Browsing by Author "Yanik, Elizabeth L"

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    Cost-effectiveness of adult lumbar scoliosis surgery: an as-treated analysis from the adult symptomatic scoliosis surgery trial with 5-year follow-up.
    (Spine deformity, 2020-12) Glassman, Steven D; Carreon, Leah Y; Shaffrey, Christopher I; Kelly, Michael P; Crawford, Charles H; Yanik, Elizabeth L; Lurie, Jon D; Bess, R Shay; Baldus, Christine R; Bridwell, Keith H

    Study design

    Longitudinal comparative cohort.

    Objective

    The purpose of this study is to report on the cost-effectiveness of surgical versus non-surgical treatment for Adult Symptomatic Lumbar Scoliosis (ASLS) using the as-treated data and provide a comparison to previously reported intent-to-treat (ITT) analysis. 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. The purpose of this study is to report on the cost-effectiveness of surgical versus non-surgical treatment for ASLS using the as-treated data and provide a comparison to previously reported ITT analysis.

    Methods

    Patients with at least 5-year follow-up data within the same treatment arm were included. Data collected every 3 months included use of nonoperative modalities, medications and employment status. Costs for 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 the reported employment status and income. Quality-Adjusted Life Years (QALY) was determined using the SF-6D.

    Results

    Of 226 patients, 195 patients (73 Non-op, 122 Op) met inclusion criteria. At 5 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 2.3. The cumulative cost for the Non-Op group was $29,124 with a cumulative QALY gain of 0.4. This results in an ICER of $44,033 in favor of Op treatment.

    Conclusion

    This as-treated cost-effectiveness analysis demonstrates that surgical treatment for adult lumbar scoliosis becomes favorable at year-three, 1 year earlier than suggested by a previous intent-to-treat analysis.

    Level of evidence

    II.
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    Cost-effectiveness of Operative versus Nonoperative Treatment of Adult Symptomatic Lumbar Scoliosis an Intent-to-treat Analysis at 5-year Follow-up.
    (Spine, 2019-11) Carreon, Leah Y; Glassman, Steven D; Lurie, Jon; Shaffrey, Christopher I; Kelly, Michael P; Baldus, Christine R; Bratcher, Kelly R; Crawford, Charles H; Yanik, Elizabeth L; Bridwell, Keith H
    STUDY DESIGN:Secondary analysis using data from the NIH-sponsored study on adult symptomatic lumbar scoliosis (ASLS) that included randomized and observational arms. OBJECTIVE:The aim of this study was to perform an intent-to-treat cost-effectiveness study comparing operative (Op) versus nonoperative (NonOp) care for ASLS. SUMMARY OF BACKGROUND DATA: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. METHODS: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. RESULTS: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. CONCLUSION: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. LEVEL OF EVIDENCE:2.
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    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.
    (Journal of neurosurgery. Spine, 2020-03) Yanik, Elizabeth L; Kelly, Michael P; Lurie, Jon D; Baldus, Christine R; Shaffrey, Christopher I; Schwab, Frank J; Bess, Shay; Lenke, Lawrence G; LaBore, Adam; Bridwell, Keith H
    OBJECTIVE: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. METHODS: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). RESULTS: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. CONCLUSIONS: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.
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    ItemOpen Access
    Effect of Serious Adverse Events on Health-related Quality of Life Measures Following Surgery for Adult Symptomatic Lumbar Scoliosis.
    (Spine, 2019-09) Smith, Justin S; Shaffrey, Christopher I; Kelly, Michael P; Yanik, Elizabeth L; Lurie, Jon D; Baldus, Christine R; Edwards, Charles; Glassman, Steven D; Lenke, Lawrence G; Boachie-Adjei, Oheneba; Buchowski, Jacob M; Carreon, Leah Y; Crawford, Charles H; Errico, Thomas J; Lewis, Stephen J; Koski, Tyler; Parent, Stefan; Kim, Han Jo; Ames, Christopher P; Bess, Shay; Schwab, Frank J; Bridwell, Keith H

    Study design

    Secondary analysis of prospective multicenter cohort.

