What factors are associated with a better restoration of pelvic version after adult spinal deformity surgery?

INTRODUCTION: Poor restoration of pelvic version after adult spinal deformity (ASD) surgery is associated with an increased risk of mechanical complications and worse quality of life. We studied the factors linked to the improvement of postoperative pelvic version. MATERIALS AND METHODS: This is a retrospective analysis of a prospective multicenter ASD database. Selection criteria were: operated patients having preoperative severe pelvic retroversion as per GAP score (Relative Pelvic Version-RPV < - 15°); panlumbar fusions to the pelvis; 2-year follow-up. Group A comprised patients with any postoperative improvement of RPV score, and group B had no improvement. Groups were compared regarding baseline characteristics, surgical factors, and postoperative sagittal parameters. Parametric and non-parametric analyses were employed. RESULTS: 177 patients were studied, median age 67 years (61; 72.5), 83.6% female. Groups were homogeneous in baseline demographics, comorbidities, and preoperative sagittal parameters (p > 0.05). The difference in RPV improvement was 11.56º. Group A (137 patients) underwent a higher percentage of ALIF procedures (OR = 6.66; p = 0.049), and posterior osteotomies (OR = 4.96; p < 0.001) especially tricolumnar (OR = 2.31; p = 0.041). It also showed a lower percentage of TLIF procedures (OR = 0.45; p = 0.028), and posterior decompression (OR = 0.44; p = 0.024). Group A displayed better postoperative L4-S1 angle and relative lumbar lordosis (RLL), leading to improved sacral slope (and RPV), and global alignment (RSA). Group A patients had longer instrumentations (11.45 vs 10; p = 0.047) and hospitalization time (13 vs 11; p = 0.045). All postoperative sagittal parameters remained significantly better in group A through follow-up. However, differences between the groups narrowed over time. CONCLUSIONS: ALIF procedures and posterior column osteotomies improved pelvic version postoperatively, and associated better L4-S1 and lumbar lordosis restoration, indirectly improving all other sagittal parameters. However, these improvements seemed to fade during the 2-year follow-up.

Which sagittal plane assessment method is most predictive of complications after adult spinal deformity surgery?

PURPOSE: Different methods of sagittal alignment assessment compete for predicting adverse events after adult spinal deformity (ASD) surgery. We wanted to study which method provides greater benefit. METHODS: Retrospective study of 391 patients operated for ASD, with > 6 instrumented levels, fused to the pelvis, and 2 years of follow-up. Three alignment methods were analyzed 6-week postoperatively: (1) Roussouly mismatch; (2) GAP score/GAP categories; (3) T4-L1-Hip axis. Binary logistic regression generated models that best predict the following adverse events: mechanical complications (MC): in general and isolated (PJK, PJF, rod breakage); reinterventions (in general and after MC); and readmissions. ROC/AUC analysis was also implemented. In a second regression round, we added different variables that were selected on univariate analysis-demographic, surgical, and radiographic-to complete the models. RESULTS: The best predictor parameters in most models were T4-L1PA mismatch and GAP score; we could not prove a predictive ability of the Roussouly mismatch. The T4-L1PA mismatch best predicted general MC, PJK, PJK + PJF, and readmission, while the GAP score best predicted PJF and reinterventions (for MC and for any complication). However, the variance explained by these models was limited (Nagelkerke's R2 = 0.031-0.113), with odds ratios ranging from 1.070 to 1.456. ROC curves plotted an AUC between 0.57 and 0.70. Introducing additional variables (demographic, surgical, and radiographic) improved prediction in all the models (Nagelkerke's R2 = 0.082-0.329) and allowed predicting rod breakage. CONCLUSION: The T4-L1-Hip axis and GAP score show potential in predicting adverse events, surpassing the Roussouly method. Despite partial efficacy in complication anticipation, recognizing postoperative sagittal alignment as a key modifiable risk factor, the crucial need arises to integrate diverse variables, both modifiable and non-modifiable, for enhanced predictive accuracy. LEVEL OF EVIDENCE: Level IV.

Reliability of a New Digital Tool for Photographic Analysis in Quantifying Body Asymmetry in Scoliosis.

