Radiation exposure in fluoroscopy-guided anterior total hip arthroplasty: a systematic review.

PURPOSE: To investigate the average fluoroscopy time, as well as the patient and surgical staff average radiation exposure in the context of intraoperative fluoroscopy use during anterior total hip arthroplasty (THA). METHODS: PubMed, Cochrane, Embase, Web of Science and Scopus were systematically searched for studies pertaining to intraoperative anterior THA fluoroscopy (PROSPERO ID 258049). The comprehensive literary search was conducted using "THA," "fluoroscopy" and "radiation exposure" as the search criteria, which resulted in 187 total papers. Of these 187 papers, 11 studies were included in this systematic review as they involved anterior THA and specifically contained data regarding radiation exposure dose and/or time. RESULTS: Eleven studies were included, enrolling 1839 patients. The average fluoroscopy time was 21.4 (95% confidence interval [CI] 16.6-26.1) seconds, whereas the average patient radiation dose was 1.8 × 10-3 (95% CI 7.4 × 10-4-2.9 × 10-3) Gy. CONCLUSIONS: Although several studies fail to report fluoroscopy time and radiation dose in THA patients, fluoroscopy-guided THA has emerged as a safe procedure. Additional studies may analyze if radiation exposure during the surgeon's THA learning curve is significantly higher, as well as what protocols may potentially reduce radiation exposure even further.

Clinical photographs in the assessment of adult spinal deformity: a comparison to radiographic parameters.

OBJECTIVE: The goal of this study was to reliably predict sagittal and coronal spinal alignment with clinical photographs by using markers placed at easily localized anatomical landmarks. METHODS: A consecutive series of patients with adult spinal deformity were enrolled from a single center. Full-length standing radiographs were obtained at the baseline visit. Clinical photographs were taken with reflective markers placed overlying C2, S1, the greater trochanter, and each posterior-superior iliac spine. Sagittal radiographic parameters were C2 pelvic angle (CPA), T1 pelvic angle (TPA), and pelvic tilt. Coronal radiographic parameters were pelvic obliquity and T1 coronal tilt. Linear regressions were performed to evaluate the relationship between radiographic parameters and their photographic "equivalents." The data were reanalyzed after stratifying the cohort into low-body mass index (BMI) (< 30) and high-BMI (≥ 30) groups. Interobserver and intraobserver reliability was assessed for clinical measures via intraclass correlation coefficients (ICCs). RESULTS: A total of 38 patients were enrolled (mean age 61 years, mean BMI 27.4 kg/m2, 63% female). All regression models were significant, but sagittal parameters were more closely correlated to photographic parameters than coronal measurements. TPA and CPA had the strongest associations with their photographic equivalents (both r2 = 0.59, p < 0.001). Radiographic and clinical parameters tended to be more strongly correlated in the low-BMI group. Clinical measures of TPA and CPA had high intraobserver reliability (all ICC > 0.99, p < 0.001) and interobserver reliability (both ICC > 0.99, p < 0.001). CONCLUSIONS: The photographic measures of spinal deformity developed in this study were highly correlated with their radiographic counterparts and had high inter- and intraobserver reliability. Clinical photography can not only reduce radiation exposure in patients with adult spinal deformity, but also be used to assess deformity when full-spine radiographs are unavailable.

Surgical outcomes in rigid versus flexible cervical deformities.

OBJECTIVE: Cervical deformity (CD) patients have severe disability and poor health status. However, little is known about how patients with rigid CD compare with those with flexible CD. The main objectives of this study were to 1) assess whether patients with rigid CD have worse baseline alignment and therefore require more aggressive surgical corrections and 2) determine whether patients with rigid CD have similar postoperative outcomes as those with flexible CD. METHODS: This is a retrospective review of a prospective, multicenter CD database. Rigid CD was defined as cervical lordosis (CL) change < 10° between flexion and extension radiographs, and flexible CD was defined as a CL change ≥ 10°. Patients with rigid CD were compared with those with flexible CD in terms of cervical alignment and health-related quality of life (HRQOL) at baseline and at multiple postoperative time points. The patients were also compared in terms of surgical and intraoperative factors such as operative time, blood loss, and number of levels fused. RESULTS: A total of 127 patients met inclusion criteria (32 with rigid and 95 with flexible CD, 63.4% of whom were females; mean age 60.8 years; mean BMI 27.4); 47.2% of cases were revisions. Rigid CD was associated with worse preoperative alignment in terms of T1 slope minus CL, T1 slope, C2-7 sagittal vertical axis (cSVA), and C2 slope (C2S; all p < 0.05). Postoperatively, patients with rigid CD had an increased mean C2S (29.1° vs 22.2°) at 3 months and increased cSVA (47.1 mm vs 37.5 mm) at 1 year (p < 0.05) compared with those with flexible CD. Patients with rigid CD had more posterior levels fused (9.5 vs 6.3), fewer anterior levels fused (1 vs 2.0), greater blood loss (1036.7 mL vs 698.5 mL), more 3-column osteotomies (40.6% vs 12.6%), greater total osteotomy grade (6.5 vs 4.5), and mean osteotomy grade per level (3.3 vs 2.1) (p < 0.05 for all). There were no significant differences in baseline HRQOL scores, the rate of distal junctional kyphosis, or major/minor complications between patients with rigid and flexible CD. Both rigid and flexible CD patients reported significant improvements from baseline to 1 year according to the numeric rating scale for the neck (-2.4 and -2.7, respectively), Neck Disability Index (-8.4 and -13.3, respectively), modified Japanese Orthopaedic Association score (0.1 and 0.6), and EQ-5D (0.01 and 0.05) (p < 0.05). However, HRQOL changes from baseline to 1 year did not differ between rigid and flexible CD patients. CONCLUSIONS: Patients with rigid CD have worse baseline cervical malalignment compared with those with flexible CD but do not significantly differ in terms of baseline disability. Rigid CD was associated with more invasive surgery and more aggressive corrections, resulting in increased operative time and blood loss. Despite more extensive surgeries, rigid CD patients had equivalent improvements in HRQOL compared with flexible CD patients. This study quantifies the importance of analyzing flexion-extension images, creating a prognostic tool for surgeons planning CD correction, and counseling patients who are considering CD surgery.

