Faculty Bibliography

STUDY DESIGN/METHODS:Retrospective analysis of prospectively collected data. OBJECTIVE:To investigate the effect of the approach of the transforaminal lumbar interbody fusion [TLIF; open vs . minimally invasive (MIS)] on reoperation rates due to ASD at 2 to 4-year follow-up. SUMMARY OF BACKGROUND DATA/BACKGROUND:Adjacent segment degeneration is a complication of lumbar fusion surgery, which may progress to adjacent segment disease (ASD) and cause debilitating postoperative pain potentially requiring additional operative management for relief. MIS TLIF surgery has been introduced to minimize this complication but the impact on ASD incidence is unclear. MATERIALS AND METHODS/METHODS:For a cohort of patients undergoing 1 or 2-level primary TLIF between 2013 and 2019, patient demographics and follow-up outcomes were collected and compared among patients who underwent open versus MIS TLIF using the Mann-Whitney U test, Fischer exact test, and binary logistic regression. RESULTS:Two hundred thirty-eight patients met the inclusion criteria. There was a significant difference in revision rates due to ASD between MIS and open TLIFs at 2 (5.8% vs . 15.4%, P =0.021) and 3 (8% vs . 23.2%, P =0.03) year follow-up, with open TLIFs demonstrating significantly higher revision rates. The surgical approach was the only independent predictor of reoperation rates at both 2 and 3-year follow-ups (2 yr, P =0.009; 3 yr, P =0.011). CONCLUSIONS:Open TLIF was found to have a significantly higher rate of reoperation due to ASD compared with the MIS approach. In addition, the surgical approach (MIS vs . open) seems to be an independent predictor of reoperation rates.

STUDY DESIGN/METHODS:Retrospective. OBJECTIVE:The objective of this study is to describe the rate of postoperative morbidity before and after two-year (2Y) follow-up for patients undergoing surgical correction of adult spinal deformity (ASD). SUMMARY OF BACKGROUND DATA/BACKGROUND:Advances in modern surgical techniques for deformity surgery have shown promising short-term clinical results. However, the permanence of radiographic correction, mechanical complications, and revision surgery in ASD surgery remains a clinical challenge. Little information exists on the incidence of long-term morbidity beyond the acute postoperative window. METHODS:ASD patients with complete baseline and five-year (5Y) health-related quality of life and radiographic data were included. The rates of adverse events, including proximal junctional kyphosis (PJK), proximal junctional failure (PJF), and reoperations up to 5Y were documented. Primary and revision surgeries were compared. We used logistic regression analysis to adjust for demographic and surgical confounders. RESULTS:Of 118 patients eligible for 5Y follow-up, 99(83.9%) had complete follow-up data. The majority were female (83%), mean age 54.1 years and 10.4 levels fused and 14 undergoing three-column osteotomy. Thirty-three patients had a prior fusion and 66 were primary cases. By 5Y postop, the cohort had an adverse event rate of 70.7% with 25 (25.3%) sustaining a major complication and 26 (26.3%) receiving reoperation. Thirty-eight (38.4%) developed PJK by 5Y and 3 (4.0%) developed PJF. The cohort had a significantly higher rate of complications (63.6% vs. 19.2%), PJK (34.3% vs. 4.0%), and reoperations (21.2% vs. 5.1%) before 2Y, all P <0.01. The most common complications beyond 2Y were mechanical complications. CONCLUSIONS:Although the incidence of adverse events was high before 2Y, there was a substantial reduction in longer follow-up indicating complications after 2Y are less common. Complications beyond 2Y consisted mostly of mechanical issues.

Introduction Post-operative physical therapy (PT) following anterior cervical discectomy and fusion (ACDF) surgery is often performed to improve a patient's functional ability and reduce neck pain. However, current literature evaluating the benefits of post-operative PT using patient-reported outcomes (PROs) is limited and remains inconclusive. Here we compare post-operative improvement between patients who did and did not undergo formal PT after ACDF using Patient-Reported Outcomes Measurement Information System (PROMIS) scores. Methods A retrospective observational study examining patients who underwent one- or two-level primary ACDF or cervical disc replacement (CDR) at an academic orthopedic hospital and who had PROMIS scores recorded pre-operatively and through two-year follow-up. Patients were stratified according to whether or not they attended formal postoperative PT. PROMIS scores and patient demographics were compared using the Mann-Whitney U test, Fisher's exact test, chi-square test of independence, and Student's t-test within and between cohorts. Results Two hundred and twenty patients were identified. Demographic differences between PT and no PT groups include age (PT 54.1 vs. no PT 49.5, p=0.005) and BMI (PT 28.1 vs. no PT 29.8, p=0.028). The only significant difference in post-operative PROMIS scores was in physical health scores at three months post-operatively (no PT 43.9 vs. PT 39.1, p=0.008). Physical health scores improved from baseline to one-year follow-up in both cohorts (PT +3.5, p=0.025; no PT +6.6, p=0.008). There were no significant differences when comparing improvements in physical health scores between groups at six months and one year. Conclusion In conclusion, there was no significance to support the benefits of post-operative PT as measured by PROMIS scores. No significant differences in PROMIS were observed between groups from pre-operative baseline scores to six-month and one-year follow-ups.

