Faculty Bibliography

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.

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.

INTRODUCTION/BACKGROUND:Complex surgery for adult spinal deformity has high rates of complications, reoperations, and readmissions. Preoperative discussions of high-risk operative spine patients at a multidisciplinary conference may contribute to decreased rates of these adverse outcomes through appropriate patient selection and surgical plan optimization. With this goal, we implemented a high-risk case conference involving orthopedic and neurosurgery spine, anesthesia, intraoperative monitoring neurology, and neurological intensive care. METHODS:Included in this retrospective review were patients ≥ 18 years old meeting one of the following high-risk criteria: 8 + levels fused, osteoporosis with 4 + levels fused, three column osteotomy, anterior revision of the same lumbar level, or planned significant correction for severe myelopathy, scoliosis (> 75˚), or kyphosis (> 75˚). Patients were categorized as Before Conference (BC): surgery before 2/19/2019 or After Conference (AC): surgery after 2/19/2019. Outcome measures include intraoperative and postoperative complications, readmissions, and reoperations. RESULTS:263 patients were included (96 AC, 167 BC). AC was older than BC (60.0 vs 54.6, p = 0.025) and had lower BMI (27.1 vs 28.9, p = 0.047), but had similar CCI (3.2 vs 2.9 p = 0.312), and ASA Classification (2.5 vs 2.5, p = 0.790). Surgical characteristics, including levels fused (10.6 vs 10.7, p = 0.839), levels decompressed (1.29 vs 1.25, p = 0.863), 3 column osteotomies (10.4% vs 18.6%, p = 0.080), anterior column release (9.4% vs 12.6%, p = 0.432), and revision cases (53.1% vs 52.4%, p = 0.911) were similar between AC and BC. AC had lower EBL (1.1 vs 1.9L, p < 0.001) and fewer total intraoperative complications (16.7% vs 34.1%, p = 0.002), including fewer dural tears (4.2% vs 12.6%, p = 0.025), delayed extubations (8.3% vs 22.8%%, p = 0.003), and massive blood loss (4.2% vs 13.2%, p = 0.018). Length of stay (LOS) was similar between groups (7.2 vs 8.2 days, 0.251). AC had a lower incidence of deep surgical site infections (SSI, 1.0% vs 6.6%, p = 0.038), but a higher rate of hypotension requiring vasopressor therapy (18.8% vs 4.8%, p < 0.001). Other postoperative complications were similar between groups. AC had lower rates of reoperation at 30 (2.1% vs 8.4%, p = 0.040) and 90 days (3.1 vs 12.0%, p = 0.014) and lower readmission rates at 30 (3.1% vs 10.2%, p = 0.038) and 90 days (6.3 vs 15.0%, p = 0.035). On logistic regression, AC patients had higher odds of hypotension requiring vasopressor therapy and lower odds of delayed extubation, intraoperative RBC, and intraoperative salvage blood. CONCLUSIONS:Following implementation of a multidisciplinary high-risk case conference, 30- and 90-day reoperation and readmission rates, intraoperative complications, and postoperative deep SSIs decreased. Hypotensive events requiring vasopressors increased, but did not result in longer LOS or greater readmissions. These associations suggest a multidisciplinary conference may help improve quality and safety for high-risk spine patients. particularly through minimizing complications and optimizing outcomes in complex spine surgery.

Background: Identify the external applicability of the American College of Surgeons"™ National Surgical Quality Improvement Program (NSQIP) risk calculator in the setting of adult spinal deformity (ASD) and subsets of patients based on deformity and frailty status. Methods: ASD patients were isolated in our single-center database and analyzed for the shared predictive variables displayed in the NSQIP calculator. Patients were stratified by frailty (not frail <0.03, frail 0.3"“0.5, severely frail >0.5), deformity [T1 pelvic angle (TPA) > 30, pelvic incidence minus lumbar lordosis (PI-LL) > 20], and reoperation status. Brier scores were calculated for each variable to validate the calculator"™s predictability in a single center"™s database (Quality). External validity of the calculator in our ASD patients was assessed via Hosmer-Lemeshow test, which identified whether the differences between observed and expected proportions are significant. Results: A total of 1606 ASD patients were isolated from the Quality database (48.7 years, 63.8% women, 25.8 kg/m²); 33.4% received decompressions, and 100% received a fusion. For each subset of ASD patients, the calculator predicted lower outcome rates than what was identified in the Quality database. The calculator showed poor predictability for frail, deformed, and reoperation patients for the category "any complication" because they had Brier scores closer to 1. External validity of the calculator in each stratified patient group identified that the calculator was not valid, displaying P values >0.05. Conclusion: The NSQIP calculator was not a valid calculator in our single institutional database. It is unable to comment on surgical complications such as return to operating room, surgical site infection, urinary tract infection, and cardiac complications that are typically associated with poor patient outcomes. Physicians should not base their surgical plan solely on the NSQIP calculator but should consider multiple preoperative risk assessment tools.

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.

