Faculty Bibliography

STUDY DESIGN/METHODS:Retrospective cohort study. OBJECTIVE:This study aimed to evaluate the utility of the modified frailty index (mFI-5) in a population of patients undergoing spine surgery. SUMMARY OF BACKGROUND DATA/BACKGROUND:The original modified frailty index (mFI-11) published as an American College of Surgeons National Surgical Quality Improvement Program 11-factor index was modified to mFI-5 after variables were removed from recent renditions. METHODS:Surgical spine patients were isolated using current procedural terminology codes. mFI-11 (11) and mFI-5 (5) were calculated from 2005 to 2012. mFI was determined by dividing the factors present by available factors. To assess correlation, Spearman rho was used. Predictive values of indices were generated by binary logistic regression. Patients were stratified into groups by mFI-5: not frail (NF, <0.3), mildly frail (MF, 0.3-0.5), severely frail (SF, >0.5). Means comparison tests analyzed frailty and clinical outcomes. RESULTS:After calculating the mFI-5 and the mFI-11, Spearman rho between the two indices was 0.926(P < 0.001). Each index established significant (all P < 0.001) predictive values for unplanned readmission (11 = odds ratio [OR]: 5.65 [2.92-10.94]; 5 = OR: 3.68 [1.85-2.32]), post-op complications (11 = OR: 8.56 [7.12-10.31]; 5 = OR: 13.32 [10.89-16.29]), and mortality (11 = OR: 41.29 [21.92-77.76]; 5 = OR: 114.82 [54.64-241.28]). Frailty categories by mFI-5 were: 83.2% NF, 15.2% MF, and 1.6% SF. From 2005 to 2016, rates of NF decreased (88.8% to 82.2%, P < 0.001), whereas MF increased (9.2% to 16.2%, P < 0.001), and SF remained constant (2% to 1.6%, P > 0.05). With increase in severity, postoperative rates of morbidities and complications increased. CONCLUSION/CONCLUSIONS:The five-factor National Surgical Quality Improvement Program modified frailty index is an effective predictor of postoperative events following spine surgery. Severity of frailty score by the mFI-5 was associated with increased morbidity and mortality. The mFI-5 within a surgical spine population can reliably predict post-op complications. This tool is less cumbersome than mFI-11 and relies on readily accessible variables at the time of surgical decision-making.Level of Evidence: 3.

Background/UNASSIGNED:Adolescent idiopathic scoliosis (AIS) is a common cause of spinal deformity in adolescents. AIS can be associated with certain intraspinal anomalies such as syringomyelia (SM). This study assessed the rate o f SM in AIS patients and compared trends in surgical approach and postoperative outcomes in AIS patients with and without SM. Methods/UNASSIGNED:-tests and Chi-squared tests for categorical and discrete variables, respectively. Results/UNASSIGNED:< 0.001). Conclusions/UNASSIGNED:These results indicate that patients concordant with AIS and SM may be treated more cautiously (lower invasiveness score and less fusions) than those without SM.

OBJECTIVE:The goal of this study was to assess the conversion rate from baseline cervical alignment to postoperative cervical deformity (CD) and the corresponding proximal junctional kyphosis (PJK) rate in patients undergoing thoracolumbar adult spinal deformity (ASD) surgery. METHODS:The operative records of patients with ASD with complete radiographic data beginning at baseline up to 3 years were included. Patients with no baseline CD were postoperatively stratified by Ames CD criteria (T1 slope-cervical lordosis mismatch [TS-CL] > 20°, cervical sagittal vertical axis [cSVA] > 40 mm), where CD was defined as fulfilling one or more of the Ames criteria. Severe CD was defined as TS-CL > 30° or cSVA > 60 mm. Follow-up intervals were established after ASD surgery, with 6 weeks postoperatively defined as early; 6 weeks-1 year as intermediate; 1-2 years as late; and 2-3 years as long-term. Descriptive analyses and McNemar tests identified the CD conversion rate, PJK rate (< -10° change in uppermost instrumented vertebra and the superior endplate of the vertebra 2 levels superior to the uppermost instrumented vertebra), and specific alignment parameters that converted. RESULTS:Two hundred sixty-six patients who underwent ASD surgery (mean age 59.7 years, 77.4% female) met the inclusion criteria; 103 of these converted postoperatively, and the remaining 163 did not meet conversion criteria. Thirty-eight patients converted to CD early, 26 converted at the intermediate time point, 29 converted late, and 10 converted in the long-term. At conversion, the early group had the highest mean TS-CL at 25.4° ± 8.5° and the highest mean cSVA at 33.6 mm-both higher than any other conversion group. The long-term group had the highest mean C2-7 angle at 19.7° and the highest rate of PJK compared to other groups (p = 0.180). The early group had the highest rate of conversion to severe CD, with 9 of 38 patients having severe TS-CL and only 1 patient per group converting to severe cSVA. Seven patients progressed from having only malaligned TS-CL at baseline (with normal cSVA) to CD with both malaligned TS-CL and cSVA by 6 weeks. Conversely, only 2 patients progressed from malaligned cSVA to both malaligned cSVA and TS-CL. By 1 year, the former number increased from 7 to 26 patients, and the latter increased from 2 to 20 patients. The revision rate was highest in the intermediate group at 48.0%, versus the early group at 19.2%, late group at 27.3%, and long-term group at 20% (p = 0.128). A higher pelvic incidence-lumbar lordosis mismatch, lower thoracic kyphosis, and a higher thoracic kyphosis apex immediately postoperatively significantly predicted earlier rather than later conversion (all p < 0.05). Baseline lumbar lordosis, pelvic tilt, and sacral slope were not significant predictors. CONCLUSIONS:Patients with ASD with normative cervical alignment who converted to CD after thoracolumbar surgery had varying radiographic findings based on timing of conversion. Although the highest number of patients converted within 6 weeks postoperatively, patients who converted in the late or long-term follow-up intervals had higher rates of concurrent PJK and greater radiographic progression.