Age and Gender Confound PROMIS Scores in Spine Patients With Back and Neck Pain.

STUDY DESIGN: This was a single-center retrospective review. OBJECTIVES: To explore how age and gender affect PROMIS scores compared with traditional health-related quality of life (HRQL) in spine patients. METHODS: Patients presenting with a primary complaint of back pain (BP) or neck pain (NP) were included. Legacy HRQLs were Oswestry Disability Index (ODI), Neck Disability Index (NDI), and Visual Analogue Scale (VAS). PROMIS Physical Function (PF), Pain Intensity (Int), and Pain Interference (Inf) were also administered to patients in a clinical setting. Patients were grouped by chief complaint, age (18-44, 45-64, 65+ years) and gender. Two parallel analyses were conducted to identify the effects of age and gender on patient-reported outcomes. Age groups were compared after propensity-score matching by VAS-pain and gender. Separately, genders were compared after propensity-score matching by age and VAS-pain. RESULTS: A total of 484 BP and 128 NP patients were matched into gender cohorts (n = 201 in each BP group, 46 in each NP group). Among BP patients, female patients demonstrated worse disability by ODI (44.15 vs 38.45, P = .005); PROMIS-PF did not differ by gender. Among NP patients, neither legacy HRQLs nor PROMIS differed by gender when controlling for NP and age. BP and NP patients were matched into age cohorts (n = 135 in each BP group and n = 14 in each BP group). Among BP patients, ANOVA revealed differences between groups when controlling for BP and gender: ODI (P < .001), PROMIS-PF (P = .018), PROMIS-Int (P < .001) PROMIS-Inf (P < .001). Among NP patients, matched age groups differed significantly in terms of NDI (P = .032) and PROMIS-PF (P = .022) but not PROMIS-Int or PROMIS-Inf. CONCLUSIONS: Age and gender confound traditional HRQLs as well as PROMIS domains. However, PROMIS offers age and gender-specific scores, which traditional HRQLs lack.

Obesity Alters Spinopelvic Alignment Changes From Standing to Relaxed Sitting: the Influence of the Soft-tissue Envelope.

BACKGROUND: Changes in spinopelvic and lower extremity alignment between standing and relaxed sitting have important clinical implications with regard to stability of total hip arthroplasty. This study aimed to analyze the effect of body mass index (BMI) on lumbopelvic alignment and motion at the hip joint. METHODS: A retrospective review of patients who underwent full-body stereoradiographs in standing and relaxed sitting for total hip arthroplasty planning was conducted. Spinopelvic parameters measured included spinopelvic tilt (SPT), pelvic incidence (PI), lumbar lordosis (LL), PI minus LL (PI-LL), proximal femoral shaft angle (PFSA), and standing-to-sitting hip range of motion. Propensity score matching controlled for age, gender, PI, and hip ostoarthritis grade. Patients were stratified into normal (NORMAL; BMI, 18.5-24.9), overweight (OW; 25.0-29.9), and obese (OB; 30.0-34.9) groups. Alignment parameters were compared using one-way analysis of variance. RESULTS: There were 84 patients in each group after propensity score matching. Standing alignment between BMI groups was similar for all parameters (P > .05) except for PFSA (P < .001). Significant differences were noted for sitting alignment between patients who are NORMAL, OW, and OB in: SPT (P = .007), PI-LL (P = .018), and LL (P = .029). PFSA between groups was not significantly different (P > .05). Significant differences were found for sitting-to-standing alignment across groups in PFSA change (P < .001), SPT change (P = .006), PI-LL change (P = .005), LL change (P = .037), and hip flexion (P < .001). CONCLUSIONS: Significant differences in sitting and standing-to-sitting change in lumbopelvic alignment based on BMI suggest obese patients recruit more posterior spinopelvic tilt when sitting to compensate for soft-tissue impingement that occurs anterior to the hip joint and limiting hip flexion.

ODI Cannot Account for All Variation in PROMIS Scores in Patients With Thoracolumbar Disorders.

