Faculty Bibliography

Background/UNASSIGNED:Factors that are relevant to the decision regarding the use of surgical treatment for degenerative spondylolisthesis include disease-state severity and patient quality-of-life expectations. Some factors may not be easily appraised by the surgeon. In prospective trials involving patients undergoing nonoperative and operative treatment, there are instances of crossover in which patients from the nonoperative group undergo surgery. Identifying and understanding patient characteristics that may influence crossover from nonoperative to operative treatment will aid understanding of what motivates patients toward pursuing surgery. Methods/UNASSIGNED:Patients with degenerative spondylolisthesis who were randomized to nonoperative care in a prospective, multicenter study were evaluated over 8 years of enrollment. Two cohorts were defined: (1) the surgery cohort (patients who underwent surgery at any point) and (2) the nonoperative cohort (patients who did not undergo surgery). A Cox proportional hazards model, modeling time to surgery, was used to explore demographic data, clinical diagnoses, and patient expectations and attitudes after adjusting for other variables. A subanalysis was performed on surgery within 6 months after enrollment and surgery >6 months after enrollment. Results/UNASSIGNED:One hundred and forty-five patients who had been randomized to nonoperative treatment, 80 of whom crossed over to surgery, were included. In analyzing baseline differences between the 2 cohorts, patients who underwent surgery were younger; however, there were no significant difference between the cohorts in terms of race, sex, or comorbidities. Treatment preference, greater Oswestry Disability Index score, marital status, and no joint problems were predictors of crossover to surgery. Clinical factors, including stenosis, neurological deficits, and listhesis levels, did not show a significant relationship with crossover. At the time of long-term follow-up, the surgery cohort showed significantly greater long-term improvement in health-related quality of life (p < 0.001). The difference was maintained throughout follow-up. Conclusions/UNASSIGNED:Neurological symptoms and diagnoses, including listhesis and stenosis severity, did not predict crossover from nonoperative care to surgery. Attitudes toward surgery, greater Oswestry Disability Index score, marital status, and no joint problems were independent predictors of crossover from nonoperative to operative care. Certain demographic characteristics were associated with higher rates of crossover, although they were connected to patient attitudes toward surgery. Level of Evidence/UNASSIGNED:Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Background/UNASSIGNED:This study aims to describe properties of adult spinal deformity (ASD) revisions relative to primary surgeries and determine clinical variables that can predict revision. ASD is a common pathology that can lead to decreased quality of life, pain, physical limitations, and dissatisfaction with self-image. Durability of interventions for deformity treatment is of paramount concern to surgeons, as revision rates remain high. Methods/UNASSIGNED:Patients undergoing thoracolumbar fusion, five or more levels, for scoliosis (primary diagnosis ICD-9 737.x) were identified on a state-wide database. Primary and revision (returning for re-fusion procedure) surgeries were compared based on demographic, hospital stay, and clinical characteristics. Differences between primary and revision surgeries, and predictors of primary surgeries requiring revision, utilized binary logistic regression controlling for age, comorbidity burden, and levels fused. Results/UNASSIGNED:A total of 1,063 patients (average 7.4 levels fused, mean age: 47.6 years, 69.0% female) undergoing operative treatment for ASD were identified, of which 123 (average 7.1 levels fused, 11.6%, mean age 61.43, 80.5% female) had surgical revision. Primary surgeries were ~0.3 levels longer (P=0.013), used interbody ~11% more frequently (P=0.020), and used BMP ~12% less frequently (P=0.008). Revisions occurred 176.4 days after the primary on average. The most frequent causes of revisions were: 43.09% implant failure, 24.39% acquired kyphosis, and 14.63% enduring scoliosis. After controlling for age, comorbidities, and levels fused older, more comorbid, female, and white-race patients were more likely to be revised. Upon multivariate regression, after controlling for age and levels fused, overall complications remained non-different (OR: 0.8, 95% CI: 0.6-1.2). However, revision remained an independent predictor for infection (OR: 5.5, 95% CI: 2.8-10.5). Conclusions/UNASSIGNED:In a statewide database with individual patient follow up of up to 4 years 10% of ASD patients undergoing scoliosis correction required revision. Revision surgeries had higher infection incidence.

