Faculty Bibliography

BACKGROUND CONTEXT: Advancements in artificial intelligence (AI), machine learning, and minimally-invasive (MIS) technique may offer enhanced preoperative planning, intraoperative robotic or navigational guidance, and prediction of postoperative complications for adult spinal deformity patients. Despite relatively widespread utilization, few studies in the literature assess the clinical and radiographic impact of AI in MIS surgery. PURPOSE: To assess the impact of artificial intelligence on peri- and postoperative course in minimally-invasive adult spinal deformity corrective surgery. STUDY DESIGN/SETTING: Retrospective cohort review. PATIENT SAMPLE: This study included 524 MIS patients. OUTCOME MEASURES: Intra- and postoperative complication rates; reoperation rate; HRQLs METHODS: Operative cervical deformity patients 18 years old with complete pre-(BL) and up to 2-year (2Y) postop radiographic/HRQL data were stratified by primary utilization AI-based patient-specific rod customization and robotic or navigational assistance in pre- and perioperative course (AI+) or not (AI-). Differences in demographics, clinical outcomes, radiographic alignment targets, perioperative factors and complication rates were assessed via means comparison analysis. Analysis of covariance (ANCOVA) assessed postoperative complications while controlling for BL age and gender.
RESULT(S): A total of 133 MIS patients were included (51.74+/-11.59 years, 41% female, 30.85+/-6.93 kg/m²). Of these patients, 44 (33.1%) were classified as AI+. At baseline, patient groups were comparable in BL age, BMI and CCI (all p>.05), though AI+ patients were more likely to be male (p=.040). Patient groups were comparable in terms of both regional and global radiographic alignment, as well as HRQLs at BL (all p>.05). Surgically, AI+ patients had significantly shorter operative times overall (p=.022) and decreased EBL (p=.001), as well as decreased likelihood of undergoing corpectomy (p=.001). Furthermore, AI+ patients reported significantly lower hospital LOS vs AI- patients (p=.012). At 2 years postoperatively, AI+ patients with custom rods were noted to have significantly improved segmental alignment in terms of decreased pelvic tilt (S1PT) and pelvic incidence (S1PI) (both p <.001). Adjusted complications analysis revealed that AI+ patients were significantly less likely to experience any postoperative complication (p=.003), neurological complications (p=.021) or complication requiring reoperation (p=.003).
CONCLUSION(S): Artificial intelligence and machine learning technologies may provide a substantial benefit to patients undergoing minimally-invasive adult spinal deformity surgery. The findings in this study demonstrate that patients operated on using AI-based robotic or navigational guidance, as well as the utilization of customized instrumentation, may reduce intraoperative invasiveness, shorten hospital length of stay, and decrease complication rates. As such, surgeons should consider utilization of AI-based technology in practice. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: The impact of neuromuscular disorders such as multiple sclerosis (MS) on outcomes following long segment (4+ level) fusion is underreported. PURPOSE: To identify the impact of MS on two-year (2Y) postoperative complications and revisions following 4 level fusion for ASD. STUDY DESIGN/SETTING: Retrospective cohort. PATIENT SAMPLE: Patients undergoing 4+ level fusion for ASD were identified from the New York State Statewide Planning and Research Cooperative System. OUTCOME MEASURES: Two-year postoperative complications and reoperations.
METHOD(S): Patients undergoing 4-level fusion for ASD were identified from the New York Statewide Planning and Research Cooperative System. Patients with a baseline diagnosis of MS were also identified. Patients with infectious/traumatic/neoplastic indications were excluded. Subjects were 1:1 propensity score-matched (MS to no-MS) by age, sex, and race and compared for rates of 2-year postoperative complications and reoperations. Logistic regression models were utilized to determine risk factors for adverse outcomes at 2 years.
RESULT(S): A total of 86 patients were included (n=43 per group). Age (50.1 vs 50.1 years, p=0.225), sex and race were comparable between groups. MS pts incurred higher charges for their surgical visit ($125,906 vs $84,006, p=0.007) with similar LOS (8.1 vs 5.3 days, p>0.05). MS patients experienced comparable rates of overall medical complications (30.1% vs 25.6%) and surgical complications (34.9% vs 30.2%) all p>0.05. MS pts had similar rates of 2-year revisions (16.3% vs 9.3%, p=0.333). MS was not associated with medical, surgical or overall complications or revisions at minimum 2-year follow-up.
