Factors Associated with the Maintenance of Cost-Effectiveness at 5 Years in Adult Spinal Deformity Corrective Surgery.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: To evaluate factors associated with the long-term durability of cost-effectiveness (CE) in ASD patients. BACKGROUND: A substantial increase in costs associated with the surgical treatment for adult spinal deformity (ASD) has given precedence to scrutinize the value and utility it provides. METHODS: We included 327 operative ASD patients with 5-year (5 Y) follow-up. Published methods were used to determine costs based on CMS.gov definitions and were based on the average DRG reimbursement rates. Utility was calculated using quality-adjusted life-years (QALY) utilizing the Oswestry Disability Index (ODI) converted to Short-Form Six-Dimension (SF-6D), with a 3% discount applied for its decline with life expectancy. The CE threshold of $150,000 was used for primary analysis. RESULTS: Major and minor complication rates were 11% and 47% respectively, with 26% undergoing reoperation by 5 Y. The mean cost associated with surgery was $91,095±$47,003, with a utility gain of 0.091±0.086 at 1Y, QALY gained at 2 Y of 0.171±0.183, and at 5 Y of 0.42±0.43. The cost per QALY at 2 Y was $414,885, which decreased to $142,058 at 5 Y.With the threshold of $150,000 for CE, 19% met CE at 2 Y and 56% at 5 Y. In those in which revision was avoided, 87% met cumulative CE till life expectancy. Controlling analysis depicted higher baseline CCI and pelvic tilt (PT) to be the strongest predictors for not maintaining durable CE to 5 Y (CCI OR: 1.821 [1.159-2.862], P=0.009) (PT OR: 1.079 [1.007-1.155], P=0.030). CONCLUSIONS: Most patients achieved cost-effectiveness after four years postoperatively, with 56% meeting at five years postoperatively. When revision was avoided, 87% of patients met cumulative cost-effectiveness till life expectancy. Mechanical complications were predictive of failure to achieve cost-effectiveness at 2 Y, while comorbidity burden and medical complications were at 5 Y.

Persistent Lower Extremity Compensation for Sagittal Imbalance After Surgical Correction of Complex Adult Spinal Deformity: A Radiographic Analysis of Early Impact.

BACKGROUND AND OBJECTIVES: Achieving spinopelvic realignment during adult spinal deformity (ASD) surgery does not always produce ideal outcomes. Little is known whether compensation in lower extremities (LEs) plays a role in this disassociation. The objective is to analyze lower extremity compensation after complex ASD surgery, its effect on outcomes, and whether correction can alleviate these mechanisms. METHODS: We included patients with complex ASD with 6-week data. LE parameters were as follows: sacrofemoral angle, knee flexion angle, and ankle flexion angle. Each parameter was ranked, and upper tertile was deemed compensation. Patients compensating and not compensating postoperatively were propensity score matched for body mass index, frailty, and T1 pelvic angle. Linear regression assessed correlation between LE parameters and baseline deformity, demographics, and surgical details. Multivariate analysis controlling for baseline deformity and history of total knee/hip arthroplasty evaluated outcomes. RESULTS: Two hundred and ten patients (age: 61.3 ± 14.1 years, body mass index: 27.4 ± 5.8 kg/m2, Charlson Comorbidity Index: 1.1 ± 1.6, 72% female, 22% previous total joint arthroplasty, 24% osteoporosis, levels fused: 13.1 ± 3.8) were included. At baseline, 59% were compensating in LE: 32% at hips, 39% knees, and 36% ankles. After correction, 61% were compensating at least one joint. Patients undercorrected postoperatively were less likely to relieve LE compensation (odds ratio: 0.2, P = .037). Patients compensating in LE were more often undercorrected in age-adjusted pelvic tilt, pelvic incidence, lumbar lordosis, and T1 pelvic angle and disproportioned in Global Alignment and Proportion (P < .05). Patients matched in sagittal age-adjusted score at 6 weeks but compensating in LE were more likely to develop proximal junctional kyphosis (odds ratio: 4.1, P = .009) and proximal junctional failure (8% vs 0%, P = .035) than those sagittal age-adjusted score-matched and not compensating in LE. CONCLUSION: Perioperative lower extremity compensation was a product of undercorrecting complex ASD. Even in age-adjusted realignment, compensation was associated with global undercorrection and junctional failure. Consideration of lower extremities during planning is vital to avoid adverse outcomes in perioperative course after complex ASD surgery.

Predictors of pelvic tilt normalization: a multicenter study on the impact of regional and lower-extremity compensation on pelvic alignment after complex adult spinal deformity surgery.