Background/UNASSIGNED:Effects of nonoperative treatments on surgical outcomes for patients who failed conservative management for cervical spine pathologies remain unknown. The objective is to describe conservative modality use in patients indicated for surgery for degenerative cervical spine conditions and its impact on perioperative outcomes. Methods/UNASSIGNED:tests were performed to determine differences between groups and impact on outcomes. Results/UNASSIGNED: < .05). Conclusions/UNASSIGNED:Radiculopathy patients receiving epidurals returned to work after 1 year more frequently. PT was associated with shorter hospitalizations, greater SF-36 bodily pain norm and physical component score improvements, and increased return-to-work rates after 1 and 2 years. No statistically significant nonoperative treatment was associated with return-to-work rate in myelopathy patients. Clinical Relevance/UNASSIGNED:These findings suggest certain preoperative conservative treatment modalities are associated with improved outcomes in radiculopathy patients.

BACKGROUND: Hospital length of stay (LOS), 30-day readmission rate, and other metrics are increasingly being used to evaluate quality of surgical care. The factors most relevant to cervical spondylotic myelopathy (CSM) are not yet established. OBJECTIVE: To identify peri-operative factors associated with extended LOS and/or 30-day readmission following elective surgery for CSM. METHODS: Surgical CSM patients at institutions represented by the American-College-of-Surgeons-National-Surgical-Quality-Improvement-Program (ACS-NSQIP) from 2010-2012 were included. Patients with fracture, >/=9 levels fused, or cancer were excluded. Extended LOS was defined as 75th percentile of the cohort. Univariate analysis and multivariate logistic regression identified predictors for extended LOS, 30-day readmission, and reoperation. Linear regression modeling was used to evaluate variables. RESULTS: 3057 surgical CSM cases were isolated. Age (OR-1.496), diabetes (OR-1.691), American Society of Anesthesiologists (ASA) class (OR-2.081), posterior surgical approach (OR-2.695), and operative time (OR-1.008) were all positive predictors (P<0.05) for extended LOS (>/=4 days). 32% of the cohort (976 patients) had 30-day readmission data. Among these, 915 patients were not readmitted (93.8%), while 61 (6.2%) were. Diabetes (OR-1.460) and ASA-class (OR-2.539) were significant positive predictors for hospital readmission. Age (OR-0.918) was a negative predictor of re-operation in readmitted patients, and pulmonary comorbidities (OR-4.584) were a positive predictor (P<0.05). CONCLUSIONS: Patients with diabetes and higher ASA-Class were at increased risk for extended LOS and readmission within 30-days. Patients with increased operative time have greater risk for extended LOS. Pre-operative pulmonary comorbidities increased reoperation risk, while increased age reduced the risk. Attention to these factors may benefit CSM patients.

OBJECTIVE: The etiologies and epidemiology of traumatic cervical spine fracture have not been described with sufficient power or recency. Our goal is to describe demographics, incidence, etiology, spinal cord injuries (SCIs), concurrent injuries, treatments, and complications of traumatic cervical spine fractures. METHODS: Retrospective review of the Nationwide Inpatient Sample. ICD-9 E-Codes identified trauma cases from 2005-2013. Patients with cervical fracture were isolated. Demographics, incidence, etiology, fracture levels, concurrent injuries, surgical procedures, and complications were analyzed. T-tests elucidated significance for continuous variables, chi-square for categorical variables. Level of significance P<0.05. RESULTS: 488,262 patients isolated (age:55.96, male:60.0%, white:77.5%). Incidence (2005:4.1% vs 2013:5.4%), Charlson-Comorbidity-Index (2005:0.6150 vs. 2013:1.1178), and total charges (2005:$71,228.60 vs. 2013:$108,119.29) have increased since 2005, while length of stay (LOS) decreased (2005:9.22 vs. 2013:7.86) (all P<0.05). Most common etiologies were MVA (29.3%), falls (23.7%) and pedestrian accidents (15.7%). Most frequent fracture types were closed at C2 (32.0%) and C7 (20.9%). Concurrent injury rates have significantly increased since 2005 (2005:62.3% vs. 2013:67.6%). Common concurrent injuries included fractures to the rib/sternum/larynx/trachea (19.6%). Overall fusion rates have increased since 2005 (2005:15.7% vs 2013:18.0%), while decompressions and halo insertion rates have decreased (all P<0.05). SCIs have significantly decreased since 2005, except for upper-cervical central cord syndrome. Complication rates have significantly increased since 2005 (2005:31.6% vs. 2013:36.2%). Common complications included Anemia (7.7%), Mortality (6.6%), and ARDS (6.6%). CONCLUSION: Incidence, complications, concurrent injuries, and fusions have increased since 2005. LOS, SCIs, decompressions and halo insertions have decreased. Indicated trends should guide future research in management guidelines.