CONCLUSION(S): Patients with MS experienced similar postoperative course compared to those without MS following 4-level fusion for ASD. This data supports the findings of multiple previously published case series' that long segment fusions for ASD can be performed relatively safely in patients with MS. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: As surgical techniques for deformity correction evolve towards minimizing tissue trauma, further clarity is warranted to define differences in complication profiles between cMIS and open surgeries. PURPOSE: To compare cMIS and open surgery reoperation rates and identify contributing etiologies to reoperation in each cohort. STUDY DESIGN/SETTING: Prospective multicenter observational series. PATIENT SAMPLE: Database enrollment required age =18 years, adult spinal deformity and circumferential minimally invasive spine surgery. OUTCOME MEASURES: Reoperation rate, patient reported outcomes (PROMS), spinopelvic parameters, mechanical failures (defined as rod breakage/dislocation, screw breakage/loosening, set screw loosening, proximal/distal junctional kyphosis, pseudoarthrosis) and other factors contributing to re-operation such as wound infection, medial breach, nerve impingement by screw, vertebral body fracture, sagittal/coronal imbalance, and wound infection.
METHOD(S): A total of 85 patients (pts) with cMIS for ASD with 2-year follow-up (2YFU) were identified and propensity matched to 85 patients in open cohort. Propensity matching was performed based on pre-operative PT, PI-LL, BMI, and SVA. Patient demographic variables, reoperation rate, and complications contributing to reoperation were compared with uni- and multi-variate analysis at any time in each cohort (33 open, 17 cMIS). PROMS at 2YFU were compared in the reoperated cohorts.
RESULT(S): Total of 33 reoperation in the open cohort vs 17 in cMIS were identified. The reoperation rate was significantly higher in the open cohort at 39% (33/85) compared to 20% (17/85) in the cMIS cohort (P= 0.012). The reoperation rate in open cohort related to mechanical failure was 52% (17/33) compared to 35% (6/17) in cMIS cohort (P= 0.43). No significant difference was found in rates of specific etiologies contributing to complications in the cMIS vs open reoperation cohorts under uni- and multivariate analysis. The change in spinopelvic parameters among the two reoperation cohorts at 2YFU were statistically not significant (deltaCVA, deltaSVA, deltaPI-LL, deltaPT, deltaLL CA, deltaTL CA). Under univariate analysis, the following PROMS were similar: ODI, NRS Leg and Back Pain, EQ5D, EQ5D-VAS, SF-36 PCS,SF-36 MCS. However, SRS-22 in open cohort was significantly higher at 2YFU (3.55 +/- 0.73 open vs. 3,10 +/- 0.56 MIS, p = 0.029).
CONCLUSION(S): Findings in our ongoing study show that cMIS procedures were associated with a significantly lower reoperation rate compared to open surgical approaches. PROMS and the change in spinopelvic parameters were similar at 2YFU in both reoperated cohorts (except for SRS-22 favored open cohort). FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Adult cervical deformity (ACD) can have profound impact on health-related quality of life (HRQL). Operative treatment for ACD is associated with high complication rates due to the complexity of surgery and the frailty of the patients affected. Very few studies have focused on outcomes of operative ACD treatment. PURPOSE: To assess whether operative treatment for ACD significantly improves HRQL at minimum 2-yr followup. STUDY DESIGN/SETTING: Multicenter, prospective cohort study. PATIENT SAMPLE: Operatively treated ACD patients. OUTCOME MEASURES: Neck Disability Index (NDI), modified Japanese Orthopaedic Association (mJOA), EuroQol-5D (EQ-5D), and numeric rating scale (NRS) for neck and back pain.
METHOD(S): Operatively treated ACD patients were assessed at baseline, standardized follow-up intervals and through direct mailings. Patient-reported outcomes measures (PROMs) included: NDI, mJOA, EQ-5D and NRS for neck and back pain. Complications were classified as perioperative (=30 days) or delayed (>30 days). Analyses focused on patients with minimum 2-yr followup.
