Social mobility in the Tang Dynasty as the Imperial Examination rose and aristocratic family pedigree declined, 618-907 CE.

Data from the distant past are fertile ground for testing social science theories of education and social mobility. In this study, we construct a dataset from 3,640 tomb epitaphs of males in China's Tang Dynasty (618-907 CE), which contain granular and extensive information about the ancestral origins, family background, and career histories of the deceased elites. Our statistical analysis of the complete profiles yields evidence of the transition away from an aristocratic society in three key trends: 1) family pedigree (i.e., aristocracy) mattered less for career achievement over time, 2) passing the Imperial Examination (Keju) became an increasingly important predictor of one's career achievement, and 3) father's position always mattered throughout the Tang, especially for men who did not pass the Keju. The twilight of medieval Chinese aristocracy, according to the data, began in as early as the mid-seventh century CE.

Keyhole Endoscopic-Assisted Transcervical Approach to the Upper and Middle Retrostyloid Parapharyngeal Space: An Anatomic Feasibility Study.

Objectives The aim of this study was to describe the anatomical nuances, feasibility, limitations, and surgical exposure of the parapharyngeal space (PPS) through a novel minimally invasive keyhole endoscopic-assisted transcervical approach (MIKET). Design Descriptive cadaveric study. Setting Microscopic and endoscopic high-quality images were taken comparing the MIKET approach with a conventional combined transmastoid infralabyrinthine transcervical approach. Participants Five colored latex-injected specimens (10 sides). Main Outcome Measures Qualitative anatomical descriptions in four surgical stages; quantitative and semiquantitative evaluation of relevant landmarks. Results A 5 cm long inverted hockey stick incision was designed to access a corridor posterior to the parotid gland after independent mobilization of nuchal and cervical muscles to expose the retrostyloid PPS. The digastric branch of the facial nerve, which runs 16.5 mm over the anteromedial part of the posterior belly of the digastric muscle before piercing the parotid fascia, was used as a landmark to identify the main trunk of the facial nerve. MIKET corridor was superior to the crossing of the accessory nerve over the internal jugular vein within 17.3 mm from the jugular process. Further exposure of the occipital condyle, vertebral artery, and the jugular bulb was achieved. Conclusion The novel MIKET approach provides in the cadaver straightforward access to the upper and middle retrostyloid PPS through a natural corridor without injuring important neurovascular structures. Our work sets the anatomical nuances and limitations that should guide future clinical studies to prove its efficacy and safety either as a stand-alone procedure or as an adjunct to other approaches, such as the endonasal endoscopic approach.

Improved Surgical Correction Relative to Patient-Specific Ideal Spinopelvic Alignment Reduces Pelvic Nonresponse for Severely Malaligned Adult Spinal Deformity Patients.

BACKGROUND: Persistent pelvic compensation following adult spinal deformity (ASD) corrective surgery may impair quality of life and result in persistent pathologic lower extremity compensation. Ideal age-specific alignment targets have been proposed to improve surgical outcomes, though it is unclear whether reaching these ideal targets reduces rates of pelvic nonresponse following surgery. Our aim was to assess the relationship between pelvic nonresponse, age-specific alignment, and lower-limb compensation following surgery for ASD. METHODS: Single-center retrospective cohort study. ASD patients were grouped: those who did not improve in Scoliosis Research Society-Schwab pelvic tilt (PT) modifier (pelvic nonresponders [PNR]), and those who improved (pelvic responders [PR]). Groups were propensity score matched for preoperative PT and assessed for differences in spinal and lower extremity alignment. Rates of pelvic nonresponse were compared across patient groups who were undercorrected, overcorrected, or matched age-specific postoperative alignment targets. RESULTS: A total of 146 surgical ASD patients, 47.9% of whom showed pelvic nonresponse following surgery, were included. After propensity score matching, PNR (N = 29) and PR (N = 29) patients did not differ in demographics, preoperative alignment, or levels fused; however, PNR patients have less preoperative knee flexion (9° vs 14°, P = 0.043). PNR patients had inferior postoperative pelvic incidence and lumbar lordosis (PI-LL) alignment (17° vs 3°) and greater pelvic shift (53 vs 31 mm). PNR and PR patients did not differ in rates of reaching ideal age-specific postoperative alignment for sagittal vertical axis (SVA) or PI-LL, though patients who matched ideal PT had lower rates of PNR (25.0% vs 75.0%). For patients with moderate and severe preoperative SVA, more aggressive correction relative to either ideal postoperative PT or PI-LL was associated with significantly lower rates of pelvic nonresponse (all P < 0.05). CONCLUSIONS: For patients with moderate to severe baseline truncal inclination, more aggressive surgical correction relative to ideal age-specific PI-LL was associated with lower rates of pelvic nonresponse. Postoperative alignment targets may need to be adjusted to optimize alignment outcomes for patients with substantial preoperative sagittal deformity. CLINICAL RELEVANCE: These findings increase our understanding of the poor outcomes that occur despite ideal realignment. Surgical correction of severe global sagittal deformity should be prioritized to mitigate these occurrences.

Bariatric Surgery Lowers Rates of Spinal Symptoms and Spinal Surgery in a Morbidly Obese Population.