STUDY DESIGN/UNASSIGNED:Retrospective cohort study. OBJECTIVES/UNASSIGNED:The interactions between hip osteoarthritis (OA) and spinal malalignment are poorly understood. The purpose of this study was to assess the influence of total hip arthroplasty (THA) on standing spinopelvic alignment. METHODS/UNASSIGNED:In this retrospective cohort study, patients undergoing THA for OA with pre-and postoperative full-body radiographs were included. Standing spinopelvic parameters were measured. Contralateral hip was graded on the Kellgren-Lawrence scale. Pre-and postoperative alignment parameters were compared by paired t-test. The severity of preoperative thoracolumbar deformity was measured using TPA. Linear regression was performed to assess the impact of preoperative TPA and changes in spinal alignment. Patients were separated into low and high TPA (<20 or >/=20 deg) and change in parameters were compared between groups by t-test. Similarly, the influence of K-L grade, age, and PI were also tested. RESULTS/UNASSIGNED:= .004). Preoperative TPA was significantly associated with the change in PI-LL, SVA, and TPA. High TPA patients significantly decreased SVA more than low TPA patients. There was no significant impact of contralateral hip OA, PI, or age on change in alignment parameters. CONCLUSION/UNASSIGNED:Spinopelvic alignment changes after THA, evident by a reduction in SVA. Preoperative spinal sagittal deformity impacts this change. Level of evidence: III.

STUDY DESIGN/METHODS:This was a retrospective cohort study of a national dataset. PURPOSE/OBJECTIVE:The purpose of this study was to consider the influence of frailty on the development of hospital-acquired conditions (HACs) in adult spinal deformity (ASD). SUMMARY OF BACKGROUND DATA/BACKGROUND:HACs frequently include reasonably preventable complications. Eleven events are identified as HACs by the Affordable Care Act. In the surgical ASD population, factors leading to HACs are important to identify to optimize health care. METHODS:Patients 18 years and older undergoing corrective surgery for ASD identified in the American College of Surgeons' National Surgical Quality Improvement Program (ACS-NSQIP). The relationship between HACs and frailty as defined by the NSQIP modified 5-factor frailty index (mFI-5) were assessed using χ2 and independent sample t tests. The mFI-5 is assessed on a scale 0-1 [not frail (NF): <0.3, mildly frail (MF): 0.3-0.5, and severely frail (SF): > 0.5]. Binary logistic regression measured the relationship between frailty throughout HACs. RESULTS:A total of 9143 ASD patients (59.1 y, 56% female, 29.3 kg/m2) were identified. Overall, 37.6% of procedures involved decompression and 100% fusion. Overall, 6.5% developed at least 1 HAC, the most common was urinary tract infection (2.62%), followed by venous thromboembolism (2.10%) and surgical site infection (1.88%). According to categorical mFI-5 frailty, 82.1% of patients were NF, 16% MF, and 1.9% SF. Invasiveness increased with mFI-5 severity groups but was not significant (NF: 3.98, MF: 4.14, SF: 4.45, P>0.05). Regression analysis of established factors including sex [odds ratio (OR): 1.22; 1.02-146; P=0.030], diabetes mellitus (OR: 0.70; 0.52-0.95; P=0.020), total operative time (OR: 1.01; 1.00-1.01; P<0.001), body mass index (OR: 1.02; 1.01-1.03; P=0.008), and frailty (OR: 8.44; 4.13-17.26; P<0.001), as significant predictors of HACs. Overall, increased categorical frailty severity individually predicted increased total length of stay (OR: 1.023; 1.015-1.030; P<0.001) and number of complications (OR: 1.201; 1.047-1.379; P=0.009). CONCLUSIONS:For patients undergoing correction surgery for ASD, the incidence of HACs increased with worsening frailty score. Such findings suggest the importance of medical optimization before surgery for ASD.

