Adult Symptomatic Lumbar Scoliosis Research Articles

Cost-effectiveness Improves for Operative vs Nonoperative Treatment of Adult Symptomatic Lumbar Scoliosis at Eight-Year Follow-up.

Secondary data analysis of the NIH sponsored study on Adult Symptomatic Lumbar Scoliosis (ASLS). The purpose of this study is to perform a cost-effectiveness analysis comparing operative versus non-operative care for ASLS eight years after enrollment. A prior cost-effectiveness analysis of the current cohort comparing operative to non-operative care at five years after enrollment showed and ICER of $44,033 in the As-Treated analysis and a ICER of $27,480 in the Intent-to-treat analysis. Data was collected every three months for the first two years, then every six months for the remainder of the study. Data included use of non-operative modalities, medications and employment status. Costs for index and revision surgeries and non-operative modalities were determined using Medicare Allowable rates. Medication costs were determined using the RedBook and indirect costs were calculated based on reported employment status and income. Quality Adjusted Life Years (QALY) was determined using the SF6D. There were 101 cases in the Operative (Op) and 103 in the Non-operative (Non-Op) group with complete eight year data. Thirty-eight patients (37%) in the Non-Op group had surgery from 3 to 72 months after enrollment. An As-Treated analysis including only cases who never had surgery (N=65) or cases with complete eight-year post-operative data (N=101) showed that operative treatment was favored with an ICER of $20,569 per QALY gained which is within Willingness-to-Pay (WTP) thresholds. An Intent-to-Treat analysis demonstrated greater QALY gains and lower cost in the Op group (ICER = $-13,911). However, Intent-to-Treat analysis is influenced by Non-Op patients who crossed over to operative treatment at variable times during follow-up. Operative treatment was more cost-effective than non-operative treatment for ASLS at eight-year follow-up. The ICER continued to improve as compared to the five-year values ($20,569 vs. $44,033).

Individual differences in postoperative recovery trajectories for adult symptomatic lumbar scoliosis.

The Adult Symptomatic Lumbar Scoliosis-1 (ASLS-1) trial demonstrated the benefit of adult symptomatic lumbar scoliosis (ASLS) surgery. However, the extent to which individuals differ in their postoperative recovery trajectories is unknown. This study's objective was to evaluate variability in and factors moderating recovery trajectories after ASLS surgery. The authors used longitudinal, multilevel models to analyze postoperative recovery trajectories following ASLS surgery. Study outcomes included the Oswestry Disability Index (ODI) score and Scoliosis Research Society-22 (SRS-22) subscore, which were measured every 3 months until 2 years postoperatively. The authors evaluated the influence of preoperative disability level, along with other potential trajectory moderators, including radiographic, comorbidity, pain/function, demographic, and surgical factors. The impact of different parameters was measured using the R2, which represented the amount of variability in ODI/SRS-22 explained by each model. The R2 ranged from 0 (no variability explained) to 1 (100% of variability explained). Among 178 patients, there was substantial variability in recovery trajectories. Applying the average trajectory to each patient explained only 15% of the variability in ODI and 21% of the variability in SRS-22 subscore. Differences in preoperative disability (ODI/SRS-22) had the strongest influence on recovery trajectories, with patients having moderate disability experiencing the greatest and most rapid improvement after surgery. Reflecting this impact, accounting for the preoperative ODI/SRS-22 level explained an additional 56%-57% of variability in recovery trajectory, while differences in the rate of postoperative change explained another 7%-9%. Among the effect moderators tested, pain/function variables-such as visual analog scale back pain score-had the biggest impact, explaining 21%-25% of variability in trajectories. Radiographic parameters were the least influential, explaining only 3%-6% more variance than models with time alone. The authors identified several significant trajectory moderators in the final model, such as significant adverse events and the number of levels fused. ASLS patients have highly variable postoperative recovery trajectories, although most reach steady state at 12 months. Preoperative disability was the most important influence, although other factors, such as number of levels fused, also impacted recovery.

147. Proximal junctional failure in primary thoracolumbar fusion/fixation to the sacrum/pelvis for adult symptomatic lumbar scoliosis: long-term follow-up of a prospective multicenter cohort of 160 patients