STUDY DESIGN/METHODS:Retrospective analysis of outcomes in cervical spine and shoulder arthroscopy patients. OBJECTIVE:The objective of this study is to assess differential improvements in health-related quality of life for cervical spine surgery compared with shoulder surgery. SUMMARY OF BACKGROUND DATA/BACKGROUND:An understanding of outcome differences between different types of orthopedic surgeries is helpful in counseling patients about expected postoperative recovery. This study compares outcomes in patients undergoing cervical spine surgery with arthroscopic shoulder surgery using computer-adaptive Patient-reported Outcome Information System scores. MATERIALS AND METHODS/METHODS:Patients undergoing cervical spine surgery (1-level or 2-level anterior cervical discectomy and fusion, cervical disc replacement) or arthroscopic shoulder surgery (rotator cuff repair±biceps tenodesis) were grouped. Patient-reported Outcome Information System scores of physical function, pain interference, and pain intensity at baseline and at 3, 6, and 12 months were compared using paired t tests. RESULTS:Cervical spine (n=127) and shoulder (n=91) groups were similar in sex (25.8% vs. 41.8% female, P=0.731) but differed in age (51.6±11.6 vs. 58.60±11.2, P<0.05), operative time (148.3±68.6 vs. 75.9±26.9 min, P<0.05), American Society of Anesthesiologists (ASAs) (2.3±0.6 vs. 2.0±0.5, P=0.001), smoking status (15.7% vs. 4.4%, P=0.008), and length of stay (1.1±1.0 vs. 0.3±0.1, P=0.000). Spine patients had worse physical function (36.9 ±12.6 vs. 49.4±8.6, P<0.05) and greater pain interference (67.0±13.6 vs. 61.7±4.8, P=0.001) at baseline. Significant improvements were seen in all domains by 3 months for both groups, except for physical function after shoulder surgery. Spine patients had greater physical function improvements at all timepoints (3.33 vs. -0.43, P=0.003; 4.81 vs. 0.08, P=0.001; 6.5 vs. -5.24, P=<0.05). Conversely, shoulder surgery patients showed better 6-month improvement in pain intensity over spine patients (-8.86 vs. -4.46, P=0.001), but this difference resolved by 12 months. CONCLUSIONS:Cervical spine patients had greater relative early improvement in physical function compared with shoulder patients, whereas pain interference and intensity did not significantly differ between the 2 groups after surgery. This will help in counseling patients about relative difference in recovery and improvement between the 2 surgery types. 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.

PURPOSE/OBJECTIVE:Single position surgery has demonstrated to reduce hospital length of stay, operative times, blood loss, postoperative pain, ileus, and complications. ALIF and LLIF surgeries offer advantages of placing large interbody devices under direct compression and can be performed by a minimally invasive approach in the lateral position. Furthermore, simultaneous access to the anterior and posterior column is possible in the lateral position without the need for patient repositioning. The purpose of this study is to outline the anatomical and technical considerations for performing anterior lumbar interbody fusion (ALIF) in the lateral decubitus position. METHODS:Surgical technique and technical considerations for reconstruction of the anterior column in the lateral position by ALIF at the L4-5 and L5-S1 levels. RESULTS:Topics outlined in this review include: Operating room layout and patient positioning; surgical anatomy and approach; vessel mobilization and retractor placement for L4-5 and L5-S1 lateral ALIF exposure, in addition to comparative technique of disc space preparation, trialing and implant placement compared to the supine ALIF procedure. CONCLUSIONS:Anterior exposure performed in the lateral decubitus position allows safe-, minimally invasive access and implant placement in ALIF. The approach requires less peritoneal and vessel retraction than in a supine position, in addition to allowing simultaneous access to the anterior and posterior columns when performing 360° Anterior-Posterior fusion.