Background: Advancements in non-ionizing methods for quantifying spinal deformities are crucial for assessing and monitoring scoliosis. In this study, we analyzed the observer variability of a newly developed digital tool for quantifying body asymmetry from clinical photographs. Methods: Prospective observational multicenter study. Initially, a digital tool was developed using image analysis software, calculating quantitative measures of body asymmetry. This tool was integrated into an online platform that exports data to a database. The tool calculated 10 parameters, including angles (shoulder height, axilla height, waist height, right and left waistline angles, and their difference) and surfaces of the left and right hemitrunks (shoulders, waists, pelvises, and total). Subsequently, an online training course on the tool was conducted for twelve observers not involved in its development (six research coordinators and six spine surgeons). Finally, 15 standardized back photographs of adolescent idiopathic scoliosis patients were selected from a multicenter image bank, representing various clinical scenarios (different age, gender, curve type, BMI, and pre- and postoperative images). The 12 observers measured the photographs at two different times with a three-week interval. For the second round, the images were randomly mixed. Inter- and intra-observer variabilities of the measurements were analyzed using intraclass correlation coefficients (ICCs), and reliability was measured by the standard error of measurement (SEM). Group comparisons were made using Student's t-test. Results: The mean inter-observer ICC for the ten measurements was 0.981, the mean intra-observer ICC was 0.937, and SEM was 0.3-1.3°. The parameter with the strongest inter- and intra-observer validity was the difference in waistline angles 0.994 and 0.974, respectively, while the highest variability was found with the waist height angle 0.963 and 0.845, respectively. No test-retest differences (p > 0.05) were observed between researchers (0.948 ± 0.04) and surgeons (0.925 ± 0.05). Conclusion: We developed a new digital tool integrated into an online platform demonstrating excellent reliability and inter- and intra-observer variabilities for quantifying body asymmetry in scoliosis patients from a simple clinical photograph. The method could be used for assessing and monitoring scoliosis and body asymmetry without radiation.

The reunion with my patients: their journey and experience 30 years after their intervention for adolescent idiopathic scoliosis via CD instrumentation.

PURPOSE: Our objective was to collect the experience and current attitude of those patients, now adults, operated on for adolescent idiopathic scoliosis (AIS) more than 25 years ago with CD instrumentation (CDI). METHODS: Prospective qualitative cross-sectional study with interpretive phenomenological analysis approach of AIS patients operated in a single center with CDI between 1985 and 1995. Patients underwent a semi-structured interview with their original surgeon. Seven agreed themes were open for conversation, and several subthemes emerged related to their experience during their journey in life. Filed notes were recorded and transcribed verbatim. We used the method of content, semantic and pragmatic analysis. RESULTS: We contacted 103 patients, 100 agreed to participate. Mean age was 47.5 ± 3.3, mean follow-up was 30.9 ± 2.7 years. Three fundamental concerns stood out: discomfort with self-image; low back pain with daily activities; and lack of spinal flexibility. 50% were engaged in continuous physical exercise, and only some referred limitations with load-bearing work. Patients commonly described negative memories of the conservative treatment, but positive memories of the surgical process. In general, there was a good adaptation to social life (occupation, social and family relationships). Two-thirds were married, and 65 women had offspring. A frequent concern was the excess of radiographs over the years, and three developed breast cancer. CONCLUSIONS: Factors such as dissatisfaction with self-image, low back pain, and spine stiffness were relevant to patients throughout their journeys. Despite this, the great majority were satisfied with the treatment received, which allowed them to lead an integrated life in society. LEVEL OF EVIDENCE: Level II.

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

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

Relationship between pelvic incidence-adjusted relative spinopelvic parameters, global sagittal alignment and lower extremity compensations.

