procedure. There were no wrong-level surgeries. Compared with fluoroscopy, ION for MI-TLIF resulted in lower operative times (92 vs. 108 min, P 0.0001), fluoroscopy time (26 vs. 144 s, P 0.0001), and radiation dose (44.6 vs. 63.1 mGy, P = 0.002), with equivalent time-demand and length of stay. ION lowered the radiation dose by 29% for patients and 55% for operating room personnel.Skin-anchored ION does not increase time-demand compared with fluoroscopy, is feasible, safe and accurate, and results in low radiation exposure.3.

The evaluation and management of spinal disorders is complex and constantly evolving. Back pain and spinal deformity are substantial contributors to hospital and outpatient physician visits even for young patients. With new insights into the etiology, clinical presentation, and evaluation, children can be more accurately diagnosed and treated. Patients with adolescent idiopathic scoliosis may undergo selective fusion to preserve motion segments, and in some cases, vertebral body tethering or other growth-modification techniques may provide correction with motion preservation in this rapidly changing specialty. The understanding of spinopelvic parameters (pelvic incidence, pelvic tilt, sacral slope) and sagittal balance as they relate to clinical health status has provided surgeons with valuable guidance when managing pediatric and adult spinal deformity. An evidence-based approach to the management of spinal disorders across the continuum of ages has the goal of improving the value of care through optimization of outcomes and limitation of costs and complications. There are new paradigms in the management of spinal disorders and evidence-based approaches to the evaluation and management of patients across the ages.

Background Context The presence of missing data is a limitation of large datasets, including the National Surgical Quality Improvement Program (NSQIP). In addressing this issue, most studies use complete case analysis, which excludes cases with missing data, thus potentially introducing selection bias. Multiple imputation, a statistically rigorous approach that approximates missing data and preserves sample size, may be an improvement over complete case analysis. Purpose The present study aims to evaluate the impact of using multiple imputation in comparison with complete case analysis for assessing the associations between preoperative laboratory values and adverse outcomes following anterior cervical discectomy and fusion (ACDF) procedures. Study Design/Setting This is a retrospective review of prospectively collected data. Patient Sample Patients undergoing one-level ACDF were identified in NSQIP 2012–2015. Outcome Measures Perioperative adverse outcome variables assessed included the occurrence of any adverse event, severe adverse events, and hospital readmission. Methods Missing preoperative albumin and hematocrit values were handled using complete case analysis and multiple imputation. These preoperative laboratory levels were then tested for associations with 30-day postoperative outcomes using logistic regression. Results A total of 11,999 patients were included. Of this cohort, 63.5% of patients had missing preoperative albumin and 9.9% had missing preoperative hematocrit. When using complete case analysis, only 4,311 patients were studied. The removed patients were significantly younger, healthier, of a common body mass index, and male. Logistic regression analysis failed to identify either preoperative hypoalbuminemia or preoperative anemia as significantly associated with adverse outcomes. When employing multiple imputation, all 11,999 patients were included. Preoperative hypoalbuminemia was significantly associated with the occurrence of any adverse event and severe adverse events. Preoperative anemia was significantly associated with the occurrence of any adverse event, severe adverse events, and hospital readmission. Conclusions Multiple imputation is a rigorous statistical procedure that is being increasingly used to address missing values in large datasets. Using this technique for ACDF avoided the loss of cases that may have affected the representativeness and power of the study and led to different results than complete case analysis. Multiple imputation should be considered for future spine studies.

To determine the rate of preoperative modifiable laboratory abnormalities (both major and minor) and the association with early postoperative medical and surgical complications. All patients undergoing thoracolumbar three-column osteotomy between 2013 and 2016 with preoperative laboratory data were identified. Potential preoperative modifiable laboratory abnormalities (major and minor) were assessed including hyponatremia (sodium

Spine disorders are common, cause significant pain and functional limitation, and are costly. Variation in the utilization of services and outcomes of spine care have raised questions among payers about the value of the spine care they are buying. Value for spine care can be achieved through a focus on delivering the highest quality and most appropriate care consistent with patient preferences. A coordinated, multidisciplinary approach is needed to achieve high-value care. Routine measurement of outcomes is needed to prove it.

