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Computed tomography (CT) measurement of Hounsfield Units (HU) has been described as a tool for assessing BMD. For surgeons considering a revision lumbar fusion, knowledge of the BMD of the UIV is of value for surgical planning. However, the presence of metal artifact from instrumentation presents a potential confounder, and prior studies have not validated measurements of HU in this setting.To determine if HU can be measured reliably at the supra-adjacent and upper instrumented levels of a lumbar fusion.Retrospective observational cohort PATIENT SAMPLE: Consecutive series of patients who had lumbar CT scans after an instrumented posterior lumbar fusion.Hounsfield Units at the upper instrumented vertebra and levels proximal.We analysed pre- and postoperative CT scans of 50 patients who underwent L2 and distal instrumented lumbar fusion whose scans were no greater than 1 year apart, obtaining HU measurements of analogous axial cuts at the upper instrumented level (immediately caudal to the halo of the pedicle screw), as well as additional control levels above the construct.The HU at the pre-and postoperative UIV exhibited a strong correlation (r=0.917, p.001), as did one (r=0.887, p.001) and two (r=0.853, p.001) levels above the UIV. There were significant but predictable reductions in the postoperative HU compared to preoperative at one (-9.0±26.2) and two (-12.2±30.2) levels above the UIV, as well as T12 (-13.9±42.2). There was no significant difference in HU at the UIV (4.6±34.1).Postoperative HU at the UIV was strongly correlated with and not significantly different from the preoperative HU. Although the HU in the vertebrae proximal to the UIV were slightly lower postoperatively, this change was predictable using a correction factor.

BACKGROUND CONTEXT Excessive use of postoperative imaging after lumbar surgery has been documented, becoming a target for cutting costs. This must be balanced with the patient's need for information and allay their postoperative concerns. PURPOSE To determine the incidence and associated costs of patient interactions with the healthcare system, outside the standard follow up routine, in the first postoperative year. STUDY DESIGN Retrospective longitudinal cohort. PATIENT SAMPLE Consecutive series of 200 patients who underwent lumbar fusions from 2018 to 2019 from a multi-surgeon single tertiary spine center. OUTCOME MEASURES All healthcare encounters: phone calls, office and emergency department visits, and additional testing METHODS A consecutive series of 200 patients who underwent lumbar fusions from 2018 to 2019 were identified. All non-routine healthcare encounters: phone calls, office and emergency department visits, and additional testing were collected. Direct costs for all healthcare services were determined using the Medicare Allowable rates. Indirect costs were determined using local, median income, length of office visits, and distance from the clinic to the patient's home. RESULTS Of 200 patients, 14 with thoracic fusion were excluded. The mean age of the 186 included patients was 58.26 years and 85 (46%) were male. Forty-seven percent (87/186) had only routine postoperative visits and 24 had revision surgery. Seventy-five patients made a total of 102 phone calls, 55 office visits, leading to 38 diagnostic studies none of which led to an additional intervention. Using Medicare Allowable rates, the mean direct cost was $776 per patient and the using a median income of $16/h the mean indirect cost was $124 per patient. There were no differences in the baseline characteristics among the patients who only had routine post-op encounters, had non-routine encounters or had a repeat surgery. CONCLUSIONS Forty percent of the patients undergoing lumbar surgery had a healthcare encounter outside their routine follow up that did not result in additional intervention after their index operation. These potentially unnecessary encounters create additional cost and inconvenience to both the patient and healthcare system. Providing patient reassurance is important and providers should identify ways to reduce associated costs through patient education, virtual visits, or new technologies to monitor patient's postoperative progress.

Patients with advanced pyogenic spondylodiscitis can present with neurologic deficits. However, the prevalence, severity, and outcome of the neurologic deficits are not well known. A systematic review was performed to improve the knowledge of this commonly encountered clinical scenario. The considerable number of severe neurologic deficits in addition to their poor recovery, even after surgical intervention, demonstrates that the early diagnosis of pyogenic spondylodiscitis is crucial. Prompt surgical intervention is likely associated with a greater chance of improvement of neurologic status than nonsurgical treatment.

Symptomatic postoperative epidural hematomas are rare, with an incidence of 0.10% to 0.69%. Risk factors have varied in the literature, but multiple studies have reported advanced age, preoperative or postoperative coagulopathy, and multilevel laminectomy as risk factors for hematoma. The role of pharmacologic anticoagulation after spine surgery remains unclear, but multiple studies suggest it can be done safely with a low risk of epidural hematoma. Prophylactic suction drains have not been found to lower hematoma incidence. Most symptomatic postoperative epidural hematomas present within the first 24 to 48 hours after surgery but can present later. Diagnosis of a symptomatic hematoma requires correlation of clinical signs and symptoms with a compressive hematoma on MRI. Patients will usually first complain of a marked increase in axial pain, followed by radicular symptoms in the extremities, followed by motor weakness and sphincter dysfunction. An MRI should be obtained emergently, and if it confirms a compressive hematoma, surgical evacuation should be carried out as quickly as possible. The prognosis for neurologic improvement after evacuation depends on the time delay and the degree of neurologic impairment before evacuation.

BACKGROUND: Novel methods of bone density assessment using computed tomography (CT) and magnetic resonance imaging (MRI) have been increasingly reported in the spine surgery literature. Correlations between these newer measurements and traditional Dual-Energy X-ray Absorptiometry (DEXA) is not well known. The purpose of this study is to perform an updated systematic review of correlations between bone mineral density (BMD) from CT or MRI and DEXA. METHODS: Articles published between 2011 and 2021 that reported correlations between the CT-HU or MRI measurements to DEXA t-scores or BMD of lumbar spine or hip were included in this systematic review. RESULTS: A total of 25 studies (15 CT, 10 MRI) met the inclusion criteria with a total number of 2,745 patients. The pooled correlation coefficient of spine CT-HU versus spine DEXA, spine CT-HU versus hip DEXA and spine CT-HU versus lowest t-score were 0.60, 0.50 and 0.60 respectively. Regarding spine DEXA parameters, the pooled r(2) for spine CT-HU versus spine t-score was 0.684 and spine CT-HU versus spine BMD was 0.598. Furthermore, in patients undergoing spine surgery in four studies, the pooled correlation between spine CT and spine DEXA was (r(2): 0.64). In MRI studies, the pooled r(2) of spine MRI versus spine DEXA and spine MRI versus hip DEXA were -0.41 and -0.44 respectively. CONCLUSIONS: CT-HU has stronger correlations with DEXA than MRI measurements. Lumbar CT-HU has the highest pooled correlation (r(2) = 0.6) with both spine DEXA and lowest skeletal t-score followed by lumbar CT-HU with hip DEXA (r(2) = 0.5) and lumbar MRI with hip (r(2) = 0.44) and spine (r(2) = 0.41) DEXA. Both imaging modalities achieved only a moderate correlation with DEXA. Few studies in both modalities have investigated the correlation in spine surgery populations and the available data shows that the correlations are worse in the degenerative spine population. A careful interruption of CT HU and MRI measurement when evaluation of BMD as they only moderately correlated with DEXA scores. At this time, it is unclear which modality is a better predictor of mechanical complications and clinical outcomes in spine surgery patients.

Regional differences in outcomes after spine surgery are poorly understood. We assessed disability and quality-of-life outcomes by geographic region in the United States using the NeuroPoint Alliance Quality Outcomes Database.We queried the prospective Quality Outcomes Database patient registry to identify patients who underwent elective 1- or 2-level lumbar surgery for grade I degenerative spondylolisthesis from July 2014 through June 2016. Primary outcome measures included Oswestry Disability Index (ODI) and EuroQOL-5D (EQ-5D) reported at 24 months postoperatively. Differences in EQ-5D and ODI were compared across geographic regions of the United States (Northeast, Midwest, South, West).We identified 608 patients from 12 centers who underwent surgery. Of these, 517 (85.0%) had ODI data and 492 (80.9%) had EQ-5D data at 24 months. Southern states had the largest representation (304 patients; 5 centers), followed by Northeastern (114 patients; 3 centers), Midwestern (96 patients; 2 centers), and Western (94 patients; 2 centers) states. Baseline ODI scores were significantly different among regions, with the South having the greatest baseline disability burden (Northeast: 40.9 ± 16.9, South: 51.2 ± 15.8, Midwest: 40.9 ± 17.8, West: 45.0 ± 17.1, P0.001). The change in ODI at 24 months postoperatively was significantly different among regions, with the South showing the greatest ODI improvement (Northeast: -21.1 ± 18.2, South: -26.5 ± 20.2, Midwest: -18.2 ± 22.9, West: -21.7 ± 19.6, P0.001). All regions had ≥60% achievement of the minimum clinically important difference in ODI at 24 months postoperatively. No regional differences were observed for EQ-5D.Significant regional variation exists for disability outcomes, but not quality of life, at 24 months after spinal surgery for grade I degenerative spondylolisthesis.