PURPOSE: In response to sagittal malalignment, compensatory spinal and lower extremity mechanisms are recruited. Thoracolumbar realignment surgery has been shown to yield reciprocal changes in these compensations. Thus, whole-body radiographic assessment has come to the fore. This study aimed to evaluate the relationship between spinopelvic parameters and lower extremity compensation angles and to examine their coupled change with deformity correction. METHODS: This was a multicenter retrospective analysis of patients who had ≥ 4 levels posterior fusion, whole-body radiographs, and ≥ 2 years follow-up. Relative Pelvic Version (RPV), Relative Lumbar Lordosis (RLL), Relative Spinopelvic Alignment (RSA), Femoral Obliquity Angle (FOA), Knee Flexion Angle (KFA) and Global Sagittal Axis (GSA) were measured preoperatively and 6 week postoperatively. Kruskal-Wallis tests were performed to assess the relation of relative spinopelvic parameters to global sagittal alignment and lower extremity compensation angles. Spearman's correlations were performed to assess correlations of pre-to-postoperative changes. RESULTS: 193 patients (156F, 37 M) were included. The mean age was 57.2 ± 16.6 years. The mean follow-up duration was 50.6 (24-90) months. On average, 10.3 ± 3.8 levels were fused. Among the cohort, 124 (64.2%) had a sacral or sacroiliac fixation, and 43 (22.3%) had 3-column osteotomies. Preoperative FOA, KFA and GSA significantly differed between RPV, RLL and RSA categories. Significant weak-to-strong correlations were observed between spinopelvic parameters, global sagittal alignment and lower extremity compensation angles (rho range: - 0.351 to 0.767). CONCLUSIONS: PI-adjusted relative spinopelvic parameters significantly correlated with measurements of the lower extremity compensation. Postoperative changes in RPV, RLL and RSA reflected changes in FOA, KFA and GSA. These measurements may serve as a valuable proxy for surgical planning when whole-body imaging is not available.

Outcomes of Growth-friendly Instrumentation in Osteogenesis Imperfecta: A Preliminary Report.

BACKGROUND: There is limited literature on the outcomes in patients with osteogenesis imperfecta (OI) undergoing growth-friendly instrumentation (GFI). The purpose of this study was to report the outcomes of GFI in patients with early-onset scoliosis (EOS) and OI. We hypothesized that similar trunk elongation could be obtained in OI patients, but with higher complication rates. METHODS: A multicenter database was studied for patients with EOS and OI etiology who had GFI from 2005 to 2020, with a minimum 2-year follow-up. Demographic, radiographic, clinical, and patient-reported outcomes data were collected and compared with an idiopathic EOS cohort matched 2:1 for age, follow-up duration, and curve magnitude. RESULTS: Fifteen OI patients underwent GFI at a mean age of 7.3±3.0 years, with an average follow-up of 7.3±3.9 years. OI patients had a mean preoperative coronal curve of 78.1±14.5 and achieved 35% correction after index surgery. There were no differences in major coronal curves and coronal percent correction between the OI and idiopathic groups at all time points. T1-S1 length (cm) was lower for the OI group at baseline (23.3±4.6 vs. 27.7±7.0; P =0.028) but both groups had similar growth (mm) per month (1.0±0.6 vs. 1.2±1.1; P =0.491). OI patients had a significantly increased risk of proximal anchor failure, which occurred in 8 OI patients (53%) versus 6 idiopathic patients (20%) ( P =0.039). OI patients who underwent preoperative halo-traction (N=4) had greater T1-S1 length gain (11.8±3.2 vs. 7.3±2.8; P =0.022) and greater percent major coronal curve correction (45±11 vs. 23±17; P =0.042) at final follow-up versus patients with no halo-traction (N=11). Staged foundation fusion was performed in 2 cases. CONCLUSION: Compared with matched idiopathic EOS patients, OI patients undergoing GFI achieved similar radiographic outcomes but sustained greater rates of anchor failures, likely due to weakened bone. Preoperative halo-traction was a useful adjunct and may improve final correction. Staged foundation fusion is an idea to consider for difficult cases. LEVEL OF EVIDENCE: Therapeutic-III.

Sagittal realignment: surgical restoration of the global alignment and proportion score parameters: a subgroup analysis. What are the consequences of failing to realign?