Background: The number of elderly patients undergoing adult spinal deformity (ASD) surgery has increased with the advent of new techniques and more nuanced understanding of global malalignment as patients age. The relationship between inpatient physical activity after ASD surgery and postoperative complications in elderly patients has not been reported; thus, we sought to investigate this relationship. Methods: We performed a medical record review of 185 ASD patients older than 65 years (age: 71.5 ± 4.7; body mass index: 30.0 ± 6.1, American Society of Anesthesiologists: 2.7 ± 0.5, and levels fused: 10.5 ± 3.4). We derived the number of feet walked over the first 3 days after surgery from physical therapy documentation and evaluated for association with 90-day perioperative complications. Patients who sustained an incidental durotomy were excluded from the study. Results: The 185 patients were divided into groups based on whether they were among the 50th percentile for number of feet walked (62 ft). Walking less than 62 ft after ASD surgery was associated with higher incidence of postoperative complications (54.3%, P = 0.05), cardiac complications (34.8%, P = 0.03), pulmonary complications (21.7%, P = 0.01), and ileus (15.2%, P = 0.03). Patients who developed any postoperative complication (106 ± 172 vs 211 ± 279 ft, P = 0.001), ileus (26 ± 49 vs 174 ± 248 ft, P = 0.001), deep venous thrombosis (23 ± 30 vs 171 ± 247 ft, P = 0.001), and cardiac complications (58 ± 94 vs 192 ± 261 ft) walked less than patients who did not. Conclusion: Elderly patients who walked less than 62 ft in the first 3 days after ASD surgery have a higher rate of postoperative complications, specifically pulmonary and ileus compared with those patients who walked more. Steps walked after ASD surgery may be a helpful and practical addition to the surgeon"™s armamentarium for monitoring the recovery of their patients. Clinical Relevence: Monitoring the steps walked by patients after ASD surgery can be a practical and useful tool for surgeons to track and improve their patients"™ recovery.

Background: Given the physical and economic burden of complications in spine surgery, reducing the prevalence of perioperative adverse events is a primary concern of both patients and health care professionals. This study aims to identify specific perioperative factors predictive of developing varying grades of postoperative complications in adult spinal deformity (ASD) patients, as assessed by the Clavien-Dindo complication classification (Cc) system. Methods: Surgical ASD patients ≥18 years were identified in the American College of Surgeons"™ National Surgical Quality Improvement Program from 2005 to 2015. Postoperative complications were stratified by Cc grade severity: minor (I, II, and III) and severe (IV and V). Stepwise regression models generated dataset-specific predictive models for Cc groups. Model internal validation was achieved by bootstrapping and calculating the area under the curve (AUC) of the model. Significance was set at P < 0.05. Results: Included were 3936 patients (59 ± 16 years, 63% women, 29 ± 7 kg/m²) undergoing surgery for ASD (4.4 ± 4.7 levels, 71% posterior approach, 11% anterior, and 18% combined). Overall, 1% of cases were revisions, 39% of procedures involved decompression, 27% osteotomy, and 15% iliac fixation. Additionally, 66% of patients experienced at least 1 complication, 0% of which were Cc grade I, 51% II, 5% III, 43% IV, and 1% V. The final model predicting severe Cc (IV"“V) complications yielded an AUC of 75.6% and included male sex, diabetes, increased operative time, central nervous system tumor, osteotomy, cigarette pack-years, anterior decompression, and anterior lumbar interbody fusion. Final models predicting specific Cc grades were created. Conclusions: Specific predictors of adverse events following ASD-corrective surgery varied for complications of different severities. Multivariate modeling showed smoking rate, osteotomy, diabetes, anterior lumbar interbody fusion, and higher operative time, among other factors, as predictive of severe complications, as classified by the Clavien-Dindo Cc system. These factors can help in the identification of high-risk patients and, consequently, improve preoperative patient counseling. Clinical Relevance: The findings of this study provide a foundation for identifying ASD patients at high risk of postoperative complications .