<h3>BACKGROUND CONTEXT</h3> Proximal junctional kyphosis (PJK) is a common adverse event in adult spinal deformity (ASD) surgery. Proximal junctional failure (PJF) is a severe form of PJK that often warrants revision surgery. Previous reports on PJK/PJF have been limited by heterogeneous patient populations and relatively short follow-up. <h3>PURPOSE</h3> The objectives of this study were to better understand risk factors for PJF and assess its long-term incidence and revision rates in a prospectively-collected, homogenous patient population (primary adult symptomatic lumbar scoliosis [ASLS]) with long-term follow-up. <h3>STUDY DESIGN/SETTING</h3> Retrospective review of prospectively-collected multicenter patient cohort. <h3>PATIENT SAMPLE</h3> This study included 160 ASLS patients. <h3>OUTCOME MEASURES</h3> Occurrence of PJF; Patient-reported outcome measures (ODI, SRS-22r, SF-36). <h3>METHODS</h3> We reviewed data from ASLS-1, an NIH-sponsored multicenter prospective study. Inclusion criteria were: age=40 years with ASLS (Cobb >30° and ODI >20 or SRS-22 7 levels. PJF was defined as postop proximal junctional angle (PJA) change=20°, fracture of the upper-most instrumented vertebra (UIV) or UIV+1 with 20% vertebral body height loss, anterolisthesis of UIV/UIV +1 =3 mm, and/or UIV screw dislodgment. Demographic, clinical, radiographic and surgical data were collected. Comparative and multivariate analysis were performed comparing patients with and without PJF. <h3>RESULTS</h3> A total of 160 patients were included (mean age 61 yrs; 141 women) with mean follow-up of 4.3 yrs (range: 0.1-6.1 yrs). Forty-six patients (28.7%) developed PJF at a median of 0.92 yrs (interquartile range: 0.14-1.23 yrs) postop. PJF incidences at 1, 2, 3, and 4 yrs were 14.4%, 21.9%, 25.9%, and 27.4%, respectively. On univariate analysis, factors associated with PJF included greater age (p=0.03), greater body mass index (BMI; p=0.03), worse baseline PROMs (ODI; SRS-22r: subscore, pain, function, mental health; SF-36 PCS; all p <0.04), greater use of posterior column osteotomies (p=0.004), and worse TK (p=0.0031) and PJA (P <0.001 on first postop standing imaging. Use of hooks at the UIV was protective against PJF (p=0.03). On regression analysis (excluding postop imaging measures), factors associated with PJF were greater BMI (OR=1.077, 95%CI=1.007-1.153, p=0.03), lower preop PJA (OR=0.607, 95%CI=0.407-0.906, p=0.01), and greater preop TK (OR=1.362, 95%CI=1.082-1.715, p=0.009). Patients with PJF had significantly worse PROMs at last follow-up (ODI; SRS-22r subscore and self-image; SF-36 PCS; all p <0.04). Sixteen (34.8%) of the patients with PJF underwent revision surgery; recurrent PJF occurred in 3 of the 16. <h3>CONCLUSIONS</h3> In this homogenous population of primary ASLS patients, the PJF rate was 28.7% at mean 4.3-yr follow-up with a revision rate of 34.8%. Higher risk of PJF was associated with greater age and BMI, use of posterior column osteotomies, lower preop PJA, and greater preop TK. Use of UIV hooks was protective against PJF. These findings demonstrate that PJF remains a challenge and that new strategies to mitigate its occurrence are needed. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Patient-reported outcome measure clustering after surgery for adult symptomatic lumbar scoliosis.

Adult symptomatic lumbar scoliosis (ASLS) is a widespread and debilitating subset of adult spinal deformity. Although many patients benefit from operative treatment, surgery entails substantial cost and risk for adverse events. Patient-reported outcome measures (PROMs) are patient-centered tools used to evaluate the appropriateness of surgery and to assist in the shared decision-making process. Framing realistic patient expectations should include the possible functional limitation to improvement inherent in surgical intervention, such as multilevel fusion to the sacrum. The authors' objective was to predict postoperative ASLS PROMs by using clustering analysis, generalized longitudinal regression models, percentile analysis, and clinical improvement analysis of preoperative health-related quality-of-life scores for use in surgical counseling. Operative results from the combined ASLS cohorts were examined. PROM score clustering after surgery investigated limits of surgical improvement. Patients were categorized by baseline disability (mild, moderate, moderate to severe, or severe) according to preoperative Scoliosis Research Society (SRS)-22 and Oswestry Disability Index (ODI) scores. Responder analysis for patients achieving improvement meeting the minimum clinically important difference (MCID) and substantial clinical benefit (SCB) standards was performed using both fixed-threshold and patient-specific values (MCID = 30% of remaining scale, SCB = 50%). Best (top 5%), worst (bottom 5%), and median scores were calculated across disability categories. A total of 171/187 (91%) of patients with ASLS achieved 2-year follow-up. Patients rarely achieved a PROM ceiling for any measure, with 33%-43% of individuals clustering near 4.0 for SRS domains. Patients with severe baseline disability (< 2.0) SRS-pain and SRS-function scores were often left with moderate to severe disability (2.0-2.9), unlike patients with higher (≥ 3.0) initial PROM values. Patients with mild disability according to baseline SRS-function score were unlikely to improve. Crippling baseline ODI disability (> 60) commonly left patients with moderate disability (median ODI = 32). As baseline ODI disability increased, patients were more likely to achieve MCID and SCB (p < 0.001). Compared to fixed threshold values for MCID and SCB, patient-specific values were more sensitive to change for patients with minimal ODI baseline disability (p = 0.008) and less sensitive to change for patients with moderate to severe SRS subscore disability (p = 0.01). These findings suggest that ASLS surgeries have a limit to possible improvement, probably due to both baseline disability and the effects of surgery. The most disabled patients often had moderate to severe disability (SRS < 3, ODI > 30) at 2 years, emphasizing the importance of patient counseling and expectation management.

Validation of Adult Spinal Deformity Surgical Outcome Prediction Tools in Adult Symptomatic Lumbar Scoliosis.