INTRODUCTION: The Global Alignment and Proportion (GAP) score incorporates three domains directly modified with surgery (relative pelvic version-RPV, relative lumbar lordosis-RLL, lumbar distribution index-LDI) and one indirectly restored (relative spinopelvic alignment-RSA). We analyzed our surgical realignment performance and the consequences of domain-specific realignment failure on mechanical complications and PROMs. MATERIALS AND METHODS: From an adult spinal deformity prospective multicenter database, we selected patients: fused to pelvis, upper instrumented vertebra at or above L1, and 2 years of follow-up. Descriptive, univariate and multivariate analyses were employed. RESULTS: The sample included 333 patients. RLL-6w showed the highest success rate (58.3% aligned), but 16.5% of patients were classified in the "Severe hypolordosis" and "Hyperlordosis" subgroups. RPV-6w was the most challenging to realign, with 51.6% moderate or severe retroversion. Regarding RSA-6w, 21.9% had severe positive malalignment. Correct alignment of RPV-6w (p = 0.025) and RSA-6w (p = 0.002) proved to be protective factors against the development of mechanical complications. Severe pelvic retroversion (p = 0.026) and severe positive malalignment (p = 0.007) were risk factors for mechanical complications. RSA-6w "Severe positive malalignment" was associated with less improvement in PROMs: ∆ODI (8.83 vs 17.2; p = 0.011), ∆SRS-22 total (0.54 vs 0.87; p = 0.007), and ∆SF-36PCS (3.47 vs 7.76; p = 0.04); MCID for ODI (37.0 vs 55.5%; p = 0.023), and SRS-22 (40.8 vs 60.1%; p = 0.015); and PASS for ODI (17.6 vs 31.7%; p = 0.047). CONCLUSIONS: RPV was the most underperformed modifiable parameter. Severe pelvic retroversion and severe positive malalignment influenced the occurrence of mechanical complications. Severe positive malalignment affected PROMs improvement.

Revision surgery following long lumbopelvic constructs for adult spinal deformity: prospective experience from two dedicated databases.

PURPOSE: Pan Lumbar Arthodesis (PLA) are often required for Adult Spinal Deformity (ASD) correction, reducing significantly the compensatory capacity in case of postoperative sagittal malalignment. Few papers have investigated outcomes and complications in this vulnerable subset of patients. The objective of this study was to assess revision surgery rate for PLA in ASD, its risk factors and impact on clinical outcomes. METHODS: Retrospective multicenter review of prospective ASD data from 7 hospitals covering Europe and Asia. ASD patients included in two prospective databases having a posterior instrumentation spanning the whole lumbar region with more than 2-years of follow-up were reviewed. Demographic, surgical, radiographic parameters and Health-Related Quality of Life (HRQoL) scores were analyzed. Univariate and multivariate regression models analyzed risk factors for revision surgery as well as surgical outcomes. Patients with Early versus Late and PJK versus Non-PJK mechanical complications were also compared. RESULTS: Out of 1359 ASD patients included in the database 589 (43%) had a PLA and 357 reached 2-years mark. They were analyzed and compared to non-PLA patients. Average age was 67 and 82% were females. 100 Patients (28.1%) needed 114 revision surgeries (75.4% for mechanical failures). Revised patients were more likely to have a nerve system disorder, higher BMI and worst immediate postoperative alignment (as measured by GAP Parameters). These risk factors were also associated with earlier mechanical complications and PJK. Deformity and HRQoL parameters were comparable at baseline. Non-revised patients had significantly better clinical outcomes at 2-years (SRS 22 scores, ODI, Back pain). Multivariate analysis could identify nerve system disorder (OR 4.8; CI 1.8-12.6; p = 0.001), postoperative sagittal alignment (GAP Score) and high BMI (OR 1.07; CI 1.01-1.13; p = 0.004) as independent risk factors for revisions. CONCLUSIONS: Revision surgery due to mechanical failures is relatively common after PLA leading to worse clinical outcomes. Prevention strategies should focus on individualized restoration of sagittal alignment and better weight control to decrease stress on these rigid constructs in non-compliant spines. Nerve system disorders independently increase revision risk in PLA. LEVEL OF EVIDENCE II: Prognosis.

Does the use of postoperative brace help preventing mechanical complications following adult deformity surgery?

PURPOSE: There is scarce information regarding the effectiveness of postoperative braces in decreasing mechanical complications and reinterventions following adult deformity surgery. METHODS: Retrospective matched cohort study from a prospective adult deformity multicenter database. We selected operated patients, fused to the pelvis, > 6 instrumented levels, and minimum 2 year follow-up. Three hundred and eighty patients were separated into two groups (Brace-3 months TLSO-vs No Brace) and then matched controlling for age, gender and frailty. We studied demographic, intraoperative, and postoperative spinopelvic parameters. Both groups were compared regarding complications and reinterventions in the first 2 postoperative years, using univariate and multivariate logistic regression analysis. RESULTS: We finally analyzed 359 matched patients, mean age of 65.3 ± 8.9 years, frailty-index (0.43 ± 0.15), and mostly females (84%). 224 patients wore a postoperative brace (B) and 135 didn't (NoB). They showed no difference in intraoperative variables and postoperative spinopelvic alignment. They differed (P < 0.05) in: Pelvic incidence (B:58° ± 13 vs NoB:54.5° ± 13); BMI (B:25.8 ± 4 vs NoB:27.4 ± 5); upper instrumented vertebra (B:81.7% T8-L1 vs NoB:72.6% T8-L1), and the use of multiple rods (B:47.3% vs NoB:18.5%). Univariate analysis showed a higher rate of mechanical complications and reinterventions when not using a brace. As well as higher NRS-back and leg pain at 6 weeks. However, multivariate analysis selected the use of multiple rods as the only independent factor protecting against mechanical complications (OR: 0.38; CI 95% 0.22-0.64) and reinterventions (OR: 0.41; CI 95% 0.216-0.783). CONCLUSION: After controlling for potential confounders, our study could not identify the protective effect of postoperative braces preventing mechanical complications and reinterventions in the first two postoperative years.