STUDY DESIGN: Retrospective review of single institution. OBJECTIVE: To assess the relationship between Patient-Reported Outcomes Measurement Information System (PROMIS) and Oswestry Disability Index (ODI) scores in thoracolumbar patients. METHODS: Included: Patients ≥18 years with a thoracolumbar spine condition (spinal stenosis, disc herniation, low back pain, disc degeneration, spondylolysis). Bivariate correlations assessed the linear relationships between ODI and PROMIS (Physical Function, Pain Intensity, and Pain Interference). Correlation cutoffs assessed patients with high and low correlation between ODI and PROMIS. Linear regression predicted the relationship of ODI to PROMIS. RESULTS: A total of 206 patients (age 53.7 ± 16.6 years, 49.5% female) were included. ODI correlated with PROMIS Physical Function (r = -0.763, P < .001), Pain Interference (r = 0.800, P < .001), and Pain Intensity (r = 0.706, P < .001). ODI strongly predicted PROMIS for Physical Function (R 2 = 0.58, P < .001), Pain Intensity (R 2 = 0.50, P < .001), and Pain Interference (R 2 = 0.64, P < .001); however, there is variability in PROMIS that ODI cannot account for. ODI questions about sitting and sleeping were weakly correlated across the 3 PROMIS domains. Linear regression showed overall ODI score as accounting for 58.3% (R 2 = 0.583) of the variance in PROMIS Physical Function, 63.9% (R 2 = 0.639) of the variance in Pain Interference score, and 49.9% (R 2 = 0.499) of the variance in Pain Intensity score. CONCLUSIONS: There is a large amount of variability with PROMIS that cannot be accounted for with ODI. ODI questions regarding walking, social life, and lifting ability correlate strongly with PROMIS while sitting, standing, and sleeping do not. These results reinforce the utility of PROMIS as a valid assessment for low back disability, while indicating the need for further evaluation of the factors responsible for variation between PROMIS and ODI.

Hospital-acquired conditions occur more frequently in elective spine surgery than for other common elective surgical procedures.

Hospital-acquired conditions (HACs) have been the focus of recent initiatives by the Centers for Medicare and Medicaid Services in an effort to improve patient safety and outcomes. Spine surgery can be complex and may carry significant comorbidity burden, including so called "never events." The objective was to determine the rates of common HACs that occur within 30-days post-operatively for elective spine surgeries and compare them to other common surgical procedures. Patients: >18 y/o undergoing elective spine surgery were identified in the American College of Surgeons' NSQIP database from 2005 to 2013. Patients were stratified by whether they experienced >1 HAC, then compared to those undergoing other procedures including bariatric surgery, THA and TKA. Of the 90,551 spine surgery patients, 3021 (3.3%) developed at least one HAC. SSI was the most common (1.4%), followed by UTI (1.3%), and VTE (0.8%). Rates of HACs in spine surgery were significantly higher than other elective procedures including bariatric surgery (2.8%) and THA (2.8%) (both p < 0.001). Spine surgery and TKA patients had similar rates of HACs(3.3% vs 3.4%, p = 0.287), though spine patients experienced higher rates of SSI (1.4%vs0.8%, p < 0.001) and UTI (1.3%vs1.1%, p < 0.001) but lower rates of VTE (0.8%vs1.6%, p < 0.001). Spine surgery patients had lower rates of HACs overall (3.3%vs5.9%) when compared to cardiothoracic surgery patients (p < 0.001). When compared to other surgery types, spine procedures were associated with higher HACs than bariatric surgery patients and knee and hip arthroplasties overall but lower HAC rates than patients undergoing cardiothoracic surgery.

PROMIS is superior to established outcome measures in capturing disability resulting from sagittal malalignment in patients with back pain.

INTRODUCTION: Patient reported outcomes measurement information system (PROMIS) is a quality of life metric that has gained increased popularity due to computer adaptive testing. Previous studies have shown that PROMIS correlates with Oswestry Disability Index (ODI) in patients with back pain and takes significantly less time to complete. However, the ability of PROMIS to capture disability from spinal malalignment relative to established metrics is unknown. The aim of the present study is to validate the correlation between ODI and PROMIS in patients with back pain, analyze correlations of PROMIS and legacy metrics to sagittal alignment, and identify major drivers of PROMIS scores and ODI in patients with back pain. METHODS: A retrospective review was conducted of a prospectively collected outcome measures database (PROMIS, ODI, VAS Back, VAS Leg, VAS Neck, and VAS Arm) of spine patients > 18 years. Inclusion criteria for the present study was a chief complaint of back pain and full length weight bearing X-rays within 30 days of health related quality of life (HRQL) completion. Demographic information, radiographic alignment, psychiatric diagnoses, and comorbidities were recorded. PROMIS metrics were correlated to legacy metrics (ODI and VAS). Next, outcome metrics were correlated with sagittal alignment variables T1 Pelvic Angle (TPA), SVA, PT, and PI-LL. Patients were grouped based on the presence of spinal deformity (defined radiographically as any one of SVA > 4 cm, PI-LL > 10°, PT > 20°) and mean HRQL scores were investigated for the adult spinal deformity (ASD) and non-ASD groups. Finally, drivers of PROMIS PF scores and ODI scores were determined using multiple stepwise regression. RESULTS: 150 patients met inclusion criteria including 60 patients with ASD and 90 patients without. For the whole cohort, PROMIS PF correlated with ODI (r = - 0.651, p < 0.001), VAS Back (r = - 0.260, p = 0.014) and Charleson Comorbidity Index (r = - 0.336, p < 0.001). PROMIS PF had higher correlations than ODI for each sagittal alignment parameter tested, including TPA, SVA, PT, and PI-LL. When patients with ASD were compared to non-ASD patients, the PROMIS score was different between the groups but the ODI and VAS scores were not. Finally, stepwise linear regression showed that SVA, PI-LL, and VAS Leg were significant drivers of PROMIS PF (r2 = 0.406, p < 0.001). VAS Leg and VAS Back were significant contributors to ODI (r2 = 0.376, p < 0.001). CONCLUSIONS: In a cohort of 150 patients with back pain, PROMIS correlated strongly with legacy outcome metrics, including VAS and ODI. PROMIS PF correlated more strongly with sagittal malalignment than ODI. Additionally, patients with spinal deformity had significantly worse PROMIS PF scores but similar ODI scores as patients without ASD. Finally, sagittal alignment was found to be a significant driver of PROMIS PF scores but not ODI scores. PROMIS PF should be utilized as a disability assessment tool in patients with spinal deformity due to ease of use, strong correlations with legacy metrics, and ability to capture disability resulting from sagittal alignment.