STUDY DESIGN: Retrospective analysis of New York State Inpatient Database years 2004-2013. OBJECTIVE: Assess rates of spinal diagnoses and procedures before and after bariatric surgery (BS). SUMMARY OF BACKGROUND DATA: BS for morbid obesity helps address common comorbidity burdens and improves quality of life for patients. The effects of BS on spinal disorders and surgical intervention have yet to be investigated. MATERIALS AND METHODS: Patients included in analysis if they underwent BS and were seen at the hospital before and after this intervention. Spinal conditions and rates of surgery assessed before and after BS using χ 2 tests for categorical variables. Multivariable logistic regression analysis used to compare rates in BS patients to control group of nonoperative morbidly obese patients. Logistic testing controlled for comorbidities, age, biological sex. RESULTS: A total of 73,046 BS patients included (age 67.88±17.66 y, 56.1% female). For regression analysis, 299,504 nonbariatric, morbidly obese patients included (age 53.45±16.52 y, 65.6% female). Overall, rates of spinal symptoms decreased following BS (7.40%-5.14%, P <0.001). Cervical, thoracic, lumbar spine diagnoses rates dropped from 3.28% to 2.99%, 2.91% to 2.57%, and 5.39% to 3.92% (all P <0.001), respectively. Most marked reductions seen in cervical spontaneous compression fractures, cervical disc herniation, thoracic radicular pain, spontaneous lumbar compression fractures, lumbar spinal stenosis, lumbar spondylosis. Controlling for comorbidities, age and sex, obese nonbariatric patients more likely to have encounters associated with several cervical, thoracic or lumbar spinal diagnoses and procedures, especially for cervical spontaneous compression fracture, radicular pain, lumbar spondylosis, lumbar spinal stenosis, posterior procedures. BS significantly lowered comorbidity burden for many specific factors. CONCLUSIONS: BS lowered rates of documented spinal disorders and procedures in a morbidly obese population. These findings provide evidence of additional health benefits following BS, including reduction in health care encounters for spinal disorders and rates of surgical intervention.

A predictive model of perioperative myocardial infarction following elective spine surgery.

Myocardial infarction (MI), and its predictive factors, has been an understudied complication following spine operations. The objective was to assess the risk factors for perioperative MI in elective spine surgery patients as a retrospective case control study. Elective spine surgery patients with a perioperative MI were isolated in the NSQIP. The relationship between MI and non-MI spine patients was assessed using chi-squared and independent samples t-tests. Univariate/multivariate analyses assessed predictive factors of MI. Logistic regression with stepwise model selection was employed to create a model to predict MI occurrence. The study included 196,523 elective spine surgery patients (57.1 yrs, 48%F, 30.4 kg/m2), and 436 patients with acute MI (Spine-MI). Incidence of MI did not change from 2010 to 2016 (0.2%-0.3%, p = 0.298). Spine-MI patients underwent more fusions than patients without MI (73.6% vs 58.4%, p < 0.001), with an average of 1.03 levels fused. Spine-MI patients also had significantly more SPO (5.0% vs 1.8%, p < 0.001) and 3CO (0.9% vs 0.2%, p < 0.001), but less decompression-only procedures (26.4% vs 41.6%, p < 0.001). Spine-MI underwent more revisions (5.3% vs 2.9%, p = 0.003), had greater invasiveness scores (3.41 vs 2.73, p < 0.001) and longer operative times (211.6 vs 147.3 min, p < 0.001). Mortality rate for Spine-MI patients was 4.6% versus 0.05% (p < 0.001). Multivariate modeling for Spine-MI predictors yielded an AUC of 83.7%, and included history of diabetes, cardiac arrest and PVD, past blood transfusion, dialysis-dependence, low preoperative platelet count, superficial SSI and days from operation to discharge. A model with good predictive capacity for MI after spine surgery now exists and can aid in risk-stratification of patients, consequently improving preoperative patient counseling and optimization in the peri-operative period.

Frequency and Implications of Concurrent Complications Following Adult Spinal Deformity Corrective Surgery.

STUDY DESIGN: Retrospective review. OBJECTIVE: Identify co-occurring perioperative complications and associated predictors in a population of patients undergoing surgery for adult spinal deformity (ASD). SUMMARY OF BACKGROUND DATA: Few studies have investigated the development of multiple, co-occurring complications following ASD-corrective surgery. Preoperative risk stratification may benefit from identification of factors associated with multiple, co-occurring complications. METHODS: Elective ASD patients in National Surgical Quality Improvement Program (NSQIP) 2005 to 2016 were isolated; rates of co-occurring complications and affected body systems were assessed via cross tabulation. Random forest analysis identified top patient and surgical factors associated with complication co-occurrence, using conditional inference trees to identify significant cutoff points. Binary logistic regression indicated effect size of top influential factors associated with complication co-occurrence at each factor's respective cutoff point. RESULTS: Included: 6486 ASD patients. The overall perioperative complication rate was 34.8%; 28.5% of patients experienced one complication, 4.5% experienced two, and 1.8% experienced 3+. Overall, 11% of complication co-occurrences were pulmonary/cardiovascular, 9% pulmonary/renal, and 4% integumentary/renal. By complication type, the most common co-occurrences were transfusion/urinary tract infection (UTI) (24.3%) and transfusion/pneumonia (17.7%). Surgical factors of operative time ≥400 minutes and fusion ≥9 levels were the strongest factors associated with the incidence of co-occurring complications, followed by patient-specific variables like American Society of Anesthesiologists (ASA) physical status classification grade ≥2 and age ≥65 years. Regression analysis further showed associations between increasing complication number and longer length of stay (LOS), (R2 = 0.202, P < 0.001), non-home discharge (R2 = 0.111, P = 0.001), and readmission (R2 = 0.010, P < 0.001). CONCLUSION: For surgical ASD patients, the overall rate of co-occurring perioperative complications was 6.3%. Body systems most commonly affected by complication co-occurrences were pulmonary and cardiovascular, and common co-occurrences included transfusion/UTI (24.3%) and transfusion/pneumonia (17.7%). Increasing number of perioperative complications was associated with greater LOS, non-home discharge, and readmission, highlighting the importance of identifying risk factors for complication co-occurrences.Level of Evidence: 3.

The Patient-Reported Outcome Measurement Information System (PROMIS) Better Reflects the Impact of Length of Stay and the Occurrence of Complications Within 90 Days Than Legacy Outcome Measures for Lumbar Degenerative Surgery.