OBJECTIVE:History of previous cervical spine surgery is a frequently cited cause of worse outcomes after cervical spine surgery. The purpose of this study was to determine any differences in clinical outcomes after cervical spine surgery between patients with and without a history of previous cervical spine surgery. METHODS:A multicenter prospective database was reviewed retrospectively to identify patients with cervical spondylosis undergoing surgery with a minimum 2-year follow-up. Patients were divided into 2 groups: patients with (W) or without (WO) previous history of cervical spine surgery. Statistical analyses of Health-Related Quality of Life scores were analyzed with statistical software to fit linear mixed models for continuous longitudinal outcome. RESULTS:A total of 1286 patients (377 W, 909 WO) met criteria for inclusion. Overall, patients in both groups experienced an improvement in their Health-Related Quality of Life scores. However, patients in the W group had significantly decreased improvement compared with WO patients in the Neck Disability Index score and the following SF-36 domain scores: Role Physical, Bodily Pain, General Health, Vitality, Social Functioning, Health Transition, and Physical Component Summary at all time points (P < 0.05). There was no statistically significant difference between the W and WO groups in operative time, estimated blood loss, length of stay, or complications (P > 0.05). CONCLUSIONS:Patients with a history of previous cervical spine surgery had inferior improvement in quality of life outcome scores. Patients with a history of previous surgical intervention who elect to undergo subsequent surgeries should be appropriately counseled about expected results.

STUDY DESIGN: Retrospective analysis of prospective data from the degenerative spondylolisthesis (DS) arm of the Spine Patient Outcomes Research Trial. OBJECTIVE: To identify risk factors for reoperation in patients treated surgically for DS and compare outcomes between patients who underwent reoperation with non-reoperative patients. SUMMARY OF BACKGROUND DATA: Several studies have examined outcomes following surgery for DS, but few have identified risk factors for reoperation. METHOD: Analysis included patients with neurogenic claudication (>12 weeks), clinical neurological signs, spinal stenosis, and DS on standing lateral x-rays. Univariate and multivariate analyses were used to investigate patient characteristics and risk factors. Treatment effects (TE) were calculated and compared between study groups. RESULTS: Of 406 patients, 72% underwent instrumented fusion, 21% non-instrumented fusion, and 7% decompression alone. At 8 years, the reoperation rate was 22%, of which 28% occurred within one year, 54% within 2 years, 70% within 4 years, and 86% within 6 years. The reasons for reoperation included recurrent stenosis or progressive spondylolisthesis (45%), complications such as hematoma, dehiscence, or infection (36%), or new condition (14%). Re-operative patients were younger (62.2 vs 65.3, p = 0.008). Significant risk factors were use of antidepressants (p = 0.008, HR 2.08) or having no neurogenic claudication upon enrollment (p = 0.02, HR 1.82). Patients who were smokers, diabetics, obese, or on workman's compensation were not at greater risk for reoperation. At eight year follow-up, scores for SF-36 bodily pain (BP), ODI, and stenosis frequency index were better in non-re-operative patients. TE favored non-re-operative patients for SF-36 BP, physical function, ODI, stenosis bothersomeness index and satisfaction with symptoms (p < 0.001). CONCLUSION: The incidence of reoperation for patients with DS was 22% eight years following surgery. Patients with a history of no neurogenic claudication and patients taking antidepressants were more likely to undergo reoperation. Outcomes scores and TE were more favorable in non-re-operative patients. LEVEL OF EVIDENCE: 2.