MRI Radiological Predictors of Requiring Microscopic Lumbar Discectomy After Lumbar Disc Herniation.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To investigate radiological differences in lumbar disc herniations (herniated nucleus pulposus [HNP]) between patients receiving microscopic lumbar discectomy (MLD) and nonoperative patients. METHODS: Patients with primary treatment for an HNP at a single academic institution between November 2012 to March 2017 were divided into MLD and nonoperative treatment groups. Using magnetic resonance imaging (MRI), axial HNP area; axial canal area; HNP canal compromise; HNP cephalad/caudal migration and HNP MRI signal (black, gray, or mixed) were measured. T test and chi-square analyses compared differences in the groups, binary logistic regression analysis determined odds ratios (ORs), and decision tree analysis compared the cutoff values for risk factors. RESULTS: A total of 285 patients (78 MLD, 207 nonoperative) were included. Risk factors for MLD treatment included larger axial HNP area (P < .01, OR = 1.01), caudal migration, and migration magnitude (P < .05, OR = 1.90; P < .01, OR = 1.14), and gray HNP MRI signal (P < .01, OR = 5.42). Cutoff values for risks included axial HNP area (70.52 mm2, OR = 2.66, P < .01), HNP canal compromise (20.0%, OR = 3.29, P < .01), and cephalad/caudal migration (6.8 mm, OR = 2.43, P < .01). MLD risk for those with gray HNP MRI signal (67.6% alone) increased when combined with axial HNP area >70.52 mm2 (75.5%, P = .01) and HNP canal compromise >20.0% (71.1%, P = .05) cutoffs. MLD risk in patients with cephalad/caudal migration >6.8 mm (40.5% alone) increased when combined with axial HNP area and HNP canal compromise (52.4%, 50%; P < .01). CONCLUSION: Patients who underwent MLD treatment had significantly different axial HNP area, frequency of caudal migration, magnitude of cephalad/caudal migration, and disc herniation MRI signal compared to patients with nonoperative treatment.

Pelvic Compensation in Sagittal Malalignment: How Much Retroversion Can the Pelvis Accommodate?

STUDY DESIGN: Single-center retrospective study. OBJECTIVE: Investigate how differing degrees of pelvic incidence (PI) modulate the recruitment of pelvic tilt (PT) in response to similar amounts of sagittal malalignment as measured by T1-Pelvic Angle (TPA). SUMMARY OF BACKGROUND DATA: Past research has shown that some patients do not recruit PT in response to sagittal malalignment. Given the anatomic relationship between PI and PT, we sought to determine whether differing PI is associated with variable recruitment of PT. METHODS: Single-center retrospective study of 2077 patients undergoing full body radiographs and TPA>10°. Five groups of patients (Very Low, Low, Average, High, and Very High PI) were defined utilizing PI ranges on a Gaussian distribution. Linear regression (LR) evaluated correlation of TPA to PT within each PI group. Multivariate LR evaluated whether correlation between TPA and PT differed between each PI group. RESULTS: Mean PT increased with increasing levels of PI (P < 0.05). Within the full cohort, PT correlated with TPA (r = 0.80, P < 0.001). Multivariate LR revealed significant differences between slopes and intercepts of the linear relationship between PT and TPA within the PI groups. Compared with patients with an average PI, patients with Very Low PI had 3.4° lower PT while holding TPA constant (P < 0.001). Further, patients with Very High PI displayed a PT of 1.9° higher than patients with an Average PI while holding TPA constant (P = 0.01). A similar difference of -1.8°, and 1.2° with respect to the Average PI group was observed in the Low and High PI groups, respectively (P < 0.001). Means and standard deviations of PT at varying levels of TPA were defined for PI groups. CONCLUSION: This is the first study which demonstrated that PI is associated with varied recruitment of PT while maintaining constant sagittal malalignment. The results reported herein are intended to allow surgeons to assess a patient's magnitude of compensatory PT for an individual patient's PI. LEVEL OF EVIDENCE: 3.

Incidence of Acute, Progressive, and Delayed Proximal Junctional Kyphosis Over an 8-Year Period in Adult Spinal Deformity Patients.