RESULT(S): Of 169 ACD patients, the 102 (60%) with minimum 2-yr followup (mean=3.4 yrs, SD=1.9 yrs, range=2 to 8.1 yrs) had a mean age of 62 yrs (SD=11) and 64% were women. Surgical approaches included anterior-only (22.8%), posterior-only (39.6%) and combined (37.6%). The mean numbers of vertebrae fused anteriorly and posteriorly were 4.3 (SD=1.1) and 9.4 (SD=3.4), respectively, with 16% having a 3-column osteotomy. PROMs significantly improved from baseline to last follow-up, including NDI (47.3 to 33.0), mJOA (12.0 to 12.8; for patients with baseline score 0.05). Overall, 58 (56.9%) patients had at least 1 complication, 41 (40.2%) had at least 1 perioperative complication, and 35 (34.3%) had at least 1 delayed complication. The most common complications included dysphagia (18.6%), distal junctional kyphosis (6.9%), instrumentation failure (6.9%), cardiac events (6.9%), dysphonia (4.9%), nerve sensory deficit (3.9%) and respiratory failure (3.9%). For patients with at least 2-yr follow-up, 12 patients underwent a total of 15 reoperations (9 had 1 and 3 had 2). Notably, the 67 patients who did not achieve 2-yr follow-up were similar to study patients based on demographics, comorbidities and baseline PROMs. Reflective of the frailty of this patient population, there were 18 deaths among the 67 patients without minimum 2-yr followup. These deaths occurred between 0.2 and 34.8 months following surgery. Although most occurred at least 6 months after surgery and likely were not directly related to surgery, 4 occurred within 4 months of surgery, including 1 due OSA/narcotics, 1 due to pneumonia, and 2 with unknown causes.
CONCLUSION(S): This multicenter, prospective analysis demonstrates that operative treatment for ACD provides significant improvement of HRQL at minimum 2-yr (mean 3.4-yr) followup. These findings may prove useful for patient counseling in the context of the substantial impact of ACD. Further studies will be needed to assess the long-term durability and cost-effectiveness of surgical treatment for ACD. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Malalignment following adult spinal deformity (ASD) surgery can negatively impact clinical outcomes and increase risk of mechanical complications. Despite improved definition of ideal alignment for ASD surgery and increasingly sophisticated preoperative alignment planning tools, it remains unclear whether the preoperative goals for alignment are actually achieved with surgery. PURPOSE: The objective of this study was to assess whether preoperative goals for sagittal alignment following ASD surgery are consistently achieved. STUDY DESIGN/SETTING: Multicenter, prospective cohort study. PATIENT SAMPLE: Operatively treatedASD patients. OUTCOME MEASURES: Sagittal vertical axis (SVA), pelvic incidence to lumbar lordosis mismatch (PI-LL), T4-T12 thoracic kyphosis (TK).
METHOD(S): From 2018-2021, ASD patients were enrolled into a prospective ASD study based on three criteria: deformity severity (PI-LL>25degree, TPA>30degree, SVA>15cm, TCobb>70degree or TLCobb>50degree), procedure complexity (>12 levels fused, 3CO or ACR), and/or patient age (>65 and >7 levels fused). The operating surgeon documented sagittal alignment goals prior to surgery, including SVA, PI-LL mismatch and TK. Alignment goals were compared with achieved alignment at 6 weeks postop and the overall mean and SD were calculated for the offset (achieved minus goal) for each measure. Goal alignment was considered attained if the offset was within +/-1 SD of the goal. Demographic, surgical and baseline radiographic measures demonstrating significant association with achieving alignment goal on univariate analysis were used for multivariate regression analysis.
RESULT(S): The 266 enrolled patients had a mean age of 61.0 yrs (SD=14.6 yrs) and 68% were women. Mean number of instrumented levels was 13.6 (SD=3.8) and 24% had a 3-column osteotomy (3CO). Mean (SD) offsets were: SVA=-8.5 mm (45.6 mm), PI-LL=-4.6degree (14.6degree), TK=7.2degree (14.7degree), reflecting a tendency to undercorrect SVA and PI-LL relative to goal and to increase TK relative to goal. Surgeons achieved goal alignment (within 1 SD) for SVA, PI-LL, and TK in 74.4%, 71.4%, and 68.8% of cases, respectively. On regression analysis: goal SVA was more likely to be achieved with lower baseline SVA (OR=0.993, 95%CI=0.988-0.997, p=0.001) and greater baseline TK (OR=1.016, 95%CI=1.002-1.031, p=0.029); goal PI-LL was more likely to be achieved with greater patient age (OR=1.021, 95%CI=1.002-1.039, p=0.026) and history of previous TL spine surgery (OR=2.028, 95% CI=1.136-3.621, p=0.017); and goal TK was more likely to be achieved with lower baseline SVA (OR=0.995, 95%CI=0.991-0.999; p=0.014). The proportions of patients with achieved alignment within 1 SD of goal were not significantly different for patients with a UIV above T7 vs those with a UIV at or below T7 for SVA (p=0.20), PI-LL (p=0.49) or TK (p=0.06). Notably, patient-specific rods were used in 21 patients and were not associated with greater achievement of goal alignment for any parameter (p>0.8), with similar tendencies to undercorrect SVA and PI-LL and increase TK (p>0.6).