Study design Cost-effectiveness analysis. Objective To investigate 7-years cost-effectiveness of two-level cervical disc replacement (CDR) and anterior cervical discectomy and fusion (ACDF). Summary of background data CDR and ACDF are both effective treatment strategies for managing degenerative conditions of the cervical spine. CDR has been shown to be a more-cost effective intervention in the short term, but the long-term cost-effectiveness has not been established. Methods We analyzed 7-years follow-up data from the two-level Medtronic Prestige LP investigational device exemption study. Short-form 36 (SF-36) data were converted into health utility scores using the SF-6D algorithm. Costs were based on direct costs from the payer perspective, and effectiveness was measured as quality-adjusted life years (QALYs). The willingness-to-pay (WTP) threshold was set to $50,000/QALY. A probabilistic sensitivity analysis was conducted via Monte Carlo simulation. Results Two-level CDR had a 7-year cost of $176,654.19, generated 4.65 QALYs, and had a cost-effectiveness ratio of $37,993.53/QALY. Two-level ACDF had a 7-year cost of $158,373.48, generated 4.44 QALYs, and had a cost-effectiveness ratio of $35,635.72. CDR was associated with an incremental cost of $18,280.71 and an incremental effectiveness of 0.21 QALYs, resulting in an incremental cost-effectiveness ratio (ICER) of $89,021.04, above the WTP threshold. Our Monte Carlo simulation demonstrated CDR would be chosen 46% of the time based on 10,000 simulations. Conclusion Two-level CDR and ACDF are both cost-effective procedures at 7-year follow up for treating degenerative conditions of the cervical spine. Based on an ICER of $89,021.04/QALY, we cannot conclude which treatment is the more cost-effective option at 7-years. CDR would be chosen 46% of the time based on 10,000 iterations of our Monte Carlo probabilistic sensitivity analysis. Level of evidence 3.

Study Design: Propensity score matched retrospective cohort study. Objectives: Obesity is a major confounder in determining the independent effect of metabolic syndrome (MetS) on complications after spinal surgery. The purpose of this study is to differentiate MetS from obesity as an independent influence on perioperative outcomes after elective lumbar spine fusion. Methods: One- to 3-level posterior spinal fusion cases were identified from the 2011-2014 American College of Surgeons’ National Surgical Quality Improvement Program. To determine the effects of MetS outside of obesity itself, patients with MetS were first compared to a no-MetS cohort and then to an obese-only no-MetS cohort. Two propensity score matches based on demographics, comorbidities, surgical complexity, and diagnosis were used to match patients in 1:1 ratios and compare outcomes. Logistic regression with propensity score adjustment was further utilized as a secondary method of reducing selection bias. Results: Out of 18 605 patients that met criteria for inclusion, 1903 (10.2%) met our definition of MetS. Patients with MetS had a higher rate of wound complications (3.8% vs 2.7% obese no MetS, P = .045; vs 2.6% no MetS, P = .035), readmissions (7.4% vs 2.2% obese no MetS, P < .001; vs 4.6% no MetS, P < .001), and extended length of stay (29.1% vs 23.9% obese no MetS, P < .001; vs 23.5% no MetS, P < .001). Patients with MetS were more likely to experience a wound complication (odds ratio = 1.47, 95% confidence interval = 1.02-2.12) or readmission (odds ratio = 1.48, 95% confidence interval = 1.22-1.80). Conclusions: Even after controlling for obesity, MetS is an independent risk factor for adverse short-term outcomes. These findings have various implications for preoperative risk stratification and reduction strategies.

Study Design: Prospective cohort study. Objectives: To describe the rate of short-term complications following the posterior use of recombinant human bone morphogenetic protein–2 (rhBMP-2) in cervical deformity (CD) surgery. Methods: CD patients from 2013 to 2015 were enrolled in a prospective, multicenter database. Patients were divided into those receiving rhBMP-2 (BMP) and no rhBMP-2 (NOBMP). The relationship between BMP use, demographic variables surgical variables, radiographic parameters and complications was evaluated. Results: A total of 100 patients (47 BMP, 53 NOBMP) were included. Follow-up time averaged 7.6 months (range 3-12 months). An average of 13.6mg of BMP was used per person with 1.49 mg per level. Compared with the NOBMP group, patients in the BMP group were older (P = .03). BMP was more commonly used in patients that and had longer prior fusions (6.0 vs 2.5, P < .01). There were no differences between groups with regards to a history of surgery, Charlson Comorbidity Index, estimated blood loss, operation time, fusion levels, and surgical approach. The maintenance of radiographic parameters at 6-month follow-up was similar. There were no differences in terms of total complication incidence, total complications per person, major complications per person or any specific complication. Linear regression and Pearson correlation analysis did not reveal any strong r2 values (r2 = 0.09, 0.08, 0.06) between the use of BMP and complications (major or operative). Conclusions: BMP use was not directly associated with an increased incidence of early complications in this prospective cohort of operative adult CD patients. Its use was associated with increased number of levels instrumented and fused.

