Failure of nonoperative care in adult symptomatic lumbar scoliosis: incidence, timing, and risk factors for conversion from nonoperative to operative treatment.

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.

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.

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.

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.

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.

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

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.

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.

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.

Cost-effectiveness of adult lumbar scoliosis surgery: an as-treated analysis from the adult symptomatic scoliosis surgery trial with 5-year follow-up.

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.

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.

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.

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

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.

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

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.

Operative Versus Nonoperative Treatment for Adult Symptomatic Lumbar Scoliosis.

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.

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

STUDY DESIGN: Longitudinal cohort. OBJECTIVE: To 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 DATA: Reoperation 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. METHODS: A 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. RESULTS: Thirty-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. CONCLUSION: In 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 EVIDENCE: Level II.

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

STUDY DESIGN: 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. OBJECTIVE: 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. SUMMARY OF BACKGROUND DATA: Little is known about PROs in the nonoperative management of ASLS or the prevalence and impact of SAEs on PROs. METHODS: 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. RESULTS: 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). CONCLUSION: A high percentage (25.7%) of ASLS patients managed nonoperatively experienced SAEs. Those patients who sustained a SAE had less improvement in reported outcomes. LEVEL OF EVIDENCE: 2.

Health-Related Quality of Life Scores Underestimate the Impact of Major Complications in Lumbar Degenerative Scoliosis Surgery.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: To examine Charlson Comorbidity Index (CCMI) as a marker for deterioration in health status not reflected in standard Health Related Quality of Life (HRQOL) measures. SUMMARY OF BACKGROUND DATA: HRQOL has become a primary metric for assessing outcomes following spinal deformity surgery. However, studies have reported limited impact of complications on postoperative HRQOL outcomes. METHODS: We examined serial CCMI, complications, and HRQOL outcomes for 138 adult lumbar deformity patients treated surgically with a minimum two-year follow-up that included 126 females (91%) with a mean age of 59.8 years (range, 40.2-78.5). Patients with no, minor, or major complications were compared at baseline and at one and two years postoperation. RESULTS: Minor complications were observed in 26 patients (19%) and major complications in 15 (11%). Major complications included motor deficit (7), deep vein thrombosis (4), and respiratory failure (3). There was no difference in preoperative SF-36 Physical Component Summary or Scoliosis Research Society-22R (SRS-22R) scores among the groups at baseline. Preoperative CCMI was lowest in the No Complication group (3.52 ± 1.70) followed by the Major (4.00 ± 1.13) and Minor Complication groups (4.15 ± 1.71, p = .165). At one year, there was a significantly greater CCMI deterioration in the Major Complication group (0.80 ± 1.01) compared to both the Minor (0.08 ± 0.27) and No Complication groups (0.27 ± 0.47, p < .001). There was no significant difference in SF-36 Physical Component Summary or SRS-22R scores among the three groups. Similar findings were observed at two years. CONCLUSIONS: Despite similar one- and two-year HRQOL improvement, patients with major complications had greater deterioration in CCMI. As CCMI is predictive of medical and surgical risk, patients who sustained a major complication now carry a greater likelihood of adverse outcomes with future interventions, including any subsequent spinal surgery. Although this increased risk may not alter the patient's perception of his or her current health status, it may be important, and should be recognized as part of the shared decision-making process. LEVEL OF EVIDENCE: Level II, high-quality prognostic study.

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

STUDY DESIGN: Longitudinal cohort. OBJECTIVES: To 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 DATA: The MCID and SCB thresholds for the SRS22R domains in patients with ASD and adolescent idiopathic scoliosis have been reported. METHODS: Patients 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. RESULTS: The 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. CONCLUSION: The 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 EVIDENCE: Level II.

Baseline Patient-Reported Outcomes Correlate Weakly With Radiographic Parameters: A Multicenter, Prospective NIH Adult Symptomatic Lumbar Scoliosis Study of 286 Patients.