    Objective

    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).

    Summary of background data

    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.

    Methods

    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.

    Results

    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).

    Conclusion

    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.

    Level of evidence

    2.
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    Failure of nonoperative care in adult symptomatic lumbar scoliosis: incidence, timing, and risk factors for conversion from nonoperative to operative treatment.
    (Journal of neurosurgery. Spine, 2023-06) Clohisy, John CF; Smith, Justin S; Kelly, Michael P; Yanik, Elizabeth L; Baldus, Christine R; Bess, Shay; Shaffrey, Christopher I; Kim, Han Jo; LaBore, Adam; Pham, Vy; Bridwell, Keith H

    Objective

    The Adult Symptomatic Lumbar Scoliosis (ASLS) study is a prospective multicenter trial with randomized and observational cohorts comparing operative and nonoperative treatment for ASLS. The objective of the present study was to perform a post hoc analysis of the ASLS trial to examine factors related to failure of nonoperative treatment in ASLS.

    Methods

    Patients from the ASLS trial who initially received at least 6 months of nonoperative treatment were followed for up to 8 years after trial enrollment. Baseline patient-reported outcome measures (Scoliosis Research Society-22 [SRS-22] questionnaire and Oswestry Disability Index), radiographic data, and other clinical characteristics were compared between patients who did and did not convert to operative treatment during follow-up. The incidence of operative treatment was calculated and independent predictors of operative treatment were identified using multivariate regression.

    Results

    Of 135 nonoperative patients, 42 (31%) crossed over to operative treatment after 6 months and 93 (69%) received only nonoperative treatment. In the observational cohort, 23 (22%) of 106 nonoperative patients crossed over to surgery. In the randomized cohort, 19 (66%) of 29 patients randomized to nonoperative treatment crossed over to surgery. The most impactful factors associated with crossover from nonoperative to operative treatment were enrollment in the randomized cohort and baseline SRS-22 subscore < 3.0 at the 2-year follow-up, closer to 3.4 at 8 years. In addition, baseline lumbar lordosis (LL) < 50° was associated with crossover to operative treatment. Each 1-point decrease in baseline SRS-22 subscore was associated with a 233% higher risk of conversion to surgery (hazard ratio [HR] 2.33, 95% confidence interval [CI] 1.14-4.76, p = 0.0212). Each 10° decrease in LL was associated with a 24% increased risk of conversion to operative treatment (HR 1.24, 95% CI 1.03-1.49, p = 0.0232). Enrollment in the randomized cohort was associated with a 337% higher probability of proceeding with operative treatment (HR 3.37, 95% CI 1.54-7.35, p = 0.0024).

    Conclusions

    Enrollment in the randomized cohort, a lower baseline SRS-22 subscore, and lower LL were associated with conversion from nonoperative treatment to surgery in patients (observational and randomized) who were initially managed nonoperatively in the ASLS trial.
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    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.
    (Journal of neurosurgery. Spine, 2021-04) Smith, Justin S; Kelly, Michael P; Yanik, Elizabeth L; Baldus, Christine R; Buell, Thomas J; Lurie, Jon D; Edwards, Charles; Glassman, Steven D; Lenke, Lawrence G; Boachie-Adjei, Oheneba; Buchowski, Jacob M; Carreon, Leah Y; Crawford, Charles H; Errico, Thomas J; Lewis, Stephen J; Koski, Tyler; Parent, Stefan; Lafage, Virginie; Kim, Han Jo; Ames, Christopher P; Bess, Shay; Schwab, Frank J; Shaffrey, Christopher I; Bridwell, Keith H

    Objective

    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.

    Methods

    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.

    Results

    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.