Association between sagittal alignment and loads at the adjacent segment in the fused spine: a combined clinical and musculoskeletal modeling study of 205 patients with adult spinal deformity.

PURPOSE: Sagittal malalignment is a risk factor for mechanical complications after surgery for adult spinal deformity (ASD). Spinal loads, modulated by sagittal alignment, may explain this relationship. The aims of this study were to investigate the relationships between: (1) postoperative changes in loads at the proximal segment and realignment, and (2) absolute postoperative loads and postoperative alignment measures. METHODS: A previously validated musculoskeletal model of the whole spine was applied to study a clinical sample of 205 patients with ASD. Based on clinical and radiographic data, pre-and postoperative patient-specific alignments were simulated to predict loads at the proximal segment adjacent to the spinal fusion. RESULTS: Weak-to-moderate associations were found between pre-to-postop changes in lumbar lordosis, LL (r = - 0.23, r = - 0.43; p < 0.001), global tilt, GT (r = 0.26, r = 0.38; p < 0.001) and the Global Alignment and Proportion score, GAP (r = 0.26, r = 0.37; p < 0.001), and changes in compressive and shear forces at the proximal segment. GAP score parameters, thoracic kyphosis measurements and the slope of upper instrumented vertebra were associated with changes in shear. In patients with T10-pelvis fusion, moderate-to-strong associations were found between postoperative sagittal alignment measures and compressive and shear loads, with GT showing the strongest correlations (r = 0.75, r = 0.73, p < 0.001). CONCLUSIONS: Spinal loads were estimated for patient-specific full spinal alignment profiles in a large cohort of patients with ASD pre-and postoperatively. Loads on the proximal segments were greater in association with sagittal malalignment and malorientation of proximal vertebra. Future work should explore whether they provide a causative mechanism explaining the associated risk of proximal junction complications.

Long-term opioid medication profile of European adult spinal deformity patients: minimum five years follow-up study.

BACKGROUND CONTEXT: There remains significant variability in the use of postoperative opioids. On one end, it is proven that appropriate pain control is a critical aspect of patient management; on the other end, past few decades have been associated with major increases in opioid-related overdoses and addiction treatment. We hypothesized that several pre- and postoperative risk factors affecting long-term opioid use could be identified. PURPOSE: Evaluation of factors associated with minimum 5-year postoperative opioid use following adult spinal deformity surgery. STUDY DESIGN/SETTING: Prospectively followed study group database. PATIENT SAMPLE: Adult spinal deformity patients who underwent elective spine surgery between 2009 and 2016 were included. OUTCOME MEASURES: Opioid usage or otherwise at minimum 5 years follow-up. Use of nonopioid analgesics, weak and strong opioids METHODS: Retrospective analysis of patients undergoing elective spinal deformity surgery. A total of 37 factors comprising patient characteristics, radiographic measurements, operative details, preoperative and early postoperative opioid use, and mechanical complications and revisions were analyzed. Details on identified factors were provided. RESULTS: A total of 265 patients (215F, 50M) from five sites were included. The mean follow-up duration was 68.4±11.7 (60-102) months. On average, 10.6±3.5 levels were fused. Preoperatively, 64 (24.2%) patients were using opioids. The rate of opioid users increased to 33.6% at 6 weeks and decreased to 21.5% at 6 months. During follow-up, there were patients who discontinued opioids, while others have started and/or restarted using opioids. As a result, 59 (22.3%) patients were still on opioids at the latest follow-up. Multivariate analyses showed that factors independently affecting opioid use at an average of 68 months postoperatively, in order of significance, were opioid use at sixth weeks, preoperative opioid use and opioid use at sixth months with the odds ratios of 2.88, 2.51, and 2.38 respectively. At these time points, factors such as age, number of comorbidities, tobacco use, the time of the last prior spine surgery and postoperative sagittal plane alignment affected opioid usage rates. CONCLUSIONS: Opioid usage at 6 weeks was found to be more predictive of long-term opioid use compared to preoperative use. Patients should be well informed to have realistic expectations regarding opioid use when considering adult spinal deformity surgery.

