Faculty Bibliography

PURPOSE/OBJECTIVE:AI algorithms have shown promise in medical image analysis. Previous studies of ASD clusters have analyzed alignment metrics-this study sought to complement these efforts by analyzing images of sagittal anatomical spinopelvic landmarks. We hypothesized that an AI algorithm would cluster preoperative lateral radiographs into groups with distinct morphology. METHODS:This was a retrospective review of a multicenter, prospectively collected database of adult spinal deformity. A total of 915 patients with adult spinal deformity and preoperative lateral radiographs were included. A 2 × 3, self-organizing map-a form of artificial neural network frequently employed in unsupervised classification tasks-was developed. The mean spine shape was plotted for each of the six clusters. Alignment, surgical characteristics, and outcomes were compared. RESULTS:Qualitatively, clusters C and D exhibited only mild sagittal plane deformity. Clusters B, E, and F, however, exhibited marked positive sagittal balance and loss of lumbar lordosis. Cluster A had mixed characteristics, likely representing compensated deformity. Patients in clusters B, E, and F disproportionately underwent 3-CO. PJK and PJF were particularly prevalent among clusters A and E. Among clusters B and F, patients who experienced PJK had significantly greater positive sagittal balance than those who did not. CONCLUSIONS:This study clustered preoperative lateral radiographs of ASD patients into groups with highly distinct overall spinal morphology and association with sagittal alignment parameters, baseline HRQOL, and surgical characteristics. The relationship between SVA and PJK differed by cluster. This study represents significant progress toward incorporation of computer vision into clinically relevant classification systems in adult spinal deformity. LEVEL OF EVIDENCE IV/UNASSIGNED:Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

BACKGROUND CONTEXT/BACKGROUND:In 2008, the Centers for Medicare and Medicaid Services (CMS) established a list of hospital-acquired conditions (HACs) with significant deleterious effects on both patients and providers. Adult spinal deformity (ASD) surgery is complex and highly invasive, and as such may result in significant morbidity including these HACs. PURPOSE/OBJECTIVE:Identify predictors for developing the most common HACs among adult spinal deformity(ASD) patients undergoing corrective surgery. STUDY DESIGN/SETTING/METHODS:Retrospective analysis PATIENT SAMPLE: 1,171 ASD patients OUTCOME MEASURES: HACs, Health-Related Quality of Life scores(HRQLs), Reoperation, Integrated Health State (IHS) METHODS: ASD pts undergoing surgery (>18yrs, scoliosis ≥20°, SVA≥5cm, PT≥25° and/or TK >60°) with complete data at BL and up to 2 years post-op were included. Patients were stratified by presence of >1 HAC, defined as at least one superficial/deep SSI, UTI, DVT, or PE within a 30-day post-op window. Random forest analysis generated 5,000 Conditional Inference Trees to compute a variable importance table for top predictors of HACs. An area-under-the-curve (AUC) methodology compared normalized HRQL scores between groups to determine an IHS with 2-year follow-up. RESULTS:1,171 pts (59.8yrs, 76.2%F, 28.1kg/m2) underwent corrective ASD surgery, with 1,053 pts in the non-HAC group and 118 in the HAC group. Of these pts, 25.4% had UTI, 15.4% DVT, 19.2% superficial SSI, 20.8% deep SSI, and 19.2% PE. HAC pts were on average older (63.5 vs 59.3, p=0.004) and more often frail (51.3vs39.7%,p=0.021)than non-HAC pts. Postop LOS and reoperation were most associated with HAC groups: [1] LOS>7 days [2] reoperation. Patient-related predictors of HACs were [3] age>50yr, [4] frailty, and [13] BMI>31. Procedure-related predictors of HACs were [5] operative-time >405mins, [6] levels fused >9, EBL>1450mL, and [11] decompression. BL radiographic predictors were [7] PT>20°,[9] PI-LL>6°, [10] TL Cobb angle>15°,[12] SVA C7-S1>29mm. No differences were observed between groups with regards to IHS ODI(0.73vs0.74,p=0.863), SRS(1.3vs1.3,p=0.374), NRS Back (0.6vs0.6,p=0.158). HAC had higher rates of reoperation than non-HAC (0.08 vs 0.01, p=0.066), and any HAC within 30-days of index was a significant predictor of reoperation (OR:2.448 [1.94-3.09],p<0.001). CONCLUSIONS:In a population of ASD patients, HACs were associated with length of stay, reoperation, age, and frailty. Radiographic parameters such as pelvic tilt>20°, PI-LL>6°, & SVA>29mm also increased odds of HACs, and should raise postoperative awareness for HAC development.