A post hoc analysis. Advances in machine learning (ML) have led to tools offering individualized outcome predictions for adult spinal deformity (ASD). Our objective is to examine the properties of these ASD models in a cohort of adult symptomatic lumbar scoliosis (ASLS) patients. ML algorithms produce patient-specific probabilities of outcomes, including major complication (MC), reoperation (RO), and readmission (RA) in ASD. External validation of these models is needed. Thirty-nine predictive factors (12 demographic, 9 radiographic, 4 health-related quality of life, 14 surgical) were retrieved and entered into web-based prediction models for MC, unplanned RO, and hospital RA. Calculated probabilities were compared with actual event rates. Discrimination and calibration were analyzed using receiver operative characteristic area under the curve (where 0.5=chance, 1=perfect) and calibration curves (Brier scores, where 0.25=chance, 0=perfect). Ninety-five percent confidence intervals are reported. A total of 169 of 187 (90%) surgical patients completed 2-year follow up. The observed rate of MCs was 41.4% with model predictions ranging from 13% to 68% (mean: 38.7%). RO was 20.7% with model predictions ranging from 9% to 54% (mean: 30.1%). Hospital RA was 17.2% with model predictions ranging from 13% to 50% (mean: 28.5%). Model classification for all three outcome measures was better than chance for all [area under the curve=MC 0.6 (0.5-0.7), RA 0.6 (0.5-0.7), RO 0.6 (0.5-0.7)]. Calibration was better than chance for all, though best for RA and RO (Brier Score=MC 0.22, RA 0.16, RO 0.17). ASD prediction models for MC, RA, and RO performed better than chance in a cohort of adult lumbar scoliosis patients, though the homogeneity of ASLS affected calibration and accuracy. Optimization of models require samples with the breadth of outcomes (0%-100%), supporting the need for continued data collection as personalized prediction models may improve decision-making for the patient and surgeon alike.

169 Individual Differences in Postoperative Recovery Trajectories for Adult Symptomatic Lumbar Scoliosis

INTRODUCTION: The Adult Symptomatic Lumbar Scoliosis-1 (ASLS-1) trial demonstrated the overall benefit of ASLS surgery. However, the extent to which individuals differ in their postoperative recovery trajectories is unknown. METHODS: We included adult patients that underwent surgical treatment as part of the ASLS-1 study. We used multilevel models to analyze postoperative recovery trajectories in Oswestry Disability Index (ODI) and Scoliosis Research Society-22 (SRS-22) sub-scores, which were measured every three months until two years after surgery. The impact of baseline disability was measured using the conditional R2, which measured the variance explained by allowing each patient to have their own intercept (i.e., baseline disability). In addition, we created multilevel, multivariable models that identified the most influential trajectory moderators, including radiographic, comorbidity, pain/function, demographic, and surgical factors. The performance of these models was quantified using the marginal R2, which represented the amount of variability in ODI/SRS-22 collectively explained by each model. RESULTS: Among 178 included patients, there was substantial variability in recovery trajectories. Applying the average trajectory to each patient explained 15% of the variability in ODI and 21% of the variability in SRS sub-scores. However, accounting for differences in baseline disability levels explained an additional 56-57% of the variability in recovery trajectories. The final model predicting recovery trajectory for ODI explained 50% of the variability in recovery trajectories. The final model for SRS-22 explained 57% of the variability in recovery trajectories. CONCLUSION: ASLS patients have highly variable postoperative recovery trajectories, largely related to differences in baseline disability but also impacted by moderators such as number of levels fused.

Orthopedic disease burden in adult patients with symptomatic lumbar scoliosis: results from a prospective multicenter study.

Although the health impact of adult symptomatic lumbar scoliosis (ASLS) is substantial, these patients often have other orthopedic problems that have not been previously quantified. The objective of this study was to assess disease burden of other orthopedic conditions in patients with ASLS based on a retrospective review of a prospective multicenter cohort. The ASLS-1 study is an NIH-sponsored prospective multicenter study designed to assess operative versus nonoperative treatment for ASLS. Patients were 40-80 years old with ASLS, defined as a lumbar coronal Cobb angle ≥ 30° and Oswestry Disability Index ≥ 20, or Scoliosis Research Society-22 questionnaire score ≤ 4.0 in pain, function, and/or self-image domains. Nonthoracolumbar orthopedic events, defined as fractures and other orthopedic conditions receiving surgical treatment, were assessed from enrollment to the 4-year follow-up. Two hundred eighty-six patients (mean age 60.3 years, 90% women) were enrolled, with 173 operative and 113 nonoperative patients, and 81% with 4-year follow-up data. At a mean (± SD) follow-up of 3.8 ± 0.9 years, 104 nonthoracolumbar orthopedic events were reported, affecting 69 patients (24.1%). The most common events were arthroplasty (n = 38), fracture (n = 25), joint ligament/cartilage repair (n = 13), and cervical decompression/fusion (n = 7). Based on the final adjusted model, patients with a nonthoracolumbar orthopedic event were older (HR 1.44 per decade, 95% CI 1.07-1.94), more likely to have a history of tobacco use (HR 1.63, 95% CI 1.00-2.66), and had worse baseline leg pain scores (HR 1.10, 95% CI 1.01-1.19). Patients with ASLS have high orthopedic disease burden, with almost 25% having a fracture or nonthoracolumbar orthopedic condition requiring surgical treatment during the mean 3.8 years following enrollment. Comparisons with previous studies suggest that the rate of total knee arthroplasty was considerably greater and the rates of total hip arthroplasty were at least as high in the ASLS-1 cohort compared with the similarly aged general US population. These conditions may further impact health-related quality of life and outcomes assessments of both nonoperative and operative treatment approaches in patients with ASLS.