CONCLUSION(S): Surgeons failed to achieve goal alignment of each sagittal parameter in ~25% of patients operated for ASD, with a tendency to undercorrect SVA and PI-LL and increase TK. Patients at greatest risk tended to be those with more severe baseline deformity. Further advancements are needed to enable more consistent translation of preoperative alignment planning to the operating room. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Adult spinal deformity (ASD) corrective surgery is often a highly invasive procedure portending patients to both immediate and long-term complications. However, the impact of each of these complications and their timing of occurrence on cost-utility has yet to be assessed. PURPOSE: To compare the economic impact of certain complications before and after two years following ASD surgery. STUDY DESIGN/SETTING: Retrospective. PATIENT SAMPLE: A total of 689 ASD Patients. OUTCOME MEASURES: Complications, cost utility.
METHOD(S): ASD patients with minimum 3-year and up to 5-year data were included. Complication groups were defined as follows: 1) any complication, 2) major, 3) medical [cardiac event, ileus, etc.], 4) mechanical [implant failure, rod fracture, 5) radiographic [PJK, pseudarthrosis, adjacent segment disease], and 6) reoperation. Complications were stratified by occurrence before or after two years postoperatively. Published methods converted ODI to SF-6D. QALYs utilized a 3% discount rate for residual decline. Cost was calculated using the PearlDiver database and assessed for Complications and Comorbidities and Major Complications and Comorbidities according to CMS.gov definitions. Reimbursement consisted of a standardized estimate using regression analysis of Medicare pay-scales for services within a 30-day window. Marginalized means for utility gained and Cost per QALY were calculated, controlling for age, history of prior fusion, and baseline deformity and disability.
RESULT(S): There were 244 ASD patients included, with an average age of 59+/-15 yrs, that were predominantly female (77%) and a high CCI (1.7+/-1.7). By 2Y, comp rates: 76% 1 complication, 18% major, 16% medical, 16% neurological, 50% radiographic, 5% infection and 20% mechanical, and 64 patients (26%) required reoperation. After 2Y, comp rates: 32% 1 complication, 4% major, 0.4% medical, 2% neurological, 22% radiographic, and 5% mechanical, and 6 patients (2.5%) required reoperation. Overall, any complications occurring after 2 years had a lower cost and cost-utility than those before two years, while major complications happening after two years had worse cost-utility due to lower utility gained (0.320 vs. 0.441, p=.1). Patients developing PJK by and after two years had the lowest cost-utility of any time points. When examining complications occurring before 2 years, patients suffering a mechanical complication accrued the highest overall cost ($130,482.22) followed by infection and PJF. Those suffering a mechanical complication also had the highest utility gained of any complication before 2 years, lowering their cost-utility below that of infection. In contrast, despite having a lower utility gained, those suffering a mechanical complication after 2 years had a lower cost ($109,197.71 vs $130,482.22, p=.041) and cost-utility overall. Similarly, patients developing PJF after 2 years accrued a higher utility gained, lower cost and cost-utility ($77,227.84 vs. $96,873.57, p=.038) than those developing PJF before 2 years.