Background context Patients undergoing single-level posterior lumbar decompression and fusion (PLDF) usually do not need transfusions. However, patients undergoing two or three-level PLDF occasionally require transfusion postoperatively even when estimated blood loss (EBL) or blood loss from drains appears acceptable. Estimating the volume of HBL is critical in perioperative fluid management. Purpose To determine the volume of hidden blood loss (HBL) in 2- or 3- level PLDF. Study Design Single center, multi-surgeon, secondary analysis from a prospective randomized clinical trial of cell-saver use. Patient Sample Patients enrolled in a prospective randomized trial of cell-saver undergoing two- or three-level PLDF were included in this analysis. Methods Total blood loss was calculated using four estimation formulas including Bourke's, Gross’, Camarasa's, and Lopez-Picado's formulas. HBL was determined by subtracting the visible loss (EBL and blood loss from drains) from the calculated total blood loss. Results A total of 89 patients (36 males, mean age 62 years) were included. Seventy-five patients underwent open two-level fusion while 14 had three-level fusions. Intervertebral fusion was performed in 20 patients. Mean surgical time was 261 minutes, and EBL was 685 ml. Mean blood loss from drains was 824 ml. Seventy patients received allogenic blood while 47 Cell Saver blood reinfused intraoperatively. Hidden blood loss was calculated to be 678 ml, 963 ml, 1267 ml, and 819 ml using each formula. Conclusions HBL following two or three-level PLDF was substantial and more than EBL. Postoperative management of blood loss should take HBL into account.

BACKGROUND CONTEXT Health literacy, defined as “the degree to which individuals have the capacity to obtain, process, and understand basic health information and services needed to make appropriate health decisions,” has been demonstrated to affect access to care and appropriate healthcare utilization. PURPOSE To determine the impact of health literacy in the evaluation and management of patients with chronic low back pain. STUDY DESIGN Cross sectional. PATIENT SAMPLE Patients seen at a multisurgeon spine specialty clinic. OUTCOME MEASURES Oswestry Disability Index, EQ-5D, and Numeric Rating Scales (0–10) for back and leg pain. METHODS The Newest Vital Sign (NVS) and Health Literacy Survey, Oswestry Disability Index, EQ-5D and pain scales were administered to patients undergoing evaluation and treatment for lumbar degenerative disease in the outpatient setting. Patients were surveyed regarding their use of medication, therapy, and pain management modalities. RESULTS Of 201 patients approached for participation, 186 completed the health literacy surveys. Thirty (17%) were assessed as having limited literacy, 52 (28%) as possibly having limited literacy and 104 (56%) having adequate literacy based on their NVS scores. The cohort with low NVS scores also had low Health Literacy Survey Scores. Patients with limited literacy had worse back and leg pain scores compared with patients with possibly limited literacy and adequate literacy. Patients with adequate health literacy were more likely to use medications (80% vs. 53%, p = .017) and were more likely to see a specialist (34% vs. 17%) compared with those with limited literacy. Patients with limited health literacy were not more likely to see a chiropractor (7% vs. 7%), but reported more visits (19 vs. 8). CONCLUSIONS Patients with lower health literacy reported worse back and leg pain scores, indicating either more severe disease or a fundamental difference in their responses to standard health-related quality of life measures. This study also suggests that patients with limited health literacy may underutilize some resources and overutilize other resources. Further study is needed to clarify these patterns, and to examine their impact on health status and clinical outcomes.

BACKGROUND CONTEXT The recent opioid crisis in the US highlights opioid related side-effects and the dire need to reduce opioid exposure with alternative approaches. Prior studies reported that as many as 25% of opioid naive patients undergoing lumbar fusion surgery are still consuming opioids at 2 years postoperative. Currently, opioids are a primary component of anesthesia during spinal surgery. We developed an opioid sparing anesthesia (OSA) protocol for lumbar spinal fusion surgery to mitigate opioid exposure. PURPOSE To compare surgical, peri- and postoperative process measures and in-hospital opioid consumption in patients receiving OSA vs traditional anesthesia. STUDY DESIGN/SETTING Retrospective, single center propensity-matched observational cohort study. PATIENT SAMPLE Patients who underwent 1-4 level lumbar fusion for degenerative conditions. OUTCOME MEASURES Daily and total opioid consumption in morphine milligram equivalents (MME). Methods Patients undergoing Results Of 143 OSA patients meeting inclusion criteria, 134 OSA patients were successfully propensity matched to 134 non-OSA patients. Consistent with propensity matching, there was no difference in baseline demographic parameters between cohorts. Patients undergoing OSA had reduced EBL (197mL vs 324mL, p=0.000) and OR time (153min vs 193min, p=0.000) compared to non-OSA. Emergence time (9.9min vs 11.6min, p=0.151) and PACU time (90min vs 88min, p=0.688) was similar between cohorts. There was no difference in LOS (3.3day vs 3.5 days, p=0.599). Daily opioid consumption was reduced from POD 1 (114MME vs 139MME, p=0.002) and maintained each day with decreased total consumption (195MME vs 272MME, p=0.002). Pain score on transfer out of PACU was decreased for OSA patients as well (4.8 vs 6.0, p=0.000). Conclusions In a matched comparison of OSA vs traditional anesthesia for 1-4 lumbar spinal fusions in degenerative conditions we found a reduction in EBL, OR Time, PACU pain scores, and daily/total opioid in hospital consumption. The findings of this pilot study justify ongoing efforts to optimize OSA and undertake larger prospective studies of OSA protocols. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Background Context Although lumbar disc herniation (LDH) classically presents with lower extremity radiculopathy, there are patients who have substantial associated back pain. Purpose The present study aims to determine if patients with LDH with substantial back pain improve with decompression alone. Study Design This is a longitudinal observational cohort study. Patient Sample Patients enrolled in the Quality and Outcomes Database with LDH and a baseline back pain score of ≥5 of 10 who underwent single- or two-level lumbar discectomy only. Outcome Measures Back and leg pain scores (0–10), Oswestry Disability Index (ODI), and EuroQoL 5D were measured. Methods Standard demographic and surgical variables were collected, as well as patient-reported outcomes at baseline and at 3 and 12 months postoperatively. Results The mean age of the cohort was 49.8 years and 1,195 (52.8%) were male. Mean body mass index was 30.1 kg/m2. About half of the patients (1,103, 48.8%) underwent single-level discectomy and the other half (1,159, 51.2%) had two-level discectomy. Average blood loss was 44 cc. Most of the patients (2,217, 98%) were discharged home with routine postoperative care. The average length of stay was 0.53 days. At 3 and 12 months postoperatively, there were statistically significant (p Conclusions Patients with LDH who have substantial back pain can be counseled to expect improvement in their back pain scores 12 months after a discectomy.

The pelvic incidence defines the amount of lordosis required in the lumbar spine, and a lumbar lordosis within 11° of the pelvic incidence defines alignment of the lumbo-pelvic region. Pelvic tilt is a compensatory mechanism that allows patients to achieve sagittal balance in the setting of decreased lumbar lordosis with the primary compensatory mechanisms being hip extension and knee flexion. Planning an adult lumbar deformity operation requires a comprehensive history and physical examination and thorough radiographic evaluation with the goal of restoring alignment between the pelvic incidence and lumbar lordosis and restoring a normal pelvic tilt.