BACKGROUND Surgical treatments for adult cervical spinal deformity (ACSD) are often complex and have high complication rates. OBJECTIVE To assess all-cause mortality following ACSD surgery. METHODS ACSD patients presenting for surgical treatment were identified from a prospectively collected multicenter database. Clinical and surgical parameters and all-cause mortality were assessed. RESULTS Of 123 ACSD patients, 120 (98%) had complete baseline data (mean age, 60.6 yr). The mean number of comorbidities per patient was 1.80, and 80% had at least 1 comorbidity. Surgical approaches included anterior only (15.8%), posterior only (50.0%), and combined anterior/posterior (34.2%). The mean number of vertebral levels fused was 8.0 (standard deviation [SD] = 4.5), and 23.3% had a 3-column osteotomy. Death was reported for 11 (9.2%) patients at a mean of 1.1 yr (SD = 0.76 yr; range = 7 d to 2 yr). Mean follow-up for living patients was 1.2 yr (SD = 0.64 yr). Causes of death included myocardial infarction (n = 2), pneumonia/cardiopulmonary failure (n = 2), sepsis (n = 1), obstructive sleep apnea/narcotics (n = 1), subsequently diagnosed amyotrophic lateral sclerosis (n = 1), burn injury related to home supplemental oxygen (n = 1), and unknown (n = 3). Deceased patients did not significantly differ from alive patients based on demographic, clinical, or surgical parameters assessed, except for a higher major complication rate (excluding mortality; 63.6% vs 22.0%, P = .006). CONCLUSION All-cause mortality at a mean of 1.2 yr following surgery for ACSD was 9.2% in this prospective multicenter series. Causes of death were reflective of the overall high level of comorbidities. These findings may prove useful for treatment decision making and patient counseling in the context of the substantial impact of ACSD.

BACKGROUND Despite the potential for profound impact of adult cervical deformity (ACD) on function and health-related quality of life (HRQOL), there are few high-quality studies that assess outcomes of surgical treatment for these patients. OBJECTIVE To determine the impact of surgical treatment for ACD on HRQOL. METHODS We conducted a prospective cohort study of surgically treated ACD patients eligible for 1-yr follow-up. Baseline deformity characteristics, surgical parameters, and 1-yr HRQOL outcomes were assessed. RESULTS Of 77 ACD patients, 55 (71%) had 1-yr follow-up (64% women, mean age of 62 yr, mean Charlson Comorbidity Index of 0.6, previous cervical surgery in 47%). Diagnoses included cervical sagittal imbalance (56%), cervical kyphosis (55%), proximal junctional kyphosis (7%) and coronal deformity (9%). Posterior fusion was performed in 85% (mean levels = 10), and anterior fusion was performed in 53% (mean levels = 5). Three-column osteotomy was performed in 24% of patients. One year following surgery, ACD patients had significant improvement in Neck Disability Index (50.5 to 38.0, P < .001), neck pain numeric rating scale score (6.9 to 4.3, P < .001), EuroQol 5 dimension (EQ-5D) index (0.51 to 0.66, P < .001), and EQ-5D subscores: mobility (1.9 to 1.7, P = .019), usual activities (2.2 to 1.9, P = .007), pain/discomfort (2.4 to 2.1, P < .001), anxiety/depression (1.8 to 1.5, P = .014). CONCLUSION Based on a prospective multicenter series of ACD patients, surgical treatment provided significant improvement in multiple measures of pain and function, including Neck Disability Index, neck pain numeric rating scale score, and EQ-5D. Further follow-up will be necessary to assess the long-term durability of these improved outcomes.