BACKGROUND: Proximal junctional kyphosis (PJK) is a common radiographic complication of adult spinal deformity (ASD) corrective surgery. Although previous literature has reported a 5 to 61% incidence of PJK, these studies are limited by small sample sizes and short-term follow-up. OBJECTIVE: To assess the incidence of PJK utilizing a high-powered ASD database. METHODS: Retrospective review of a prospective multicenter ASD database. Operative ASD patients > 18 yr old from 2009 to 2017 were included. PJK was defined as ≥ 10° for the sagittal Cobb angle between the inferior upper instrumented vertebra (UIV) endplate and the superior endplate of the UIV + 2. Chi-square analysis and post hoc testing assessed annual and overall incidence of acute (6-wk follow-up [f/u]), progressive (increase in degree of PJK from 6 wk to 1 yr), and delayed (1-yr, 2-yr, and 3-yr f/u) PJK development. RESULTS: A total of 1005 patients were included (age: 59.3; 73.5% F; body mass index: 27.99). Overall PJK incidence was 69.4%. Overall incidence of acute PJK was 48.0%. Annual incidence of acute PJK has decreased from 53.7% in 2012 to 31.6% in 2017 (P = .038). Overall incidence of progressive PJK was 35.0%, with stable rates observed from 2009 to 2016 (P = .297). Overall incidence of 1-yr-delayed PJK was 9.3%. Annual incidence of 1-yr-delayed PJK has decreased from 9.2% in 2009 to 3.2% in 2016 (P < .001). Overall incidence of 2-yr-delayed PJK development was 4.3%. Annual incidence of 2-yr-delayed PJK has decreased from 7.3% in 2009 to 0.9% in 2015 (P < .05). Overall incidence of 3-yr-delayed PJK was 1.8%, with stable rates observed from 2009 to 2014 (P = .594). CONCLUSION: Although progressive PJK has remained a challenge for physicians over time, significantly lower incidences of acute and delayed PJK in recent years may indicate improving operative decision-making and management strategies.

Spinopelvic Compensatory Mechanisms for Reduced Hip Motion (ROM) in the Setting of Hip Osteoarthritis.

STUDY DESIGN: Retrospective review from a single institution. OBJECTIVE: To investigate the effect of hip osteoarthritis (OA) on spinopelvic compensatory mechanisms as a result of reduced hip range of motion (ROM) between sitting and standing. SUMMARY OF BACKGROUND DATA: Hip OA results in reduced hip ROM and contracture, causing pain during postural changes. Hip flexion contracture is known to reduce the ability to compensate for spinal deformity while standing; however, the effects of postural spinal alignment change between sitting and standing is not well understood. METHODS: Sit-stand radiographs of patients without prior spinal fusion or hip prosthesis were evaluated. Hip OA was graded by Kellgren-Lawrence grades and divided into low-grade (LOA; grade 0-2) and severe (SOA; grade 3 or 4) groups. Radiographic parameters evaluated were pelvic incidence (PI), pelvic tilt (PT), lumbar lordosis (LL), PI-LL, thoracic kyphosis (TK), SVA, T1-pelvic angle (TPA), T10-L2, proximal femoral shaft angle (PFSA), and hip flexion (PT change-PFSA change). Changes in sit-stand parameters were compared between LOA and SOA groups. RESULTS: 548 patients were included (LOA = 311; SOA = 237). After propensity score matching for age, body mass index, and PI, 183 LOA and 183 SOA patients were analyzed. Standing analysis demonstrated that SOA had higher SVA (31.1 vs. 21.7), lower TK (-36.2 vs. -41.1), and larger PFSA (9.1 vs. 7.4) (all p < .05). Sitting analysis demonstrated that SOA had higher PT (29.7 vs. 23.3), higher PI-LL (21.6 vs. 12.4), less LL (31.7 vs. 41.6), less TK (-33.2 vs. -38.6), and greater TPA (27.9 vs. 22.5) (all p < .05). SOA had less hip ROM from standing to sitting versus LOA (71.5 vs. 81.6) (p < .05). Therefore, SOA had more change in PT (15.2 vs. 7.3), PI-LL (20.6 vs. 13.7), LL (-21.4 vs. -13.1), and T10-L2 (-4.9 vs. -1.1) (all p < .001), allowing the femurs to change position despite reduced hip ROM. SOA had greater TPA reduction (15.1 vs. 9.6) and less PFSA change (86.7 vs. 88.8) compared with LOA (both p < .001). CONCLUSIONS: Spinopelvic compensatory mechanisms are adapted for reduced hip joint motion associated with hip OA in standing and sitting. LEVEL OF EVIDENCE: Level III.

Correction to: Prior bariatric surgery lowers complication rates following spine surgery in obese patients.

The AHRQ (Agency for Healthcare Research and Quality) has requested the correction of the result Tables 1-3 of this study: All stated numbers below 10 shall be modified to read "<10" instead.

Diminishing Clinical Returns of Multilevel Minimally Invasive Lumbar Interbody Fusion.

STUDY DESIGN: Single institution retrospective clinical review. OBJECTIVE: To investigate the relationship between levels fused and clinical outcomes in patients undergoing open and minimally invasive surgical (MIS) lumbar fusion. SUMMARY OF BACKGROUND DATA: Minimally invasive spinal fusion aims to reduce the morbidity associated with conventional open surgery. As multilevel arthrodesis procedures are increasingly performed using MIS techniques, it is necessary to weigh the risks and benefits of multilevel MIS lumbar fusion as a function of fusion length. METHODS: Patients undergoing <4 level lumbar interbody fusion were stratified by surgical technique (MIS or open), and grouped by fusion length: 1-level, 2-levels, 3+ levels. Demographics, Charlson Comorbidity Index (CCI), surgical factors, and perioperative complication rates were compared between technique groups at different fusion lengths using means comparison tests. RESULTS: Included: 361 patients undergoing lumbar interbody fusion (88% transforaminal, 14% lateral; 41% MIS). Breakdown by fusion length: 63% 1-level, 22% 2-level, 15% 3+ level. Op-time did not differ between groups at 1-level (MIS: 233 min vs. Open: 227, P = 0.554), though MIS at 2-levels (332 min vs. 281) and 3+ levels (373 min vs. 323) were longer (P = 0.033 and P = 0.231, respectively). While complication rates were lower for MIS at 1-level (15% vs. 30%, P = 0.006) and 2-levels (13% vs. 27%, P = 0.147), at 3+ levels, complication rates were comparable (38% vs. 35%, P = 0.870). 3+ level MIS fusions had higher rates of ileus (13% vs. 0%, P = 0.008) and a trend of increased adverse pulmonary events (25% vs. 7%, P = 0.110). MIS was associated with less EBL at all lengths (all P < 0.01) and lower rates of anemia at 1-level (5% vs. 18%, P < 0.001) and 2-levels (7% vs. 16%, P = 0.193). At 3+ levels, however, anemia rates were similar between groups (13% vs. 15%, P = 0.877). CONCLUSION: MIS lumbar interbody fusions provided diminishing clinical returns for multilevel procedures. While MIS patients had lower rates of perioperative complications for 1- and 2-level fusions, 3+ level MIS fusions had comparable complication rates to open cases, and higher rates of adverse pulmonary and ileus events. LEVEL OF EVIDENCE: 3.