STUDY DESIGN/METHODS:Retrospective Cohort Study. OBJECTIVE:Assess whether modifying spinal alignment goals to accommodate frailty considerations will decrease mechanical complications and maximize clinical outcomes. SUMMARY OF BACKGROUND DATA/BACKGROUND:The Global Alignment and Proportion(GAP) score was developed to assist in reducing mechanical complications, but has had less success predicting such events in external validation. Higher frailty and many of its components have been linked to development of implant failure. Therefore, modifying the GAP score with frailty may strengthen its ability to predict mechanical complications. METHODS:We included 412 surgical ASD patients with two-year(2Y) follow-up. Frailty was quantified using the ASD modified Frailty Index(mASD-FI). Outcomes: proximal junctional kyphosis(PJK) and failure(PJF), major mechanical complications, and 'Best Clinical Outcome'(BCO), defined as ODI<15 and SRS-22 Total>4.5. Logistic regression analysis established a six-week score based on GAP score,frailty and ODI US-Norms. Logistic regression followed by conditional inference tree(CIT) analysis generated categorical thresholds. Multivariable logistic regression analysis controlling for confounders was used to assess the performance of the frailty modified GAP score. RESULTS:Baseline frailty categories: 57% Not Frail,30% frail,14% severely frail. Overall, 39% of patients developed PJK, 8% PJF, 21% mechanical complications, 22% underwent reoperation, and 15% met BCO. The modified ASD-FI demonstrated correlation with developing PJF, mechanical complications, undergoing reoperation, and meeting BCO at 2Y(all P<0.05). Regression analysis generated the following equation: Frailty-Adjusted Realignment Score(FAR Score) =0.49*mASD-FI + 0.38*GAP Score. Thresholds for the FAR score(0-13): Proportioned:<3.5,Moderately Disproportioned:3.5-7.5,Severely Disproportioned:>7.5. Multivariable logistic regression assessing FAR Score demonstrated associations with mechanical complications, reoperation, and meeting Best Clinical Outcome by two years(all P<0.05), whereas the original GAP score was only significant for reoperation. CONCLUSION/CONCLUSIONS:This study demonstrated adjusting alignment goals in adult spinal deformity surgery for a patient's baseline frailty status and disability may be useful in minimizing the risk of complications and adverse events, outperforming the original GAP score in terms of prognostic capacity. LEVEL OF EVIDENCE/METHODS:III.

BACKGROUND:Patients with less severe adult spinal deformity undergo surgical correction and often achieve good clinical outcomes. However, it is not well understood how much clinical improvement is due to sagittal correction rather than treatment of the spondylotic process. PURPOSE/OBJECTIVE:Determine baseline thresholds in radiographic parameters that, when exceeded, may result in substantive clinical improvement from surgical correction. STUDY DESIGN/METHODS:Retrospective. METHODS:ASD patients with BL and 2-year(2Y) data were included. Parameters assessed: SVA, PI-LL, PT, T1PA, L1PA, L4-S1 Lordosis, C2-C7 SVA(cSVA), C2-T3, C2 Slope(C2S). Outcomes: Good Outcome(GO) at 2Y: [Meeting either: 1) SCB for ODI(change greater than 18.8), or 2) ODI<15 and SRS-Total>4.5. Binary logistic regression assessed each parameter to determine if correction was more likely needed to achieve GO. Conditional inference tree(CIT) run machine learning analysis generated baseline thresholds for each parameter, above which, correction was necessary to achieve GO. RESULTS:We included 431 ASD patients. There were 223(50%) that achieved a GO by two years. Binary logistic regression analysis demonstrated, with increasing baseline severity in deformity, sagittal correction was more often seen in those achieving GO for each parameter(all P<0.001). Of patients with baseline T1PA above the threshold, 95% required correction to meet Good Outcome(95% vs. 54%,P<0.001). A baseline PI-LL above 10° (74% of patients meeting GO) needed correction to achieve GO (OR: 2.6,[95% CI 1.4-4.8]). A baseline C2 slope above 15° also necessitated correction to obtain clinical success (OR: 7.7,[95% CI 3.7-15.7]). CONCLUSION/CONCLUSIONS:Our study highlighted point may be present at which sagittal correction has an outsized influence on clinical improvement, reflecting the line where deformity becomes a significant contributor to disability. These new thresholds give us insight into which patients may be more suitable for sagittal correction, as opposed to intervention for the spondylotic process only, leading to a more efficient utility of surgical intervention for adult spinal deformity. LEVEL OF EVIDENCE/METHODS:III.

