Faculty Bibliography

OBJECT/OBJECTIVE:This case series examined patients undergoing caudal extension of prior fusion without alteration of the prior UIV to assess patient outcomes and rates of PJK/PJF. METHODS:Patients eligible for 2-year minimum follow-up undergoing caudal extension of prior fusion with unchanged UIVs were identified. These patients were evaluated for PJK/PJF, and patient reported outcomes were recorded. RESULTS:In total, 40 patients were included. Mean follow-up duration was 2.2 years (SD 0.3). Patients in this cohort had poor preoperative sagittal alignment (PI-LL 26.7°, TPA 29.0°, SVA 93.4mm) and achieved substantial sagittal correction (ΔSVA -62.2mm, ΔPI-LL -19.8°, ΔTPA -11.1°) following caudal extension surgery. At final follow-up, there was a 0% rate of PJF among patients undergoing caudal extension of previous fusion without creation of a new UIV, but 27.5% of patients experienced PJK. Patients experienced significant improvement in both ODI and SRS-22r total score at 2-years post-operatively (p<0.05). In total, 7.5% (n=3) of patients underwent further revision, at an average of 1.1 years (SD 0.54) after the surgery with unaltered UIV. All three of these patients underwent revision for rod fracture with no revisions for PJK/PJF. CONCLUSIONS:Patients undergoing caudal extension of previous fusions for sagittal alignment correction have high rates of clinical success, low revision surgery rates, and very low rates of PJF. Minimizing repetitive tissue trauma at the UIV may result in decreased PJF risk, as the PJF rate in this cohort of unaltered UIV patients is below historical PJF rates of patients undergoing sagittal balance correction.

OBJECT/OBJECTIVE:Sexual function is an important factor which contributes to quality of life. ASD patients may have sexual limitations due to lumbar spinal stiffness which may be affected by long-segment fusion. METHODS:This study utilized a multi-center, prospectively defined, consecutive cohort of ASD patients. The primary outcome in this study was the LSDI question 10: "Choose the statement that best describes the effect of low back stiffness on your ability to engage in sexual intercourse". RESULTS:In total, 368 patients were included in this study, including 76 males and 292 females of which 80.7% (n=293) underwent 9 or more level fusion and 74.4% (n=270) had pelvic fixation. Baseline LSDI sexual function scores averaged 1.7 (SD 1.3), which improved to 1.3 (SD 1.2) at 2-year follow-up (p = 0.0008). After adjusting for confounding factors, worse LSDI sexual function score was strongly associated with worse ODI, SRS total, and SF-36 PCS and MCS scores at both baseline and 2-year follow-up (p<0.05 for all comparisons). Predictors of poorer baseline sexual function included older age, increased SVA, and increased back pain (p<0.05 for all comparisons). Predictors of improvement in sexual function at 2-year follow-up included SVA improvement (p=0.0032) and decreased postoperative back pain (p<0.0001). CONCLUSIONS:This study found that sexual dysfunction scores due to lumbar stiffness significantly improved following surgery for ASD. Additionally, lumbar stiffness related sexual dysfunction is strongly related to overall outcome measured by ODI and SRS total score, highlighting the importance of sexual health on overall outcome in ASD patients.

BACKGROUND CONTEXT/BACKGROUND:Considerable debate exists regarding the optimal surgical approach for adult spinal deformity (ASD). It remains unclear which approach, posterior-only or combined anterior-posterior (AP), is more cost-effective. Our goal is to determine the 2-year cost per quality-adjusted life year (QALY) for each approach. PURPOSE/OBJECTIVE:To compare the 2-year cost-effectiveness of surgical treatment for ASD between the posterior-only approach and combined AP approach. STUDY DESIGN/METHODS:Retrospective economic analysis of a prospective, multicenter database PATIENT SAMPLE: From a prospective, multicenter surgical database of ASD, patients undergoing 5 or more level fusions through a posterior-only or AP approach were identified and compared. METHODS:QALYs gained were determined using baseline, 1-year, and 2-year post-operative Short Form 6D. Cost was calculated from actual, direct hospital costs including any subsequent readmission or revision. Cost-effectiveness was determined using cost/QALY gained. RESULTS:The AP approach showed significantly higher index cost than the posterior-only approach ($84,329 vs $64,281). This margin decreased at 2-year follow-up with total costs of $89,824 and $73,904, respectively. QALYs gained at two years were similar with 0.21 and 0.17 in the posterior-only and the AP approaches, respectively. The cost/QALY at two years after surgery was significantly higher in the AP approach ($525,080) than in the posterior-only approach ($351,086). CONCLUSIONS:We assessed 2-year cost-effectiveness for the surgical treatment through posterior-only and AP approaches. The posterior-only approach is less expensive both for the index surgery and at 2-year follow-up. The QALY gained at 2-years was similar between the two approaches. Thus, posterior-only approach was more cost-effective than the AP approach under our study parameters. However, both approaches were not cost-effective at 2-year follow-up.