    Conclusions

    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.
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    Operative Versus Nonoperative Treatment for Adult Symptomatic Lumbar Scoliosis.
    (The Journal of bone and joint surgery. American volume, 2019-02) Kelly, Michael P; Lurie, Jon D; Yanik, Elizabeth L; Shaffrey, Christopher I; Baldus, Christine R; Boachie-Adjei, Oheneba; Buchowski, Jacob M; Carreon, Leah Y; Crawford, Charles H; Edwards, Charles; Errico, Thomas J; Glassman, Steven D; Gupta, Munish C; Lenke, Lawrence G; Lewis, Stephen J; Kim, Han Jo; Koski, Tyler; Parent, Stefan; Schwab, Frank J; Smith, Justin S; Zebala, Lukas P; Bridwell, Keith H

    Background

    The effectiveness of operative compared with nonoperative treatment at initial presentation (no prior fusion) for adult lumbar scoliosis has not, to our knowledge, been evaluated in controlled trials. The goals of this study were to evaluate the effects of operative and nonoperative treatment and to assess the benefits of these treatments to help treating physicians determine whether patients are better managed operatively or nonoperatively.

    Methods

    Patients with adult symptomatic lumbar scoliosis (aged 40 to 80 years, with a coronal Cobb angle measurement of ≥30° and an Oswestry Disability Index [ODI] score of ≥20 or Scoliosis Research Society [SRS]-22 score of ≤4.0) from 9 North American centers were enrolled in concurrent randomized or observational cohorts to evaluate operative versus nonoperative treatment. The primary outcomes were differences in the mean change from baseline in the SRS-22 subscore and ODI at 2-year follow-up. For the randomized cohort, the initial sample-size calculation estimated that 41 patients per group (82 total) would provide 80% power with alpha equal to 0.05, anticipating 10% loss to follow-up and 20% nonadherence in the nonoperative arm. However, an interim sample-size calculation estimated that 18 patients per group would be sufficient.

    Results

    Sixty-three patients were enrolled in the randomized cohort: 30 in the operative group and 33 in the nonoperative group. Two hundred and twenty-three patients were enrolled in the observational cohort: 112 in the operative group and 111 in the nonoperative group. The intention-to-treat analysis of the randomized cohort found that, at 2 years of follow-up, outcomes did not differ between the groups. Nonadherence was high in the randomized cohort (64% nonoperative-to-operative crossover). In the as-treated analysis of the randomized cohort, operative treatment was associated with greater improvement at the 2-year follow-up in the SRS-22 subscore (adjusted mean difference, 0.7 [95% confidence interval (CI), 0.5 to 1.0]) and in the ODI (adjusted mean difference, -16 [95% CI, -22 to -10]) (p < 0.001 for both). Surgery was also superior to nonoperative care in the observational cohort at 2 years after treatment on the basis of SRS-22 subscore and ODI outcomes (p < 0.001). In an overall responder analysis, more operative patients achieved improvement meeting or exceeding the minimal clinically important difference (MCID) in the SRS-22 subscore (85.7% versus 38.7%; p < 0.001) and the ODI (77.4% versus 38.3%; p < 0.001). Thirty-four revision surgeries were performed in 24 (14%) of the operative patients.

    Conclusions

    On the basis of as-treated and MCID analyses, if a patient with adult symptomatic lumbar scoliosis is satisfied with current spine-related health, nonoperative treatment is advised, with the understanding that improvement is unlikely. If a patient is not satisfied with current spine health and expects improvement, surgery is preferred.

    Level of evidence

    Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.
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    Orthopedic disease burden in adult patients with symptomatic lumbar scoliosis: results from a prospective multicenter study.
    (Journal of neurosurgery. Spine, 2021-08) Smith, Justin S; Shaffrey, Christopher I; Baldus, Christine R; Kelly, Michael P; Yanik, Elizabeth L; Lurie, Jon D; Ames, Christopher P; Bess, Shay; Schwab, Frank J; Bridwell, Keith H

    Objective

    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.

    Methods

    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.

    Results

    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).

    Conclusions

    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.
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    Patient-reported outcome measure clustering after surgery for adult symptomatic lumbar scoliosis.
    (Journal of neurosurgery. Spine, 2022-01) Wondra, James P; Kelly, Michael P; Yanik, Elizabeth L; Greenberg, Jacob K; Smith, Justin S; Bess, Shay; Shaffrey, Christopher I; Lenke, Lawrence G; Bridwell, Keith

    Objective

    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.