CONCLUSION(S): Mechanical complications had the single greatest impact on cost and cost-utility when occurring before or after 2 years following correction of adult spinal deformity. However, mechanical and radiographic complications occurring after 2 years had less detrimental effects on both cost and cost-utility. This study increases our understanding of the complications following adult spinal deformity correction in order to mitigate the outcomes that most drastically impact the economic benefit of surgical intervention. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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PURPOSE/OBJECTIVE:To develop age- and BMI-adjusted alignment targets to improve patient-specific management and operative treatment outcomes. METHODS:Retrospective review of a single-center stereographic database. ASD patients receiving operative or non-operative treatment, ≥ 18y/o with complete baseline (BL) ODI scores and radiographic parameters (PT, SVA, PILL, TPA) were included. Patients were stratified by age consistent with US-Normative values (norms) of SF-36(< 35, 35-55, 45-54, 55-64, 65-74, ≥ 75y/o), and dichotomized by BMI (Non-Obese < 30; Obese ≥ 30). Linear regression analysis established normative age- and BMI-specific radiographic thresholds, utilizing previously published age-specific US-Normative ODI values converted from SF-36 PCS (Lafage et al.), in conjunction with BL age and BMI means. RESULTS:486 patients were included (Age: 52.5, Gender: 68.7%F, mean BMI: 26.2, mean ODI: 32.7), 135 of which were obese. Linear regression analysis developed age- and BMI-specific alignment thresholds, indicating PT, SVA, PILL, and TPA to increase with both increased age and increased BMI (all R > 0.5, p < 0.001). For non-obese patients, PT, SVA, PILL, and TPA ranged from 10.0, - 25.8, - 9.0, 3.1 in patients < 35y/o to 27.8, 53.4, 17.7, 25.8 in patients ≥ 75 y/o. Obese patients' PT, SVA, PILL, and TPA ranged from 10.5, - 7.6, - 7.1, 5.8 in patients < 35 y/o to 28.3, 67.0, 19.15, 27.7 in patients ≥ 75y/o. Normative SVA values in obese patients were consistently ≥ 10 mm greater compared to non-obese values, at all ages. CONCLUSION/CONCLUSIONS:Significant associations exist between age, BMI, and sagittal alignment. While BMI influenced age-adjusted alignment norms for PT, SVA, PILL, and TPA at all ages, obesity most greatly influenced SVA, with normative values similar to non-obese patients who were 10 years older. Age-adjusted alignment thresholds should take BMI into account, calling for less rigorous alignment objectives in older and obese patients.

BACKGROUND CONTEXT: Tranexamic acid (TXA) is commonly used to lower blood loss in ASD surgery. Despite widespread use of TXA in ASD surgery, there is a lack of consensus regarding the optimal dosing intraoperatively. PURPOSE: This study aims to assess differences in blood loss and complications between high-dose, medium-dose, and low-dose TXA regimens. Complex ASD patients who receive high-dose TXA will have decreased blood loss compared to those who receive low-dose TXA. STUDY DESIGN/SETTING: Retrospective Review. PATIENT SAMPLE: A total of 265 ASD patients in a multi-center prospective study were retrospectively analyzed. OUTCOME MEASURES: Blood loss (ml), Major Blood Loss (>90th percentile ml), units transfused intraoperatively, units transfused perioperatively.
METHOD(S): Patients were separated into three cohorts by TXA regimen: 1) low-dose patients had =20mg/kg loading dose with =2mg/kg/hr maintenance dose 2) medium-dose patients had 20-50 mg/kg loading dose with 2-5 mg/kg/hr maintenance dose. 3) high-dose patients had =50mg/kg loading dose with =5mg/kg/hr maintenance dose. Major or minor blood loss was defined as above or below the 90th percentile of our cohort respectively. Multivariable analysis controlled for levels fused, BMI, platelets, Hgb, OR time, 3CO, and radiographic alignment.
RESULT(S): Fifty-four (20%) patients received low-dose regimen, 133 (50%) received medium-dose and 80 (30%) received high dose. Mean blood loss was 1,551+/-1,295 ml, intraoperative units RBCs 1.52+/-2, and perioperative units RBCs 2.3+/-2.3. Mean major blood loss was 4,566+/-1,516ml and minor blood loss 1,236+/-755ml. Compared to the low-dose group, patients in the high-dose group had 77.8% decreased odds of major blood loss (OR 0.222; P=0.007), decreased blood loss (Coef. -540.92ml; P=0.019), units transfused intraoperatively (Coef. -.739 units; P < 0.001), and units transfused perioperatively (Coef. -0.328 units; P=0.025). Compared to medium-dose group, the high-dose group had less units transfused intraoperatively (Coef. -.59 units; P < 0.001) and perioperatively (Coef. -.42 units; P < 0.001) with no difference in blood loss. There was no difference between the medium and low dose groups in blood loss or units transfused. There was no association between high-dose TXA regimen and increased rates of DVT, PE, or any medical complication before six weeks. No patients had a seizure.