OBJECTIVE: The objective was to determine the degree of regional decompensation to pelvic tilt (PT) normalization after complex adult spinal deformity (ASD) surgery. METHODS: Operative ASD patients with 1 year of PT measurements were included. Patients with normalized PT at baseline were excluded. Predicted PT was compared to actual PT, tested for change from baseline, and then compared against age-adjusted, Scoliosis Research Society-Schwab, and global alignment and proportion (GAP) scores. Lower-extremity (LE) parameters included the cranial-hip-sacrum angle, cranial-knee-sacrum angle, and cranial-ankle-sacrum angle. LE compensation was set as the 1-year upper tertile compared with intraoperative baseline. Univariate analyses were used to compare normalized and nonnormalized data against alignment outcomes. Multivariable logistic regression analyses were used to develop a model consisting of significant predictors for normalization related to regional compensation. RESULTS: In total, 156 patients met the inclusion criteria (mean ± SD age 64.6 ± 9.1 years, BMI 27.9 ± 5.6 kg/m2, Charlson Comorbidity Index 1.9 ± 1.6). Patients with normalized PT were more likely to have overcorrected pelvic incidence minus lumbar lordosis and sagittal vertical axis at 6 weeks (p < 0.05). GAP score at 6 weeks was greater for patients with nonnormalized PT (0.6 vs 1.3, p = 0.08). At baseline, 58.5% of patients had compensation in the thoracic and cervical regions. Postoperatively, compensation was maintained by 42% with no change after matching in age-adjusted or GAP score. The patients with nonnormalized PT had increased rates of thoracic and cervical compensation (p < 0.05). Compensation in thoracic kyphosis differed between patients with normalized PT at 6 weeks and those with normalized PT at 1 year (69% vs 35%, p < 0.05). Those who compensated had increased rates of implant complications by 1 year (OR [95% CI] 2.08 [1.32-6.56], p < 0.05). Cervical compensation was maintained at 6 weeks and 1 year (56% vs 43%, p = 0.12), with no difference in implant complications (OR 1.31 [95% CI -2.34 to 1.03], p = 0.09). For the lower extremities at baseline, 61% were compensating. Matching age-adjusted alignment did not eliminate compensation at any joint (all p > 0.05). Patients with nonnormalized PT had higher rates of LE compensation across joints (all p < 0.01). Overall, patients with normalized PT at 1 year had the greatest odds of resolving LE compensation (OR 9.6, p < 0.001). Patients with normalized PT at 1 year had lower rates of implant failure (8.9% vs 19.5%, p < 0.05), rod breakage (1.3% vs 13.8%, p < 0.05), and pseudarthrosis (0% vs 4.6%, p < 0.05) compared with patients with nonnormalized PT. The complication rate was significantly lower for patients with normalized PT at 1 year (56.7% vs 66.1%, p = 0.02), despite comparable health-related quality of life scores. CONCLUSIONS: Patients with PT normalization had greater rates of resolution in thoracic and LE compensation, leading to lower rates of complications by 1 year. Thus, consideration of both the lower extremities and thoracic regions in surgical planning is vital to preventing adverse outcomes and maintaining pelvic alignment.

Cost Benefit of Implementation of Risk Stratification Models for Adult Spinal Deformity Surgery.

STUDY DESIGN/SETTING: Retrospective cohort study. OBJECTIVE: Assess the extent to which defined risk factors of adverse events are drivers of cost-utility in spinal deformity (ASD) surgery. METHODS: ASD patients with 2-year (2Y) data were included. Tertiles were used to define high degrees of frailty, sagittal deformity, blood loss, and surgical time. Cost was calculated using the Pearl Diver registry and cost-utility at 2Y was compared between cohorts based on the number of risk factors present. Statistically significant differences in cost-utility by number of baseline risk factors were determined using ANOVA, followed by a generalized linear model, adjusting for clinical site and surgeon, to assess the effects of increasing risk score on overall cost-utility. RESULTS: By 2 years, 31% experienced a major complication and 23% underwent reoperation. Patients with ≤2 risk factors had significantly less major complications. Patients with 2 risk factors improved the most from baseline to 2Y in ODI. Average cost increased by $8234 per risk factor (R2 = .981). Cost-per-QALY at 2Y increased by $122,650 per risk factor (R2 = .794). Adjusted generalized linear model demonstrated a significant trend between increasing risk score and increasing cost-utility (r2 = .408, P < .001). CONCLUSIONS: The number of defined patient-specific and surgical risk factors, especially those with greater than two, were associated with increased index surgical costs and diminished cost-utility. Efforts to optimize patient physiology and minimize surgical risk would likely reduce healthcare expenditures and improve the overall cost-utility profile for ASD interventions.Level of evidence: III.

Clinical and Economic Impact of Proximal Junctional Kyphosis on Pediatric and Adult Spinal Deformity Patients.

The common goal of pediatric and adult spinal reconstructive procedures is to minimize long-term risk of disability, pain, and mortality. A common complication that has proved particularly problematic in the adult spinal deformity population and that has been an area of increased research and clinical focus is proximal junctional kyphosis (PJK). The incidence of PJK ranges from 10%-40% based on criteria used to define the condition. Clinically, PJK complication is associated with increased pain, decreased self-image and Scoliosis Research Society scores, and severe neurological injuries affecting the patient's quality of life. Economically, direct costs of PJK complication-associated revision surgery ranges from $20,000 to $120,000, which places an enormous burden on patients, providers, and payers. To mitigate the risk of PJK occurrence postoperatively, it is paramount to develop consistent guidelines in defining and classifying PJK in addition to extensive preoperative planning and risk stratification that is patient specific. This article will provide an overview on the clinical and economic impact of PJK in pediatric and adult spine deformity patients with an emphasis on the role of patient factors and predictive analytics, challenges in developing a consistent PJK classification, and current treatment and prevention strategies.

Are We Focused on the Wrong Early Postoperative Quality Metrics? Optimal Realignment Outweighs Perioperative Risk in Adult Spinal Deformity Surgery.