BACKGROUND: The Patient-Reported Outcome Measurement Information System (PROMIS) and legacy outcome measures like the Oswestry Disability Index (ODI) have not been compared for their sensitivity in reflecting the impact of perioperative complications and length of stay (LOS) in a surgical thoracolumbar population. The purpose of this study is to assess the strength of PROMIS and ODI scores as they correlate with LOS and complication outcomes of surgical thoracolumbar patients. METHODS: Retrospective cohort study. Included: patients ≥18 years undergoing thoracolumbar surgery with available preoperative and 3-month postoperative ODI and PROMIS scores. Pearson correlation assessed the linear relationships between LOS, complications, and scores for PROMIS (physical function, pain intensity, pain interference) and ODI. Linear regression predicted the relationship between complication incidence and scores for ODI and PROMIS. RESULTS: Included: 182 patients undergoing thoracolumbar surgery. Common diagnoses were stenosis (62.1%), radiculopathy (48.9%), and herniated disc (47.8%). Overall, 58.3% of patients underwent fusion, and 50.0% underwent laminectomy. Patients showed preoperative to postoperative improvement in ODI (50.2 to 39.0), PROMIS physical function (10.9 to 21.4), pain intensity (92.4 to 78.3), and pain interference (58.4 to 49.8, all P < .001). Mean LOS was 2.7 ± 2.8 days; overall complication rate was 16.5%. Complications were most commonly cardiac, neurologic, or urinary (all 2.2%). Whereas preoperative to postoperative changes in ODI did not correlate with LOS, changes in PROMIS pain intensity (r = 0.167, P = .024) and physical function (r = -0.169, P = .023) did. Complications did not correlate with changes in ODI or PROMIS score; however, postoperative scores for physical function (r = -0.205, P = .005) and pain interference (r = 0.182, P = .014) both showed stronger correlations with complication occurrence than ODI (r = 0.143, P = .055). Regression analysis showed postoperative physical function (R 2 = 0.037, P = .005) and pain interference (R 2 = 0.028, P = .014) could predict complications; ODI could not. CONCLUSIONS: PROMIS domains of physical function and pain interference better reflected perioperative complications and LOS than the ODI. These results suggest PROMIS may offer more utility as an outcomes assessment instrument. LEVEL OF EVIDENCE: 3.

A cost benefit analysis of increasing surgical technology in lumbar spine fusion.

BACKGROUND CONTEXT: Numerous advances have been made in the field of spine fusion, such as minimally invasive (MIS) or robotic-assisted spine surgery. However, it is unknown how these advances have impacted the cost of care. PURPOSE: Compare the economic outcomes of lumbar spine fusion between open, MIS, and robot-assisted surgery patients. STUDY DESIGN/SETTING: Retrospective review of a single center spine surgery database. PATIENT SAMPLE: Three hundred sixty propensity matched patients. OUTCOME MEASURES: Costs, EuroQol-5D (EQ5D), cost per quality adjusted life years (QALY). METHODS: Inclusion criteria: surgical patients >18 years undergoing lumbar fusion surgery. Patients were categorized into 3 groups based on procedure type: open, MIS, or robotic. Open patients undergoing poster spinal fusion were considered as the control group. MIS patients included those undergoing transforaminal or lateral lumbar interbody fusion with percutaneous screws. Robotic patients were those undergoing robot-assisted fusion. Propensity score matching was performed between all groups for the number of levels fused. Costs were calculated using the PearlDiver database, which reflects both private insurance and Medicare reimbursement claims for ICD-9 codes. For robotic cases, costs were reflective of operational fees and initial purchase cost. Complications and comorbidities and major complications and comorbidities were assessed according to CMS.gov manual definitions. QALYs and cost per QALY were calculated using a 3% discount rate to account for residual decline to life expectancy (78.7 years). Costs per QALY were calculated for both 1 year and life expectancy, assuming no loss of benefit. A 10,000 trial Monte Carlo simulation with probabilistic sensitivity analysis (PSA) assessed our model parameters and costs. RESULTS: Three hundred sixty propensity matched patients (120 open, 120 MIS, 120 robotic) met inclusion criteria. Descriptive statistics for the cohort were: age 58.8±13.5, 50% women, BMI 29.4±6.3, operative time 294.4±119.0, LOS 4.56±3.31 days, estimated blood loss 515.9±670.0 cc, and 2.3±2.2 average levels fused. Rates of post-op complications were significantly higher in robotic cases versus open and MIS (43% vs. 21% and 22% for open and MIS, p<.05). However, revision rates were comparable between all groups (3% open, 3% MIS, 5% robotic, p>.05). After factoring in complications, revisions, and purchasing and operating fees, the costs of robotic cases was significantly higher than both open and MIS surgery ($60,047.01 vs. $42,538.98 open and $41,471.21 MIS). In a subanalysis of 42 patients with baseline (BL) and 1Y EQ5D data, the cost per QALY at 1Y for open, MIS, and robot-assisted cases was $296,624.48, $115,911.69, and $592,734.30. If utility gained was sustained to life expectancy, the cost per QALY was $14,905.75, $5,824.71, $29,785.64 for open, MIS, and robot-assisted cases. Results of the PSA were consistent with MIS surgery having the most incremental cost effectiveness when compared to open and robotic surgery. CONCLUSIONS: Numerous advances have been made in the field of spine surgery, however, there has been limited discussion of the effect these advances have on economic outcomes. When matched for levels fused, robot-assisted surgery patients had significantly higher rates of complications and 30% higher costs of surgery compared to minimally invasive and open spine surgery patients. While 1 year economic outcomes were not optimal for robotic surgery cases, the projected costs per QALYs at life expectancy were well below established acceptable thresholds. The above findings may be reflective of an educational learning curve and emerging surgical technologies undergoing progressive refinement.