BACKGROUND CONTEXT Comparative studies of patients with cervical spondylosis treated with either cervical disc replacement (CDR) or anterior cervical discectomy and fusion (ACDF) are sparse in number. Previous studies have demonstrated good outcomes in patients undergoing CDR with moderate cervical spondylosis involving the disc, uncovertebral or facet joints. PURPOSE To compare clinical outcomes in patients with moderate cervical spondylosis undergoing CDR vs, the gold standard, ACDF. STUDY DESIGN/SETTING Retrospective review of prospectively collected data. PATIENT SAMPLE Patients who underwent one or 2-level CDR or ACDF with moderate cervical spondylosis, quantified using a validated grading scale, were identified, and prospectively collected data was retrospectively reviewed. OUTCOME MEASURES Neck Disability Index (NDI), VAS-Neck, VAS-Arm and PROMIS Physical Function (PROMIS-PF) computer adaptive test score. Methods Patients who underwent one or two-level CDR or ACDF with moderate cervical spondylosis, quantified using a validated grading scale, were identified, and prospectively collected data was retrospectively reviewed. Cervical spondylosis was graded by assessing disc height, facet arthrosis, and uncovertebral joint degeneration. Each of these characteristics was given a score of 0, 1 or 2 with increasing scores correlating with more severe disease. Demographic, operative, and cervical spondylosis grades and achievement of MCID for each PRO was analyzed and compared between the two groups. Results A total of 66 patients were included in the present study, of which 35 (53%) were treated with CDR and 31 (47%) with ACDF. Average follow up was 15.5 months. Patients treated with ACDF were significantly older (58.7 vs 43.0 years-old, P Conclusions The results of the present study demonstrate that patients with moderate cervical spondylosis treated with CDR reported similar postoperative patient reported outcomes to those treated with ACDF. The use of CDR in patients with spondylosis of the uncovertebral joint, facet joint, or disc space height loss may result in similar outcomes compared to ACDF treated patients, while preserving motion and avoiding the biologic demand of obtaining a fusion across the involved cervical levels. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Several previous randomized controlled trials have documented the success of cervical disc replacement (CDR) in treating radiculopathy and/or myelopathy, but many did not systematically compare outcomes of patients with radiculopathy versus those with myelopathy. Currently, there is still controversy about whether CDR utilization in patients with components of myelopathy can result in equivalent outcomes when compared to its use in patients with only radiculopathy. PURPOSE The purpose of the present study was to compare the minimally clinically important difference (MCID) across multiple patient-reported outcomes (PROs) in patients undergoing CDR for cervical spondylotic radiculopathy versus myeloradiculopathy. STUDY DESIGN/SETTING Retrospective review of prospectively collected data. PATIENT SAMPLE Patients who underwent one or two-level CDR with radiculopathy versus myeloradiculopathy. OUTCOME MEASURES Neck Disability Index (NDI), VAS-Neck, VAS-Arm, Short Form-12 Health Survey (SF-12) Physical Component Score (PCS), SF-12 Mental Component Score (MCS), PROMIS Physical Function (PF). METHODS Demographic variables and operative characteristics were analyzed for differences between patients with radiculopathy versus myeloradiculopathy. PROs were assessed for differences between the two diagnosis groups as well as improvements within each group following surgery. An MCID analysis of PROs for each diagnosis group was performed and the percentage of patients achieving the MCID was compared between the two diagnosis groups. RESULTS A total of 85 patients were included in the present study, of which 48 (56%) had radiculopathy and 37 (44%) had myeloradiculopathy. Average follow-up was 13.4 months. There were no significant differences in preoperative demographic variables, or the number and distribution of cervical levels treated between the two diagnosis groups. There were no significant differences in preoperative NDI, Neck-VAS, Arm-VAS, SF-12 PCS, SF-12 MCS, and PROMIS PF scores between the two groups. At the final postoperative visit, there was no significant difference in each PRO assessed between the radiculopathy and myeloradiculopathy groups and both groups demonstrated statistically significant improvement in each PRO compared to preoperative values (P CONCLUSIONS This is the first study to compare the MCID across various PROs in patients with radiculopathy versus myelopathy undergoing CDR. The percentage of patients achieving the MCID was not significantly different at each postoperative period assessed in the radiculopathy and myeloradiculopathy groups. In addition, the percentage of patients achieving the MCID continued to increase from 6-weeks to final follow-up in both groups for almost all PROs assessed. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.