    Methods

    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.

    Results

    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).

    Conclusions

    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.
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    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.
    (Journal of neurosurgery. Spine, 2023-03) Lazaro, Bruno; Sardi, Juan Pablo; Smith, Justin S; Kelly, Michael P; Yanik, Elizabeth L; Dial, Brian; Hills, Jeffrey; Gupta, Munish C; Baldus, Christine R; Yen, Chun Po; Lafage, Virginie; Ames, Christopher P; Bess, Shay; Schwab, Frank; Shaffrey, Christopher I; Bridwell, Keith H

    Objective

    Proximal junctional failure (PJF) is a severe form of proximal junctional kyphosis. Previous reports on PJF have been limited by heterogeneous cohorts and relatively short follow-ups. The authors' objectives herein were to identify risk factors for PJF and to assess its long-term incidence and revision rates in a homogeneous cohort.

    Methods

    The authors reviewed data from the Adult Symptomatic Lumbar Scoliosis 1 trial (ASLS-1), a National Institutes of Health-sponsored prospective multicenter study. Inclusion criteria were an age ≥ 40 years, ASLS (Cobb angle ≥ 30° and Oswestry Disability Index [ODI] ≥ 20 or Scoliosis Research Society revised 22-item questionnaire [SRS-22r] score ≤ 4.0 in pain, function, or self-image domains), and primary thoracolumbar fusion/fixation to the sacrum/pelvis of ≥ 7 levels. PJF was defined as a postoperative proximal junctional angle (PJA) change > 20°, fracture of the uppermost instrumented vertebra (UIV) or UIV+1 with > 20% vertebral height loss, spondylolisthesis of UIV/UIV+1 > 3 mm, or UIV screw dislodgment.

    Results

    One hundred sixty patients (141 women) were included in this analysis and had a median age of 62 years and a mean follow-up of 4.3 years (range 0.1-6.1 years). Forty-six patients (28.8%) had PJF at a median of 0.92 years (IQR 0.14, 1.23 years) following surgery. Based on Kaplan-Meier analyses, PJF rates at 1, 2, 3, and 4 years were 14.4%, 21.9%, 25.9%, and 27.4%, respectively. On univariate analysis, PJF was associated with greater age (p = 0.0316), greater body mass index (BMI; p = 0.0319), worse baseline patient-reported outcome measures (PROMs; ODI, SRS-22r, and SF-12 Physical Component Summary [PCS]; all p < 0.04), the use of posterior column osteotomies (PCOs; p = 0.0039), and greater postoperative thoracic kyphosis (TK; p = 0.0031) and PJA (p < 0.001). The use of UIV hooks was protective against PJF (p = 0.0340). On regression analysis (without postoperative measures), PJF was associated with greater BMI (HR 1.077, 95% CI 1.007-1.153, p = 0.0317), lower preoperative PJA (HR 0.607, 95% CI 0.407-0.906, p = 0.0146), and greater preoperative TK (HR 1.362, 95% CI 1.082-1.715, p = 0.0085). Patients with PJF had worse PROMs at the last follow-up (ODI, SRS-22r subscore and self-image, and SF-12 PCS; p < 0.04). Sixteen PJF patients (34.8%) underwent revision, and PJF recurred in 3 (18.8%).

    Conclusions

    Among 160 primary ASLS patients with a median age of 62 years and predominant coronal deformity, the PJF rate was 28.8% at a mean 4.3-year follow-up, with a revision rate of 34.8%. On univariate analysis, PJF was associated with a greater age and BMI, worse baseline PROMs, the use of PCOs, and greater postoperative TK and PJA. The use of UIV hooks was protective against PJF. On multivariate analysis (without postoperative measures), a higher risk of PJF was associated with greater BMI and preoperative TK and lower preoperative PJA.
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    Rod fractures in thoracolumbar fusions to the sacrum/pelvis for adult symptomatic lumbar scoliosis: long-term follow-up of a prospective, multicenter cohort of 160 patients.
    (Journal of neurosurgery. Spine, 2023-02) Sardi, Juan Pablo; Lazaro, Bruno; Smith, Justin S; Kelly, Michael P; Dial, Brian; Hills, Jeffrey; Yanik, Elizabeth L; Gupta, Munish; Baldus, Christine R; Yen, Chun Po; Lafage, Virginie; Ames, Christopher P; Bess, Shay; Schwab, Frank; Shaffrey, Christopher I; Bridwell, Keith H