Operative versus nonoperative treatment for adult symptomatic lumbar scoliosis at 5-year follow-up: durability of outcomes and impact of treatment-related serious adverse events.

Although short-term adult symptomatic lumbar scoliosis (ASLS) studies favor operative over nonoperative treatment, longer outcomes are critical for assessment of treatment durability, especially for operative treatment, because the majority of implant failures and nonunions present between 2 and 5 years after surgery. The objectives of this study were to assess the durability of treatment outcomes for operative versus nonoperative treatment of ASLS, to report the rates and types of associated serious adverse events (SAEs), and to determine the potential impact of treatment-related SAEs on outcomes. The ASLS-1 (Adult Symptomatic Lumbar Scoliosis-1) trial is an NIH-sponsored multicenter prospective study to assess operative versus nonoperative ASLS treatment. Patients were 40-80 years of age and had ASLS (Cobb angle ≥ 30° and Oswestry Disability Index [ODI] ≥ 20 or Scoliosis Research Society [SRS]-22 subscore ≤ 4.0 in the Pain, Function, and/or Self-Image domains). Patients receiving operative and nonoperative treatment were compared using as-treated analysis, and the impact of related SAEs was assessed. Primary outcome measures were ODI and SRS-22. The 286 patients with ASLS (107 with nonoperative treatment, 179 with operative treatment) had 2-year and 5-year follow-up rates of 90% (n = 256) and 74% (n = 211), respectively. At 5 years, compared with patients treated nonoperatively, those who underwent surgery had greater improvement in ODI (mean difference -15.2 [95% CI -18.7 to -11.7]) and SRS-22 subscore (mean difference 0.63 [95% CI 0.48-0.78]) (p < 0.001), with treatment effects (TEs) exceeding the minimum detectable measurement difference (MDMD) for ODI (7) and SRS-22 subscore (0.4). TEs at 5 years remained as favorable as 2-year TEs (ODI -13.9, SRS-22 0.52). For patients in the operative group, the incidence rates of treatment-related SAEs during the first 2 years and 2-5 years after surgery were 22.38 and 8.17 per 100 person-years, respectively. At 5 years, patients in the operative group who had 1 treatment-related SAE still had significantly greater improvement, with TEs (ODI -12.2, SRS-22 0.53; p < 0.001) exceeding the MDMD. Twelve patients who received surgery and who had 2 or more treatment-related SAEs had greater improvement than nonsurgically treated patients based on ODI (TE -8.34, p = 0.017) and SRS-22 (TE 0.32, p = 0.029), but the SRS-22 TE did not exceed the MDMD. The significantly greater improvement of operative versus nonoperative treatment for ASLS at 2 years was durably maintained at the 5-year follow-up. Patients in the operative cohort with a treatment-related SAE still had greater improvement than patients in the nonoperative cohort. These findings have important implications for patient counseling and future cost-effectiveness assessments.

156. Operative vs nonoperative treatment for adult symptomatic lumbar scoliosis at 5-6-year follow-up: outcomes and impact of related serious adverse events

BACKGROUND CONTEXT Although short-term adult symptomatic lumbar scoliosis (ASLS) outcomes studies favor operative over nonoperative treatment, long-term outcomes are critical for assessment of treatment durability. PURPOSE To assess whether operative treatment for ASLS provides greater improvement of patient-reported outcomes measures than nonoperative treatment at 5-6-year follow-up. STUDY DESIGN/SETTING Secondary analysis of prospective multicenter cohort. PATIENT SAMPLE Adults with symptomatic lumbar scoliosis enrolled into an NIH-sponsored study to assess outcomes of operative and nonoperative treatments. OUTCOME MEASURES Scoliosis Research Society-22 subscore (SRS-22 subscore), Oswestry Disability Index (ODI), occurrence of related serious adverse events (SAEs) METHODS The ASLS study is an NIH-sponsored multicenter prospective study to assess operative vs nonoperative treatment for ASLS, with randomized and observational treatment arms. Patients were 40-80 years of age with ASLS (Cobb >30° and ODI >20 or SRS-22 subscore (SRS-22) RESULTS The 286 ASLS patients (108 nonoperative, 178 operative) had follow-up rates at 2 and 5-6 years of 90% (256) and 74% (212), respectively. At 5 years, compared with nonoperative, operative patients had greater improvement in SRS-22 subscore (adjusted mean difference, 0.6 [95% CI, 0.5 to 0.6]) and ODI (adjusted mean difference, -14 [95% CI, -18 to -9]) (p CONCLUSIONS The significantly greater clinical improvement of operative vs nonoperative treatment for ASLS at 2 years is maintained at 5-6-year follow-up. Overall, operative patients with a related SAE still had greater improvement than nonoperative patients, but for operative patients with 2+ SAEs, the TEs were markedly reduced. These findings have important implications for patient counseling and cost-effectiveness assessments. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

133. Cost effectiveness of adult lumbar scoliosis surgery: an as-treated analysis from the adult symptomatic scoliosis surgery trial with five-year follow-up