BACKGROUND: While reimbursement is centered on 90-day outcomes, many patients may still achieve optimal, long-term outcomes following adult spinal deformity (ASD) surgery despite transient short-term complications. OBJECTIVE: Compare long-term clinical success and cost-utility between patients achieving optimal realignment and suboptimally aligned peers. STUDY DESIGN/SETTING: Retrospective cohort study of a prospectively collected multicenter database. METHODS: ASD patients with two-year (2Y) data included. Groups were propensity score matched (PSM) for age, frailty, body mass index (BMI), Charlson Comorbidity Index (CCI), and baseline deformity. Optimal radiographic criteria are defined as meeting low deformity in all three (Scoliosis Research Society) SRS-Schwab parameters or being proportioned in Global Alignment and Proportionality (GAP). Cost-per-QALY was calculated for each time point. Multivariable logistic regression analysis and ANCOVA (analysis of covariance) adjusting for baseline disability and deformity (pelvic incidence (PI), pelvic incidence minus lumbar lordosis (PI-LL)) were used to determine the significance of surgical details, complications, clinical outcomes, and cost-utility. RESULTS: A total of 930 patients were considered. Following PSM, 253 "optimal" (O) and 253 "not optimal" (NO) patients were assessed. The O group underwent more invasive procedures and had more levels fused. Analysis of complications by two years showed that the O group suffered less overall major (38% vs. 52%, p = 0.021) and major mechanical complications (12% vs. 22%, p = 0.002), and less reoperations (23% vs. 33%, p = 0.008). Adjusted analysis revealed O patients more often met MCID (minimal clinically important difference) in SF-36 PCS, SRS-22 Pain, and Appearance. Cost-utility-adjusted analysis determined that the O group generated better cost-utility by one year and maintained lower overall cost and costs per QALY (both p < 0.001) at two years. CONCLUSIONS: Fewer late complications (mechanical and reoperations) are seen in optimally aligned patients, leading to better long-term cost-utility overall. Therefore, the current focus on avoiding short-term complications may be counterproductive, as achieving optimal surgical correction is critical for long-term success.

Improvements in Outcomes and Cost After Adult Spinal Deformity Corrective Surgery Between 2008 and 2019.

STUDY DESIGN: A retrospective cohort study. OBJECTIVE: To assess whether patient outcomes and cost-effectiveness of adult spinal deformity (ASD) surgery have improved over the past decade. BACKGROUND: Surgery for ASD is an effective intervention, but one that is also associated with large initial healthcare expenditures. Changes in the cost profile for ASD surgery over the last decade has not been evaluated previously. MATERIALS AND METHODS: ASD patients who received surgery between 2008 and 2019 were included. Analysis of covariance was used to establish estimated marginal means for outcome measures [complication rates, reoperations, health-related quality of life, total cost, utility gained, quality adjusted life years (QALYs), cost-efficiency (cost per QALY)] by year of initial surgery. Cost was calculated using the PearlDiver database and represented national averages of Medicare reimbursement for services within a 30-day window including length of stay and death differentiated by complication/comorbidity, revision, and surgical approach. Internal cost data was based on individual patient diagnosis-related group codes, limiting revisions to those within two years (2Y) of the initial surgery. Cost per QALY over the course of 2008-2019 were then calculated. RESULTS: There were 1236 patients included. There was an overall decrease in rates of any complication (0.78 vs . 0.61), any reoperation (0.25 vs . 0.10), and minor complication (0.54 vs . 0.37) between 2009 and 2018 (all P <0.05). National average 2Y cost decreased at an annual rate of $3194 ( R2 =0.6602), 2Y utility gained increased at an annual rate of 0.0041 ( R2 =0.57), 2Y QALYs gained increased annually by 0.008 ( R2 =0.57), and 2Y cost per QALY decreased per year by $39,953 ( R2 =0.6778). CONCLUSION: Between 2008 and 2019, rates of complications have decreased concurrently with improvements in patient reported outcomes, resulting in improved cost effectiveness according to national Medicare average and individual patient cost data. The value of ASD surgery has improved substantially over the course of the last decade.

Patient satisfaction after multiple revision surgeries for adult spinal deformity.

OBJECTIVE: Revision surgery is often necessary for adult spinal deformity (ASD) patients. Satisfaction with management is an important component of health-related quality of life. The authors hypothesized that patients who underwent multiple revision surgeries following ASD correction would exhibit lower self-reported satisfaction scores. METHODS: This was a retrospective cohort study of 668 patients who underwent ASD surgery and were eligible for a minimum 2-year follow-up. Visits were stratified by occurrence prior to the index surgery (period 0), after the index surgery only (period 1), after the first revision only (period 2), and after the second revision only (period 3). Patients were further stratified by prior spine surgery before their index surgery. Scoliosis Research Society-22 (SRS-22r) health-related quality-of-life satisfaction subscore and total satisfaction scores were evaluated at all periods using multiple linear regression and adjustment for age, sex, and Charlson Comorbidity Index. RESULTS: In total, 46.6% of the study patients had undergone prior spine surgery before their index surgery. The overall revision rate was 21.3%. Among patients with no spine surgery prior to the index surgery, SRS-22r satisfaction scores increased from period 0 to 1 (from 2.8 to 4.3, p < 0.0001), decreased after one revision from period 1 to 2 (4.3 to 3.9, p = 0.0004), and decreased further after a second revision from period 2 to 3 (3.9 to 3.3, p = 0.0437). Among patients with spine surgery prior to the index procedure, SRS-22r satisfaction increased from period 0 to 1 (2.8 to 4.2, p < 0.0001) and decreased from period 1 to 2 (4.2 to 3.8, p = 0.0011). No differences in follow-up time from last surgery were observed (all p > 0.3). Among patients with multiple revisions, 40% experienced rod fracture, 40% proximal junctional kyphosis, and 33% pseudarthrosis. CONCLUSIONS: Among patients undergoing ASD surgery, revision surgery is associated with decreased satisfaction, and multiple revisions are associated with additive detriment to satisfaction among patients initially undergoing primary surgery. These findings have direct implications for preoperative patient counseling and establishment of postoperative expectations.