Radiation Exposure in Posterior Lumbar Fusion: A Comparison of CT Image-Guided Navigation, Robotic Assistance, and Intraoperative Fluoroscopy.

STUDY DESIGN: Retrospective clinical review. OBJECTIVE: To assess the use of intraoperative computed tomography (CT) image-guided navigation (IGN) and robotic assistance in posterior lumbar surgery and their relationship with patient radiation exposure and perioperative outcomes. METHODS: Patients ≥18 years old undergoing 1- to 2-level transforaminal lateral interbody fusion in 12-month period were included. Chart review was performed for pre- and intraoperative data on radiation dose and perioperative outcomes. All radiation doses are quantified in milliGrays (mGy). Univariate analysis and multivariate logistic regression analysis were utilized for categorical variables. One-way analysis of variance with post hoc Tukey test was used for continuous variables. RESULTS: A total of 165 patients were assessed: 12 IGN, 62 robotic, 56 open, 35 fluoroscopically guided minimally invasive surgery (MIS). There was a lower proportion of women in open and MIS groups (P = .010). There were more younger patients in the MIS group (P < .001). MIS group had the lowest mean posterior levels fused (P = .015). Total-procedure radiation, total-procedure radiation/level fused, and intraoperative radiation was the lowest in the open group and highest in the MIS group compared with IGN and robotic groups (all P < .001). Higher proportion of robotic and lower proportion of MIS patients had preoperative CT (P < .001). Estimated blood loss (P = .002) and hospital length of stay (P = .039) were lowest in the MIS group. Highest operative time was observed for IGN patients (P < .001). No differences were observed in body mass index, Charlson Comorbidity Index, and postoperative complications (P = .313, .051, and .644, respectively). CONCLUSION: IGN and robotic assistance in posterior lumbar fusion were associated with higher intraoperative and total-procedure radiation exposure than open cases without IGN/robotics, but significantly less than MIS without IGN/robotics, without differences in perioperative outcomes. Fluoro-MIS procedures reported highest radiation exposure to patient, and of equal concern is that the proportion of total radiation dose also applied to the surgeon and operating room staff in fluoro-MIS group is higher than in IGN/robotics and open groups.

Expandable cages increase the risk of intraoperative subsidence but do not improve perioperative outcomes in single level transforaminal lumbar interbody fusion.

BACKGROUND CONTEXT: Expandable cages (EXP) are being more frequently utilized in transforaminal lumbar interbody fusions (TLIF). EXP were designed to reduce complications related to neurological retraction, enable better lordosis restoration, and improve ease of insertion, particularly in the advent of minimally invasive surgical (MIS) techniques, however they are exponentially more expensive than the nonexpandable (NE) alternative. PURPOSE: To investigate the clinical results of expandable cages in single level TLIF. STUDY DESIGN/SETTING: Retrospective review at a single institution. PATIENT SAMPLE: Two hundred and fifty-two single level TLIFs from 2012 to 2018 were included. OUTCOME MEASURES: Clinical characteristics, perioperative and neurologic complication rates, and radiographic measures. METHODS: Patients ≥18 years of age who underwent single level TLIF with minimum 1 year follow-up were included. OUTCOME MEASURES: clinical characteristics, perioperative and neurologic complications. Radiographic analysis included pelvic incidence-lumbar lordosis (PI-LL) mismatch, segmental lumbar lordosis (LL) mismatch, disc height restoration, and subsidence ≥2 mm. Statistical analysis included independent t tests and chi-square analysis. For nonparametric variables, Mann-Whitney U test and Spearman partial correlation were utilized. Multivariate regression was performed to assess relationships between surgical variables and recorded outcomes. For univariate analysis significance was set at p<.05. Due to the multiple comparisons being made, significance for regressions was set at p<.025 utilizing Bonferroni correction. RESULTS: Two hundred and fifty-two TLIFs between 2012 and 2018 were included, with 152 NE (54.6% female, mean age 59.28±14.19, mean body mass index (BMI) 28.65±5.38, mean Charlson Comorbidity Index (CCI) 2.20±1.89) and 100 EXP (48% female, mean age 58.81±11.70, mean BMI 28.68±6.06, mean CCI 1.99±1.66) with no significant differences in demographics. Patients instrumented with EXP cages had a shorter length of stay (3.11±2.06 days EXP vs. 4.01±2.64 days NE; Z=-4.189, p<.001) and a lower estimated blood loss (201.31±189.41 mL EXP vs. 377.82±364.06 mL NE; Z=-6.449, p<.001). There were significantly more MIS-TLIF cases and bone morphogenic protein (BMP) use in the EXP group (88% MIS, p<.001 and 60% BMP, p<.001) as illustrated in Table 1. There were no significant differences between the EXP and NE groups in rates of radiculitis and neuropraxia. In multivariate regression analysis, EXP were not associated with a difference in perioperative outcomes or complications. Radiographic analyses demonstrated that the EXP group had a lower PI-LL mismatch than the NE cage group at baseline (3.75±13.81° EXP vs. 12.75±15.81° NE; p=.001) and at 1 year follow-up (3.81±12.84° EXP vs. 8.23±12.73° NE; p=.046), but change in regional and segmental alignment was not significantly different between groups. Multivariate regression demonstrated that EXP use was a risk factor for intraoperative subsidence (2.729[1.185-6.281]; p=.018). CONCLUSIONS: Once technique was controlled for, TLIFs utilizing EXP do not have significantly improved neurologic or radiographic outcomes compared with NE. EXP increase risk of intraoperative subsidence. These results question the value of the EXP given the higher cost.

A cost utility analysis of treating different adult spinal deformity frailty states.