BACKGROUND CONTEXT Adult spinal deformity is a relatively prevalent condition for which surgical treatment has become increasingly common but concerns surrounding complications, revision rates and cost-effectiveness remain unresolved. Of these issues, cost-effectiveness is perhaps the most difficult to quantify as the requisite data is difficult to obtain. PURPOSE The purpose of this study is to report on the cost-effectiveness of surgical vs nonsurgical treatment for adult symptomatic lumbar scoliosis (ASLS) using the as-treated data and provide a comparison to previously reported intent-to-treat (ITT) analysis. STUDY DESIGN/SETTING Secondary analysis of data from the NIH sponsored study on ASLS that included randomized and observational arms. PATIENT SAMPLE Patients enrolled in the NIH sponsored study on ASLS that included randomized and observational cohorts with at least five-year follow-up data within the same treatment arm. OUTCOME MEASURES Quality Adjusted Life Years (QALY) derived from the SF-6D. METHODS Patients with at least five-year follow-up data within the same treatment arm were included. Data collected every three months included use of nonoperative modalities, medications and employment status. Costs for surgeries and nonoperative modalities were determined using Medicare allowable rates. Medication costs were determined using the RedBook and indirect costs were calculated based on reported employment status and income. Quality Adjusted Life Years (QALY) was determined using the SF-6D. RESULTS Of 286 patients, 195 patients (73 Nonop, 122 Op) met inclusion criteria. At five years, 29 (24%) patients in the Op group had a revision surgery of whom two had two revisions and one had three revisions. The cumulative cost for the Op group was $111,451 with a cumulative QALY gain of 2.29. The cumulative cost for the Non-Op group was $29,124 with a cumulative QALY gain of 0.41. This results in an ICER of $44,033 in favor of Op treatment. CONCLUSIONS This as-treated cost effectiveness analysis demonstrates that surgical treatment for adult lumbar scoliosis becomes favorable at year-three, one year earlier than suggested by a previous intent-to-treat analysis. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Effect modifiers for patient-reported outcomes in operatively and nonoperatively treated patients with adult symptomatic lumbar scoliosis: a combined analysis of randomized and observational cohorts.

Adult symptomatic lumbar scoliosis (ASLS) is a common and disabling condition. The ASLS-1 was a multicenter, dual-arm study (with randomized and observational cohorts) examining operative and nonoperative care on health-related quality of life in ASLS. An aim of ASLS-1 was to determine patient and radiographic factors that modify the effect of operative treatment for ASLS. Patients 40-80 years old with ASLS were enrolled in randomized and observational cohorts at 9 North American centers. Primary outcomes were the differences in mean change from baseline to 2-year follow-up for the SRS-22 subscore (SRS-SS) and the Oswestry Disability Index (ODI). Analyses were performed using an as-treated approach with combined cohorts. Factors examined were prespecified or determined using regression tree analysis. For each potential effect modifier, subgroups were created using clinically relevant cutoffs or via regression trees. Estimates of within-group and between-group change were compared using generalized linear mixed models. An effect modifier was defined as a treatment effect difference greater than the minimal detectable measurement difference for both SRS-SS (0.4) and ODI (7). Two hundred eighty-six patients were enrolled and 256 (90%) completed 2-year follow-up; 171 received operative treatment and 115 received nonoperative treatment. Surgery was superior to nonoperative care for all effect subgroups considered, with the exception of those with nearly normal pelvic incidence-lumbar lordosis (PI-LL) match (≤ 11°). Male patients and patients with more (> 11°) PI-LL mismatch at baseline had greater operative treatment effects on both the SRS-SS and ODI compared to nonoperative treatment. No other radiographic subgroups were associated with treatment effects. High BMI, lower socioeconomic status, and poor mental health were not related to worse outcomes. Numerous factors previously related to poor outcomes with surgery, such as low mental health, lower socioeconomic status, and high BMI, were not related to outcomes in ASLS in this exploratory analysis. Those patients with higher PI-LL mismatch did improve more with surgery than those with normal alignment. On average, none of the factors considered were associated with a worse outcome with operative treatment versus nonoperative treatment. These findings may guide future prospective analyses of factors related to outcomes in ASLS care.

Cost-effectiveness of Operative versus Nonoperative Treatment of Adult Symptomatic Lumbar Scoliosis an Intent-to-treat Analysis at 5-year Follow-up.

Secondary analysis using data from the NIH-sponsored study on adult symptomatic lumbar scoliosis (ASLS) that included randomized and observational arms. The aim of this study was to perform an intent-to-treat cost-effectiveness study comparing operative (Op) versus nonoperative (NonOp) care for ASLS. The appropriate treatment approach for ASLS continues to be ill-defined. NonOp care has not been shown to improve outcomes. Surgical treatment has been shown to improve outcomes, but is costly with high revision rates. Patients with at least 5-year follow-up data were included. Data collected every 3 months included use of NonOp modalities, medications, and employment status. Costs for index and revision surgeries and NonOp modalities were determined using Medicare Allowable rates. Medication costs were determined using the RedBook and indirect costs were calculated based on reported employment status and income. Qualityadjusted life year (QALY) was determined using the SF6D. There were 81 of 95 cases in the Op and 81 of 95 in the NonOp group with complete 5-year follow-up data. Not all patients were eligible 5-year follow-up at the time of the analysis. All patients in the Op and 24 (30%) in the NonOp group had surgery by 5 years. At 5 years, the cumulative cost for Op was $96,000 with a QALY gain of 2.44 and for NonOp the cumulative cost was $49,546 with a QALY gain of 0.75 with an incremental cost-effectiveness ratio (ICER) of $27,480 per QALY gain. In an intent-to-treat analysis, neither treatment was dominant, as the greater gains in QALY in the surgery group come at a greater cost. The ICER for Op compared to NonOp treatment was above the threshold generally considered cost-effective in the first 3 years of the study but improved over time and was highly cost-effective at 4 and 5 years. 2.