STUDY DESIGN: A retrospective review of a prospectively collected database, the Nationwide Inpatient Sample (NIS), years 2003 to 2012. OBJECTIVES: The aim of this study was to examine trends in the management of scoliosis in elderly (age >75 yrs) patients from 2003 to 2012. SUMMARY OF BACKGROUND DATA: Scoliosis incidence rises with increasing age, and age has been shown to be an independent risk factor for surgical complications in scoliosis surgery. Previous studies have displayed increasing surgical frequency on elderly scoliotic patients in the last decade, but have not investigated complications in the same years. METHODS: ICD-9 coding identified elderly (age >/=75 yrs) patients with a primary diagnosis of scoliosis undergoing lumbar fusion or decompression. Analysis of variance (ANOVA) comparisons and linear trend analysis described changes from 2003 to 2012 in surgical invasiveness (Mirza scale: levels fused/decompressed/instrumented and by approach), intraoperative complications, and Charlson Comorbidity Index (CCI). Secondary outcome measures included cost and discharge outcomes. RESULTS: Eight thousand one elderly patients with ASD from 2003 to 2012 were included for analysis. Fusion incidence increased on average 13.8% per year (P < 0.001), surgical invasiveness by Mirza scale increased from 2.0 in 2003 to 5.9 in 2012 (P < 0.001), and CCI increased from 0.77 to 1.44 (p < 0.001). Over the same interval, elderly patients undergoing fusion displayed overall reduction in complications (excluding anemia)-from 26.7% to 8.6% (P < 0.001); specifically, surgical complications decreased from 11.7% to 0.7% (P < 0.001) and respiratory complications decreased from 6.7% to 1.4% (P = 0.004). CONCLUSION: From 2003 to 2012, surgical management of ASD in the elderly population increased in incidence and complexity, while number of patient comorbidities increased and in-hospital morbidity decreased. This may indicate increased willingness of surgeon's to operate on elderly patients, and reflect a development of overall understanding of deformity in the past decade. LEVEL OF EVIDENCE: 3.

BACKGROUND CONTEXT: Radiographic parameters including sagittal balance, coronal balance, and lumbar lordosis have been increasingly implicated as potential determinants or markers of functioning in patients with scoliosis. In an effort to stratify disease severity preoperatively and assess response to treatment for patients undergoing spine surgery, several patientreported functional measures have been employed including the Scoliosis Research Society Questionnaire (SRS-30), Oswestry Disability Index (ODI) and the Short Form Health Survey (SF-12). The degree to which radiographic and functional measures of spinal disease correlate and interact remains unclear. PURPOSE: The purpose of this study was to assess the correlation between SRS-30, ODI, and SF-12 scores and radiographic alignment measures in adult patients with scoliosis. STUDY DESIGN/SETTING: Retrospective review of a prospectively maintained multi-institution database. PATIENT SAMPLE: A total of 1850 adult patients seen in consultation for scoliosis. OUTCOME MEASURES: ODI, SRS-30, SF12-PCS, SF12-MCS. Pelvic incidence, pelvic obliquity, lumbar lordosis, absolute values of sagittal (C7- sacrum) and coronal balance. METHODS: The relationship of four patient-reported outcomes (PROM) as well as five radiographic measures was assessed. Given the large sample size, nearly all correlations were statistically significant, but many were clinically meaningless. We focused our analysis on those variables with a univariate correlation >=0.20. To assess the relevant impact, these variables were then entered into a linear model adjusting for baseline demographic variables of body mass index (BMI), gender, pain location, smoking status, and number of comorbidities. Additionally, lumbar lordosis was separated into clinically relevant groups, and a one-way ANCOVA (analysis of covariance), controlling for the above variables, was used to assess the impact on PROMs. RESULTS: The absolute value of the correlations between the four PROMs was at least 0.20; all results were moderate, between 0.20 and 0.36, with the exception of ODI and PCS at -0.70. Neither the MCS or SRS-30 had any meaningful correlation with any radiographic measures with no correlation coefficient reaching 0.10. The ODI and PCS had similar correlations with sagittal balance (0.22 and -0.20, respectively) and the ODI had a significant correlation with lordosis (0.28). ODI scores increased 0.90 (0.62- 1.16) points for each centimeter of imbalance, and decreased 0.11 (0.08- 0.14) for each degree of lordosis. When comparing patients with 10 cm of sagittal imbalance to those with 5 cm or less, the effect in favor of 5 cm or less was: ODI-14.34 (-9.47, -19.22); SRS-30 0.48 (0.80, 0.17); PCS 7.89 (4.67, 11.12); MCS 0.29 (-0.45, 0.63). CONCLUSIONS: Outcomes commonly used in assessing patients with scoliosis have statistically significant but clinically small correlations, with the exception of the ODI and PCS, both of which focus on pain and function. Lumbar lordosis and sagittal balance were significant predictors of selfreported pain and function. Patients with greater than 10 cm of sagittal imbalance had significantly worse scores in three of four measures when compared to those with less than 5 cm of imbalance