The Impact of Adult Thoracolumbar Spinal Deformities on Standing to Sitting Regional and Segmental Reciprocal Alignment.

BACKGROUND: Regional and segmental changes of the lumbar spine have previously been described as patients transition from standing to sitting; however, alignment changes in the cervical and thoracic spine have yet to be investigated. So, the aim of this study was to assess cervical and thoracic regional and segmental changes in patients with thoracolumbar deformity versus a nondeformed thoracolumbar spine population. METHODS: This study was a retrospective cohort study of a single center's database of full-body stereoradiographic imaging and clinical data. Patients were ≥ 18 years old with nondeformed spines (nondegenerative, nondeformity spinal pathologies) or thoracolumbar deformity (ASD: PI-LL > 10°). Patients were propensity-score matched for age and maximum hip osteoarthritis grade and were stratified by Scoliosis Research Society (SRS)-Schwab classification by PI-LL, SVA, and PT. Patients with lumbar transitional anatomy or fusions were excluded. Outcome measures included changes between standing and sitting in global alignment parameters: sagittal vertical axis (SVA), pelvic incidence minus lumbar lordosis (PI-LL), pelivc tilt (PT), thoracic kyphosis, cervical alignment, cervical SVA, C2-C7 lordosis (CL), T1 slop minus CL (TS-CL), and segmental alignment from C2 to T12. Another analysis was performed using patients with cervical and thoracic segmental measurements. RESULTS: A total of 338 patients were included (202 nondeformity, 136 ASD). After propensity-score matching, 162 patients were included (81 nondeformity, 81 ASD). When categorized by SRS-Schwab classification, all nondeformity patients were nonpathologically grouped for PI-LL, SVA, and PT, whereas ASD patients had mix of moderately and markedly deformed modifiers. There were significant differences in pelvic and global spinal alignment changes from standing to sitting between nondeformity and ASD patients, particularly for SVA (nondeformed: 49.5 mm versus ASD: 27.4 mm; P < .001) and PI-LL (20.12° versus 13.01°, P < .001). With application of the Schwab classification system upon the cohort, PI-LL (P = .040) and SVA (P = .007) for severely classified deformity patients had significantly less positional alignment change. In an additional analysis of patients with segmental measurements from C2 to T12, nondeformity patients showed significant mobility of T2-T3 (-0.99° to -0.54°, P = .023), T6-T7 (-3.39° to -2.89°, P = .032), T7-T8 (-2.68° to -2.23°, P = .048), and T10-T11 (0.31° to 0.097°, P = .006) segments from standing to sitting. ASD patients showed mobility of the C6-C7 (1.76° to 3.45°, P < .001) and T11-T12 (0.98° to 0.54°, P = 0.014) from standing to sitting. The degree of mobility between nondeformity and ASD patients was significantly different in C6-C7 (-0.18° versus 1.69°, P = .003), T2-T3 (0.45° versus -0.27°, P = .034), and T10-T11 (0.45° versus -0.30°, P = .001) segments. With application of the Schwab modifier system upon the cohort, mobility was significant in the C6-C7 (nondeformed: 0.18° versus moderately deformed: 2.12° versus markedly deformed: 0.92°, P = .039), T2-T3 (0.45° versus -0.08° versus -0.63°, P = .020), T6-T7 (0.48° versus 0.36° versus -1.85°, P = .007), and T10-T11 (0.45° versus -0.21° versus -0.23°, P = .009) segments. CONCLUSIONS: Nondeformity patients and ASD patients have significant differences in mobility of global spinopelvic parameters as well as segmental regions in the cervical and thoracic spine between sitting and standing. This study aids in our understanding of flexibility and compensatory mechanisms in deformity patients, as well as the possible impact on unfused segments when considering deformity corrective surgery.