BACKGROUND CONTEXT: Previous orthopedic literature has shown that patients with diabetes mellitus (DM) are more likely to develop complications in the postoperative period. To date, however, no study has assessed the specific pre- and postoperative risk factors that may contribute to this association for diabetic patients undergoing adult spinal deformity surgery. PURPOSE: Establish relevant risk factors for postoperative complications in a cohort of diabetic patients undergoing spinal deformity surgery. STUDY DESIGN/SETTING: Single-center retrospective cohort study. PATIENT SAMPLE: A total of 138 patients with DM who underwent spinal deformity surgery at a single academic hospital from 2012-2019. OUTCOME MEASURES: Primary outcomes were the development of any post-operative complications. These complications included the development of neurologic complications, urinary complications, cardiac complications, pulmonary complications, venous thromboembolism (VTE) and surgical site infections (SSI).
METHOD(S): This study is a retrospective cohort review of diabetic patients undergoing spinal deformity surgery, with 5 levels fused at a single academic medical center. Patients' age, BMI, levels fused, pre- and postoperative hemoglobin (Hgb), hematocrit (HCT) and preoperative HbA1C were collected. T-test and chi-square analyses were used to compare relevant outcomes. Significance was set to p<0.05.
RESULT(S): A total of 138 patients with DM met the inclusion criteria and were included in the analysis. Of these, 50.7% of the total cohort developed a postoperative complication within 90 days of the index surgery. Patients who developed postoperative complications were noted to have significantly lower postoperative Hgb (9.82+/-1.46 g/dL vs 10.72+/-1.76 g/dL, p=0.002) postoperative HCT (28.8+/-3.92% vs 32.60+/-4.61%, p<0.001) and significantly greater number of levels fused (9.49+/-3.74 vs 7.47+/-3.16, p=0.001). Diabetic patients who developed cardiac complications had significantly lower postoperative Hgb (9.47+/-1.50 g/dL vs 10.40+/-1.66 g/dL, p=0.021) and HCT (27.87+/-3.16% vs 31.15+/-4.72%, p=0.003) compared with those who did not. Diabetic patients who developed urinary complications were noted to be older on average (72.56+/-8.20 vs 64.43+/-11.70 years, p=0.043), while patients who developed VTE and pulmonary complications were noted to have significantly higher numbers of levels fused (VTE: 14.00+/-3.61 vs 8.37+/-3.51, p=0.007; PC: 10.82+/-4.14 vs 8.29+/-3.49, p=0.025)Finally, diabetic patients who developed a surgical site infection had significantly lower postoperative HCT (26.74+/-3.27% vs 30.86+/-4.64%, p=0.022) than those who did not. Multivariate logistic regression analysis showed that postoperative HCT (OR: 0.765 [0.613-1.098], p=0.001) and number of levels fused (OR: 1.243 [1.084-1.425], p=0.002) were predictive of development of any postoperative complication, when controlled for BMI, age, and and postoperative Hgb. Postoperative HCT was an independent predictor of the development of cardiac complications (OR: 0.827 [0.692-0.989], p=0.037) and SSI (OR: 0.709 [0.528-0.952], p=0.022).
CONCLUSION(S): Postoperative HCT is predictive of the development of postoperative complications in general, and more specifically the development of cardiac complications and surgical site infections. Along with blood-glucose and HbA1C, it should be closely monitored perioperatively in diabetic patients undergoing spinal deformity surgery. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Diabetic patients with elevated hemoglobin A1C (HbA1C) are at higher risk of developing complications after surgery than their nondiabetic peers. This is especially true of wound complications, including wound infections. Previous research has shown this relationship to be multifactorial, so more investigation is needed into these complications. PURPOSE: Establish pertinent factors which contribute to increased wound complication incidence among diabetic patients undergoing thoracolumbar fusion. STUDY DESIGN/SETTING: Single center retrospective cohort study. PATIENT SAMPLE: This study included 228 patients with a diagnosis of diabetes mellitus who underwent thoracic, lumbar, or thoracolumbar posterior spinal fusion (PSF) from 2013-2018 with preoperative HbA1C values. Patients without preoperative HbA1C results or undergoing cervical fusions were excluded. OUTCOME MEASURES: Development of wound complications and infection in the perioperative period were recorded for analysis. Wound complications were defined as dehiscence, superficial SSI and deep SSI.
METHOD(S): Significant perioperative complications were determined using t-test and chi-square analyses. Complications were tested against confounding factors using binary logistic regressions. Efficacy of various preoperative demographic measures as markers for complication was determined using Receiver Operating Characteristic (ROC) analyses. Cutoff points were calculated by Youden's index. Significance set at p <0.05.
RESULT(S): A total of 228 patients met inclusion. Significant differences in BMI were noted between patients who developed infection (n=7) and those who did not (37.5 kg/m² vs 32.0 kg/m²; p=0.039). In addition, binary logistic regression showed that, controlled for HbA1C, BMI was a significant predictor of infection (OR: 1.110; p=0.043). ROC curve demonstrated an AUC of 0.754 (p=0.022) and Youden's J calculated the cutoff point to be 34.08 kg/m² (Spec: 64.3%, Sens: 85.7%). No differences between those with postop wound complications were noted in HbA1C (7.29 vs 6.88; p=0.345), age (70.14 vs 64.92; p=0.197), gender (vs 71.4% female vs 55.5% female; p=0.469), smoking status (28.6% smoking history vs 33.9% smoking history), levels fused (2.71 vs 2.62; p=0.931), LOS (3.29 vs 4.82; p=0.243). Sub-analysis of superficial infections revealed no significant differences in HbA1C (7.15 vs 6.88; p=0.565), age (70.8 vs 64.9; p=0.175), BMI (36.5 vs 32.1; p=0.114), levels fused (2.5 vs 2.6; p=0.911), gender (66.7% female vs 55.4% female; p=0.697), smoking status (33.3% smoking history vs 33.7% smoking history; p=1.000), or LOS (2.8 vs 4.8; p=0.159). Subanalysis of deep SSI revealed only one infection.
CONCLUSION(S): BMI above 34.08 kg/m² is a significant predictor of postoperative infection in diabetic patients undergoing posterior fusion. To ensure optimal outcomes, diabetic patients should be encouraged to get below this threshold before surgery. More research must be done to further establish the relationship of BMI with regard to superficial and deep infections. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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