Effect of Serious Adverse Events on Health-related Quality of Life Measures Following Surgery for Adult Symptomatic Lumbar Scoliosis.

Secondary analysis of prospective multicenter cohort. To assess effect of serious adverse events (SAEs) on 2- and 4-year patient-reported outcomes measures (PROMs) in patients surgically treated for adult symptomatic lumbar scoliosis (ASLS). Operative treatment for ASLS can improve health-related quality of life, but has high rates of SAEs. How these SAEs effect health-related quality of life remain unclear. The ASLS study assessed operative versus nonoperative ASLS treatment, with randomized and observational arms. Patients were 40- to 80-years-old with ASLS, defined as lumbar coronal Cobb ≥30° and Oswestry Disability Index (ODI) ≥20 or Scoliosis Research Society-22 (SRS-22) ≤4.0 in pain, function, and/or self-image domains. SRS-22 subscore and ODI were compared between operative patients with and without a related SAE and nonoperative patients using an as-treated analysis combining randomized and observational cohorts. Two hundred eighty-six patients were enrolled, and 2- and 4-year follow-up rates were 90% and 81%, respectively, although at the time of data extraction not all patients were eligible for 4-year follow-up. A total of 97 SAEs were reported among 173 operatively treated patients. The most common were implant failure/pseudarthrosis (n = 25), proximal junctional kyphosis/failure (n = 10), and minor motor deficit (n = 8). At 2 years patients with an SAE improved less than those without an SAE based on SRS-22 (0.52 vs. 0.79, P = 0.004) and ODI (-11.59 vs. -17.34, P = 0.021). These differences were maintained at 4-years for both SRS-22 (0.51 vs. 0.86, P = 0.001) and ODI (-10.73 vs. -16.69, P = 0.012). Despite this effect, patients sustaining an operative SAE had greater PROM improvement than nonoperative patients (P<0.001). Patients affected by SAEs following surgery for ASLS had significantly less improvement of PROMs at 2- and 4-year follow-ups versus those without an SAE. Regardless of SAE occurrence, operatively treated patients had significantly greater improvement in PROMs than those treated nonoperatively. 2.

19. Adult symptomatic lumbar scoliosis patients have high orthopedic disease burden beyond their spinal deformities: results from a prospective multicenter study

BACKGROUND CONTEXT Although the health impact of adult symptomatic lumbar scoliosis (ASLS) is substantial, these patients often have other orthopedic disease burden that may further negatively impact their health-related quality of life (HRQL) and recovery following ASLS treatment. This additional disease burden has not been well quantified in the ASLS population. PURPOSE To assess nonthoracolumbar orthopedic (NTO) disease burden in ASLS patients enrolled in a prospective multicenter study. STUDY DESIGN/SETTING Retrospective review of prospective multicenter cohort. PATIENT SAMPLE Patients enrolled in the ASLS prospective multicenter study of operative vs nonoperative treatment. OUTCOME MEASURES Occurrence of non-thoracolumbar orthopedic events, Scoliosis Research Society-22r (SRS-22), Oswestry Disability Index (ODI), SF-12 physical component summary (PCS). METHODS The ASLS study is a prospective multicenter study to assess operative vs nonoperative treatment for ASLS, with randomized and observational arms. Patients recruited were 40-80 years old with ASLS, defined as a lumbar coronal Cobb >30° and ODI >20 or SRS-22 RESULTS Two hundred eighty-six patients (mean age 60 yrs, 90% women) were enrolled, with as-treated cohorts of 173 operative and 113 nonoperative patients, and 4-yr follow-up rate of 81%. At a mean follow-up of 3.8 yrs (SD=0.9 yrs), 108 NTO events were reported, affecting 71 (24.8%) patients. The most common NTO events included: arthroplasty (n=39), fractures (n=26), joint ligament/cartilage repair (n=13), cervical surgery (n=7), and carpal tunnel release (n=5). Patients with an NTO event were significantly older (63 vs 59 yrs, p CONCLUSIONS ASLS patient have a high NTO disease burden, with almost 25% of patients in this prospective multicenter study having an orthopedic condition requiring surgical treatment or a fracture within 3.8 yrs following study enrollment. Patients with an NTO event were more likely to have any history of smoking and had worse baseline spinal deformity and disability. These conditions may further impact HRQL and recovery following ASLS treatment. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

98. Differences in functional treadmill tests in patients with adult symptomatic lumbar scoliosis treated operatively and nonoperatively