OBJECTIVE:Patients with nonoperative (N-Op) adult spinal deformity (ASD) have inferior long-term spinopelvic alignment and clinical outcomes. Predictors of lower quality-of-life measures in N-Op populations have yet to be sufficiently investigated. The aim of this study was to identify patient-related factors and radiographic parameters associated with inferior health-related quality-of-life (HRQOL) scores in N-Op ASD patients. METHODS:N-Op ASD patients with complete radiographic and outcome data at baseline and 2 years were included. N-Op patients and operative (Op) patients were propensity score matched for baseline disability and deformity. Patient-related factors and radiographic alignment parameters (pelvic tilt [PT], sagittal vertical axis [SVA], pelvic incidence [PI]-lumbar lordosis [LL] mismatch, mismatch between cervical lordosis and T1 segment slope [TS-CL], cervical-thoracic pelvic angle [PA], and others) at baseline and 2 years were analyzed as predictors for moderate to severe 2-year Oswestry Disability Index (ODI > 20) and failing to meet the minimal clinically importance difference (MCID) for 2-year Scoliosis Research Society Outcomes Questionnaire (SRS) scores (< 0.4 increase from baseline). Conditional inference decision trees identified predictors of each HRQOL measure and established cutoffs at which factors have a global effect. Random forest analysis (RFA) generated 5000 conditional inference trees to compute a variable importance table for top predictors of inferior HRQOL. Statistical significance was set at p < 0.05. RESULTS:Six hundred sixty-two patients with ASD (331 Op patients and 331 N-Op patients) with complete radiographic and HRQOL data at their 2-year follow-up were included. There were no differences in demographics, ODI, and Schwab deformity modifiers between groups at baseline (all p > 0.05). N-Op patients had higher 2-year ODI scores (27.9 vs 20.3, p < 0.001), higher rates of moderate to severe disability (29.3% vs 22.4%, p = 0.05), lower SRS total scores (3.47 vs 3.91, p < 0.001), and higher rates of failure to reach SRS MCID (35.3% vs 15.7%, p < 0.001) than Op patients at 2 years. RFA ranked the top overall predictors for moderate to severe ODI at 2 years for N-Op patients as follows: 1) frailty index > 2.8, 2) BMI > 35 kg/m2, T4PA > 28°, and 4) Charlson Comorbidity Index > 1. Top radiographic predictors were T4PA > 28° and C2-S1 SVA > 93 mm. RFA also ranked the top overall predictors for failure to reach 2-year SRS MCID for N-Op patients, as follows: 1) T12-S1 lordosis > 53°, 2) cervical SVA (cSVA) > 28 mm, 3) C2-S1 angle > 14.5°, 4) TS-CL > 12°, and 5) PT > 23°. The top radiographic predictors were T12-S1 Cobb angle, cSVA, C2-S1 angle, and TS-CL. CONCLUSIONS:When controlling for baseline deformity in N-Op versus Op patients, subsequent deterioration in frailty, BMI, and radiographic progression over a 2-year follow-up were found to drive suboptimal patient-reported outcome measures in N-Op cohorts as measured by validated ODI and SRS clinical instruments.

STUDY DESIGN/UNASSIGNED:Retrospective cohort study. OBJECTIVE/UNASSIGNED:To assess the impact of race on complications following spinal tumor surgery. METHODS/UNASSIGNED:Adults with cancer who underwent spine tumor surgery were identified in the American College of Surgeons National Surgical Quality Improvement Program datasets from 2012 to 2016. Clavien-Dindo Grade I-II (minor complications) and Clavien-Dindo Grade III-V (major complications including 30-day mortality) complications were compared between non-Hispanic Whites (NHW) and Black patients. A multivariable analysis was also conducted. RESULTS/UNASSIGNED:= .011). CONCLUSION/UNASSIGNED:Black patients who underwent metastatic spinal tumor surgery were at a significantly increased risk of perioperative morbidity compared to NHW patients independent of baseline and operative characteristics. Major complications did not differ between groups. Race should be further studied in the context of metastatic spine disease to improve our understanding of these disparities.