The purpose of this study was to determine whether the risk of dislocation and/or revision following THA is increased in patients with a history of prior lumbar fusion given the alterations in dynamic pelvic motion following LSF.A total of 62,387 patients (5% Medicare part B claims database) were identified from 1997 to 2014 with primary THA. From this group, 1809 patients (2.9%) were stratified to identify those with prior lumbar fusion within 5 years of primary THA to compare risk of dislocation and revision with those without lumbar fusion. Multivariate cox regression analysis was performed adjusting for age, socioeconomic status, race, census, region, gender, Charlson score, preexisting conditions, and type of fusion.Between years 2002 and 2014, there was a 293% increase in the number of patients with prior lumbar fusion undergoing THA. Prevalence of hip dislocation in patients with lumbar fusion before THA was 7.4% compared to 4.8% without fusion, P.001. There was an 80% increase in dislocation in the fusion group at 6 months, 71% at 1 year, and 60% at 2 years. There was a 48% increased risk of failure leading to revision hip surgery in patients with fusion at 6 months, 41% at 1 year, and 47% at 2 years. Dislocation was the most common mode of failure leading to revision in both the fusion group (20.8%) and the nonfusion group (16%).Results of this study demonstrate that lumbar fusion before THA is an independent risk factor for dislocation leading to increased risk of revision THA.

The Scoliosis Research Society-22r (SRS-22r) has been shown to be reliable, valid and responsive to change in patients with adult spinal deformity (ASD) undergoing surgery. The minimum clinically important difference (MCID) quantifies a threshold value of improvement that is clinically relevant to the patient. Health-related quality of life scores depend on age. The purpose of this study was to assess MCID threshold values stratified by age for SRS-22r domains in patients with ASD undergoing surgical correction.We identified a consecutive series of 184 Japanese ASD patients who completed the SRS-22r and Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) preoperatively and 1 year postoperatively. Effectiveness as measured on the JOABPEQ was used as the anchor to determine MCID for the Function, Pain, and Mental health domains using receiver-operating-characteristic (ROC) curve analysis. We performed MCID analysis stratified by age (70 or ≥70).Mean preoperative SRS-22r Function score was 2.69 improving to 3.23 at postoperatively (p 0.001). Mean preoperative SRS-22r Pain score was 3.04 improving to 3.78 at postoperatively (p 0.001). Mean preoperative SRS-22r Mental health score was 2.72 improving to 3.25 at postoperatively (p 0.001). There was a statistically difference in change in domain score between "not effective" and "effective" (p 0.001). The ROC curve analysis methods yielded MCID values of 0.58 for Function, 0.55 for Pain, and 0.70 for Mental health domains. There was difference of MCID value for Function and Mental health domain between aged70 and ≥70; 0.78 and 0.55 for Function; 0.70 and 0.48 for Mental health.Results of this study showed that MCID threshold values for SRS-22 Function and Mental health domains in older than 70 was lower than in younger than 70, potentially implying that older patients have lower expectation.

BACKGROUND CONTEXT In patients with lumbar spinal stenosis, it is crucial for clinicians to identify all symptomatic levels. Prior studies have demonstrated that CT-myelography has a greater sensitivity in revealing stenosis (94.4%) compared to MRI (75.9%). CT-myelograms demonstrate weight-bearing changes as opposed to single position and single time point changes on MRI. However, CT-myelography is invasive, requiring injection of contrast dye into the thecal sac. PURPOSE The purpose of this study is to identify patients in whom additional levels of stenosis are likely to be recognized by a CT-myelogram following an MRI scan. STUDY DESIGN/SETTING Retrospective observational cohort at a single multi-surgeon spine center. PATIENT SAMPLE Patients ≥45 years old who had an MRI followed by a CT-myelogram within 6 months with a diagnosis of stenosis, spondylolisthesis, or degenerative scoliosis. OUTCOME MEASURES Additional levels of moderate to severe stenosis identified on CT-myelogram vs MRI. METHODS Medical records were reviewed to collect standard demographic and surgical data and to note if patients were deemed to have single-level or multi-level stenosis clinically. MRIs and CT-Myelograms obtained within six months of each other were reviewed and each lumbar level was recorded as mild, moderate, or severe based on the radiologist's report. Fisher's exact test was performed with change in recorded level of stenosis from MRI to CT-Myelogram as the primary outcome of interest. Results Of 207 patients, 139 (67%) had clinically reported multilevel stenosis and 68 (33%) had single-level stenosis. CT-Myelogram identified a greater proportion of additional stenotic levels in patients with clinically reported multilevel stenosis (80/139, 58%) compared to patients with single-level stenosis (27/68, 40%, p=0.018). When classifying patients based on MRI findings of stenosis instead of clinical diagnosis, 90 (43%) patients had multi-level stenosis, and 117 (56%) had single-level stenosis. In patients with radiologist-reported multilevel stenosis, CT-myelogram also identified a greater proportion of additional stenotic levels (55/90, 61%) compared to patients with radiologist-reported single level stenosis (52/117, 44%, p=0.025). Conclusions CT myelography is significantly more likely to provide valuable additional information in patients with multilevel stenosis as compared to patients with single level stenosis. This finding was consistent regardless of whether the distinction of single-level or multilevel stenosis was determined by clinical diagnosis or based solely off the MRI report. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT A recent administrative database (PearlDiver) study reported increased 30-day complications with the utilization of robotic-assisted (RA) enabling technology. The authors reported increased fixation-related complications (3%) and infection rates (19%) in RA surgeries. Although there is ample evidence regarding improved pedicle screw accuracy with RA surgery, the complication profile has been called into question. PURPOSE The objective of the study is to compare 90-day complication rates between RA and nonrobotic-assisted (NRA) lumbar spinal fusions in propensity-matched cohorts. STUDY DESIGN/SETTING Retrospective single center observational propensity-matched observational cohort study. PATIENT SAMPLE Patients who underwent 1- to 3-level lumbar fusion surgery for degenerative conditions. OUTCOME MEASURES Surgical and medical (major/minor) complications at intraoperative, immediately postoperative, 30- and 90-day postoperative intervals. Additionally, reoperations and readmissions within 90 days. METHODS Of 146 RA cases that met inclusion criteria, 114 were successfully propensity matched to 114 patients from 214 cases who had 1-3 level lumbar fusion without robotic assistance based on age, sex, BMI, smoking status, surgical approach (posterior-only or anterior-posterior), ASA grade, revision vs primary, number of surgical levels, and number of interbody levels. We excluded tumor, trauma, infection or deformity cases. Continuous variables were compared using unpaired t-tests and categorical variables were compared using Fisher's exact test with significance set at 0.05. RESULTS Consistent with propensity matching, there was no difference in patient demographics and baseline characteristics between groups. Neither group had intraoperative fixation-related complications or required a return to OR for malpositioned screws. All cause intraoperative complication rates were similar between NRA (5.3%) and RA groups (10.5%, p=0.366). Immediate postoperative medical complication rate was also similar between NRA (6.1%) and RA groups (1.8%, p=0.089). Thirty-day complication rates (NRA:15.8% vs RA:12.3%, p=0.446), 90-day complication rates (NRA:15.8% vs RA:14.9%, p=0.854), reoperation rates (NRA:6.1% vs RA:3.5%, p=0.354), and readmission rates (NRA:7.0% vs RA:6.1%, p=0.789) showed no difference between NRA and RA groups. There was no difference between return to OR for infection between the cohorts (NRA:6 [5%] vs RA:1 [0.8%], p=0.119). There was, however, improved length of stay (LOS) in the RA group compared to NRA group (2.5 vs 3.17 days, p=0.018). CONCLUSIONS In propensity-matched cohorts, patients undergoing 1- to 3-level level RA posterior lumbar fusion for degenerative conditions did not have increased 90-day complication rate, and had a shorter length of stay compared to NRA patients. There findings differ from a prior administrative database study as the RA group in the current study had 0% return to OR for malpositioned screws and 0.8% return to OR for infection. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Computed tomography (CT) measurement of Hounsfield Units (HU) has been described as a tool for assessing bone mineral density (BMD). For surgeons considering a revision lumbar fusion, knowledge of the BMD of the upper instrumented verterbra (UIV) is of value for surgical planning. However, the presence of metal artifact from instrumentation presents a potential confounder and prior studies have not validated measurements of HU in this setting. PURPOSE The purpose of this study is to determine if HU can be measured reliably at instrumented levels after a lumbar fusion. STUDY DESIGN/SETTING Retrospective observational cohort at a single multisurgeon spine center. PATIENT SAMPLE Consecutive series of patients who had lumbar CT Scans after an instrumented posterior lumbar fusion. OUTCOME MEASURES Hounsfield Units at the upper instrumented vertebra and levels proximal. METHODS We analyzed pre- and postoperative CT scans of 50 patients who underwent L2 and distal instrumented lumbar fusion whose scans were no greater than 1 year apart, obtaining HU measurements of analogous axial cuts at the upper instrumented level (immediately caudal to the halo of the pedicle screw), as well as additional control levels above the construct. RESULTS The HU at the pre-and postoperative UIV exhibited a strong correlation (r=0.917, p CONCLUSIONS Postoperative HU at the UIV was strongly correlated with and not significantly different from the preoperative HU. Although the HU in the vertebrae proximal to the UIV were slightly lower postoperatively, this change was predictable using a correction factor. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Although short-term adult symptomatic lumbar scoliosis (ASLS) outcomes studies favor operative over nonoperative treatment, long-term outcomes are critical for assessment of treatment durability. PURPOSE To assess whether operative treatment for ASLS provides greater improvement of patient-reported outcomes measures than nonoperative treatment at 5-6-year follow-up. STUDY DESIGN/SETTING Secondary analysis of prospective multicenter cohort. PATIENT SAMPLE Adults with symptomatic lumbar scoliosis enrolled into an NIH-sponsored study to assess outcomes of operative and nonoperative treatments. OUTCOME MEASURES Scoliosis Research Society-22 subscore (SRS-22 subscore), Oswestry Disability Index (ODI), occurrence of related serious adverse events (SAEs) METHODS The ASLS study is an NIH-sponsored multicenter prospective study to assess operative vs nonoperative treatment for ASLS, with randomized and observational treatment arms. Patients were 40-80 years of age with ASLS (Cobb >30° and ODI >20 or SRS-22 subscore (SRS-22) RESULTS The 286 ASLS patients (108 nonoperative, 178 operative) had follow-up rates at 2 and 5-6 years of 90% (256) and 74% (212), respectively. At 5 years, compared with nonoperative, operative patients had greater improvement in SRS-22 subscore (adjusted mean difference, 0.6 [95% CI, 0.5 to 0.6]) and ODI (adjusted mean difference, -14 [95% CI, -18 to -9]) (p CONCLUSIONS The significantly greater clinical improvement of operative vs nonoperative treatment for ASLS at 2 years is maintained at 5-6-year follow-up. Overall, operative patients with a related SAE still had greater improvement than nonoperative patients, but for operative patients with 2+ SAEs, the TEs were markedly reduced. These findings have important implications for patient counseling and cost-effectiveness assessments. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Medical comorbidities, particularly anxiety or depression, may potentially influence how patients perceive clinical benefit after surgery. The current study defined and compared minimum clinically important difference (MCID) thresholds in patients with and without anxiety/depression and obesity undergoing fusion for grade 1 degenerative spondylolisthesis. PURPOSE To determine if preoperative psychiatric diagnoses, more than obesity, alters the MCID threshold in patients undergoing fusion for spondylolisthesis. STUDY DESIGN/SETTING Retrospective analysis of multicenter, prospective database. PATIENT SAMPLE Patients who underwent lumbar fusion for grade 1 degenerative spondylolisthesis from January 2014 to August 2017 enrolled in the Quality Outcomes Database (QOD). OUTCOME MEASURES Oswestry Disability Index (ODI), EuroQOL5D (EQ-5D), back (BP, 0-10) and leg pain (LP, 0-10) scores METHODS The QOD was queried for patients who underwent lumbar fusion for grade 1 degenerative spondylolisthesis from January 2014 to August 2017. Patient Reported Outcomes (PROs) included ODI, EQ-5D, BPand LP scores. Both anchor-based and distribution-based methods for MCID calculation were used. RESULTS Of 462 eligible cases, 356 (77%) had complete baseline and 12-month PROs. The MCID values for ODI were similar in patients with and without a diagnosis of obesity (20.58 and 20.69, respectively), and with and without anxiety/depression (24.72 and 22.56, respectively). The MCID values for BP, LP, and EQ-5D were also similar among all groups regardless of method used to determine MCID. CONCLUSIONS MCID thresholds for ODI, EQ5D, back pain and leg pain in patients with and without anxiety/depression and obesity undergoing spinal fusion for grade 1 degenerative spondylolisthesis are similar. Preoperative clinical and shared decision-making may be improved by understanding that preop medical comorbidities do not affect how patients determine an important clinical change postoperatively. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Background: The Romberg test is used to identify balance issues in patients with Cervical Spondylotic Myelopathy (CSM), but has subjective interpretation. The purpose of this study is to evaluate force plate pressure readings during a Romberg test to quantify postural control. Methods: Quantitative Romberg force plate readings with eyes open and closed in patients with CSM were obtained and changes in balance measurements were compared to a normal population (N = 28, mean age 39 ± 7 years). Results: We identified 30 CSM patients with a mean age of 58 ± 10 years. Majority of patients presented with pain (90%) and neurologic symptoms (83%). Cord compression on imaging was identified in 90%. Mean eyes closed Romberg measurements were larger compared to eyes open measurements in CSM patients (p