BACKGROUND CONTEXT Adult symptomatic lumbar Scoliosis (ASLS) has become increasingly prevalent as the population ages. ASLS can be accompanied by neurogenic claudication, leading to difficulty walking. Functional treadmill testing (FTT) has been previously described as an objective tool to evaluate patients suffering from neurogenic claudication. FTT may provide an objective tool to evaluate patients with ASLS and identify patients who may benefit from surgical treatment. PURPOSE To determine if FTT demonstrates objective significant differences between patients treated surgically and nonsurgically for ASLS. STUDY DESIGN/SETTING Secondary analysis using data from the NIH sponsored study on ASLS that included randomized and observational arms. PATIENT SAMPLE Patients enrolled in the NIH sponsored study on ASLS. OUTCOME MEASURES Functional treadmill test, back and leg pain scores METHODS One hundred and eighty-seven patients who underwent nonsurgical (n=88) or surgical treatment (n=99) of ASLS with complete baseline and two-year post-treatment FTTs were identified. FTT parameters included maximum speed, time to onset of symptoms, distance ambulated, time ambulated, and the difference in back and leg pain before and after testing. RESULTS At baseline, patients treated operatively reported an onset of symptoms on FTT significantly sooner than those treated nonoperatively (5.5min vs 7.7min, p=0.025). When compared to baseline, operatively treated patients experienced significant improvement at 2 years in time ambulated (26.5min vs 24.4 min, p=0.001). Additionally, in the operative group, the post-treadmill minus pre-treadmill BP scores (0.5 vs 1.6 p=0.001) and the post-treadmill minus pre-treadmill leg pain scores (0.4 vs 1.4, p CONCLUSIONS FTT is a useful adjunct to assess treatment outcomes in patients with ASLS. FTT results were different at baseline between patients treated operatively and nonoperatively. Patients who had surgery had improvements in their post-treadmill minus pre-treadmill back and leg pain scores at two year follow-up. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

20. Cost-effectiveness of operative vs nonoperative treatment of adult symptomatic lumbar scoliosis an intent-to-treat analysis at 5-year follow-up

BACKGROUND CONTEXT There continues to be uncertainty in the appropriate treatment approach for adult symptomatic lumbar scoliosis (ASLS). Nonoperative care has not been shown to improve outcomes. Surgical treatment has been shown to improve outcomes, but is costly with high revision rates. PURPOSE To perform an intent-to-treat cost-effectiveness study comparing operative vs nonoperative care for ASLS. STUDY DESIGN/SETTING Secondary analysis using data from the NIH sponsored study on ASLS that included randomized and observational arms. PATIENT SAMPLE Patients with at least five-year follow-up data were included. OUTCOME MEASURES SRS-22R, Oswestry Disability Index, Short Form-12. METHODS Patients with at least five-year follow-up data were included. Data collected every three months included use of nonoperative modalities, medications and employment status. Costs for index and revision surgeries and nonoperative modalities were determined using Medicare allowable rates. Medication costs were determined using the RedBook and indirect costs were calculated based on reported employment status and income. Quality adjusted life years (QALY) were determined using the SF6D. RESULTS There were 81 of 95 cases in the operative (Op) and 81 of 95 in the nonoperative (NonOp) group with complete five-year follow-up data. Not all patients were eligible for five-year follow-up at the time of the analysis. All patients in the Op and 24 (30%) in the NonOp group had surgery by five years. At five years, the cumulative cost for Op was $96,000 with a QALY gain of 2.44 and for NonOp the cumulative cost was $49,546 with a QALY gain of 0.75 with an ICER of $27,480 per QALY gain. CONCLUSIONS In an intent-to treat analysis, neither treatment was dominant, as the greater gains in QALY in the surgery group come at a greater cost. The ICER for operative compared to nonoperative treatment was above the threshold generally considered cost-effective in the first three years of the study but improved over time and was highly cost-effective at four and five years. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Prevalence and Indications for Unplanned Reoperations Following Index Surgery in the Adult Symptomatic Lumbar Scoliosis NIH-Sponsored Clinical Trial

Study DesignLongitudinal cohort. ObjectiveTo report on the prevalence and indications for unplanned reoperations following index surgery in the Adult Symptomatic Lumbar Scoliosis NIH-sponsored Clinical Trial. Summary of Background DataReoperation following adult spinal deformity surgery exposes the patient to additional surgical risk, increases the cost of care, and decreases the potential cost-effectiveness of the intervention. Accurate data regarding the prevalence and indication for reoperation will facilitate future efforts to minimize risk. MethodsA total of 153 patients underwent adult spinal deformity surgery as part of the observational, randomized, or crossover groups and were eligible for two-year follow-up. Reoperations were meticulously tracked as part of the National Institutes of Health (NIH)–mandated serious adverse event (SAE) reporting. The primary indication for reoperation was obtained from the treating surgeon’s operative report. ResultsThirty-two patients had one reoperation, two patients underwent two reoperations, and three patients underwent three reoperations. A total of 45 reoperations were performed in 37 patients. Eleven patients (7%) underwent reoperation within 90 days of the index surgery: two for superficial wound dehiscence, three for radiculopathy with screw removal, and six for acute proximal junctional failure (PJF). Four patients underwent reoperation for PJF more than 90 days from index surgery. Twenty-six patients underwent 28 reoperations for rod fracture/pseudoarthrosis. ConclusionIn a consecutive series of adult spinal deformity surgery patients with meticulous follow-up, 24% of patients required an unplanned reoperation. The most common indication for reoperation was rod fracture/pseudoarthrosis, which occurred from 9 months to 3.7 years following the index surgery and accounted for 62% (28/45) of the reoperations. The second most common indication for reoperation was PJF, which occurred from 1 month to 1.6 years following index surgery and accounted for 22% (10/45) of the reoperations. As these complications will likely increase with longer follow-up, efforts to lower the rates of these complications are warranted. Level of EvidenceLevel II.