CONCLUSION(S): In this multicenter prospectively collected database, ASD patients receiving high-dose intraoperative TXA have decreased odds of major blood loss, less RBC transfusions intraoperatively and 540ml less blood loss compared to low dose TXA, without additional risk of seizure or thromboembolic complications. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Despite multiple reports showing favorable long-term functional outcomes following adult spinal deformity (ASD) correction, it is still unclear which patient factors may impact the sustainability of these outcomes. PURPOSE: To assess the sustainability of functional gains following ASD correction and determine predictors for postoperative loss of patient functionality. STUDY DESIGN/SETTING: Retrospective cohort. PATIENT SAMPLE: A total of 689 ASD patients. OUTCOME MEASURES: Sustained clinical benefit, Oswestry Disability Index (ODI), reoperation, mechanical failure, proximal junctional failure (PJF) METHODS: ASD patients with baseline (BL) and three-year (3Y) follow-up data were considered for analysis. Only patients who met the definition of sustained clinical benefit (SCB) at one-year (1Y) were included: 1)Passias et al's threshold for ODI (ODI<31.3), 2) did not develop PJF, and 3) did not have a reoperation for a mechanical failure. Patient groups were created by those who met SCB at 3Y, and those who did not. SCB outcomes were also reported at five-years (5Y) postoperatively. Means comparison tests assessed differences in patient groups. Factors predicting SCB were identified using adjusted regression and conditional inference tree (CIT) analysis.
RESULT(S): A total of 157 patients met inclusion criteria and had SCB at 1Y. Patient breakdown for SCB was 75.0% at 3Y. Gender (78% vs 81%), BMI (25.5 vs 26.4), levels fused (10.6 vs 10.5), operative time (345 vs 362 min), and surgical invasiveness were similar between groups, all P>.05. Following surgery, patient groups were similarly aligned to Lafage et al's age-adjusted PT, PI-LL, and SVA, all P>.05. Regression and CIT analysis adjusting for BL deformity determined that patients who met SCB at 3Y were 95.4% less likely to have an ASD-mFI score > 11 (.046[.005-.420], p=0.006), 73.1% less likely to be older than 55 years at DOS (.269[.091-.798], p=.018), 69.4% less likely to have a CCI score > 0(.306[.116-.811], p=.017), and 86.9% less likely to have a BL EQ5D score <.723 (.131[.029-.585], p=.008). Adjusted for patients without follow-up, sustained clinical benefit at 5Y was 57.9%. Predictors of SCB from 3Y to 5Y included age, CCI and EQ5D, all P <.05.
CONCLUSION(S): Sustained clinical benefit was maintainable for 75.0% of the operative ASD cohort at 3Y. Similarly, a 57.9% maintenance rate of sustained clinical benefit at 5Y reflects the longevity of ASD correction. Independent predictors of sustained clinical benefit included age, frailty, comorbidities and the patient health state. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND CONTEXT: Adaptation of age-adjusted alignment has gained popularity for its correlation with clinical improvement and lowering rates of proximal junctional kyphosis. Age-adjusted parameters correlate with outcomes. However, frailty may be a better predictor of each following ASD surgery. PURPOSE: To adjust the Sagittal Age-Adjusted Score (SAAS) to accommodate frailty in alignment considerations will increase the predictability of clinical outcomes and junctional failure. STUDY DESIGN/SETTING: Retrospective. PATIENT SAMPLE: A total of 689 ASD Patients. OUTCOME MEASURES: Mechanical complications, PJF, PJK and ODI.
METHOD(S): Included: surgical ASD pts with 2Y data. Frailty assessed by ASD modified Frailty Index (ASD-mFI).
Outcome(s): proximal junctional kyphosis (PJK) and failure (PJF), major mechanical complications, and Smith et al Best Clinical Outcome (BCO), defined as ODI 4.5. Linear regression analysis established a 6W score based on SAAS component scores, frailty and ODI US norms per published by Lafage et al. Logistic regression followed by conditional inference tree (CIT) analysis generated categorical thresholds. Logistic regression analysis controlling for age, baseline deformity and revision status generated odds ratios for the continuous score. Thirty percent of the cohort was used as a random sample for internal validation.
RESULT(S): There were 412 pts included. BL frailty categories: 57% not frail, 30% frail and 14% severely frail. Overall, by 2Y, 39% of patients developed PJK, 8% PJF, 21% mechanical complications, 22% underwent reoperation and 15% met BCO. SAAS only correlated with development of PJF. The ASD-mFI demonstrated correlation with all outcomes except PJK (all p1.4, offset: 0.75-1.4, sseverely offset:.05). Internal validation saw these outcomes maintain significance between categories, with significant adjusted correlation to meeting BCO (OR: 3.8, 1.1-13.5; p=.037).
CONCLUSION(S): Consideration of physiologic age, in addition to chronological age, may be beneficial in management of operative goals to maximize clinical outcomes while minimizing junctional failure. This combination enables the spine surgeon to fortify a surgical plan for even the most challenging patients undergoing adult spinal deformity surgery. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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