In the current study, we sought to compare baseline demographic, clinical, and operative characteristics, as well as baseline and follow-up patient reported outcomes (PROs) of patients with any depressive and/or anxiety disorder undergoing surgery for low-grade spondylolisthesis using a national spine registry.The Quality Outcomes Database (QOD) was queried for patients undergoing surgery for Meyerding grade 1 lumbar spondylolisthesis undergoing 1-2 level decompression or 1 level fusion at 12 sites with the highest number of patients enrolled in QOD with 2-year follow-up data.Of the 608 patients identified, 25.6 % (n = 156) had any depressive and/or anxiety disorder. Patients with a depressive/anxiety disorder were less likely to be discharged home (p 0.001). At 3=months, patients with a depressive/anxiety disorder had higher back pain (p 0.001), lower quality of life (p 0.001) and higher disability (p = 0.013); at 2 year patients with depression and/or anxiety had lower quality of life compared to those without (p 0.001). On multivariable regression, depression was associated with significantly lower odds of achieving 20 % or less ODI (OR 0.44, 95 % CI 0.21-0.94,p = 0.03). Presence of an anxiety disorder was not associated with decreased odds of achieving that milestone at 3 months. The presence of depressive-disorder, anxiety-disorder or both did not have an impact on ODI at 2 years. Finally, patient satisfaction at 2-years did not differ between the two groups (79.8 % vs 82.7 %,p = 0.503).We found that presence of a depressive-disorder may impact short-term outcomes among patients undergoing surgery for low grade spondylolisthesis but longer term outcomes are not affected by either a depressive or anxiety disorder.