Serious Adverse Events Significantly Reduce Patient-Reported Outcomes at 2-Year Follow-up: Nonoperative, Multicenter, Prospective NIH Study of 105 Patients.

This is an analysis of a prospective 2-year study on nonoperative patients enrolled in the Adult Symptomatic Lumbar Scoliosis (ASLS) National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) trial. The purpose was to evaluate the impact of serious adverse events (SAEs) on patient-reported outcomes (PROs) in nonoperative management of ASLS as measured by Scoliosis Research Society-22 (SRS-22), Oswestry Disability Index (ODI), and Short Form-12 (SF-12) at 2-year follow-up. Little is known about PROs in the nonoperative management of ASLS or the prevalence and impact of SAEs on PROs. The ASLS trial dataset was analyzed to identify adult lumbar scoliosis patients electively choosing or randomly assigned to nonoperative treatment with minimum 2-year follow-up. Patient data were collected prospectively from 2010 to 2015 as part of NIAMS R01-AR055176-01A2 "A Multi-Centered Prospective Study of Quality of Life in Adult Scoliosis." SAEs were defined as life-threatening medical events, new significant or permanent disability, new or prolonged hospitalization, or death. One hundred five nonoperative patients were studied to 2-year follow-up. Twenty-seven patients (25.7%) had 42 SAEs; 15 (14.3%) had a SAE during the first year. The SAE group had higher body mass index (29.4 vs. 25.2; P = 0.008) and reported worse SRS-22 Function scores than the non-SAE group at baseline (3.3 vs. 3.6; P = 0.024). At 2-year follow-up, SAE patients experienced less improvement (change) in SRS-22 Self-Image (-0.07 vs. 0.26; P = 0.018) and Mental Health domains (-0.19 vs. 0.25; P = 0.002) than non-SAE patients and had lower SRS-22 Function, Self-Image, Subscore, and SF-12 Mental and Physical component scores (MCS/PCS). Fewer SAE patients reached minimal clinically important difference (MCID) threshold in SRS-22 Mental Health (14.8% vs. 43.6%; P = 0.01). A high percentage (25.7%) of ASLS patients managed nonoperatively experienced SAEs. Those patients who sustained a SAE had less improvement in reported outcomes. 2.

SRS-22R Minimum Clinically Important Difference and Substantial Clinical Benefit After Adult Lumbar Scoliosis Surgery

Study DesignLongitudinal cohort. ObjectivesTo determine if the minimum clinically important difference (MCID) and substantial clinical benefit (SCB) thresholds for the Scoliosis Research Society–22R (SRS22R) domains in patients with degenerative lumbar scoliosis are similar to those in patients with adult spinal deformity (ASD) with fusions extending into the thoracic spine. Summary of Background DataThe MCID and SCB thresholds for the SRS22R domains in patients with ASD and adolescent idiopathic scoliosis have been reported. MethodsPatients enrolled in the NIH-sponsored Adult Symptomatic Lumbar Scoliosis (ASLS) trial who underwent surgery and completed the SRS22R preoperative and the SRS30 one-year postoperative were identified. One-year postoperative answers to the last eight questions of the SRS30 were used as anchors to determine the MCID and SCB for the Pain, Appearance, and Activity domains, and the Subscore and Total score using receiver operating characteristic (ROC) curve analysis. ResultsThe sample population consisted of 147 patients. A total of 132 (89%) were females with a mean age of 59.4 years. There was a statistically significant improvement in all SRS22R scores from preoperative to one-year postoperative. There was also a statistically significant difference in domain scores among the different responses to the anchors. According to the ROC analysis, MCID was 1.17 for Appearance, 0.40 for Activity, 0.60 for Pain, 0.53 for Subscore, and 0.77 for Total; and SCB was 1.67 for Appearance, 0.60 for Activity, 0.62 for Subscore, and 1.11 for Total score. These are similar to previous reports of MCID and SCB thresholds for ASD patients who underwent fusion to the thoracic spine. ConclusionThe MCID and SCB thresholds for the SRS22R domains in patients with adult symptomatic lumbar scoliosis are very similar to the threshold values previously reported for adult deformity patients. Level of EvidenceLevel II.

105 - Cost-Effectiveness of Operative vs Nonoperative Treatment of Adult Lumbar Scoliosis

BACKGROUND CONTEXT: There continues to be uncertainty regarding the cost-effectiveness of treatments for Adult Symptomatic Lumbar Scoliosis (ASLS). Nonoperative care provides little health related quality of life (HRQOL) benefit; although these patients may have worsened without treatment. Surgery improves HRQOL, but is costly with high revision rates. This study explores this issue via a cost-effectiveness analysis using data from an NIH sponsored trial.