Return to work after adult spinal deformity surgery.

PURPOSE: To determine the proportions of patients returning to work at various points after adult spinal deformity (ASD) surgery and the associations between surgical invasiveness and time to return to work. METHODS: Using a multicenter database of patients treated surgically for ASD from 2008 to 2015, we identified 188 patients (mean age 51 ± 15 years) who self-reported as employed preoperatively and had 2-year follow-up. Per the ASD-Surgical and Radiographical Invasiveness Index (ASD-SR), 118 patients (63%) underwent high-invasiveness (HI) surgery (ASD-SR ≥ 100) and 70 (37%) had low-invasiveness (LI) surgery (ASD-SR < 100). Patients who self-reported ≥ 75% normal level of work/school activity were considered to be working full time. Chi-squared and Fisher exact tests were used to compare categorical variables (α = .05). RESULTS: Preoperatively, 69% of employed patients worked full time. Postoperatively, 15% of employed patients were full time at 6 weeks, 70% at 6 months, 83% at 1 year, and 84% at 2 years. Percentage of employed patients working full time at 2 years was greater than preoperatively (p < .001); percentage of patients returning to full time at 6 weeks was lower in the HI (5%) than in the LI group (19%) (p = .03), a difference not significant at later points. CONCLUSIONS: Most adults returned to full-time work after ASD surgery. A smaller percentage of patients in the HI group than in the LI group returned to full-time work at 6 weeks. Patients employed full time preoperatively will likely return to full-time employment after ASD surgery. LEVEL OF EVIDENCE: III.

Low-Density Pedicle Screw Constructs Are Associated with Lower Incidence of Proximal Junctional Failure in Adult Spinal Deformity Surgery.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: Determine whether screws per level and rod material/diameter are associated with incidence of proximal junctional kyphosis (PJF). SUMMARY OF BACKGROUND DATA: PJF is a common and particularly adverse complication of adult spinal deformity (ASD) surgery. There is evidence that the rigidity of posterior spinal constructs may impact risk of PJF. METHODS: Patients with ASD and 2-year minimum follow-up were included. Only patients undergoing primary fusion of more than or equal to five levels with lower instrumented vertebrae (LIV) at the sacro-pelvis were included. Screws per level fused was analyzed with a cutoff of 1.8 (determined by receiver operating characteristic curve (ROC) analysis). Multivariable logistic regression was utilized, controlling for age, body mass index (BMI), 6-week postoperative change from baseline in lumbar lordosis, number of posterior levels fused, sex, Charlson comorbidity index, approach, osteotomy, upper instrumented vertebra (UIV), osteoporosis, preoperative TPA, and pedicle screw at the UIV (as opposed to hook, wire, etc.). RESULTS: In total, 504 patients were included. PJF occurred in 12.7%. The mean screws per level was 1.7, and 56.8% of patients had less than 1.8 screws per level. No differences were observed between low versus high screw density groups for T1-pelvic angle or magnitude of lordosis correction (both P > 0.15). PJF occurred in 17.0% versus 9.4% of patients with more than or equal to 1.8 versus less than 1.8 screws per level, respectively (P < 0.05). In multivariable analysis, patients with less than 1.8 screws per level exhibited lower odds of PJF (odds ratio (OR) 0.48, P < 0.05), and a continuous variable for screw density was significantly associated with PJF (OR 3.87 per 0.5 screws per level, P < 0.05). Rod material and diameter were not significantly associated with PJF (both P > 0.1). CONCLUSION: Among ASD patients undergoing long-segment primary fusion to the pelvis, the risk of PJF was lower among patients with less than 1.8 screws per level. This finding may be related to construct rigidity. Residual confounding by other patient and surgeon-specific characteristics may exist. Further biomechanical and clinical studies exploring this relationship are warranted.Level of Evidence: 3.

Reaching the medicare allowable threshold in adult spinal deformity surgery: multicenter cost analysis comparing actual direct hospital costs versus what the government will pay.