The aim of this study was to investigate the cost utility of treating non-frail versus frail or severely frail adult spinal deformity (ASD) patients. 79 surgical ASD patients >18 years with available frailty and ODI data at baseline and 2-years post-surgery (2Y) were included. Utility data was calculated using the ODI converted to the SF-6D. QALYs utilized a 3% discount rate to account for decline to life expectancy (LE). Costs were calculated using the PearlDiver database. ICER was compared between non-operative (non-op.) and operative (op.) NF and F/SF patients at 2Y and LE. When compared to non-operative ASD, the ICER was $447,943.96 vs. $313,211.01 for NF and F/SF at 2Y, and $68,311.35 vs. $47,764.61 for NF and F/SF at LE. Frail and severely frail patients had lower cost per QALY compared to not frail patients at 2Y and life expectancy, and had lower ICER values when compared to a non-operative cohort of ASD patients. While these results support operative correction of frail and severely frail patients, it is important to note that these patients are often at worse baseline disability, which is closely related to frailty scores, and have more opportunity to improve postoperatively. Furthermore, there may be a threshold of frailty that is not operable due to the risk of severe complications that is not captured by this analysis. While future research should investigate economic outcomes at extended follow up times, these findings support the cost effectiveness of ASD surgery at all frailty states.

Biologics and Minimally Invasive Approach to TLIFs: What Is the Risk of Radiculitis?

BACKGROUND: Bone morphogenetic protein (BMP) and allograft containing mesenchymal stem cells (live cell) are popular biologic substitutes for iliac crest autograft used in transforaminal lumbar interbody fusion (TLIF). Use of these agents in the pathogenesis of postoperative radiculitis remains controversial. Recent studies have independently linked minimally invasive (MIS) TLIF with increased radiculitis risk compared to open TLIF. The purpose of this study was to assess the rate of postoperative radiculitis in open and MIS TLIF patients along with its relationship to concurrent biologic adjuvant use. METHODS: Patients ≥18 years undergoing single-level TLIF from June 2012 to December 2018 with minimum 1-year follow-up were included. Outcome measures were rate of radiculitis, intra- and postoperative complications, revision surgery; length of stay (LOS), and estimated blood loss (EBL). RESULTS: There were 397 patients: 223 with open TLIFs, 174 with MIS TLIFs. One hundred and fifty-nine surgeries used bone morphogenetic protein (BMP), 26 live cell, 212 neither. Open TLIF: higher mean EBL, LOS, and Charlson Comorbidity Index (CCI) than MIS. Postoperative radiculitis in 37 patients (9.32% overall): 16 cases MIS BMP (15.69% of their cohort), 6 MIS without BMP (8.33%), 5 open BMP (8.77%), 10 open without BMP (6.02%). MIS TLIF versus open TLIF: no differences in 1-year reoperation rates, infection/wound complication, pseudarthrosis, or postoperative complication rate. BMP versus non-BMP: no differences in reoperation rates, infection/wound complication, pseudarthrosis, or postoperative complication rate. Multivariate logistic regression found that neither BMP (P = .109) nor MIS (P = .314) was an independent predictor for postoperative radiculitis when controlled for age, gender, body mass index, and CCI. Using paired open and MIS groups (N = 168 each) with propensity score matching, these variables were still not independently associated with radiculitis (P = .174 BMP, P = .398 MIS). However, the combination of MIS with BMP was associated with increased radiculitis risk in both the entire patient cohort (odds ratio [OR]: 2.259 [1.117-4.569], P = .023, N = 397) and PSM cohorts (OR: 2.196 [1.045-4.616], P = .038, N = 336) compared to other combinations of surgical approach and biologic use. CONCLUSION: Neither the MIS approach nor BMP use is an independent risk factor for post-TLIF radiculitis. However, risk of radiculitis significantly increases when they are used in tandem. This should be considered when selecting biological adjuvants for MIS TLIF. LEVEL OF EVIDENCE: 3.

Evaluation of Health-related Quality of Life Improvement in Patients Undergoing Spine Versus Adult Reconstructive Surgery.

STUDY DESIGN: Retrospective analysis of outcomes in single-level spine and primary hip and knee arthroplasty patients. OBJECTIVE: The aim of this study was to compare baseline and postoperative outcomes in patients undergoing spine surgery procedures with total hip arthroplasty (THA) and total knee arthroplasty (TKA) to further define outcomes in orthopedic surgery. SUMMARY OF BACKGROUND DATA: Computer-adaptive Patient Reported Outcome Information System (PROMIS) allows for standardized assessment of the health-related quality of life across different disease states. METHODS: Patients who underwent spine surgery (anterior cervical discectomy and fusion, cervical disc replacement, lumbar laminectomy, microscopic lumbar discectomy, transforaminal lumbar interbody fusion or adult reconstruction surgery [THA, TKA]) were grouped. Mean Charlson Comorbidity Index (CCI), Baseline (BL), and 6-month PROMIS scores of physical function, pain interference, and pain intensity were determined. Paired t tests compared differences in CCI, BL, 6 months, and change in PROMIS scores for spine and adult reconstruction procedures. RESULTS: A total of 304 spine surgery patients (age = 58.1 ±â€Š15.6; 42.9% female) and 347 adult reconstruction patients (age = 62.9 ±â€Š11.8; 54.1% Female) were compared. Spine surgery groups had more disability and pain at baseline than adult reconstruction patients according to physical function ([21.0, 22.2, 9.07, 12.6, 10.4] vs. [35.8, 35.0], respectively, P < 0.01), pain interference ([80.1, 74.1, 89.6, 92.5, 90.6] vs. [64.0, 63.9], respectively, P < 0.01), and pain intensity ([53.0, 53.1, 58.3, 58.5, 56.1] vs. [53.4, 53.8], respectively, P < 0.01). At 6 months, spine surgery patients remained more disabled and had more pain compared to adult reconstruction patients. Over the 6-month timespan, spine patients experienced greater improvements than adult reconstruction patients in terms of physical function ([+8.7, +22.2, +9.7, +12.9, +12.1] vs. [+5.3, +3.9], respectively, P < 0.01) and pain interference scores ([-15.4,-28.1, -14.7, -13.1, -12.3] vs. [-8.3, -6.0], respectively, P < 0.01). CONCLUSION: Spinal surgery patients had lower BL and 6-month PROMIS scores, but greater relative improvement in PROMIS scores compared to adult reconstruction patients. LEVEL OF EVIDENCE: 3.