STUDY DESIGN: Prospective, cross-sectional study. OBJECTIVE: The aim of the study was to determine which radiographic parameters drive patient-reported outcomes (PROs) in primary presentation adult symptomatic lumbar scoliosis (ASLS). SUMMARY OF BACKGROUND DATA: Previous literature suggests correlations between PROs and sagittal plane deformity (sagittal vertical axis [SVA], pelvic incidence-lumbar lordosis [PI-LL] mismatch, pelvic tilt [PT]). Prior work included revision and primary adult spinal deformity patients. The present study addresses only primary presentation ASLS. METHODS: Prospective baseline data were analyzed on 286 patients enrolled in an NIH RO1 clinical trial by nine centers from 2010 to 2014. INCLUSION CRITERIA: 40 to 80 years old, lumbar Cobb (LC) 30° or higher and Scoliosis Research Society-23 score 4.0 or less in Pain, Function or Self-Image domains, or Oswestry Disability Index (ODI) 20 or higher. Patients were primary presentation (no prior spinal deformity surgery) and had complete baseline data: standing coronal/sagittal 36" radiographs and PROs (ODI, Scoliosis Research Society-23, Short Form-12). Correlation coefficients were calculated to evaluate relations between radiographic parameters and PROs for the study population and a subset of patients with ODI 40 or higher. Analysis of variance was used to identify differences in PROs for radiographic modifier groups. RESULTS: Mean age was 60.3 years. Mean spinopelvic parameters were: LL = -39.2°; SVA = 3.1 cm; sacral slope = 32.5°; PT = 23.9°; PI-LL mismatch = 16.8°. Only weak correlations (0.2-0.4) were identified between population sacral slope, SVA and SVA modifiers, and SRS function. SVA and SVA modifiers were weakly associated with ODI. Although there were more correlations in subset analysis of high-symptom patients, all were weak. Analysis of variance identified significant differences in ODI reported by SVA modifier groups. CONCLUSION: In primary presentation patients with ASLS and a subset of "high-symptom" patients (ODI ≥ 40), only weak associations between baseline PROs and radiographic parameters were identified. For this patient population, these results suggest regional radiographic parameters (LC, LL, PT, PI-LL mismatch) are not drivers of PROs and cannot be used to extrapolate effect on patient-perceived pathology. LEVEL OF EVIDENCE: 2.

Predicting Kyphosis Correction During Posterior-Only Vertebral Column Resection by the Amount of Spinal Column Shortening.

STUDY DESIGN: Retrospective. OBJECTIVE: To investigate the relationship between the amount of correction achieved (K°) and extent of vertebral column shortening (mm) with posterior vertebral column resection (PVCR). SUMMARY OF BACKGROUND DATA: There is no scientific reference to the correlation between K° and column shortening (mm) with PVCR. METHODS: Based on simple geometry, we tested the hypothesis that we could predict the amount of actual kyphosis correction (K°) by calculation on 26 kyphotic PVCR patients. Using multiple linear measurements (mm), two angular approximations (°) were calculated: the geometric approximation (G°) using the geometric calculation (G-cal), and the rough approximation (R°) by more simplistic calculation (R-cal). Both G° and R° were compared against K° as measured on the pre- and postoperative radiographs. If calculated G° and R° is close to measured K°, we can use the calculations (G-cal and R-cal) in the clinical situation. RESULTS: The mean correction of K° was 38°. K°-G° and K°-R° were not significantly greater than 3° and 6°, respectively. As K° was very close to G° and R°, K° can replace G° and R°. Therefore, we can use G-cal and R-cal in the clinical setting and we can determine how much posterior shortening and what cage size is required to obtain a certain amount of K°. CONCLUSIONS: With two calculations (G-cal & R-cal), we can determine how much vertebral column shortening (mm) we need during PVCR to obtain the amount of kyphosis correction desired (K°). In order to obtain K°, using the formula deduced from G-cal and R-cal, we can determine the shortening between the upper and lower pedicle screws and cage size.

Comparison of spinal deformity surgery in patients with non-insulin-dependent diabetes mellitus (NIDDM) versus controls.