STUDY DESIGN: Retrospective multicenter cost analysis. OBJECTIVE: To (1) determine if index episode of care (iEOC) costs of Adult Spinal Deformity (ASD) surgeries are below the Medicare Allowable (MA) threshold, and (2) identify variables that can predict iEOC cases that are below MA. Previous studies have suggested that actual direct hospital cost of Adult Spinal Deformity (ASD) surgery is higher than Medicare Allowable (MA) rates, which has become the benchmark reimbursement target for hospital accounting systems. METHODS: From a prospective, multicenter ASD surgical database, patients undergoing long instrumented fusions (> 5 level) with cost data were identified. iEOC cost was calculated utilizing actual direct hospital cost. MA rates were calculated using hospital specific, year-appropriate CMS Inpatient Pricer Payment System. Recursive partitioning identified potentially modifiable variables that can predict iEOC cost < MA. RESULTS: Administrative direct cost data from 210 patients were obtained from 4 of 11 centers. Ninety-five (45%) patients had iEOC cost < MA. There was significant variation across the four centers in both iEOC cost ($56,788-$78,878, p < 0.0001) and reimbursement ($40,623-$91,351, p < 0.0001) across deformity-specific DRGs (453,454,456,457). Academic centers were more likely to have iEOC costs < MA (67.2% vs 8.9%, p < 0.0001). Recursive partitioning (r2 = 0.309) identified rhBMP-2 use of < 24 mg, sagittal plane deformity, a combined anterior/posterior approach, and an SF36-MCS < 39 as predictive for iEOC cost < MA. Performing an anterior/posterior approach reimburses between 14.7% and 121.1% more (2.2-fold) than posterior-only approach. This change in DRG allows iEOC cost to be more likely below the MA threshold. CONCLUSION: There is significant institutional (private vs academic) variation in ASD reimbursement. BMP use, deformity type, approach, and baseline mental health impact ASD surgery cost being below Medicare reimbursement. ASD surgeries with anterior/posterior approaches are in DRGs that can potentially reimburse 2.2-fold the posterior-only surgery, making it more likely to fall below the MA threshold. LEVEL OF EVIDENCE: III.

Examination of Adult Spinal Deformity Patients Undergoing Surgery with Implanted Spinal Cord Stimulators and Intrathecal Pumps.

STUDY DESIGN: Retrospective cohort study of a prospectively collected multi-center database of adult spinal deformity (ASD) patients. OBJECTIVE: We hypothesized that patients undergoing ASD surgery with and without previous spinal cord stimulators (SCS)/ intrathecal medication pumps (ITP) would exhibit increased complication rates but comparable improvement in health-related quality of life. SUMMARY OF BACKGROUND DATA: ASD patients sometimes seek pain management with SCS or ITP before spinal deformity correction. Few studies have examined outcomes in this patient population. METHODS: Patients undergoing ASD surgery and eligible for 2-year follow-up were included. Preoperative radiographs were reviewed for the presence of SCS/ITP. Outcomes included complications, Oswestry Disability Index (ODI), Short Form-36 Mental Component Score, and SRS-22r. Propensity score matching was utilized. RESULTS: In total, of 1034 eligible ASD patients, a propensity score-matched cohort of 60 patients (30 with SCS/ITP, 30 controls) was developed. SCS/ITP were removed intraoperatively in most patients (56.7%, n = 17). The overall complication rate was 80.0% versus 76.7% for SCS/ITP versus control (P > 0.2), with similarly nonsignificant differences for intraoperative and infection complications (all P > 0.2). ODI was significantly higher among patients with SCS/ITP at baseline (59.2 vs. 47.6, P = 0.0057) and at 2-year follow-up (44.4 vs. 27.7, P = 0.0295). The magnitude of improvement, however, did not significantly differ (P = 0.45). Similar results were observed for SRS-22r pain domain. Satisfaction did not differ between groups at either baseline or follow-up (P > 0.2). No significant difference was observed in the proportion of patients with SCS/ITP versus control reaching minimal clinically important difference in ODI (47.6% vs. 60.9%, P = 0.38). Narcotic usage was more common among patients with SCS/ITP at both baseline and follow-up (P < 0.05). CONCLUSION: ASD patients undergoing surgery with SCS/ITP exhibited worse preoperative and postoperative ODI and SRS-22r pain domain; however, the mean improvement in outcome scores was not significantly different from patients without stimulators or pumps. No significant differences in complications were observed between patients with versus without SCS/ITP.Level of Evidence: 3.

Adult Spinal Deformity Surgery Is Associated with Increased Productivity and Decreased Absenteeism From Work and School.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: We hypothesized that adult spinal deformity (ASD) surgery would be associated with improved work- and school-related productivity, as well as decreased rates of absenteeism. SUMMARY OF BACKGROUND DATA: ASD patients experience markedly decreased health-related quality of life along many dimensions. METHODS: Only patients eligible for 2-year follow-up were included, and those with a history of previous spinal fusion were excluded. The primary outcome measures in this study were Scoliosis Research Society-22r score (SRS-22r) questions 9 and 17. A repeated measures mixed linear regression was used to analyze responses over time among patients managed operatively (OP) versus nonoperatively (NON-OP). RESULTS: In total, 1188 patients were analyzed. 66.6% were managed operatively. At baseline, the mean percentage of activity at work/school was 56.4% (standard deviation [SD] 35.4%), and the mean days off from work/school over the past 90 days was 1.6 (SD 1.8). Patients undergoing ASD surgery exhibited an 18.1% absolute increase in work/school productivity at 2-year follow-up versus baseline (P < 0.0001), while no significant change was observed for the nonoperative cohort (P > 0.5). Similarly, the OP cohort experienced 1.1 fewer absent days over the past 90 days at 2 years versus baseline (P < 0.0001), while the NON-OP cohort showed no such difference (P > 0.3). These differences were largely preserved after stratifying by baseline employment status, age group, sagittal vertical axis (SVA), pelvic incidence minus lumbar lordosis (PI-LL), and deformity curve type. CONCLUSION: ASD patients managed operatively exhibited an average increase in work/school productivity of 18.1% and decreased absenteeism of 1.1 per 90 days at 2-year follow-up, while patients managed nonoperatively did not exhibit change from baseline. Given the age distribution of patients in this study, these findings should be interpreted as pertaining primarily to obligations at work or within the home. Further study of the direct and indirect economic benefits of ASD surgery to patients is warranted.Level of Evidence: 3.