Measuring the predictability of life outcomes with a scientific mass collaboration.

How predictable are life trajectories? We investigated this question with a scientific mass collaboration using the common task method; 160 teams built predictive models for six life outcomes using data from the Fragile Families and Child Wellbeing Study, a high-quality birth cohort study. Despite using a rich dataset and applying machine-learning methods optimized for prediction, the best predictions were not very accurate and were only slightly better than those from a simple benchmark model. Within each outcome, prediction error was strongly associated with the family being predicted and weakly associated with the technique used to generate the prediction. Overall, these results suggest practical limits to the predictability of life outcomes in some settings and illustrate the value of mass collaborations in the social sciences.

Prevalence of Risk Factors for Hospital-Acquired Venous Thromboembolism in Neurosurgery and Orthopedic Spine Surgery Patients.

BACKGROUND: Hospital-acquired venous thromboembolisms (HA-VTE) are a significant source of morbidity and mortality in spine surgery patients. The purpose of this study was to review HA-VTE rates at our institution and evaluate the prevalence of known risk factors in patients who developed HA-VTE among both neurosurgical and orthopedic spine surgeries. METHODS: Retrospective chart reviews were conducted of all spine surgery patients from January 1, 2013, to July 31, 2017, to evaluate rates of HA-VTE and prevalence of known HA-VTE risk factors among these patients. Univariate and multivariate logistic regression analysis for categorical variables and independent Student t test for continuous variables were utilized with significance set at P < .05. RESULTS: The overall HA-VTE rate was 0.94% (0.61% orthopedic, 1.87% neurosurgery). Patients with VTEs had higher rates of thoracic procedure (P = .002), posterior approach (P = .001), diagnosis of fracture (P = .013) or flatback syndrome (P = .028), neurosurgery division (P < .001), and diagnosis-related group (DRG) of noncervical malignancy (P = .001). Patients with VTEs had lower rates of cervical procedure (P < .001), diagnosis of herniated nucleus pulposus (P = .006) and degenerative disc disease (P = .001), and DRG of cervical spine fusion (P < .001). In the patients who sustained VTE, the neurosurgical patients had higher rates of active cancer (22.86% vs 0%, P = .004) and age >60 (80% vs 50%, P < .001), and orthopedic patients had higher estimated blood loss (EBL) (2436 ml vs 1176 mL, P = .006) and rates of anterior-posterior surgery (22.58% vs 0%, P = .003). Neurosurgery department, diagnosis of fracture, and DRG of noncervical malignancy were found to be significant independent risks for developing HA-VTE. Cervical procedures were independently associated with significantly lower risk. Postoperative anticoagulation initiated sooner in neurosurgery patients (postoperative day 1.26 vs 3.19, P < .001). CONCLUSIONS: The overall HA-VTE rate at our institution was 0.94% (0.61% orthopedic, 1.87% neurosurgery). In patients who sustained VTE, neurosurgical patients had higher rates of active cancer and age >60 years, and orthopedic patients had higher EBL and rates of anterior-posterior surgery. This highlights the different patient populations between the 2 departments and the need for individualized thromboprophylaxis regimens. LEVEL OF EVIDENCE: 4.

Radiomic Features of Primary Rectal Cancers on Baseline T2 -Weighted MRI Are Associated With Pathologic Complete Response to Neoadjuvant Chemoradiation: A Multisite Study.

BACKGROUND: Twenty-five percent of rectal adenocarcinoma patients achieve pathologic complete response (pCR) to neoadjuvant chemoradiation and could avoid proctectomy. However, pretreatment clinical or imaging markers are lacking in predicting response to chemoradiation. Radiomic texture features from MRI have recently been associated with therapeutic response in other cancers. PURPOSE: To construct a radiomics texture model based on pretreatment MRI for identifying patients who will achieve pCR to neoadjuvant chemoradiation in rectal cancer, including validation across multiple scanners and sites. STUDY TYPE: Retrospective. SUBJECTS: In all, 104 rectal cancer patients staged with MRI prior to long-course chemoradiation followed by proctectomy; curated from three institutions. FIELD STRENGTH/SEQUENCE: 1.5T-3.0T, axial higher resolution T2 -weighted turbo spin echo sequence. ASSESSMENT: Pathologic response was graded on postsurgical specimens. In total, 764 radiomic features were extracted from single-slice sections of rectal tumors on processed pretreatment T2 -weighted MRI. STATISTICAL TESTS: Three feature selection schemes were compared for identifying radiomic texture descriptors associated with pCR via a discovery cohort (one site, N = 60, cross-validation). The top-selected radiomic texture features were used to train and validate a random forest classifier model for pretreatment identification of pCR (two external sites, N = 44). Model performance was evaluated via area under the curve (AUC), accuracy, sensitivity, and specificity. RESULTS: Laws kernel responses and gradient organization features were most associated with pCR (P ≤ 0.01); as well as being commonly identified across all feature selection schemes. The radiomics model yielded a discovery AUC of 0.699 ± 0.076 and a hold-out validation AUC of 0.712 with 70.5% accuracy (70.0% sensitivity, 70.6% specificity) in identifying pCR. Radiomic texture features were resilient to variations in magnetic field strength as well as being consistent between two different expert annotations. Univariate analysis revealed no significant associations of baseline clinicopathologic or MRI findings with pCR (P = 0.07-0.96). DATA CONCLUSION: Radiomic texture features from pretreatment MRIs may enable early identification of potential pCR to neoadjuvant chemoradiation, as well as generalize across sites. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 2.