STUDY DESIGN: A retrospective review. OBJECTIVE: To quantify the exact impact of non-insulin-dependent diabetes mellitus (NIDDM) on operative complications and additional surgeries associated with spinal deformity surgery. SUMMARY OF BACKGROUND DATA: There are many references supporting diabetes mellitus (DM) as one of the major risk factors for perioperative complications in spinal surgery. However, the results vary depending on the type of DM, suggesting that insulin-dependent DM causes more complications than NIDDM, which is far more prevalent in the adult population with spinal deformity. METHODS: Among 5119 adult patients (older than 40 yr) with deformities, 23 patients with NIDDM and 23 control (group C) patients with a minimum 2-year follow-up were selected. Both groups were matched for age at surgery, sex, body mass index, number of comorbidities, smoking history, current and prior fusion levels, estimated blood loss, and the amount of transfusion. Pre- and final Scoliosis Research Society (SRS) scores and Oswestry Disability Index (ODI), number of perioperative complications, and additional surgeries were compared. Within the group with NIDDM, patients with (+) or without (-) complications were compared in terms of postoperative glucose control. RESULTS: There were no significant differences in the number of major or minor complications or additional surgeries between the 2 groups. There was no significant difference in postoperative glucose control with the NIDDM group (+) and (-). Group C reported significantly improved scores at final follow-up in all SRS domains and ODI. The group with NIDDM reported improvement in all domains except for the mental health and pain domains. However, there were no significant differences between the group with NIDDM and group C in terms of SRS and ODI scores preoperatively and postoperatively. CONCLUSION: Contrary to traditional thinking, properly selected NIDDM was not a significant risk factor for perioperative complications or additional surgeries in adult patients with spinal deformities.

Major complications in revision adult deformity surgery: risk factors and clinical outcomes with 2- to 7-year follow-up.

STUDY DESIGN: Retrospective cohort comparative study. OBJECTIVE: To determine the prevalence of major complications, identify risk factors, and assess long-term clinical benefit after revision adult spinal deformity surgery. SUMMARY OF BACKGROUND DATA: No study has analyzed risk factors for major complications in long revision fusion surgery and whether or not occurrence of a major complication affects ultimate clinical outcome. METHODS: Analysis of consecutive adult patients who underwent multilevel revision surgery for spinal deformity with a minimum 2-year follow-up was performed. All complications were classified as either major or minor. Outcome analysis was conducted with the Scoliosis Research Society and Oswestry Disability Index scores. RESULTS: A total of 166 patients (mean age = 53.8 years) were identified with a mean follow-up of 3.5 years (range: 2-7). Primary diagnoses included idiopathic/de novo scoliosis (107), degenerative (35), trauma (7), neuromuscular scoliosis (6), congenital deformity (5), ankylosing spondylitis (2), tumor (2), Scheuermann kyphosis (1), and rheumatoid arthritis (1). Most common secondary diagnoses that necessitated revision surgery were adjacent segment disease, fixed sagittal imbalance, and pseudarthrosis. Overall, 34.3% of patients developed major complications (19.3% perioperative; 18.7% follow-up). Associated risk factors for perioperative complications were patient- (age > 60 years, medical comorbidities, obesity) and surgery-related (pedicle subtraction osteotomy). Performance of a 3-column osteotomy and postoperative radiographic changes that suggested progressive loss of sagittal correction were recognized as risk factors for follow-up complications. Equivalent outcome scores were reported by patients preoperatively, but those experiencing follow-up complications reported lower scores at the final follow-up. CONCLUSION: Overall, 34.4% of patients experienced major complications after long revision fusion surgery. Different risk factors were identified for perioperative versus follow-up complications. The occurrence of a follow-up, not but perioperative, major complication seemed to have a negative impact on ultimate clinical outcome.

Comparative analysis of clinical outcome and complications in primary versus revision adult scoliosis surgery.