This retrospective cohort study describes adult cervical deformity(ACD) patients with Ames-ACD classification at baseline(BL) and 1-year post-operatively and assesses the relationship of improvement in Ames modifiers with clinical outcomes. Patients ≥ 18yrs with BL and post-op(1-year) radiographs were included. Patients were categorized with Ames classification by primary deformity descriptors (C = cervical; CT = cervicothoracic junction; T = thoracic; S = coronal) and alignment/myelopathy modifiers(C2-C7 Sagittal Vertical Axis[cSVA], T1 Slope-Cervical Lordosis[TS-CL], Horizontal Gaze[Horiz], mJOA). Univariate analysis evaluated demographics, clinical intervention, and Ames deformity descriptor. Patients were evaluated for radiographic improvement by Ames classification and reaching Minimal Clinically Important Differences(MCID) for mJOA, Neck Disability Index(NDI), and EuroQuol-5D(EQ5D). A total of 73 patients were categorized: C = 41(56.2%), CT = 18(24.7%), T = 9(12.3%), S = 5(6.8%). By Ames modifier 1-year improvement, 13(17.8%) improved in mJOA, 26(35.6%) in cSVA grade, 19(26.0%) in Horiz, and 15(20.5%) in TS-CL. The overall proportion of patients without severe Ames modifier grades at 1-year was as follows: 100% cSVA, 27.4% TS-CL, 67.1% Horiz, 69.9% mJOA. 1-year post-operatively, severe myelopathy(mJOA = 3) prevalence differed between Ames-ACD descriptors (C = 26.3%, CT = 15.4%, T = 0.0%, S = 0.0%, p = 0.033). Improvement in mJOA modifier correlated with reaching 1-year NDI MCID in the overall cohort (r = 0.354,p = 0.002). For C descriptors, cSVA improvement correlated with reaching 1-year NDI MCID (r = 0.387,p = 0.016). Improvement in more than one radiographic Ames modifier correlated with reaching 1-year mJOA MCID (r = 0.344,p = 0.003) and with reaching more than one MCID for mJOA, NDI, and EQ-5D (r = 0.272,p = 0.020). In conclusion, improvements in radiographic Ames modifier grades correlated with improvement in 1-year postoperative clinical outcomes. Although limited in scope, this analysis suggests the Ames-ACD classification may describe cervical deformity patients' alignment and outcomes at 1-year.

STUDY DESIGN/UNASSIGNED:Comparative cohort study. OBJECTIVE/UNASSIGNED:Factors that influence the lower instrumented vertebra (LIV) selection in adult cervical deformity (ACD) are less reported, and outcomes in the cervicothoracic junction (CTJ) and proximal thoracic (PT) spine are unclear. METHODS/UNASSIGNED:A prospective ACD database was analyzed using the following inclusion criteria: LIV between C7 and T5, upper instrumented vertebra at C2, and at least a 1-year follow-up. Patients were divided into CTJ (LIV C7-T2) and PT groups (LIV T3-T5) based on LIV levels. Demographics, operative details, radiographic parameters, and the health-related quality of life (HRQOL) scores were compared. RESULTS/UNASSIGNED:= 0.001). Complications and reoperations were comparable. The HRQOL scores were not different preoperatively and at 1-year follow-up. CONCLUSIONS/UNASSIGNED:The selection of PT LIV in cervical deformities was more common in patients with larger baseline deformities, who were more likely to undergo pedicle-subtraction osteotomy. Despite this, the complications and HRQOL outcomes were comparable at 1-year follow-up.

BACKGROUND:Spinal surgery is associated with an inherently elevated risk profile, and thus far there has been limited discussion about how these outpatient spine patients are benefiting from these same-day procedures against other typical outpatient orthopedic surgeries. METHODS:Orthopedic patients who received either inpatient or outpatient surgery were isolated in the American College of Surgeons National Surgical Quality of Improvement Program (2005-2016). Patients were stratified by type of orthopedic surgery received (spine, knee, ankle, shoulder, or hip). Mean comparisons and chi-squared tests assessed basic demographics. Perioperative complications were analyzed via regression analyses in regard to their principal inpatient or outpatient orthopedic surgery received. RESULTS:< .05) with complications decreasing for IN and OUT patients by 2016. CONCLUSIONS:Over the past decade, spine surgery has decreased in complications for IN and OUT procedures along with IN/OUT knee, ankle, hip, and shoulder procedures, reflecting greater tolerance for risk in an outpatient setting. LEVEL OF EVIDENCE/METHODS:3. CLINICAL RELEVANCE/CONCLUSIONS:Despite the increase in riskier spine procedures, complications have decreased over the years. Surgeons should aim to continue to decrease inpatient spine complications to the level of other orthopedic surgeries.