Combined anterior-posterior versus all-posterior approaches for adult spinal deformity correction: a matched control study.

PURPOSE: Anterior approaches are gaining popularity for adult spinal deformity (ASD) surgeries especially with the introduction of hyperlordotic cages and improvement in MIS techniques. Combined Approaches provide powerful segmental sagittal correction potential and increase the surface area available for fusion in ASD surgery, both of which would improve overall. This is the first study directly comparing surgical outcomes between combined anterior-posterior approaches and all-posterior approach in a matched ASD population. METHODS: This is a retrospective matched control cohort analysis with substitution using a multicenter prospectively collected ASD data of patients with > 2 year FU. Matching criteria include: age, American Society of Anesthesiologists Score, Lumbar Cobb angle, sagittal deformity (Global tilt) and ODI. RESULTS: In total, 1024 ASD patients were available for analysis. 29 Combined Approaches patients met inclusion criteria, and only 22 could be matched (1:2 ratio). Preoperative non-matched demographical, clinical, surgical and radiological parameters were comparable between both groups. Combined approaches had longer surgeries (548 mns vs 283) with more blood loss (2850 ml vs 1471) and needed longer ICU stays (74 h vs 27). Despite added morbidity, they had comparable complication rates but with significantly less readmissions (9.1% vs 38.1%) and reoperations (18.2% vs 43.2%) at 2 years. Combined Approaches achieved more individualised and harmonious deformity correction initially. At the 2 years control, Combined Approaches patients reported better outcomes as measured by COMI and SRS scores. This trend was maintained at 3 years. CONCLUSION: Despite an increased initial surgical invasiveness, combined approaches seem to achieve more harmonious correction with superior sagittal deformity control; they need fewer revisions and have improved long-term functional outcomes when compared to all-posterior approaches for ASD deformity correction.

Surgeons' risk perception in ASD surgery: The value of objective risk assessment on decision making and patient counselling.

BACKGROUND: Surgeons often rely on their intuition, experience and published data for surgical decision making and informed consent. Literature provides average values that do not allow for individualized assessments. Accurate validated machine learning (ML) risk calculators for adult spinal deformity (ASD) patients, based on 10 year multicentric prospective data, are currently available. The objective of this study is to assess surgeon ASD risk perception and compare it to validated risk calculator estimates. METHODS: Nine ASD complete (demographics, HRQL, radiology, surgical plan) preoperative cases were distributed online to 100 surgeons from 22 countries. Surgeons were asked to determine the risk of major complications and reoperations at 72 h, 90 d and 2 years postop, using a 0-100% risk scale. The same preoperative parameters circulated to surgeons were used to obtain ML risk calculator estimates. Concordance between surgeons' responses was analyzed using intraclass correlation coefficients (ICC) (poor < 0.5/excellent > 0.85). Distance between surgeons' and risk calculator predictions was assessed using the mean index of agreement (MIA) (poor < 0.5/excellent > 0.85). RESULTS: Thirty-nine surgeons (74.4% with > 10 years' experience), from 12 countries answered the survey. Surgeons' risk perception concordance was very low and heterogeneous. ICC ranged from 0.104 (reintervention risk at 72 h) to 0.316 (reintervention risk at 2 years). Distance between calculator and surgeon prediction was very large. MIA ranged from 0.122 to 0.416. Surgeons tended to overestimate the risk of major complications and reintervention in the first 72 h and underestimated the same risks at 2 years postop. CONCLUSIONS: This study shows that expert surgeon ASD risk perception is heterogeneous and highly discordant. Available validated ML ASD risk calculators can enable surgeons to provide more accurate and objective prognosis to adjust patient expectations, in real time, at the point of care.

Compensatory mechanisms recruited against proximal junctional kyphosis by patients instrumented from the thoracolumbar junction to the iliac.