BACKGROUND:Frailty severity may be an important determinant for impaired recovery after cervical spine deformity (CD) corrective surgery. OBJECTIVE:To evaluate postop clinical recovery among CD patients between frailty states undergoing primary procedures. METHODS:Patients >18 yr old undergoing surgery for CD with health-related quality of life (HRQL) data at baseline, 3-mo, and 1-yr postoperative were identified. Patients were stratified by the modified CD frailty index scale from 0 to 1 (no frailty [NF] <0.3, mild/severe fraily [F] >0.3). Patients in NF and F groups were propensity score matched for TS-CL (T1 slope [TS] minus angle between the C2 inferior end plate and the C7 inferior end plate [CL]) to control for baseline deformity. Area under the curve was calculated for follow-up time intervals determining overall normalized, time-adjusted HRQL outcomes; Integrated Health State (IHS) was compared between NF and F groups. RESULTS:A total of 106 CD patients were included (61.7 yr, 66% F, 27.7 kg/m2)-by frailty group: 52.8% NF, 47.2% F. After propensity score matching for TS-CL (mean: 38.1°), 38 patients remained in each of the NF and F groups. IHS-adjusted HRQL outcomes from baseline to 1 yr showed a significant difference in Euro-Qol 5 Dimension scores (NF: 1.02, F: 1.07, P = .016). No significant differences were found in the IHS Neck Disability Index (NDI) and modified Japanese Orthopedic Association between frailty groups (P > .05). F patients had more postop major complications (31.3%) compared to the NF (8.9%), P = .004, though DJK occurrence and reoperation between the groups was not significant. CONCLUSION/CONCLUSIONS:While all groups exhibited improved postop disability and pain scores, frail patients experienced greater amount of improvement in overall health state compared to baseline disability. This signifies that with frailty severity, patients have more room for improvement postop compared to baseline quality of life.

Background/UNASSIGNED:Age-adjusted alignment targets in the context of distal junctional kyphosis (DJK) development have yet to be investigated. Our aim was to assess age-adjusted alignment targets, reciprocal changes, and role of lowest instrumented level orientation in DJK development in cervical deformity (CD) patients. Methods/UNASSIGNED:CD patients were evaluated based on lowest fused level: cervical (C7 or above), upper thoracic (UT: T1-T6), and lower thoracic (LT: T7-T12). Age-adjusted alignment targets were calculated using published formulas for sagittal vertical axis (SVA), pelvic incidence-lumbar lordosis (PI-LL), pelvic tilt (PT), T1 pelvic angle (TPA), and LL-thoracic kyphosis (TK). Outcome measures were cervical and global alignment parameters: Cervical SVA (cSVA), cervical lordosis, C2 slope, C2-T3 angle, C2-T3 SVA, TS-CL, PI-LL, PT, and SVA. Subanalysis matched baseline PI to assess age-adjusted alignment between DJK and non-DJK. Results/UNASSIGNED:< 0.05). The distribution of over/under corrected patients and the offset between actual and ideal alignment for SVA, PT, TPA, PI-LL, and LL-TK were similar between DJK and non-DJK patients. DJK patients requiring reoperation had worse postoperative changes in all cervical parameters and trended toward larger offsets for global parameters. Conclusion/UNASSIGNED:CD patients with severe baseline malalignment went on to develop postoperative DJK. Age-adjusted alignment targets did not capture differences in these populations, suggesting the need for cervical-specific goals.