    Objective

    Previous reports of rod fracture (RF) in adult spinal deformity are limited by heterogeneous cohorts, low follow-up rates, and relatively short follow-up durations. Since the majority of RFs present > 2 years after surgery, true occurrence and revision rates remain unclear. The objectives of this study were to better understand the risk factors for RF and assess its occurrence and revision rates following primary thoracolumbar fusions to the sacrum/pelvis for adult symptomatic lumbar scoliosis (ASLS) in a prospective series with long-term follow-up.

    Methods

    Patient records were obtained from the Adult Symptomatic Lumbar Scoliosis-1 (ASLS-1) database, an NIH-sponsored multicenter, prospective study. Inclusion criteria were as follows: patients aged 40-80 years undergoing primary surgeries for ASLS (Cobb angle ≥ 30° and Oswestry Disability Index ≥ 20 or Scoliosis Research Society-22r ≤ 4.0 in pain, function, and/or self-image) with instrumented fusion of ≥ 7 levels that included the sacrum/pelvis. Patients with and without RF were compared to assess risk factors for RF and revision surgery.

    Results

    Inclusion criteria were met by 160 patients (median age 62 years, IQR 55.7-67.9 years). At a median follow-up of 5.1 years (IQR 3.8-6.6 years), there were 92 RFs in 62 patients (38.8%). The median time to RF was 3.0 years (IQR 1.9-4.54 years), and 73% occurred > 2 years following surgery. Based on Kaplan-Meier analyses, estimated RF rates at 2, 4, 5, and 8 years after surgery were 11%, 24%, 35%, and 49%, respectively. Baseline radiographic, clinical, and demographic characteristics were similar between patients with and without RF. In Cox regression models, greater postoperative pelvic tilt (HR 1.895, 95% CI 1.196-3.002, p = 0.0065) and greater estimated blood loss (HR 1.02, 95% CI 1.005-1.036, p = 0.0088) were associated with increased risk of RF. Thirty-eight patients (61% of all RFs) underwent revision surgery. Bilateral RF was predictive of revision surgery (HR 3.52, 95% CI 1.8-6.9, p = 0.0002), while patients with unilateral nondisplaced RFs were less likely to require revision (HR 0.39, 95% CI 0.18-0.84, p = 0.016).

    Conclusions

    This study provides what is to the authors' knowledge the highest-quality data to date on RF rates following ASLS surgery. At a median follow-up of 5.1 years, 38.8% of patients had at least one RF. Estimated RF rates at 2, 4, 5, and 8 years after surgery were 11%, 24%, 35%, and 49%, respectively. Greater estimated blood loss and postoperative pelvic tilt were significant risk factors for RF. These findings emphasize the importance of long-term follow-up to realize the true prevalence and cumulative incidence of RF.
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    ItemOpen Access
    Validation of Adult Spinal Deformity Surgical Outcome Prediction Tools in Adult Symptomatic Lumbar Scoliosis.
    (Spine, 2023-01) Wondra, James P; Kelly, Michael P; Greenberg, Jacob; Yanik, Elizabeth L; Ames, Christopher P; Pellise, Ferran; Vila-Casademunt, Alba; Smith, Justin S; Bess, Shay; Shaffrey, Christopher I; Lenke, Lawrence G; Serra-Burriel, Miquel; Bridwell, Keith H

    Study design

    A post hoc analysis.

    Objective

    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.

    Summary of background data

    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.

    Methods

    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.

    Results

    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).

    Conclusions

    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.