PROMIS Correlates With Legacy Outcome Measures in Patients With Neck Pain and Improves Upon NDI When Assessing Disability in Cervical Deformity.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To evaluate the ability of patient reported outcome measurement information system (PROMIS) assessments to capture disability related to cervical sagittal alignment and secondarily to compare these findings to legacy outcome measures. SUMMARY OF BACKGROUND DATA: PROMIS is a validated patient-reported outcome metric that is increasing in popularity due to its speed of administration relative to legacy metrics. The ability of PROMIS to capture disability from sagittal alignment and baseline health status in patients with neck pain has not been investigated. METHODS: Patients presenting with a chief complaint of neck pain from December 2016 to July 2017 were included. Demographics and comorbidities were retrospectively collected. All patients prospectively completed the neck disability index (NDI), EQ-5D, visual analog scale (VAS) neck, VAS arm, PROMIS physical function, PROMIS pain intensity, and PROMIS pain interference metrics. Cervical sagittal alignment parameters were measured on standing X-rays. The correlations between outcome measures, health status indexes, psychiatric diagnoses, and sagittal alignment were analyzed. RESULTS: Two hundred twenty-six patients were included. The sample was 58.4% female with a mean age of 55.1 years. In patients with neck pain, PROMIS physical function correlated strongly with the NDI (r = -0.763, P < 0.01), EQ-5D (r = 0.616, P < 0.01), VAS neck pain (-0.466, P < 0.01), and VAS arm pain (r = -0.388, P < 0.01). One hundred seventy-seven patients (69.96%) were included in the radiographic analysis. 20.3% of the radiographic cohort had cervical deformity and in this group, less cervical lordosis correlated with PROMIS pain intensity and EQ-5D but not NDI. In patients without cervical deformity, no outcome metric was found to correlate significantly with cervical alignment parameters. CONCLUSION: PROMIS domains correlated strongly with legacy outcome metrics. For the whole cohort, sagittal alignment was not correlated with outcomes. In patients with sagittal cervical deformity, worsening alignment correlated with PROMIS pain intensity and EQ-5D but not NDI. LEVEL OF EVIDENCE: 3.

Patient-Reported Outcomes Measurement Information System instruments: outperforming traditional quality of life measures in patients with back and neck pain.

OBJECTIVE The Patient-Reported Outcomes Measurement Information System (PROMIS) has become increasingly popular due to computer adaptive testing methodology. This study aims to validate the association between PROMIS and legacy outcome metrics and compare PROMIS to legacy metrics in terms of ceiling and floor effects and questionnaire burden. METHODS A retrospective review of an outcomes database was performed at a single institution from December 2016 to April 2017. Inclusion criteria were age > 18 years and a chief complaint of back pain or neck pain. The PROMIS computer adaptive testing Pain Interference, Physical Function (PF), and Pain Intensity domains; Oswestry Disability Index (ODI); Neck Disability Index (NDI); and visual analog scale (VAS) back, VAS leg, VAS neck, and VAS arm were completed in random order. PROMIS was compared to legacy metrics in terms of the average number of questions needed to complete each questionnaire and the score distributions in the lower and higher bounds of scores. RESULTS A total of 494 patients with back pain and 130 patients with neck pain were included. For back pain, ODI showed a strong correlation with PROMIS-PF (R = −0.749, p < 0.001), Pain Intensity (R = 0.709, p < 0.001), and Pain Interference (R = 0.790, p < 0.001) domains. Additionally, the PROMIS Pain Intensity domain correlated to both VAS back and neck pain (R = 0.642, p < 0.001 for both). PROMIS-PF took significantly fewer questions to complete compared to the ODI (4.123 vs 9.906, p < 0.001). When assessing for instrument sensitivity, neither survey presented a significant ceiling and floor effect in the back pain population (ODI: 0.40% and 2.63%; PROMIS-PF: 0.60% and 1.41%). In the neck pain cohort, NDI showed a strong correlation with PROMIS-PF (R = 0.771, p < 0.001). Additionally, PROMIS Pain Intensity correlated to VAS neck (R = 0.642, p < 0.001). The mean number of questions required to complete the questionnaire was much lower for PROMIS-PF compared to NDI (4.417 vs 10, p < 0.001). There were no significant differences found in terms of ceiling and floor effects for neck complaints (NDI: 2.3% and 6.92%; PROMIS-PF: 0.00% and 5.38%) or back complaints (ODI: 0.40% and 2.63%; PROMIS-PF: 1.41% and 0.60%). CONCLUSIONS PROMIS correlates strongly with traditional disability measures in patients with back pain and neck pain. For both back and neck pain, the PROMIS-PF required patients to answer significantly fewer questions to achieve similar granularity. There were no significant differences in ceiling and floor effects for NDI or ODI when compared with the PROMIS-PF instrument.

Impact of presenting patient characteristics on surgical complications and morbidity in early onset scoliosis.