BACKGROUND CONTEXT Adult spinal deformity is a relatively prevalent condition for which surgical treatment has become increasingly common but concerns surrounding complications, revision rates and cost-effectiveness remain unresolved. Of these issues, cost-effectiveness is perhaps the most difficult to quantify as the requisite data is difficult to obtain. PURPOSE The purpose of this study is to report on the cost-effectiveness of surgical vs nonsurgical treatment for adult symptomatic lumbar scoliosis (ASLS) using the as-treated data and provide a comparison to previously reported intent-to-treat (ITT) analysis. STUDY DESIGN/SETTING Secondary analysis of data from the NIH sponsored study on ASLS that included randomized and observational arms. PATIENT SAMPLE Patients enrolled in the NIH sponsored study on ASLS that included randomized and observational cohorts with at least five-year follow-up data within the same treatment arm. OUTCOME MEASURES Quality Adjusted Life Years (QALY) derived from the SF-6D. METHODS Patients with at least five-year follow-up data within the same treatment arm were included. Data collected every three months included use of nonoperative modalities, medications and employment status. Costs for surgeries and nonoperative modalities were determined using Medicare allowable rates. Medication costs were determined using the RedBook and indirect costs were calculated based on reported employment status and income. Quality Adjusted Life Years (QALY) was determined using the SF-6D. RESULTS Of 286 patients, 195 patients (73 Nonop, 122 Op) met inclusion criteria. At five years, 29 (24%) patients in the Op group had a revision surgery of whom two had two revisions and one had three revisions. The cumulative cost for the Op group was $111,451 with a cumulative QALY gain of 2.29. The cumulative cost for the Non-Op group was $29,124 with a cumulative QALY gain of 0.41. This results in an ICER of $44,033 in favor of Op treatment. CONCLUSIONS This as-treated cost effectiveness analysis demonstrates that surgical treatment for adult lumbar scoliosis becomes favorable at year-three, one year earlier than suggested by a previous intent-to-treat analysis. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Recent studies suggest as much as 25% of patients undergoing spine surgery are still on opioids two years later. In response, we developed protocols to minimize opioid consumption following elective spine surgery. Our goal was to evaluate patients undergoing single-level Anterior Lumbar Interbody Fusions (ALIF ± posterior fixation) on MMPC compared to patients who were not (nonMMPC). PURPOSE To determine if the combination of an oral preoperative pain cocktail with transverse abdominis plane (TAP) block (multi-modal pain control: MMPC) will reduce length of stay (LOS), ileus, and in-hospital opioid consumption. STUDY DESIGN/SETTING Retrospective chart review. PATIENT SAMPLE Consecutive patients undergoing single-level ALIF for degenerative lumbar conditions by a single-surgeon. OUTCOME MEASURES Length of stay (LOS), incidence of ileus and in-hospital opioid consumption. METHODS A retrospective review of a prospective, single-surgeon, surgical database was utilized for consistency in technique. Consecutive patients undergoing single-level ALIF for degenerative lumbar conditions were identified before and after initiation of the MMPC. The MMPC consisted of a preop oral regimen of cyclobenzaprine (10mg), gabapentin (600mg), acetaminophen (1g) and methadone (10mg). Postoperatively they received a bilateral transverse abdominis plane (TAP) block with 0.5% Ropivicaine. Our primary outcome was total, in-hospital opioid consumption (morphine milligram equivalents: MME). RESULTS There were 68 patients in the MMPC cohort and 39 in the nonMMPC cohort. There was no difference in baseline demographics such as sex, BMI, smoking, or preoperative opioid use between the two groups. The MMPC cohort was older (56.7 vs 51.1 years, p=0.026). Similar rates of ileus (4 vs 6, p=0.102), no difference in LOS (3.8 vs 4.5, p=0.246) and no difference in index hospital costs was found. Although there was no difference in day of surgery MMEs (58.5 vs 68.9, p=0.387), cumulative MMEs each day after surgery was significantly lower in the MMPC cohort, with final cumulative MMEs being reduced by 62% (120.2 vs 314.8, p CONCLUSIONS The use of a MMPC regimen in patients undergoing single-level ALIF for degenerative conditions reduced opioid consumption starting on POD 1, resulting in a cumulative reduction of 62%. Further research should strive to minimize opioid use and the downstream effects. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT ALIF is a widely accepted strategy to increase lumbar lordosis and improve fusion. It may also help reduce the fractional lumbar curve. Improved fractional curve correction can level the pelvis and facilitate proximal realignment. PURPOSE To determine if the addition of an anterior lumbar interbody fusion (ALIF) to posterolateral fusion results in a more level pelvis by correcting the fractional lumbar curve. STUDY DESIGN/SETTING Retrospective comparative observational cohort. PATIENT SAMPLE Patients undergoing thoracolumbar fusion to the pelvis with S2AI screws for deformity. OUTCOME MEASURES Pre- and postop fractional curve Cobb angle, lumbar lordosis, pelvic tilt, pelvic incidence, sacral slope and percent curve correction. METHODS Patients undergoing thoracolumbar fusion to the pelvis with S2AI screws for deformity were identified and stratified into patients who had an ALIF in addition to PSF (ALIF+PSF) and those who had a posterior instrumented fusion (PSF) only. Radiographic parameters measured included preop and postop fractional curve Cobb angle, lumbar lordosis, pelvic tilt, pelvic incidence, sacral slope and percent curve correction. RESULTS There were 30 cases in the ALIF+PSF group and 31 in the PSF group. Baseline demographic characteristics of the two groups were similar. Mean preop fractional coronal Cobb (18.2° vs 14.2°, p=0.069), lumbar lordosis (30.9° vs 334.2°, p=0.379) and pelvic parameters were similar between the two groups. Postop lumbar lordosis was similar (48.4° vs 44.1°, p=0.183). Greater fractional coronal curve correction was achieved in the ALIF+PSF group (69%) compared to the PSF group (29%, p CONCLUSIONS There is a greater correction of the fractional curve in the ALIF+PSF group compared with the PSF only group. While this may not be the primary indication for ALIF, it is a benefit that may level the pelvis and facilitate overall deformity correction. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT There have been significant advancements in three-dimensional titanium printing and implant surface technology. Interbody implants using three-dimensional printed titanium (3D-Ti) and surface technology mimic trabecular bone structure, roughness/porosity, and modulus of elasticity. In addition to providing biomechanical support and scaffolding, interbody implants may have osteoinductive properties similar to bone graft by inciting cellular response and resulting in enhanced fusion. However, the actual ability of these structural improvements to affect the in vivo fusion cascade has not been clearly defined. PURPOSE To evaluate fusion of 3D-Ti without bone graft compare to PEEK and autologous iliac crest bone graft (ICBG) in a sheep interbody model. STUDY DESIGN/SETTING Randomized in vivo sheep interbody fusion animal trial. PATIENT SAMPLE Not applicable. OUTCOME MEASURES Fusion as assessed by histology, microCT, and traditional CT. METHODS Eight PEEK and eight 3D-Ti implants were randomized to anterior lumbar interbody fusions at L2-3 or L4-5 in a sheep model. The PEEK cages were implanted with autologous ICBG. CT scans were performed at 4 weeks. CT, microCT and histology were performed at sacrifice (8 weeks). The robustness of fusion was graded A-D, where A is no fusion, B is fusion spot-welding to the cage, C is fusion through the cage, and D is fusion outside of the cage. RESULTS At both 4 and 8 weeks, there was no CT evidence of fusion (type A) in PEEK + ICBG implants (0%). Histologic analysis at sacrifice revealed substantial osteolysis and cellular delamination surrounding the PEEK cage with unincorporated/floating ICBG fragments. At 4 weeks in the 3D-Ti group without graft, there were 6/8 (75%) type B fusions and 2/8 (25%) robust fusions (type D). On CT and microCT at 8 weeks, the entire 3D-Ti group (100%) showed evidence of through and outside of the cage (type D). Histologic analysis showed extensive lamellar and mature bone formation on the trabecular structure of the titanium. CONCLUSIONS In an in vivo sheep interbody fusion model, implants created with 3D-Ti and surface technology without bone graft outperform PEEK + autologous ICBG with regard to radiographic and histologic fusion. The three-dimensional titanium technology with biomechanically similar characteristics to trabecular bone allows for more rapid, robust fusion in an animal model and may minimize the need for bone grafting and osteoinductive compounds. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT There are a number of clinical situations that require the replacement of pedicle screw instrumentation. In adjacent segment degeneration and other revision situations, pedicle screw instrumentation is often exchanged in order to accommodate a different sized rod or different pedicle screw system. Although the screws in these revision situations are not overtly loose, the screws have been physiologically loaded for a period of time. Traditionally, pedicle screws are salvaged by up-sizing the core diameter until an interference fit is obtained in the pedicular isthmus. PURPOSE To determine if dual thread screws allow for increased fixation when revising previous pedicle screw instrumentation. STUDY DESIGN/SETTING Cadaveric biomechanical study. PATIENT SAMPLE Not applicable. OUTCOME MEASURES Not applicable. METHODS Pedicle screws were tested in the lumbar vertebrae from ten cadavers. Every pedicle was first tested with a 5.5 mm diameter standard screw using "break-in" loading. Screws were removed and replaced with one of the following four screw types: 5.5 mm Standard Thread, 5.5 mm Dual Thread, 6.0 mm Standard Thread, or 6.0 mm Dual Thread. The sizes were varied in an S curve fashion over all 10 spines to distribute the screw types over the five lumbar levels (L1 through L5). Failure testing was done using a stepwise increasing cyclic loading protocol for 100 cycles. RESULTS The average pedicle screw cut out load (N) was 133.71 +/- 30.50 and 158.53 +/- 55.28 for standard and dual thread screws, respectively. There was significantly increased pullout strength with dual thread screws compared to the standard thread design (p = 0.001). When comparing 5.5 mm dual thread screws to 6.0 mm standard thread screws, there was no difference in ultimate strength (137.3 +/- 32.47 vs 142.86 +/- 56.50, respectively). CONCLUSIONS In cases requiring replacement of pedicle screws, both upsizing core diameter and utilizing dual thread design may increase bony purchase. The was no difference in upsizing core diameter by 0.5 mm compared with changing screw pitch to a dual thread design. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT The Hospital Acquired Conditions Reduction Program provides a financial incentive to reduce Patient Safety Indicators (PSI), defined as potentially preventable hospital-related events associated with harmful outcomes for patients. PSI are identified by ICD coding. However, ICD coding does not always reflect the true medical course of the patient. PURPOSE To determine if addition of a clinician to the review process results in a reduction of incorrectly generated PSI. STUDY DESIGN/SETTING Retrospective chart review. PATIENT SAMPLE Patients who had spine surgery at a single institution from 2015 to 2019. OUTCOME MEASURES N/A METHODS All PSI generated at our institution were collected over a 57-month period. The number and type of spine-related PSI were compared before and after the implementation a clinical reviewer to identify incorrectly generated PSI. The financial impact of this intervention was also calculated. RESULTS From 2015 to 2019, a total of 1,290 PSI were reported with 140 (11%) attributable to spine surgery. Prior to implementation of a clinical reviewer, 112 PSI were reported over 40 months (2.8 PSI/month). Following implementation, 28 PSI were reported over 17 months, a statistically significant decrease by 1.2 PSI/month (p CONCLUSIONS Implementation of a review process with clinician collaboration to ensure ICD-10 coding accurately reflects the medical course for a patient may lead to more precise PSI reporting, with substantial cost-savings for hospitals. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Prospective registries have emerged as a feasible way to capture real-world care across large patient populations. However, the proven validity of more robust and cumbersome patient-reported outcomes instruments (PROis) must be balanced with what is feasible to apply in large-scale registry efforts.To determine the relative validity and responsiveness of common PROis in accurately determining effectiveness of lumbar fusion for degenerative lumbar spondylolisthesis in registry efforts.Prospective cohort study.Fifty-eight patients undergoing transforaminal lumbar interbody fusion (TLIF) for degenerative lumbar spondylolisthesisPatient-reported outcome measures for pain (numeric rating scale for back and leg pain [NRS-BP, NRS-LP]), disability (Oswestry Disability Index [ODI]), general health (Short Form [SF]-12), quality of life (QOL) (EuroQol five dimensions [EQ-5D]), and depression (Zung depression scale [ZDS]) were assessed.Fifty-eight patients undergoing primary TLIF for lumbar spondylolisthesis were entered into an institutional registry and prospectively followed for 2 years. Baseline and 2-year patient-reported outcomes were assessed. To assess the validity of PROis to discriminate between effective and noneffective improvements, receiver operating characteristic curves were generated for each outcomes instrument. An area under the curve (AUC) of ≥0.80 was considered an accurate discriminator. The difference between standardized response means (SRMs) in patients reporting meaningful improvement versus not was calculated to determine the relative responsiveness of each instrument.For pain and disability, ODI had AUC=0.94, suggesting it as an accurate discriminator of meaningful improvement. Oswestry Disability Index was most responsive to postoperative improvement (SRM difference: 2.18), followed by NRS-BP and NRS-LP. For general health and QOL, SF-12 physical component score (AUC: 0.90), ZDS (AUC: 0.89), and SF-12 mental component score (AUC: 0.85) were all accurate discriminators of meaningful improvement, however, EQ-5D was most accurate (AUC: 0.97). EuroQol five dimensions was also most responsive (SRM difference: 2.83).For pain and disability, ODI was the most valid and responsive measure of effectiveness of lumbar fusion. Numeric rating scale-BP and NRS-LP should not be used as substitutes for ODI in measuring effectiveness of care in registry efforts. For health-related QOL, EQ-5D was the most valid and responsive measure of improvement, however, SF-12 and ZDS are valid alternatives with less responsiveness.