Operative Treatment of Severe Scoliosis in Symptomatic Adults: Multicenter Assessment of Outcomes and Complications With Minimum 2-Year Follow-up.

BACKGROUND: Few reports focus on adults with severe scoliosis. OBJECTIVE: To report surgical outcomes and complications for adults with severe scoliosis. METHODS: A multicenter, retrospective review was performed on operatively treated adults with severe scoliosis (minimum coronal Cobb: thoracic [TH] ≥ 75°, thoracolumbar [TL] ≥ 50°, lumbar [L] ≥ 50°). RESULTS: Of 178 consecutive patients, 146 (82%; TH = 8, TL = 88, L = 50) achieved minimum 2-yr follow-up (mean age = 53.9 ± 13.2 yr, 92% women). Operative details included posterior-only (58%), 3-column osteotomy (14%), iliac fixation (72%), and mean posterior fusion = 13.2 ± 3.7 levels. Global coronal alignment (3.8 to 2.8 cm, P = .001) and maximum coronal Cobb improved significantly (P ≤.020): TH (84º to 57º; correction = 32%), TL (67º to 35º; correction = 48%), L (61º to 29º; correction = 53%). Sagittal alignment improved significantly (P < .001), most notably for L: C7-sagittal vertical axis 6.7 to 2.5 cm, pelvic incidence-lumbar lordosis mismatch 18º to 3º. Health-related quality-of-life (HRQL) improved significantly (P < .001), most notably for L: Oswestry Disability Index (44.4 ± 20.5 to 26.1 ± 18.3), Short Form-36 Physical Component Summary (30.2 ± 10.8 to 39.9 ± 9.8), and Scoliosis Research Society-22r Total (2.9 ± 0.7 to 3.8 ± 0.7). Minimal clinically important difference and substantial clinical benefit thresholds were achieved in 36% to 75% and 29% to 51%, respectively. Ninety-four (64%) patients had ≥1 complication (total = 191, 92 minor/99 major, most common = rod fracture [13.0%]). Fifty-seven reoperations were performed in 37 (25.3%) patients, with most common indications deep wound infection (11) and rod fracture (10). CONCLUSION: Although results demonstrated high rates of complications, operative treatment of adults with severe scoliosis was associated with significant improvements in mean HRQL outcome measures for the study cohort at minimum 2-yr follow-up.

Multicenter assessment of outcomes and complications associated with transforaminal versus anterior lumbar interbody fusion for fractional curve correction.

OBJECTIVE: Few studies have compared fractional curve correction after long fusion between transforaminal lumbar interbody fusion (TLIF) and anterior lumbar interbody fusion (ALIF) for adult symptomatic thoracolumbar/lumbar scoliosis (ASLS). The objective of this study was to compare fractional correction, health-related quality of life (HRQL), and complications associated with L4-S1 TLIF versus those of ALIF as an operative treatment of ASLS. METHODS: The authors retrospectively analyzed a prospective multicenter adult spinal deformity database. Inclusion required a fractional curve ≥ 10°, a thoracolumbar/lumbar curve ≥ 30°, index TLIF or ALIF performed at L4-5 and/or L5-S1, and a minimum 2-year follow-up. TLIF and ALIF patients were propensity matched according to the number and type of interbody fusion at L4-S1. RESULTS: Of 135 potentially eligible consecutive patients, 106 (78.5%) achieved the minimum 2-year follow-up (mean ± SD age 60.6 ± 9.3 years, 85% women, 44.3% underwent TLIF, and 55.7% underwent ALIF). Index operations had mean ± SD 12.2 ± 3.6 posterior levels, 86.6% of patients underwent iliac fixation, 67.0% underwent TLIF/ALIF at L4-5, and 84.0% underwent TLIF/ALIF at L5-S1. Compared with TLIF patients, ALIF patients had greater cage height (10.9 ± 2.1 mm for TLIF patients vs 14.5 ± 3.0 mm for ALIF patients, p = 0.001) and lordosis (6.3° ± 1.6° for TLIF patients vs 17.0° ± 9.9° for ALIF patients, p = 0.001) and longer operative duration (6.7 ± 1.5 hours for TLIF patients vs 8.9 ± 2.5 hours for ALIF patients, p < 0.001). In all patients, final alignment improved significantly in terms of the fractional curve (20.2° ± 7.0° to 6.9° ± 5.2°), maximum coronal Cobb angle (55.0° ± 14.8° to 23.9° ± 14.3°), C7 sagittal vertical axis (5.1 ± 6.2 cm to 2.3 ± 5.4 cm), pelvic tilt (24.6° ± 8.1° to 22.7° ± 9.5°), and lumbar lordosis (32.3° ± 18.8° to 51.4° ± 14.1°) (all p < 0.05). Matched analysis demonstrated comparable fractional correction (-13.6° ± 6.7° for TLIF patients vs -13.6° ± 8.1° for ALIF patients, p = 0.982). In all patients, final HRQL improved significantly in terms of Oswestry Disability Index (ODI) score (42.4 ± 16.3 to 24.2 ± 19.9), physical component summary (PCS) score of the 36-item Short-Form Health Survey (32.6 ± 9.3 to 41.3 ± 11.7), and Scoliosis Research Society-22r score (2.9 ± 0.6 to 3.7 ± 0.7) (all p < 0.05). Matched analysis demonstrated worse ODI (30.9 ± 21.1 for TLIF patients vs 17.9 ± 17.1 for ALIF patients, p = 0.017) and PCS (38.3 ± 12.0 for TLIF patients vs 45.3 ± 10.1 for ALIF patients, p = 0.020) scores for TLIF patients at the last follow-up (despite no differences in these parameters at baseline). The rates of total complications were similar (76.6% for TLIF patients vs 71.2% for ALIF patients, p = 0.530), but significantly more TLIF patients had rod fracture (28.6% of TLIF patients vs 7.1% of ALIF patients, p = 0.036). Multiple regression analysis demonstrated that a 1-mm increase in L4-5 TLIF cage height led to a 2.2° reduction in L4 coronal tilt (p = 0.011), and a 1° increase in L5-S1 ALIF cage lordosis led to a 0.4° increase in L5-S1 segmental lordosis (p = 0.045). CONCLUSIONS: Operative treatment of ASLS with L4-S1 TLIF versus ALIF demonstrated comparable mean fractional curve correction (66.7% vs 64.8%), despite use of significantly larger, more lordotic ALIF cages. TLIF cage height had a significant impact on leveling L4 coronal tilt, whereas ALIF cage lordosis had a significant impact on restoration of lumbosacral lordosis. The advantages of TLIF may include reduced operative duration and hospitalization; however, associated HRQL was inferior and more rod fractures were detected in the TLIF patients included in this study.