PURPOSE: The compensatory mechanisms recruited by un-instrumented patients against sagittal imbalance are well documented. However, there is a lack of information regarding instrumented patients. MATERIAL AND METHODS: We performed a retrospective analysis of data collected prospectively in a multicenter adult spinal deformity database. We included patients suffering PJK/PJF after (T8-L2) to iliac instrumentation with minimum two-year follow-up. We measured quantitative sagittal spinopelvic and qualitative sagittal distribution parameters in the immediate postoperative period (6w) and at the time of PJK/PJF appearance. We analyzed how these parameters changed comparing these two time points with univariate and multivariate logistic regression analyses. RESULTS: A total of 69 patients were included. Two different patterns at PJK/PJF were found: 36 patients activated compensation (defined as an increase in pelvic retroversion (ΔRPV > 5º), and 33 did not (ΔRPV < 5º). The difference in behavior relied mostly on the amount of not surgically restored pelvic rotation at 6w (OR: 0.6; CI95%: 0.4-9.2; P = 0.017). Non-compensators had less rotation reserve (PTx100/PI = 33.9% vs 47.8%;P < 0.001) associated with worse 6w relative pelvic version and lower lumbar arc restoration, worse 6w relative sagittal alignment and GAP-score, compared with compensators (P < 0.001). Compensators' response was based on pelvic retroversion, causing lower lumbar arc decrease, lumbar apex caudal migration, and upper lumbar arc posterior inclination. Despite compensation, a thoracic kyphosis increase in both upper and lower arches gradually evolved into a PJK/PJF. Non-compensators did not react to PJK/PJF, which forced them into kyphosis from the lumbar apex and extending cranially, mainly throughout the upper thoracic arc. CONCLUSIONS: In patients fused from the TL junction to the iliac, those having greater postoperative pelvic rotation reserve showed greater capacity to recruit compensatory mechanisms against PJK/PJF.

The Effect of Discharging Patients with Low Hemoglobin Levels on Hospital Readmission and Quality of Life after Adult Spinal Deformity Surgery.

STUDY DESIGN: Retrospective cohort. PURPOSE: This study aims to evaluate the impact of anemia on functional outcomes, health-related quality of life (HRQoL), and early hospital readmission (EHR) rates after adult spinal deformity (ASD) surgery at the time of discharge from the hospital. OVERVIEW OF LITERATURE: Concerns with risks of transfusion, insufficient evidence for its benefits, and the possibility of associated adverse outcomes have led to restrictive transfusion practices. Therefore, patients are discharged according to patient blood management programs that are implemented in hospitals nationwide to reduce unnecessary blood transfusions. However, not many comprehensive kinds of studies exist on the effect of postoperative anemia on functional life and complications. METHODS: Anemia severity was defined following the 2011 World Health Organization guidelines. All patients had HRQoL tests as well as complete blood counts pre- and postoperatively. EHR is the admission within 30 days of discharge and was used as the dependent parameter. RESULTS: This study comprised 225 surgically treated ASD patients with a median age of 62.0 years, predominantly women (80%). Of the 225 patients, 82, 137, and six had mild, moderate, and severe anemia at the time of discharge, respectively. Seventeen of the patients (mild [11, 64.7%]; moderate [5, 29.4%]; severe [1, 5.9%]) were readmitted within 30 days. The mean hemoglobin values were higher in readmitted patients (p=0.071). Infection was the leading cause of readmission (n=12), but a low hemoglobin level was not observed in any of these patients at the time of discharge. Except for Scoliosis Research Society-22 questionnaire, HRQoL improvements did not reach statistical significance in early readmitted patients in the first year after surgery. CONCLUSIONS: The results of this study demonstrated that the occurrence and the severity of postoperative anemia are not associated with EHR in surgically treated patients with ASD. The findings of the current research suggested that clinical awareness of the parameters other than postoperative anemia may be crucial. Thus, improvements in HRQoL scores were poor in early readmitted patients 1 year after surgery.

An age and sex matched study on the effect of obesity on the functional outcomes and complication rates in patients with adult spinal deformity undergoing primary multi-level thoracolumbar spinal fusion.