Background/UNASSIGNED:The decision upper-most instrumented vertebrae (UIV) in a multi-level fusion procedure can dramatically influence outcomes of corrective spine surgery. We aimed to create an algorithm for selection of UIV based on surgeon selection/reasoning of sample cases. Methods/UNASSIGNED:The clinical/imaging data for 11 adult spinal deformity (ASD) patients were presented to 14 spine deformity surgeons who selected the UIV and provided reasons for avoidance of adjacent levels. The UIV chosen was grouped into either upper thoracic (UT, T1-T6), lower thoracic (LT, T7-T12), lumbar or cervical. Disagreement between surgeons was defined as ≥3 not agreeing. We performed a descriptive analysis of responses and created an algorithm for choosing UIV then applied this to a large database of ASD patients. Results/UNASSIGNED:. 38.9%, P=0.025). Conclusions/UNASSIGNED:Our algorithm for selection of UIV emphasizes the role of proximal and regional thoracic kyphosis. Failure to follow this consensus for UT fusion was associated with twice the rate of PJK.

BACKGROUND:Data on timing of complications are important for accurate quality assessments. We sought to better define pre- and postdischarge complications occurring within 90 days of adult spinal deformity (ASD) surgery and quantify the effect of multiple complications on recovery. METHODS:We performed a review of 1040 patients who underwent ASD surgery (age: 46 ± 23; body mass index: 25 ± 7, American Society of Anesthesiologists [ASA] score: 2.5 ± 0.6, levels: 10 ± 4, revision: 9%, 3-column osteotomy: 13%). We assessed pre- and postdischarge complications and risk factors for isolated versus multiple complications, as well as the impact of multiple complications. RESULTS:= .02). Patients who developed multiple complications (9.3%) had a longer length of stay, and increased risk for readmission and unplanned reoperation. CONCLUSIONS:Knowledge regarding timing of postoperative complications in relation to discharge may better inform quality improvement measures. PE and implant-related complications play a prominent role in perioperative complications and need for readmission, with several modifiable risk factors identified. LEVEL OF EVIDENCE/METHODS:Level 3. CLINICAL RELEVANCE/CONCLUSIONS:Advances in surgical techniques and instrumentation have improved postoperative radiographic and clinical outcomes after ASD surgery. The rate of complications after complex ASD surgery remains high, both at early postoperative and long term follow-up. This study reviews complications within 90 days of surgery, with an assessment of patient and surgical risk factors. We found that modifiable risk factors for early complications after ASD surgery include COPD, and current smoking. The data presented in this study also provide surgeons with knowledge of the most common complications encountered after ASD surgery, to aid in preoperative patient discussion.

BACKGROUND:The Patient-Reported Outcome Measurement Information System (PROMIS) and legacy outcome measures like the Oswestry Disability Index (ODI) have not been compared for their sensitivity in reflecting the impact of perioperative complications and length of stay (LOS) in a surgical thoracolumbar population. The purpose of this study is to assess the strength of PROMIS and ODI scores as they correlate with LOS and complication outcomes of surgical thoracolumbar patients. METHODS:Retrospective cohort study. Included: patients ≥18 years undergoing thoracolumbar surgery with available preoperative and 3-month postoperative ODI and PROMIS scores. Pearson correlation assessed the linear relationships between LOS, complications, and scores for PROMIS (physical function, pain intensity, pain interference) and ODI. Linear regression predicted the relationship between complication incidence and scores for ODI and PROMIS. RESULTS:= .014) could predict complications; ODI could not. CONCLUSIONS:PROMIS domains of physical function and pain interference better reflected perioperative complications and LOS than the ODI. These results suggest PROMIS may offer more utility as an outcomes assessment instrument. LEVEL OF EVIDENCE/METHODS:3.

STUDY DESIGN/UNASSIGNED:Retrospective study. OBJECTIVES/UNASSIGNED:Our goal was to evaluate the rate of rod fracture and persistent pseudarthrosis in cohorts of patients treated with a dual rod or multiple-rod construct in revision surgery for pseudarthrosis. METHODS/UNASSIGNED:A dual rod construct was used in 23 patients, and a multiple rod construct in 24 patients, spanning the pseudarthrosis level. Two-year fusion grading, and rates of pseudarthrosis and implant failure, were assessed. RESULTS/UNASSIGNED:There were no differences in patient or surgical characteristics between the groups: (2- rod construct: Age 60 ± 14, Levels 10 ± 5, 3-column osteotomy:17%; multiple-rod construct: Age: 62 ± 11, Levels 9 ± 4, 3-column osteotomy:30%). Patients in the multiple rod construct were transfused a greater volume of packed red blood cells (pRBCs) intraoperatively (2.6 ± 2.9 vs. 1.1 ± 1.5 U, p < 0.0001). At 2 year follow up there was no difference in fusion grades at the previous level of pseudarthrosis, the rate of rod fracture or pseudarthrosis between the 2 groups, or rate of reoperation for pseudarthrosis, rod fracture, wound infection, hardware prominence, or PJK/PJF. CONCLUSIONS/UNASSIGNED:Our data demonstrate no difference in fusion grade, or rates of rod fracture and revision at 2 years, after utilizing a dual rod versus multiple rod construct in revision surgery for pseudarthrosis. The low complication rates seen with either configuration warrant further investigation of the optimal instrumentation configuration.