BACKGROUND CONTEXT As anchors for defining minimum clinical important difference (MCID) thresholds are determined by individual values, we sought to evaluate if MCID thresholds can be affected by cultural differences. PURPOSE The purpose of this study was to compare the MCID threshold and the proportion of adult spinal deformity (ASD) patients achieving SRS-22R MCID in North America (NA) versus Japan (Jp). STUDY DESIGN/SETTING Retrospective review of prospectively collected data. PATIENT SAMPLE Two hundred-eight cases [NA; 148 cases (male 16, female 132, average 59.8years old), Jp; 60 cases (male 4, female 56, average 65.5years old)] who followed for at least more than 2years after corrective fixation surgery for ASD patients with coronal Cobb angle of over 30° and over 40years old. OUTCOME MEASURES SRS22R MCID thresholds. METHODS There were 148 cases from NA (132 females, mean age=59.8 years) and 60 cases from Jp (56 females, mean age=65.5 years) with at least 2-year follow-up after corrective spine surgery for ASD. Except for self-image, published Jp MCID values are higher (function=0.90, pain=0.85 and self-image=1.05, subtotal=1.05) than the published NA MCID values (function=0.60, pain=0.40, self-image=1.23, subtotal=0.43). RESULTS There was statistically significant improvement in all domain scores at 2-year follow-up compared to baseline in both cohorts. Except for mental health (NA:0.32, Jp:0.72, p=.005), the mean improvement from baseline to 2 years was similar between the North American and Japanese cohorts. Except for self-image (NA:57%, Jp:58%, p=.877), the proportion of patients achieving MCID was higher in North America for function (NA:51%, Jp:30%, p=.006), pain (NA:80%, Jp:47%, p CONCLUSIONS Despite similar improvements in SRS22R domain scores from baseline to 2years postop, the proportion of patients reaching SRS22R MCID for function, pain and subtotal after ASD surgery are higher in a North American cohort compared to a Japanese cohort. This may imply that patients in North America and Japan may regard the value of these changes differently.

BACKGROUND CONTEXT Surgical decision making for cervical spondylotic myelopathy (CSM) relies on subjective reports of symptoms and interpretation of physical exam findings. The Romberg test is used to identify balance issues, but has subjective interpretation. When combined with a force plate, the amount and velocity of sway during the Romberg test can be quantified objectively. PURPOSE The study aims to quantify static balance control in myelopathic patients and use this measure for diagnosis and evaluation of disease severity. STUDY DESIGN/SETTING Cross-sectional pilot study. PATIENT SAMPLE Thirty myelopathic patients seen for surgery (mean age of 58±10 years) and 28 normal patients (N=28, mean age 39±7 years). OUTCOME MEASURES Quantitative Romberg measurements from force-plate readings for static balance control. METHODS CSM patients scheduled for surgery who had quantitative balance measurements were identified. Clinical examination findings and imaging results for CSM were reviewed. Quantitative Romberg force plate readings with eyes open and closed were obtained and changes in balance measurements were compared to a normal population (N=28, mean age 39±7 years). RESULTS We identified 30 CSM patients with a mean age of 58±10years. Majority of patients presented with pain (90%) and neurologic symptoms (83%). Cord compression identified in magnetic resonance imaging (MRI) or in CT myelograms, was reported in 90%; only 20% had T2 cord signal changes on MRI. Mean eyes closed Romberg measurements were larger compared to eyes open measurements in CSM patients [p CONCLUSIONS Static balance can be quantified in patients with CSM and is worse when compared to a normal population. Long tract signs and cord compression in imaging translates to worsening balance in myelopathic patients. The use of quantitative Romberg measurements may help diagnose and evaluate progression of CSM.

BACKGROUND CONTEXT Surgeons have used lateral flexion–extension X-ray images to identify patients with clinically substantial instability and listhesis that require fusion. PURPOSE The purpose of this study is to determine the clinical utility of flexion–extension X-ray images by evaluating associations with supine MRI and lateral standing X-ray images and patient reported outcomes (PROs) at baseline and one-year post-op. STUDY DESIGN/SETTING Longitudinal cohort from a multisurgeon, single spine specialty practice. PATIENT SAMPLE Patients enrolled in quality outcome database from a single site with grade 1 spondylolisthesis. OUTCOME MEASURES Back pain (BP), leg pain (LP), and Oswestry Disability Index (ODI). METHODS Patients enrolled in QOD from a single site with grade 1 spondylolisthesis and complete preop and one-year postop PROs, including BP, LP, and ODI, and preop lumbar supine MRIs, lateral standing and flex–ext X-ray images were identified. Slip distance and percentage on all images were measured. Slip difference between flexion and extension was calculated. RESULTS Twenty-seven patients, mean age of 60.5years, 74% female were included. Mean listhesis on flexion films was significantly greater (8.5 mm) than on supine MRI (4.8 mm, p CONCLUSIONS There were no associations between preop or postop PROs and slip severity on any of the imaging modalities. As listhesis on standing and extension films were similar and slip difference between flexion and extension was not associated with PROs, lateral extension films may have limited clinical utility. Further studies are needed to clarify radiographic indications for fusion in patients with spondylolisthesis.