BACKGROUND CONTEXT/BACKGROUND:Patients with severe cervical deformity (CD) often have profound deficits in numerous activities of daily living. The association between health status and post-operative radiographic goals is difficult to quantify. PURPOSE/OBJECTIVE:We aimed to investigate the radiographic characteristics of patients who achieved optimal health related quality of life scores following surgery for CD. STUDY DESIGN/METHODS:We performed a retrospective review of a prospectively collected database of patients with spinal deformity. PATIENT SAMPLE/METHODS:One hundred and fifty-three patients with cervical deformity OUTCOME MEASURES: Common health-related quality of life scores (HRQOLs) measurements were taken for patients treated operatively for cervical deformity including neck disability index (NDI), modified Japanese Orthopaedic Association scale (mJOA) for myelopathy and numeric rating scale for neck pain (NRS-neck), METHODS: Surgical patients with severe (can you define severe?) CD were isolated based upon a previously presented discriminant analysis which outlined a combination of preoperative cervical sagittal vertical axis (cSVA), T1 slope, maximum focal kyphosis in extension, C2 slope in extension, and number of kyphotic levels in extension. Those with available preoperative and 1-year postoperative HRQL data were included. Based on a previous study, patients were grouped into 3 distinct sagittal morphotypes of CD: focal deformity (FD), flatneck (FN=large TS-CL and lack of compensation), or cervicothoracic (CT). Post-operative outcomes were defined as "good" if a patient had ≥2 of the 3 following criteria (1) NDI <20 or meeting MCID, (2) mild myelopathy (mJOA≥14), and (3) NRS-Neck ≤5 or improved by ≥2 points from baseline. Within each distinct deformity group, patients with good outcomes were compared to those with poor outcomes (i.e. not meeting the criteria for good) for differences in demographics, HRQL scores, and alignment, via Chi-squared or student's t-tests. RESULTS:Overall, 83 of 153 patients met the criteria of severe CD and 40 patients had complete 1-year follow-up of clinical/radiographic data. Patient breakdown by deformity pattern was: CT (N=13), FN (N=17), and FD (N=17), with 7 patients meeting criteria for both FD and FN deformities. Within the FD cohort, maximal focal kyphosis (i.e. kyphosis at one level) was better corrected in patients with a "good" outcome (p = 0.03). In the FN cohort, patients with "good" outcomes presented pre-operatively with worse horizontal gaze (McGregor Slope 21° vs 6°, p=0.061) and cSVA (72mm vs 60mm, p=0.030). "Good" outcome FN patients showed significantly greater postop correction of horizontal gaze (-25° vs -5°, p = 0.031). In the CT cohort, patients with "good" outcomes had superior global alignment both pre- (SVA: -17mm vs 108mm, p <0.001) and post-operatively (50mm vs 145mm, p=0.001). CT patients with "good" outcomes also had better postop cervical alignment (cSVA 35mm vs 49mm, p=0.030), and less kyphotic segments during extension (p=0.011). In the FD cohort, there were no differences between "good" and "poor" outcomes patients in preoperative alignment; however, "good" outcome patients showed superior changes in postoperative focal kyphosis (-2° vs 5°, p=0.030). Within all three deformity pattern categories, there were no differences between "good" and "poor" outcome patients with respect to demographics or surgical parameters (levels fused, surgical approach, decompression, osteotomy, all p>0.050). CONCLUSIONS:The results of this study show each CD patient's unique deformity must be carefully examined in order to determine the appropriate alignment goals to achieve optimal HRQOLs. In particular, the recognition of the sagittal morphotype can help assist surgeons to aim for specific alignment goals for CT, FN and FD. Distinct deformity specific intra-operative goals include obtaining proper sagittal global/cervical alignment for cervicothoracic patients, correcting maximal focal kyphosis in focal deformity patients, and correcting horizontal gaze for flatneck patients.

INTRODUCTION/BACKGROUND: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: = 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.