STUDY DESIGN:Retrospective review of prospective multicenter database. OBJECTIVE:The aim of this study was to investigate how preoperative mental status affects preoperative and postoperative disability and health scores in adult spinal deformity (ASD) patients. SUMMARY OF BACKGROUND DATA:The relationship between health-related quality of life (HRQOL) and depression has previously been documented. However, the influence of depression on clinical outcomes among ASD patients is not well understood. METHODS:ASD patients with minimum 2-year follow-up were stratified based on preoperative mental health measured by Short Form 36 (SF-36) mental component score (MCS). Patients with MCS in the 25th and 75th percentile of the cohort were designated as having low and high MCS, respectively. After matching by preoperative demographics and deformity, pre- and post-HRQOL were compared between the two groups. Further analysis was performed to identify individualized questions on the SF-36 that could potentially screen for patients with low MCS. RESULTS:Five hundred thirteen patients were assessed (58.4 years' old, 79% women, mean MCS 45.5). Thresholds for low and high MCS cohorts were 35.0 and 57.3, respectively. After matching by preoperative alignment, low MCS patients had worse Oswestry Disability Index (ODI) (52.3 ± 17.0 vs. 35.7 ± 14.6, P < 0.001) and Scoliosis Research Society-22R scores for all domains (all P < 0.001) compared to high MCS patients. Similar results were maintained at 2-year postop, with low MCS patients having a worse ODI (35.2 ± 20.2 vs. 19.7 ± 18.6, P < 0.001) and MCS (42.4 ± 13.5 vs. 58.6 ± 7.1, P < 0.001). Despite similar preoperative Physical Component Score (PCS), low MCS patients were less likely to reach MCID for PCS (46.1% vs. 70.6%, P < 0.01) and had a lower satisfaction at 2-year follow-up (3.88 ± 1.07 vs. 4.39 ± 0.94, P < 0.001). Questions 5a, 9d, and 9f on the SF-36 were found to be independent predictors of low MCS. CONCLUSION:ASD patients with low MCS are more likely to experience functional limitations before and after surgery and are less likely to be satisfied postoperatively, even when similar clinical goals are achieved. Incorporating psychological factors may assist in decision making.Level of Evidence: 3.

STUDY DESIGN/UNASSIGNED:Retrospective review of a multicenter prospective registry. OBJECTIVES/UNASSIGNED:Our goal was to develop a method to risk-stratify adult spinal deformity (ASD) patients on the basis of their accumulated health deficits. We developed a novel comorbidity score (CS) specific to patients with ASD based on their preoperative health state and investigated whether it was associated with major complications, length of hospital stay (LOS), and self-reported outcomes after ASD surgery. METHODS/UNASSIGNED:We identified 273 operatively treated ASD patients with 2-year follow-up. We assessed associations between major complications and age, comorbidities, Charlson Comorbidity Index score, and Oswestry Disability Index score. Significant factors were used to construct the ASD-CS. Associations of ASD-CS with major complications, LOS, and patient-reported outcomes were analyzed. RESULTS/UNASSIGNED:< .01) in patients with ASD-CS of 7 or 8. Patients with ASD-CS of 7 or 8 had the longest mean LOS (10.7 days) and worst mean Scoliosis Research Society-22r total score at baseline; however, they experienced the greatest mean improvement (0.98 points) over 2 years. CONCLUSIONS/UNASSIGNED:The ASD-CS is significantly associated with major complications, LOS, and patient-reported outcomes in operatively treated ASD patients.