BACKGROUND CONTEXT There continues to be uncertainty in the appropriate treatment approach for adult symptomatic lumbar scoliosis (ASLS). Nonoperative care has not been shown to improve outcomes. Surgical treatment has been shown to improve outcomes, but is costly with high revision rates. PURPOSE To perform an intent-to-treat cost-effectiveness study comparing operative vs nonoperative care for ASLS. STUDY DESIGN/SETTING Secondary analysis using data from the NIH sponsored study on ASLS that included randomized and observational arms. PATIENT SAMPLE Patients with at least five-year follow-up data were included. OUTCOME MEASURES SRS-22R, Oswestry Disability Index, Short Form-12. METHODS Patients with at least five-year follow-up data were included. Data collected every three months included use of nonoperative modalities, medications and employment status. Costs for index and revision surgeries and nonoperative modalities were determined using Medicare allowable rates. Medication costs were determined using the RedBook and indirect costs were calculated based on reported employment status and income. Quality adjusted life years (QALY) were determined using the SF6D. RESULTS There were 81 of 95 cases in the operative (Op) and 81 of 95 in the nonoperative (NonOp) group with complete five-year follow-up data. Not all patients were eligible for five-year follow-up at the time of the analysis. All patients in the Op and 24 (30%) in the NonOp group had surgery by five years. At five years, the cumulative cost for Op was $96,000 with a QALY gain of 2.44 and for NonOp the cumulative cost was $49,546 with a QALY gain of 0.75 with an ICER of $27,480 per QALY gain. CONCLUSIONS In an intent-to treat analysis, neither treatment was dominant, as the greater gains in QALY in the surgery group come at a greater cost. The ICER for operative compared to nonoperative treatment was above the threshold generally considered cost-effective in the first three years of the study but improved over time and was highly cost-effective at four and five years. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Provisions in the Patient Protection and Affordable Care Act (PPAC) include alternative payment models that shift away from fee-for-service reimbursement and provide incentives to improve value. These reimbursement models could incorporate the post-discharge facility care and it is therefore important to identify drivers of additional cost, especially in the setting of unexpected non-home discharge. PURPOSE To identify factors associated with being discharged to a non-home location after an elective 1-2 level instrumented lumbar fusion that, if identified, can be useful to allow for early post-discharge planning. STUDY DESIGN/SETTING Retrospective chart review. PATIENT SAMPLE Patients undergoing 1-2 level instrumented lumbar fusions for degenerative lumbar conditions from 2016 to 2018. OUTCOME MEASURES Non-home discharge. METHODS Hospital administrative database and electronic medical record analysts identified consecutive patients undergoing 1-2 level instrumented lumbar fusions for degenerative lumbar conditions from 2016 to 2018. Discharge disposition was determined as home vs non-home (NH). A regression analysis was used to determine associations between NH discharge and an underserved zip code, ASA grade, marital status, race, insurance type, smoking status, BMI, number of levels, approach and revision surgery. RESULTS A total of 1,502 patients (601; 40% male) were included with a mean age of 57.5 years. The majority were discharged home (1,216; 81%). Of the 286 (19%) not discharged home, the majority went to a skilled nursing facility (248). Factors associated with a NH discharge were living in an underserved zip code, not being married, being on government insurance, having more levels fused, higher BMI and older age. Length of stay (5.64 vs 3.03 days, p CONCLUSIONS Patients living in an underserved zip code, not married, higher BMI, older, and having government insurance are more likely to be discharged to a non-home facility after undergoing 1-2 instrumented lumbar fusions. Identification and early intervention to place these patients even before admission may decrease the length of hospital stay and cost. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT In the future, payers may not cover unplanned 90-day emergency room (ER) visits or readmissions after elective lumbar spine surgery. Prior studies using large administrative databases lack granularity, and/or use a proxy for actual cost. We analyzed a large, single-center database to identify risk factors and subsequent costs associated with 90-day ER visits and readmissions. PURPOSE To identify risk factors and subsequent costs associated with 90-day ER visits and readmissions. STUDY DESIGN/SETTING Retrospective longitudinal cohort from a single multisurgeon, spine specialty site PATIENT SAMPLE Patients undergoing elective lumbar spine surgeries from 2013-2017. OUTCOME MEASURES Ninety-day ER visits and readmissions. METHODS A prospective, multisurgeon, single-center database merged with hospital administrative data was queried for elective lumbar spine surgeries from 2013-2017. Predictive models were created for 90-day ER visits and readmissions. RESULTS Of 5,444 patients, 729 (13%) returned to the ER, most often for pain (144, 32%). Predictors of an ER visit were prior ER visit (pER, OR:2.4), zip code (OR:1.4) and number of chronic medical conditions (OR:1.4). 421 (8%) patients were readmitted, most frequently for wound infection (123, 2%), COPD exacerbation (24, 0.4%), and sepsis (23, 0.4%). Predictors for readmission were pER (OR:1.96), multiple chronic conditions (OR:1.69), obesity (non-obese, OR:0.49), race (African American, OR:1.43), admission status (ER admission, OR:2.29) and elevated HbA1c (OR:1.80). Average direct hospital cost for an ER visit was $1,659 and readmission was $7,322, costing the institution $5.1 million over the five-year study period. CONCLUSIONS Risk factors for 90-day ER visit and readmission after elective lumbar spine surgery include medical comorbidities and socioeconomic factors. Proper patient selection, appropriate postop pain management and optimization of modifiable risk factors prior to surgery can lower the 90-day ER visits and readmissions and reduce health care costs. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Posterior spinal fusion (PSF) using all-pedicle screw constructs has become the standard surgical treatment for adolescent idiopathic scoliosis (AIS). However, some studies have shown that all-pedicle screw constructs or the use of pedicle screws at the upper instrumented vertebrae (UIV) increases the incidence of proximal junctional kyphosis (PJK). The purpose of this study is to examine the impact of different instrumentation types on the incidence of PJK following PSF for AIS. PURPOSE To determine if all-pedicle screw constructs increase the incidence of PJK following PSF for AIS, as pedicle screw placement at the UIV may violate the supra-adjacent facet capsules. STUDY DESIGN/SETTING Longitudinal cohort study. PATIENT SAMPLE Multicenter database of surgically treated AIS. OUTCOME MEASURES PJA. METHODS A multicenter database of surgically treated AIS was used. A stratified random sampling was done to obtain a representative sample from all curve types. Patients were included if they underwent PSF, and if immediate postoperative and final follow-up radiographs were available. The patients were grouped by instrumentation type: all-pedicle screw (PS), hook at UIV with distal all-pedicle screw (HT), and hybrid (HB). PJA was measured as the angle between UIV and UIV+2 on lateral full-length standing radiographs immediately postoperative and at the final follow-up. PJK was defined as PJA ≥ 10° or PJA progression of ≥ 10° at the final follow-up. RESULTS The PS, HT and HB groups included 128, 111 and 106 patients, respectively. There was no difference in baseline demographic and radiographic characteristics among the groups. Fifteen cases (4.3%) developed PJK at the latest follow-up (average 2.2 years). PJK was more common in the PS group (p CONCLUSIONS The incidence of PJK following PSF for AIS was 4.3% and was more common in an all-pedicle screw constructs compared to hybrid or UIV-hook distal pedicle screw constructs. Using hooks at UIV might be a treatment strategy to limit PJK. FDA DEVICE/DRUG STATUS Unavailable from authors at time of publication.