STUDY DESIGN: A retrospective case comparison study. OBJECTIVE: We compared clinical outcome and complications in adult patients who underwent primary (P) versus revision (R) scoliosis surgery. SUMMARY OF BACKGROUND DATA: There is a paucity of data comparing P versus R adult scoliosis patients with respect to their complication rates and clinical outcome. METHODS: Assessment of 250 consecutive adult patients who underwent P versus R surgery for idiopathic or de novo scoliosis between 2002 and 2007, with a minimum 2-year follow-up, was performed. RESULTS: There were 126 patients in the P group and 124 in the R group. Mean age at surgery (P = 51.2 vs. R = 51.6 years, P = 0.79), length of follow-up (P = 3.6 vs. R = 3.6 years, P = 0.94), comorbidities (P = 0.43), and smoking status (P = 0.98) were similar between the 2 groups. Body mass index (P = 25.5 vs. R = 27.4 kg/m, P = 0.01), number of final instrumented levels (P = 10.5 vs. R 12.1 levels, P = 0.00), fusion to the sacrum (P = 61.0% vs. R = 87.1%, P = 0.00), osteotomy (P = 14.3% vs. R = 54.9%, P = 0.00), length of surgery (P = 6.5 vs. R = 8.2 hours, P = 0.00), and estimated blood loss (P = 1072.1 vs. R = 1401.3 mL, P = 0.05) were different. Primary patients had significantly lower overall complications than revision patients (P = 45.2% vs. R = 58.2%, P = 0.042). Primary patients reported significantly higher preoperative and final clinical outcome measures in function, pain, and subscore SRS domains and ODI compared with revision patients (all P < 0.05). Patients older than 60 years of age, however, reported similar SRS and ODI scores between the 2 groups. The extent of surgical benefit patients received, that is, final minus preoperative score, was similar in all categories between the 2 groups. CONCLUSION: Adult patients undergoing primary scoliosis surgery had significantly lower overall complications compared with revision patients. Primary patients reported higher preoperative and final clinical outcome measures than revision patients, although this difference disappeared in older patients. The benefit of surgery was similar between the 2 groups.

Can we safely reduce blood loss during lumbar pedicle subtraction osteotomy procedures using tranexamic acid or aprotinin? A comparative study with controls.

STUDY DESIGN: Retrospective, observational study. OBJECTIVE: To compare the safety and efficacy of 2 pharmaceutical antifibrinolytic agents, aprotinin and tranexamic acid, in controlling blood loss during lumbar pedicle subtraction osteotomy (PSO) in adults. SUMMARY OF BACKGROUND DATA: Reconstructive spinal surgeries, in particular lumbar PSOs, have been associated with large blood losses despite interventions (intraoperative blood salvaging, controlled hypotensive anesthesia). Since the 1990s, intraoperative administration of antifibrinolytics (aprotinin, tranexamic acid, e-aminocaproic acid) has gained popularity. This study assesses the safety and efficacy of 2 antifibrinolytics, aprotinin and tranexamic acid, during adult lumbar PSO procedures at one institution. METHODS: A retrospective comparative analysis of 44 consecutive adults undergoing posterior spinal fusion procedures with lumbar PSO at one institution was performed. Patients were analyzed according to treatment group: controls (10), aprotinin (14), and tranexamic acid (20). There were no significant differences in demographic (gender, age, comorbidities) or surgical traits (length of surgery, levels fused/exposed, preoperative hematocrit, bone graft source, primary/revision) between the 3 groups. RESULTS: The aprotinin group had significantly less intraoperative blood loss (1114 +/- 992 mL; P < 0.01) than the tranexamic acid and control group (2102 +/- 1076 mL and 2260 +/- 1580 mL, respectively). The aprotinin group received significantly less blood (577 +/- 806 mL; P < 0.002) during the surgical procedure than the tranexamic acid (1838 +/- 1096 mL) and the control group (1502 +/- 1241 mL). There were no major intraoperative complications for any of the treatment groups. There were no postoperative cases of seizures, MI, CVA, DVT, or PE with any of the treatment groups. There was one acute tubular necrosis event in the aprotinin group, which resolved before discharge but did required several days of dialysis. CONCLUSION: The aprotinin treatment group lost significantly less blood and received significantly fewer blood transfusions than both the tranexamic acid and control groups without significant differences in intra- and postoperative complications. These results may justify further study of aprotinin and other antifibrinolytics for this specific indication (3-column lumbar osteotomies in the adult spinal deformity population). A multicenter randomized comparative analysis would be ideal.