Operative fusion of patients with metabolic syndrome increases risk for perioperative complications.

Metabolic syndrome is a clustering of clinical findings defined in the literature including hypertension, high glucose, abdominal obesity, high triglyceride, and low high-density lipoprotein cholesterol levels. The purpose of this study was to assess perioperative outcomes in patients undergoing spine fusion surgery with (MetS) and without (no-MetS) a history of metabolic syndrome. Included: Patients ≥18 yrs old undergoing spine fusion procedures diagnosed with MetS components with BL and 1-year follow-up were isolated in a single-center database. Patients in the two groups were propensity score matched for levels fused. 250 spine fusion patients (58 yrs, 52.2%F, 39.0 kg/m2) with an average CCI of 1.92 were analyzed. 125 patients were classified with MetS (60.2 yrs, 52%F, CCI: 3.2). MetS patients were significantly older (p = 0.012). MetS patients underwent significantly more open (Met-S: 78.4% vs No-MetS: 45.6%, p < 0.001) and posterior approached procedures (Met-S: 60.8% vs No-MetS: 47.2%, p = 0.031). Mean operative time: 272.4 ± 150 min (MetS: 288.1 min vs. no-MetS: 259.7; p = 0.089). Average length of stay: 4.6 days (MetS: 5.27 vs no-MetS: 3.95; p = 0.095). MetS patients had more post-operative complications (29.6% vs. 18.4%; p = 0.038), specifically neuro (6.4% vs 2.4%), pulmonary (4% vs. 1.6%), and urinary (4.8% vs 2.4%) complications. Binary logistic regression analyses found that MetS was an independent risk factor for post-operative complications (OR: 1.865 [1.030-3.375], p = 0.040). With longer surgeries and greater open-exposure types, MetS patients were at greater risk for complications, despite controlling for total number of levels fused. Surgeons should be aware of the increased threat to spine surgery patients with metabolic syndrome in order to optimize surgical decision-making.

Trends in Pain Medication Prescriptions and Satisfaction Scores in Spine Surgery Patients at a Single Institution.

BACKGROUND: As the opioid crisis has gained national attention, there have been increasing efforts to decrease opioid usage. Simultaneously, patient satisfaction has been a crucial metric in the American health care system and has been closely linked to effective pain management in surgical patients. The purpose of this study was to examine rates of pain medication prescription and concurrent patient satisfaction in spine surgery patients. METHODS: A total of 1729 patients undergoing spine surgery between June 25, 2017, and June 30, 2018, at a single institution by surgeons performing ≥20 surgeries per quarter, with medication data during hospitalization available, were assessed. Patients were evaluated for nonopioid pain medication prescription rates and morphine milligram equivalents (MME) of opioids used during hospitalization. Of the total cohort, 198 patients were evaluated for Press Ganey Satisfaction Survey responses. A χ2 test of independence was used to compare percentages, and 1-way analysis of variance was used to compare means across quarters. RESULTS: The mean total MME per patient hospitalization was 574.46, with no difference between quarters. However, mean MME per day decreased over time (P = .048), with highest mean 91.84 in Quarter 2 and lowest 77.50 in Quarter 4. Among all procedures, acetaminophen, nonsteroidal anti-inflammatory drugs, and steroid prescription rates increased, whereas benzodiazepine and γ-aminobutyric acid-analog prescriptions decreased. There were no significant differences between quarters for mean hospital ratings (P = .521) nor for responses to questions from the Press Ganey Satisfaction Survey regarding how often staff talk about pain (P = .164), how often staff talk about pain treatment (P = .595), or whether patients recommended the hospital (P = .096). There were also no differences between quarters for responses in all other patient satisfaction questions (P value range, .359-.988). CONCLUSIONS: Over the studied time period, opioid use decreased and nonopioid prescriptions increased during hospitalization, whereas satisfaction scores remained unchanged. These findings indicate an increasing effort in reducing opioid use among providers and suggest the ability to do so without affecting overall satisfaction rates. LEVEL OF EVIDENCE: 4. CLINICAL RELEVANCE: The opioid epidemic has highlighted the need to reduce opioid usage in orthopedic spine surgery. This study reviews the trends for inpatient management of post-op pain in orthopedic spine surgery patients in relation to patient satisfaction. There was a significant increase in non-opioid analgesic pain medications, and a reduction in opioids during the study period. During this time, patient satisfaction as measured by Press-Ganey surveys did not show a decrease. This demonstrates that treatment of post-operative pain in orthopedic spine surgery patients can be managed with less opioids, more multimodal analgesia, and patient satisfaction will not be affected.

The effect of vascular approach surgeons on perioperative complications in lateral transpsoas lumbar interbody fusions.