BACKGROUND CONTEXT Adult symptomatic lumbar Scoliosis (ASLS) has become increasingly prevalent as the population ages. ASLS can be accompanied by neurogenic claudication, leading to difficulty walking. Functional treadmill testing (FTT) has been previously described as an objective tool to evaluate patients suffering from neurogenic claudication. FTT may provide an objective tool to evaluate patients with ASLS and identify patients who may benefit from surgical treatment. PURPOSE To determine if FTT demonstrates objective significant differences between patients treated surgically and nonsurgically for ASLS. STUDY DESIGN/SETTING Secondary analysis using data from the NIH sponsored study on ASLS that included randomized and observational arms. PATIENT SAMPLE Patients enrolled in the NIH sponsored study on ASLS. OUTCOME MEASURES Functional treadmill test, back and leg pain scores METHODS One hundred and eighty-seven patients who underwent nonsurgical (n=88) or surgical treatment (n=99) of ASLS with complete baseline and two-year post-treatment FTTs were identified. FTT parameters included maximum speed, time to onset of symptoms, distance ambulated, time ambulated, and the difference in back and leg pain before and after testing. RESULTS At baseline, patients treated operatively reported an onset of symptoms on FTT significantly sooner than those treated nonoperatively (5.5min vs 7.7min, p=0.025). When compared to baseline, operatively treated patients experienced significant improvement at 2 years in time ambulated (26.5min vs 24.4 min, p=0.001). Additionally, in the operative group, the post-treadmill minus pre-treadmill BP scores (0.5 vs 1.6 p=0.001) and the post-treadmill minus pre-treadmill leg pain scores (0.4 vs 1.4, p CONCLUSIONS FTT is a useful adjunct to assess treatment outcomes in patients with ASLS. FTT results were different at baseline between patients treated operatively and nonoperatively. Patients who had surgery had improvements in their post-treadmill minus pre-treadmill back and leg pain scores at two year follow-up. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT It is unclear whether radiographic nonunion after anterior cervical discectomy and fusion (ACDF) is a relevant problem as its true prevalence is unknown. Nonunion may be under-observed, as some patients are not symptomatic enough to justify radiographic evaluation. Long-term follow-up is difficult to obtain in the ACDF population, as minimally symptomatic postop patients are the norm. PURPOSE To determine if patients with radiographic nonunion after ACDF have worse patient-reported outcomes (PROs) compared to patients with a solid fusion. STUDY DESIGN/SETTING Secondary analysis of subjects in the control ACDF arm of Medtronic Investigational Device Exemption (IDE) trials for cervical disc arthroplasty (CDA). PATIENT SAMPLE A total of 345 subjects enrolled in the control arm of IDE trials for CDA who had single-level ACDF with allograft and plate with 24-month data. OUTCOME MEASURES Short Form-36, Neck Disability Index, Neck and Arm pain Numeric Rating Scales (NRS, 0 to 10). METHODS Using the 24-month postop evaluation, subjects were divided into those who had radiographic fusion and those who did not using strict radiographic study criteria. SF-36, NDI, Neck and Arm pain NRS were collected at 6 weeks, 3, 6, 12, 24, 36, 48, 60, 72, and 84 months postop. Last observation carried-forward method was used in the analysis for secondary surgery cases, such that the scores immediately prior to a secondary surgery were used for all future events. RESULTS Fourty-four (13%) patients had radiographic nonunion and 301 (87%) were fused at 24 months postop. At 24 months, NDI, Neck and Arm pain NRS were similar between the patients with radiographic nonunion and those with radiographic union. Seven patients in the Nonunion group (16%) and 10 (3%) in the Fused group had additional surgery at the index level prior to the 24-month follow-up (p=0.003). Over the 84-month follow-up, a total of 9 patients in the Nonunion group (21%) and 22 (7%) in the Fused group had additional surgery at the index level (p=0.009). CONCLUSIONS While the radiographic nonunion rate at 24 months was 13%, PROs show that many of the radiographic nonunions were asymptomatic. Although a majority of patients with radiographic nonunion did not undergo additional surgery, index level reoperation was significantly higher (21% vs 7%) in the radiographic nonunion group. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Our previous study showed that prescribing patterns, more than surgery invasiveness or patient factors, affect post-operative opioid consumption. Since then we have instituted a Standard Escalation Pain Protocol (SEPP): patients receive 0-60 Morphine Milligram Equivalents (MME) above their baseline pre-op MME after surgery. PURPOSE The purpose of this study is to evaluate how prescribing patterns affect immediate postoperative opioid consumption in patients undergoing 1- to 2-level posterior lumbar interbody fusion with a navigated or robotic-assisted, midline exposure (MIDLIF). STUDY DESIGN/SETTING Single surgeon consecutive series. PATIENT SAMPLE Patients with degenerative lumbar pathology who had a MIDLIF from 2017 to 2018 were identified. OUTCOME MEASURES In-hospital opioid consumption. METHODS Patients with degenerative lumbar pathology who had a MIDLIF from 2017 to 2018 were identified and divided into two cohorts: patients who had surgery before the institution of SEPP (PreSEPP) and those who had surgery after (PostSEPP). Length of stay and daily opioid consumption were extracted by EMR data analysts unaware of the purpose of the study. RESULTS The PreSEPP (N=34) and PostSEPP (N=27) patients were similar at baseline in age, sex distribution, ASA grade, BMI and smoking status. Pre-Op (2.2 vs 3.6, p=0.630) and Post-op Day-0 (POD-0, 52.5 vs 38.8, p=0.192) MME consumption was similar between the two groups. At POD-1, cumulative MME consumption was higher in the Pre-SEPP (131.7) compared to the PostSEPP group (76.0, p=0.004) and this was maintained up to discharge (54% total MME reduction). Length of stay was also longer in the PreSEPP (1.97 days) compared to the PostSEPP group (1.37 days, p=0.004). CONCLUSIONS The use of a standard escalation pain protocol decreases in-hospital opioid consumption by 54% and shortens length of stay after 1-2 level lumbar spinal fusion. Similar to our previous study, prescribing pattern is an important factor affecting post-op opioid consumption. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Disease specific health status is measured using survey-based patient-reported outcomes (PROs) (eg, Oswestry Disability Index, ODI) including questions about walking, sitting, standing, traveling (driving) and sleeping (lying down). However, survey data are difficult to collect routinely and subject to multiple biases. Multiple sensor and rules-based algorithms have shown positive predictive values (PPV) greater than 85% for key functional metrics such as walking, jogging, sitting and lying down in a laboratory setting, suggesting the potential to assess measured function rather than reported function. The purpose of this study is to test the predictive capability of a single wearable sensor containing a high-end inertial measurement unit (IMU) for core elements of the ODI survey in a real-world setting. PURPOSE To determine the feasibility of using a single wearable sensor in a real-world environment to measure a subset of activities in the ODI. STUDY DESIGN/SETTING Technology feasibility. PATIENT SAMPLE Five healthy volunteers willing to wear a sensor and undergo a 60-minute activity protocol. OUTCOME MEASURES Sensor generated predictions of activity measured at the 5 ms boundary. METHODS Training data were generated from five healthy volunteers wearing a single navigation-grade IMU (SBG Systems Ellipse2-N) for 60 minutes in a real-world environment. Volunteers were asked to sit, stand, lie supine, drive and walk in an unscripted manner. Data were continuously recorded at 200Hz. A combinatorial learning approach utilized multinomial logistic regression (MLR) to classify posture and sleeping results before feeding into a layer of support-vector-machines (SVM). Twenty percent of the data were held out for testing. RESULTS A total of 1,989,878 data points were analyzed from five healthy volunteers. After the two layers (MLR followed by SVM), accuracy was found to be 98.6% across all activities. Positive predictive values were 98.4% for walking, 97.8% for sitting, 98.5% for driving, 100% for lying and 97.9% for standing. CONCLUSIONS The use of a high-end IMU combined with machine learning algorithms to classify a subset of ODI activities in a real-world setting achieved greater accuracy than multiple sensors and rules-based algorithms reported in prior studies. This type of technology offers the potential for measured function to replace or supplement patient-reported function for key patient-centric activities routinely considered reflective of health status. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Evidence-based approaches to the treatment of spinal pathology are needed as the field evolves. Patient-reported outcomes have become the standard by which therapeutic success is defined. There are 4 types of commonly used outcome measures: generic, disease specific, pain scales, and health utilities. Using this framework to evaluate outcomes allows for cost-effectiveness studies to be done and define the value of spinal care to society.