BACKGROUND CONTEXT: It has been shown that smoking is associated with delayed fusion and pseudarthrosis after spine surgery. The impact of smoking on both short- and long-term outcomes in patients undergoing spine surgery has been described. There are limited data on the impact of smoking status on outcomes after adult spinal deformity (ASD) surgery. We sought to analyze a large cohort of in a single center, to add more to our understanding of the effect of smoking both on mortality and postoperative complications. PURPOSE: To evaluate the effect of smoking on 90-day complications after ASD surgery as well as pseudarthrosis and unplanned revision at long term follow up. STUDY DESIGN/SETTING: Retrospective review of prospectively collected database. PATIENT SAMPLE: A total of 1,013 ASD patients (Age: 46 +/-23 years; mFI: 0.44 +/- 0.70; levels fused: 10.1 +/- 4.2). OUTCOME MEASURES: Outcome measures studied included perioperative complications, and long-term revision surgery rates.
METHOD(S): A total of 1,013 ASD patients (Age: 46 +/-23 ye ars; mFI: 0.44 +/- 0.70; levels fused: 10.1 +/- 4.2) were stratified based on smoking status into three groups. Current smokers group (n = 72) included all patients who were active smokers and those who quit smoking within 4 weeks of surgery. Former smokers group (n = 265) included all patients who quit smoking more than 4 weeks before surgery. Nonsmokers (n = 676) included all patients who had never smoked in their lives before surgery. Outcome measures studied included perioperative complications and long-term revision surgery rates.
RESULT(S): With regards to early complications, the readmission rate at 90 days was significantly higher in the current (12.7%) and former smokers (12.0%), compared with nonsmokers (6.1%) (p=0.007). There was a significantly higher rate of postoperative epidural hematoma in smokers (5%), compared to former and nonsmokers (0%) (p<0.001). There was a higher rate of postoperative pneumonia in smokers (4.5%) compared to former smokers (1.4%) and nonsmokers (0.07%) (p=0.038). There was no significant difference in length of stay between the groups. At minimum one-year follow up, there was a significantly higher rate of pseudarthrosis (smokers: 15.6%, former: 6.7%, non: 4.5%, p=0.041) with no significant difference in rate of revision surgery for pseudarthrosis. Smokers had a significantly higher rate of neurologic complications (29% vs 18.5%, p=0.001) compared to nonsmokers. Smokers who did not experience any resolution of the neurologic injury had greater pack year history (28.5 +/-22) versus smokers who experienced complete resolution (21.2 +/- 39.3) (p=0.02).
CONCLUSION(S): Smoking is associated with higher 90-day readmission rate, and higher rates of epidural hematoma, neurologic complication and postoperative pneumonia after ASD surgery. At one year, smokers have a higher rate of pseudarthrosis, and those with greater pack year history were less likely to experience resolution of the neurologic injury sustained at the index surgery. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: In recent years spine surgeons have utilized different techniques and approaches to perform lumbar interbody fusion surgery. We sought to analyze the difference in outcomes between traditional open transforaminal lumbar interbody fusion (O-TLIF), minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF), dual position anterior/lateral lumbar interbody fusion with posterior instrumentation (Dual ALIF/LLIF), and single position anterior/lateral lumbar interbody fusion with posterior instrumentation (Single ALIF/LLIF). PURPOSE: To analyze the perioperative and postoperative outcomes of patient undergoing TLIF, MIS TLIF, Dual ALIF/LLIF, and Single ALIF/LLIF. STUDY DESIGN/SETTING: Retrospective cohort study at a single institution. PATIENT SAMPLE: Patients undergoing O-TLIF, MIS TLIF, Dual ALIF/LLIF, or Single ALIF/LLIF from 2014 to 2020. OUTCOME MEASURES: Operative time, estimated blood loss (EBL), length of stay (LOS), radiation dose, intraoperative and postoperative complications, and return to OR within 90 days.
METHOD(S): Patients who underwent single level lumbar interbody fusion surgery were analyzed. Patient charts were reviewed for operative time, EBL, LOS, radiation dose, intraoperative and postoperative complications, and return to OR within 90 days. Differences were assessed by ANOVA.
RESULT(S): A total of 1,226 patients underwent a single level lumbar interbody fusion (440 O-TLIF, 423 MIS TLIF, 316 Dual ALIF/LLIF, 47 Single ALIF/LLIF). There were no significant differences in BMI or gender between the groups, but in the O-TLIF cohort average age (60) was higher than MIS-TLIF (54), Dual ALIF/LLIF(52), and Single ALIF/LLIF (50) p < 0.001. There were also significant differences in average operative time (221 mins O-TLIF, 212 mins MIS TLIF, 277 mins dual ALIF/LLIF, 277 mins single ALIF/LLIF, p < 0.001), EBL (360 ml O-TLIF, 167ml MIS TLIF, 235 ml Dual ALIF/LLIF, 253 ml Single ALIF/LLIF, p<0.001), radiation dose (20 mGy O-TLIF, 51 mGy MIS TLIF, 43 mGy Dual ALIF/LLIF, 62 mGy Single ALIF/LLIF, p < 0.001). There was no difference in LOS, intraoperative complications, or 90-day complications between the groups, except a higher rate of neurological deficit in dual ALIF/LLIF (1.6%, p < 0.03). Post hoc analysis demonstrated statistical significance in operative time in the Dual ALIF/LLIF as compared to all the other groups. O-TLIF demonstrated a larger EBL and less radiation as compared to all the other groups as well as a longer operative time than Single ALIF/LLIF. Dual ALIF/LLIF demonstrated a longer operative time and increased rate of neurological deficit as compared to MIS TLIF.
CONCLUSION(S): In comparing different techniques for single level lumbar interbody fusion there were similar outcomes in LOS, perioperative complications and 90-day complications between all the groups. Open TLIF was associated with increased estimate blood loss and less radiation than all the other groups Dual position ALIF/LLIF surgery was associated with a longer operative time than all the other groups. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright

BACKGROUND CONTEXT: The ACS-NSQIP and SpineSage are both easy to use and readily available online perioperative risk calculators The ACS-NSQIP calculator predicts perioperative complications after surgery, but lacks more spine-specific predictors. The SpineSage platform was developed as a tool built for predicting complications in spine surgery. While a limited number of studies have shown it be predictive of both overall and major medical complications in spine surgery, large external validation studies are limited and none have directly compared NSQIP against SpineSage in the same cohort of spine surgery patients. PURPOSE: Assess the ACS-NSQIP Risk Calculator and SpineSage informatics platform for prediction of perioperative complications in spine surgery STUDY DESIGN/SETTING: Retrospective. PATIENT SAMPLE: A total of 440 patients undergoing thoracolumbar spine with or without fusion. OUTCOME MEASURES: Any complication, serious complication, pneumonia, cardiac, dural tear, SSI, UTI, VTE, reoperation, death and LOS METHODS: Each patient was entered into the ACS-NSQIP and SpineSage calculators and predicted risk for specific complications were directly compared to actual risks. Paired t-tests compared the differences between calculators and their predictability of complications. Patients were ranked based on risk predicted for each complication and the highest tertile for each was isolated. Multivariate regression controlling for age and gender was used to determine if the highest tertile for each risk calculator had predictability in complications following spine surgery.
RESULT(S): Mean LOS 4.2+3 days, EBL 444+300 mL, operative time 256+240 min, and levels instrumented 2.1+2.3. When assessing the four complications predicted by SpineSage there were significant differences in three of the four variables, as SpineSage underpredicted the risk of all and serious-complications (p.5). Both calculator tertiles were trending towards significance for major medical complications (SpineSage: OR: 2.0, [0.94-4.23], p=.073; ACS-NSQIP: OR: 1.8,[0.96-3.48],p=.067). When examining any medical risk, only ACS NSQIP had significant predictability for any medical complication (OR: 2.1, [1.3-3.3]; p=.003).
CONCLUSION(S): Similar to previous studies, the ACS-NSQIP score underpredicted most complications, with the exception of LOS and death. In contrast to previous studies, our data suggest SpineSage was not predictive of actual rates of complications. As both calculators are highly accessible and provide at least some objective perioperative risk data points, we recommend them as a guiding tool but not as an absolute endpoint for clinical decision making as they may be inaccurate and insensitive. Further, higher powered studies elucidating the findings in this study should be conducted. Additionally, the assessment of these calculators for a specific subset of patients, such as deformity, degenerative or pediatrics, can further help guide clinicians regarding the utility of these calculators for their particular patient populations. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
Copyright