Global coronal decompensation and adult spinal deformity surgery: comparison of upper-thoracic versus lower-thoracic proximal fixation for long fusions.

OBJECTIVE: Deterioration of global coronal alignment (GCA) may be associated with worse outcomes after adult spinal deformity (ASD) surgery. The impact of fusion length and upper instrumented vertebra (UIV) selection on patients with this complication is unclear. The authors' objective was to compare outcomes between long sacropelvic fusion with upper-thoracic (UT) UIV and those with lower-thoracic (LT) UIV in patients with worsening GCA ≥ 1 cm. METHODS: This was a retrospective analysis of a prospective multicenter database of consecutive ASD patients. Index operations involved instrumented fusion from sacropelvis to thoracic spine. Global coronal deterioration was defined as worsening GCA ≥ 1 cm from preoperation to 2-year follow-up. RESULTS: Of 875 potentially eligible patients, 560 (64%) had complete 2-year follow-up data, of which 144 (25.7%) demonstrated worse GCA at 2-year postoperative follow-up (35.4% of UT patients vs 64.6% of LT patients). At baseline, UT patients were younger (61.6 ± 9.9 vs 64.5 ± 8.6 years, p = 0.008), a greater percentage of UT patients had osteoporosis (35.3% vs 16.1%, p = 0.009), and UT patients had worse scoliosis (51.9° ± 22.5° vs 32.5° ± 16.3°, p < 0.001). Index operations were comparable, except UT patients had longer fusions (16.4 ± 0.9 vs 9.7 ± 1.2 levels, p < 0.001) and operative duration (8.6 ± 3.2 vs 7.6 ± 3.0 hours, p = 0.023). At 2-year follow-up, global coronal deterioration averaged 2.7 ± 1.4 cm (1.9 to 4.6 cm, p < 0.001), scoliosis improved (39.3° ± 20.8° to 18.0° ± 14.8°, p < 0.001), and sagittal spinopelvic alignment improved significantly in all patients. UT patients maintained smaller positive C7 sagittal vertical axis (2.7 ± 5.7 vs 4.7 ± 5.7 cm, p = 0.014). Postoperative 2-year health-related quality of life (HRQL) significantly improved from baseline for all patients. HRQL comparisons demonstrated that UT patients had worse Scoliosis Research Society-22r (SRS-22r) Activity (3.2 ± 1.0 vs 3.6 ± 0.8, p = 0.040) and SRS-22r Satisfaction (3.9 ± 1.1 vs 4.3 ± 0.8, p = 0.021) scores. Also, fewer UT patients improved by ≥ 1 minimal clinically important difference in numerical rating scale scores for leg pain (41.3% vs 62.7%, p = 0.020). Comparable percentages of UT and LT patients had complications (208 total, including 53 reoperations, 77 major complications, and 78 minor complications), but the percentage of reoperated patients was higher among UT patients (35.3% vs 18.3%, p = 0.023). UT patients had higher reoperation rates of rod fracture (13.7% vs 2.2%, p = 0.006) and pseudarthrosis (7.8% vs 1.1%, p = 0.006) but not proximal junctional kyphosis (9.8% vs 8.6%, p = 0.810). CONCLUSIONS: In ASD patients with worse 2-year GCA after long sacropelvic fusion, UT UIV was associated with worse 2-year HRQL compared with LT UIV. This may suggest that residual global coronal malalignment is clinically less tolerated in ASD patients with longer fusion to the proximal thoracic spine. These results may inform operative planning and improve patient counseling.

Defining a Surgical Invasiveness Threshold for Increased Risk of a Major Complication Following Adult Spinal Deformity Surgery.