BACKGROUND CONTEXT: Lateral lumbar interbody fusion (LLIF) is a popular technique used in spine surgery. It is minimally invasive, provides indirect decompression, and allows for coronal plane deformity correction. Despite these benefits, the approach to LLIF has been linked to complications associated with the lumbosacral plexus and vascular anatomy. As a result, vascular surgeons may be recruited for the exposure portion of the procedure. PURPOSE: The purpose of this study was to compare exposure-related complication and postoperative (postop) neuropraxia rates between exposure (EXP) and spine surgeon only (SSO) groups while performing the approach for LLIF. STUDY DESIGN/SETTING: Retrospective analysis of patients treated at a single institution. PATIENT SAMPLE: Patients undergoing LLIF procedures between 2012 and 2018. OUTCOME MEASURES: Operative time, estimated blood loss, fluoroscopy, length of stay (LOS), intra- and postoperative complications, and physiologic measures including pre- and postoperative motor examinations and unresolved neuropraxia. METHODS: Patients who underwent LLIF were separated into EXP and SSO groups based on the presence or absence of vascular/general surgeon during the approach. The entire clinical history of patients with a decrease in pre- and postop motor examination was reviewed for the presence of neuropraxia. All other intra- and postop exposure-related complications were recorded for comparison. Propensity score matching (PSM) was performed to account for age, Charlson Comorbidity Index (CCI) percentage of LLIFs including L4-L5, and number of levels fused. Independent t test and chi-square analyses were used to identify significant differences between EXP and SSO groups. Statistical significance was set at p<.05. RESULTS: Two hundred and seventy-five patients underwent LLIF procedures, 155 SSO and 120 EXP. Postoperatively, 26 patients (11.1%) experienced a drop in any Medical Research Council (MRC) score, and two patients (0.7%) experienced unresolved quadriceps palsies. The mean recovery time for MRC scores was 84.4 days. Other complications included 2 pneumothoraces (0.7%), 1 iliac vein injury (0.4%), 14 cases of ileus (5.1%), 3 pulmonary emboli (1.1%), 2 deep vein thrombosis (0.7%), 3 cases of abdominal wall paresis (1.1%), and one abdominal hematoma (0.4%). After PSM, demographics including age, gender, body mass index, CCI, levels fused, and operative time were similar between cohorts. Twenty patients had changes in pre- to postop motor scores (SSO 9.4%, EXP 12.4%, p>.05). Iliopsoas motor scores decreased at the highest rate (EXP 12.4%, SSO 8.2%, p>.05) followed by quadriceps (EXP 5.2%, SSO 4.7%, p>.05). One SSO patient's postop course was complicated by a foot drop but returned to baseline within 1 year. One patient in EXP group developed an unresolved quadriceps palsy (EXP 1.0%, SSO 0.0%, p>.05). Intraoperative exposure complications included one pneumothorax (EXP 1.0%, SSO 0.0%, p>.05). There were no differences in PE/DVT, Ileus, or LOS. In the EXP cohort, three patients experienced abdominal wall paresis (EXP 2.9%, SSO 0.00%, p=.246). CONCLUSIONS: Comparing the LLIF exposures performed by EXP and SSO, we found no significant difference in the rates of complications. Additional research is needed to determine the etiology of the abdominal wall complications. In conclusion, neuropraxia- and approach-related complications are similarly low between exposure and spine surgeons.

Preoperative MRI predictors of health-related quality of life improvement after microscopic lumbar discectomy.

BACKGROUND: Lumbar herniated nucleus pulposus (HNP) is a common spinal pathology often treated by microscopic lumbar discectomy (MLD), though prior reports have not demonstrated which preoperative MRI factors may contribute to significant clinical improvement after MLD. PURPOSE: To analyze the MRI characteristics in patients with HNP that predict meaningful clinical improvement in health-related quality of life scores (HRQoL) after MLD. STUDY DESIGN/SETTING: Retrospective clinical and radiological study of patients undergoing MLD for HNP at a single institution over a 2-year period. PATIENT SAMPLE: Eighty-eight patients receiving MLD treatment for HNP. OUTCOME MEASURES: Cephalocaudal Canal Migration; Canal & HNP Anterior-Posterior (AP) Lengths and Ratio; Canal & HNP Axial Areas and Ratio; Hemi-Canal & Hemi-HNP Axial Areas and Ratio; Disc appearance (black, gray, or mixed); Baseline (BL); and 3-month (3M) postoperative HRQoL scores. METHODS: Patients >18 years old who received MLD for HNP with BL and 3M HRQoL scores of PROMIS (Physical Function, Pain Interference, and Pain Intensity), ODI, VAS Back, and VAS Leg scores were included. HNP and spinal canal measurements of cephalocaudal migration, AP length, area, hemi-area, and disc appearance were performed using T2 axial and sagittal MRI. HNP measurements were divided by corresponding canal measurements to calculate AP, Area, and Hemi-Area ratios. Using known minimal clinically important differences (MCID) for each ΔHRQoL score, patients were separated into two groups based on whether they reached MCID (MCID+) or did not reach MCID (MCID-). The MCID for PROMIS pain intensity was calculated using a decision tree. A linear regression illustrated correlations between PROMIS vs ODI and VAS Back/Leg scores. Independent t-tests and chi-squared tests were utilized to investigate significant differences in HNP measurements between the MCID+ and MCID- groups. RESULTS: There were 88 MLD patients included in the study (Age=44.6±14.9, 38.6% female). PROMIS pain interference and pain intensity were strongly correlated with ODI and VAS Back/Leg (R≥0.505), and physical function correlated with ODI and VAS Back/Leg (R=-0.349) (all p<.01). The strongest MRI predictors of meeting HRQoL MCID were gray disc appearance, HNP area (>116.6 mm2), and Hemi-Area Ratio (>51.8%). MCID+ patients were 2.7 times more likely to have a gray HNP MRI signal than a mixed or black HNP MRI signal in five out of six HRQoL score comparisons (p<.025). MCID+ patients had larger HNP areas than MCID- patients had in five out of six HRQoL score comparisons (116.6 mm2±46.4 vs 90.0 mm2±43.2, p<.04). MCID+ patients had a greater Hemi-Area Ratio than MCID- patients had in four out of six HRQoL score comparisons (51.8%±14.7 vs 43.9%±14.9, p<.05). CONCLUSIONS: Patients who met MCID after MLD had larger HNP areas and larger Hemi-HNP Areas than those who did not meet MCID. These patients were also 2.7× more likely to have a gray MRI signal than a mixed or black MRI signal. When accounting for HNP area relative to canal area, patients who met MCID had greater Hemi-HNP canal occupation than patients who did not meet MCID. The results of this study suggest that preoperative MRI parameters can be useful in predicting patient-reported improvement after MLD.