This study sought to assess comorbidity profiles unique to early-onset-scoliosis (EOS) patients by employing cluster analytics and to determine the influence of isolated comorbidity clusters on perioperative complications, morbidity and mortality using a high powered administrative database. The KID database was queried for ICD-9 codes pertaining to congenital and idiopathic scoliosis from 2003, 2006, 2009, 2012. Patients <10 y/o (EOS group) were included. Demographics, incidence and comorbidity profiles were assessed. Comorbidity profiles were stratified by body systems (neurological, musculoskeletal, pulmonary, cardiovascular, renal). K-means cluster and descriptive analyses elucidated incidence and comorbidity relationships between frequently co-occurring comorbidities. Binary logistic regression models determined predictors of perioperative complication development, mortality, and extended length-of-stay (≥75th percentile). 25,747 patients were included (Age: 4.34, Female: 52.1%, CCI: 0.64). Incidence was 8.9 per 100,000 annual discharges. 55.2% presented with pulmonary comorbidities, 48.7% musculoskeletal, 43.8% neurological, 18.6% cardiovascular, and 11.9% renal; 38% had concurrent neurological and pulmonary. Top inter-bodysystem clusters: Pulmonary disease (17.2%) with epilepsy (17.8%), pulmonary failure (12.2%), restrictive lung disease (10.5%), or microcephaly and quadriplegia (2.1%). Musculoskeletal comorbidities (48.7%) with renal and cardiovascular comorbidities (8.2%, OR: 7.9 [6.6-9.4], p < 0.001). Top intra-bodysystem clusters: Epilepsy (11.7%) with quadriplegia (25.8%) or microcephaly (20.5%). Regression analysis determined neurological and pulmonary clusters to have a higher odds of perioperative complication development (OR: 1.28 [1.19-1.37], p < 0.001) and mortality (OR: 2.05 [1.65-2.54], p < 0.001). Musculoskeletal with cardiovascular and renal anomalies had higher odds of mortality (OR: 1.72 [1.28-2.29], p < 0.001) and extLOS (OR: 2.83 [2.48-3.22], p < 0.001). EOS patients with musculoskeletal conditions were 7.9x more likely to have concurrent cardiovascular and renal anomalies. Clustered neurologic and pulmonary anomalies increased mortality risk by as much as 105%. These relationships may benefit pre-operative risk assessment for concurrent anomalies and adverse outcomes. Level of Evidence: III - Retrospective Prognostic Study.

Comparison of Patient Reported Outcome Measurement Information System With Neck Disability Index and Visual Analog Scale in Patients With Neck Pain.

STUDY DESIGN: A retrospective analysis of a patient-reported outcomes database from a single institution from December 2016 to April 2017. OBJECTIVE: To validate the association of Patient Reported Outcome Measurement Information System (PROMIS) with Neck Disability Index (NDI) in patients with neck pain and examine each instruments ability to capture concomitant arm pain and concomitant back pain. SUMMARY OF BACKGROUND DATA: PROMIS has been increasingly utilized and its computer adapted testing methodology improves assessment of pain and disability. However, literature is lacking regarding how these instruments perform in neck pain patients with concomitant arm pain or back pain. METHODS: Inclusion criteria were age >18 years and a primary complaint of neck pain. The NDI; Visual Analog Scale (VAS) back, neck, arm, and leg; and PROMIS physical function, pain intensity, and pain interference questionnaires were administered. Propensity score matching was performed to compare patients with high and low back and arm pain by controlling for neck pain. Bivariate correlations and independent samples t tests were performed to assess linear relationships and compare back and arm pain groups with PROMIS. RESULTS: Approximately, 130 patients were included. NDI correlated strongly to PROMIS physical function (r = -0.771, P < 0.001), pain intensity (r = 0.605, P < 0.001), and pain interference (r = 0.786, P < 0.001). VAS neck and arm pain also correlated to the PROMIS pain intensity instrument (VAS neck: r = 0.642, P < 0.001; VAS arm: r = 0.376, P < 0.001).After matching for neck pain, the high and low back pain groups each included 32 patients. There were significant differences in PROMIS physical function when high and low back pain groups were compared (39.07 vs. 43.68, P = 0.031). No significant difference was found for any outcome metric for high and low arm pain groups. CONCLUSION: PROMIS instruments are capable of characterizing pain and disability in patients with neck pain and are sensitive to disability in regions adjacent to the neck. LEVEL OF EVIDENCE: 3.

Comparative Analysis of Two Transforaminal Lumbar Interbody Fusion Techniques: Open TLIF Versus Wiltse MIS TLIF.

STUDY DESIGN: A retrospective cohort study at a single institution. OBJECTIVE: The aim of this study was to analyze the perioperative and postoperative outcomes of patients who underwent open transforaminal lumbar interbody fusion (O-TLIF) and bilateral minimally invasive surgery (MIS) Wiltse approach TLIF (Wil-TLIF). SUMMARY OF BACKGROUND DATA: Several studies have compared open TLIF to MIS TLIF; however, comparing the techniques using a large cohort of one-level TLIFs has not been fully explored. METHODS: We reviewed the charts of patients undergoing a single-level primary posterior lumbar interbody fusion between 2012 and 2017. The cases were categorized as Open TLIF (traditional midline exposure including lateral exposure of transverse processes) or bilateral paramedian Wiltse TLIF approach. Differences between groups were assessed by t tests. RESULTS: Two hundred twenty-seven patients underwent one-level primary TLIF (116 O-TLIF, 111 Wil-TLIF). There was no difference in age, gender, American Society of Anesthesiologists (ASA), or body mass index (BMI) between groups. Wil-TLIF had the lowest estimated blood loss (EBL; 197 vs. 499 mL O-TLIF, P ≤ 0.001), length of stay (LOS; 2.7 vs. 3.6 days O-TLIF, P ≤ 0.001), overall complication rate (12% vs. 24% O-TLIF, P = 0.015), minor complication rate (7% vs. 16% O-TLIF, P = 0.049), and 90-day readmission rate (1% vs. 8% O-TLIF, P = 0.012). Wil-TLIF was associated with the higher fluoroscopy time (83 vs. 24 seconds O-TLIF, P ≤ 0.001). There was not a significant difference in operative time, intraoperative or neurological complications, extubation time, reoperation rate, or infection rate. CONCLUSION: In comparing Wiltse MIS TLIF to Open TLIF, the minimally invasive paramedian Wiltse approach demonstrated the lowest EBL, LOS, readmission rates, and complications, but longer fluoroscopy times when compared with the traditional open approach. LEVEL OF EVIDENCE: 3.