STUDY DESIGN: Retrospective review. OBJECTIVES: The aim of this study was to define a surgical invasiveness threshold that predicts major complications after adult spinal deformity (ASD) surgery; use this threshold to categorize patients into quartiles by invasiveness; and determine the odds of major complications by quartile. SUMMARY OF BACKGROUND DATA: Understanding the relationship between surgical invasiveness and major complications is important for estimating the likelihood of major complications after ASD surgery. METHODS: Using a multicenter database, we identified 574 ASD patients (more than 5 levels fused; mean age, 60 ±â€Š15 years) with minimum 2-year follow-up. Invasiveness was calculated as the ASD Surgical and Radiographic (ASD-SR) score. Youden index was used to identify the invasiveness score cut-off associated with optimal sensitivity and specificity for predicting major complications. Resulting high- and low-invasiveness groups were divided in half to create quartiles. Odds of developing a major complication were analyzed for each quartile using logistic regression (alpha = 0.05). RESULTS: The ASD-SR cutoff score that maximally predicted major complications was 90 points. ASD-SR quartiles were 0 to 65 (Q1), 66 to 89 (Q2), 90 to 119 (Q3), and ≥120 (Q4). Risk of a major complication was 17% in Q1, 21% in Q2, 35% in Q3, and 33% in Q4 (P < 0.001). Comparisons of adjacent quartiles showed an increase in the odds of a major complication from Q2 to Q3 (odds ratio [OR] 1.8; 95% confidence interval [CI]: 1.0-3.0), but not from Q1 to Q2 or from Q3 to Q4. Patients with ASD-SR scores ≥90 were 1.9 times as likely to have a major complication than patients with scores <90 (OR 1.9, 95% CI 1.3-2.9). Mean ASD-SR scores above and below 90 points were 121 ±â€Š25 and 63 ±â€Š17, respectively. CONCLUSION: The odds of major complications after ASD surgery are significantly greater when the procedure has an ASD-SR score ≥90. ASD-SR score can be used to counsel patients regarding these increased odds.Level of Evidence: 3.

Artificial intelligence clustering of adult spinal deformity sagittal plane morphology predicts surgical characteristics, alignment, and outcomes.

PURPOSE: 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: Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

Scoliosis Research Society survey: brace management in adolescent idiopathic scoliosis.

PURPOSE: While the Scoliosis Research Society (SRS) has established criteria for brace initiation in adolescent idiopathic scoliosis (AIS), there are no recommendations concerning other management issues. As the BrAIST study reinforced the utility of bracing, the SRS Non-Operative Management Committee decided to evaluate the consensus or discord in AIS brace management. METHODS: 1200 SRS members were sent an online survey in 2017, which included 21 items concerning demographics, bracing indications, management, and monitoring. Free-text responses were analyzed and collated into common themes. Data were analyzed using Microsoft Excel 2013. RESULTS: Of 218 respondents; 207 regularly evaluate and manage patients with AIS, and 205 currently prescribe bracing. 99% of respondents use bracing for AIS and the majority (89%) use the published SRS criteria, or a modified version, to initiate bracing. 85% do not use brace monitoring and 66% use both %-Cobb correction and fit criteria to evaluate brace adequacy. In contrast, other aspects of brace management demonstrated a high degree of practice variability. This was seen with a radiographic assessment of maturity level, hours prescribed, timing and frequency of radiographic evaluation, the use of nighttime bracing only, and the method and timing of brace discontinuation. CONCLUSION: Although there is consensus in brace management amongst SRS members with respect to brace initiation and evaluation of adequacy, there is striking variability in how bracing for AIS is used. This variability may impact the overall efficacy of brace treatment and may be decreased with more robust guidelines from the SRS. LEVEL OF EVIDENCE: III.

Improvement in SRS-22R Self-Image Correlate Most with Patient Satisfaction after 3-Column Osteotomy.

STUDY DESIGN: Longitudinal cohort. OBJECTIVES: The aim of this study was to examine the relationship between patient satisfaction, patient-reported outcome measures (PROMs) and radiographic parameters in adult spine deformity (ASD) patients undergoing three-column osteotomies (3CO). SUMMARY OF BACKGROUND DATA: Identifying factors that influence patient satisfaction in ASD is important. Evidence suggests Scoliosis Research Society-22R (SRS-22R) Self-Image domain correlates with patient satisfaction in patients with ASD. METHODS: This is a retrospective review of ASD patients enrolled in a prospective, multicenter database undergoing a 3CO with complete SRS-22R pre-op and minimum 2-years postop. Spearman correlations were used to evaluate associations between the 2-year SRS Satisfaction score and changes in SRS-22R domain scores, Oswestry Disability Index (ODI), and radiographic parameters. RESULTS: Of 135 patients eligible for 2-year follow-up, 98 patients (73%) had complete pre- and 2-year postop data. The cohort was mostly female (69%) with mean BMI of 29.7 kg/m2 and age of 61.0 years. Mean levels fused was 12.9 with estimated blood loss of 2695 cc and OR time of 407 minutes; 27% were revision surgeries. There was a statistically significant improvement between pre- and 2-year post-op PROMs and all radiographic parameters except Coronal Vertical Axis. The majority of patients had an SRS Satisfaction score of ≥3.0 (90%) or ≥4.0 (68%), consistent with a moderate ceiling effect. Correlations of patient satisfaction was significant for Pain (0.43, P < 0.001), Activity (0.39, P < 0.001), Mental (0.38, P = 0.001) Self-Image (0.52, P < 0.001). ODI and Short-Form-36 Physical component summary had a moderate correlation as well, with mental component summary being weak. There was no statistically significant correlation between any radiographic or operative parameters and patient satisfaction. CONCLUSION: There was statistically significant improvement in all PROMs and radiographic parameters, except coronal vertical axis at 2 years in ASD patients undergoing 3CO. Improvement in SRS Self-Image domain has the strongest correlation with patient satisfaction.Level of Evidence: 3.