PURPOSE/OBJECTIVE:Predictors of long-term opioid usage in TLIF patients have not been previously explored in the literature. We examined the effect of pre-operative narcotic use in addition to other predictors of the pattern and duration of post-operative narcotic usage. METHODS:We conducted a retrospective cohort study at a single academic institution of patients undergoing a one- or two-level primary TLIF between 2014 and 2017. Total oral morphine milligram equivalents (MMEs) for inpatient use were calculated and used as the common unit of comparison. RESULTS: = 0.547, specificity 95%, sensitivity 58%) demonstrated that a psychiatric or chronic pain diagnosis (OR 3.95, p = 0.013, 95% CI 1.34-11.6), pre-operative opioid use (OR 8.65, p < 0.001, 95% CI 2.59-29.0), ASA class (OR 2.95, p = 0.025, 95% CI 1.14-7.63), and inpatient total MME (1.002, p < 0.001, 95% CI 1.001-1.003) were positive predictors of prolonged opioid use at 6-month follow-up, while inpatient muscle relaxant use (OR 0.327, p = 0.049, 95% CI 0.108-0.994) decreased the probability of prolonged opioid use. Patients in the pre-operative opioid use group had a significantly higher rate of opioid usage at 6 weeks (79% vs. 46%, p < 0.001), 3 months (51% vs. 14%, p < 0.001), and 6 months (40% vs. 5%, p < 0.001). CONCLUSIONS:Pre-operative opioid usage is associated with higher total inpatient opioid use and a significantly higher risk of long-term opiate usage at 6 months. Approximately 40% of pre-operative narcotic users will continue to consume narcotics at 6-month follow-up, compared with 5% of narcotic-naïve patients. These slides can be retrieved under Electronic Supplementary Material.

Study Design/UNASSIGNED:Retrospective cohort study. Objective/UNASSIGNED:To investigate radiological differences in lumbar disc herniations (herniated nucleus pulposus [HNP]) between patients receiving microscopic lumbar discectomy (MLD) and nonoperative patients. Methods/UNASSIGNED: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/UNASSIGNED:< .01). Conclusion/UNASSIGNED: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.

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.

BACKGROUND:Distal junctional kyphosis (DJK) development after cervical deformity (CD)-corrective surgery is a growing concern for surgeons and patients. Few studies have investigated risk factors that predict the occurrence of DJK. OBJECTIVE:To predict DJK development after CD surgery using predictive modeling. METHODS:CD criteria was at least one of the following: C2-C7 Coronal/Cobb > 10°, C2-7 sagittal vertical axis (cSVA) > 4 cm, chin-brow vertical angle > 25°. DJK was defined as the development of an angle <-10° from the end of fusion construct to the second distal vertebra, and change in this angle by <-10° from baseline to postoperative. Baseline demographic, clinical, and surgical information were used to predict the occurrence of DJK using generalized linear modeling both as one overall model and as submodels using baseline demographic and clinical predictors or surgical predictors. RESULTS:One hundred seventeen CD patients were included. At any postoperative visit up to 1 yr, 23.1% of CD patients developed DJK. DJK was predicted with high accuracy using a combination of baseline demographic, clinical, and surgical factors by the following factors: preoperative neurological deficit, use of transition rod, C2-C7 lordosis (CL)<-12°, T1 slope minus CL > 31°, and cSVA > 54 mm. In the model using only baseline demographic/clinical predictors of DJK, presence of comorbidities, presence of baseline neurological deficit, and high preoperative C2-T3 angle were included in the final model (area under the curve = 87%). The final model using only surgical predictors for DJK included combined approach, posterior upper instrumented vertebrae below C4, use of transition rod, lack of anterior corpectomy, more than 3 posterior osteotomies, and performance of a 3-column osteotomy. CONCLUSION/CONCLUSIONS:Preoperative assessment and consideration should be given to these factors that are predictive of DJK to mitigate poor outcomes.

BACKGROUND:Frailty is a relatively new area of study for patients with cervical deformity (CD). As of yet, little is known of how operative intervention influences frailty status for patients with CD. OBJECTIVE:To investigate drivers of postoperative frailty score and variables within the cervical deformity frailty index (CD-FI) algorithm that have the greatest capacity for change following surgery. METHODS:Descriptive analysis of the cohort were performed, paired t-tests determined significant baseline to 1 yr improvements of factors comprising the CD-FI. Pearson bivariate correlations identified significant associations between postoperative changes in overall CD-FI score and CD-FI score components. Linear regression models determined the effect of successful surgical intervention on change in frailty score. RESULTS:A total of 138 patients were included with baseline frailty scores of 0.44. Following surgery, mean 1-yr frailty score was 0.27. Of the CD-FI variables, 13/40 (32.5%) were able to improve with surgery. Frailty improvement was found to significantly correlate with baseline to 1-yr change in CBV, PI-LL, PT, and SVA C7-S1. HRQL CD-FI components reading, feeling tired, feeling exhausted, and driving were the greatest drivers of change in frailty. Linear regression analysis determined successful surgical intervention and feeling exhausted to be the greatest significant predictors of postoperative change in overall frailty score. CONCLUSION/CONCLUSIONS:Complications, correction of sagittal alignment, and improving a patient's ability to read, drive, and chronic exhaustion can significantly influence postoperative frailty. This analysis is a step towards a greater understanding of the relationship between disability, frailty, and surgery in CD.