Background: The objective of this study was to determine the effect of obesity on the functional outcomes and complication rates of patients with adult spinal deformity (ASD) undergoing multi-level thoracolumbar fusion. Methods: An age and sex matched comparison of functional outcomes [Numeric Rating Scale (NRS) back and leg scores, Core Outcome Measurement Index (COMI) back scores, Scoliosis Research Society 22 (SRS22) satisfaction and total scores, Short Form 36 (SF36) general health scores, Physical Component Score (PCS), Mental Component Score (MCS), Oswestry Disability Index (ODI) (including all domains)] at 6 months, 1, 2, 3 and 4 years and the complication rates at final follow-up between obese [body mass index (BMI) >30] and normal BMI (18.5-24.9) patients undergoing more than 3 levels of thoracolumbar fusion with a minimum 2-year follow-up. Patients who had undergone any previous spinal surgery were excluded. Results: Thirty patients were included in each arm of the study. Baseline demographics, including the number of levels fused, were similar between the groups. Estimated blood loss (EBL) was higher in obese patients (1,916 vs. 1,099 mL, P=0.001), but operative time was similar (282 vs. 320 min, P=0.351). The functional outcomes and satisfaction scores were consistently poorer in the obese group at all time-points, but their satisfaction scores were similar. Obese patients had a higher complication rate (OR 3.05, P=0.038) predominantly due to dural tears and nerve root injuries, but a similar reoperation rate. Conclusions: In patients with ASD undergoing multi-level thoracolumbar fusion, obesity results in a higher blood loss, poorer sagittal correction, poorer post-operative functional scores and higher complication rates than patients with a normal BMI. However, obesity does not affect operative times, length of hospital stay or reoperation rates. Furthermore, patients with obesity have similar post-operative satisfaction scores to patients with normal BMIs.

Quality metrics in adult spinal deformity surgery over the last decade: a combined analysis of the largest prospective multicenter data sets.

OBJECTIVE: The reported rate of complications and cost of adult spinal deformity (ASD) surgery, associated with an exponential increase in the number of surgeries, cause alarm among healthcare payers and providers worldwide. The authors conjointly analyzed the largest prospective available ASD data sets to define trends in quality-of-care indicators (complications, reinterventions, and health-related quality of life [HRQOL] outcomes) since 2010. METHODS: This is an observational prospective longitudinal cohort study. Patients underwent surgery between January 2010 and December 2016, with > 2 years of follow-up data. Demographic, surgical, radiological, and HRQOL (i.e., Oswestry Disability Index, SF-36, Scoliosis Research Society-22r) data obtained preoperatively and at 3, 6, 12, and 24 months after surgery were evaluated. Trends and changes in indicators were analyzed using local regression (i.e., locally estimated scatterplot smoothing [LOESS]) and adjusted odds ratio (OR). RESULTS: Of the 2286 patients included in the 2 registries, 1520 underwent surgery between 2010 and 2016. A total of 1151 (75.7%) patients who were treated surgically at 23 centers in 5 countries met inclusion criteria. Patient recruitment increased progressively (2010-2011 vs 2015-2016: OR 1.64, p < 0.01), whereas baseline clinical characteristics (age, American Society of Anesthesiologists class, HRQOL scores, sagittal deformity) did not change. Since 2010 there has been a sustained reduction in major and minor postoperative complications observed at 90 days (major: OR 0.59; minor: OR 0.65; p < 0.01); at 1 year (major: OR 0.52; minor: 0.75; p < 0.01); and at 2 years of follow-up (major: OR 0.4; minor: 0.80; p < 0.01) as well as in the 2-year reintervention rate (OR 0.41, p < 0.01). Simultaneously, there has been a slight improvement in the correction of sagittal deformity (i.e., pelvic incidence-lumbar lordosis mismatch: OR 1.11, p = 0.19) and a greater gain in quality of life (i.e., Oswestry Disability Index 26% vs 40%, p = 0.02; Scoliosis Research Society-22r, self-image domain OR 1.16, p = 0.13), and these are associated with a progressive reduction of surgical aggressiveness (number of fused segments: OR 0.81, p < 0.01; percent pelvic fixation: OR 0.66, p < 0.01; percent 3-column osteotomies: OR 0.63, p < 0.01). CONCLUSIONS: The best available data show a robust global improvement in quality metrics in ASD surgery over the last decade. Surgical complications and reoperations have been reduced by half, while improvement in disability increased and correction rates were maintained, in patients with similar baseline characteristics.

Obeid-Coronal Malalignment Classification Is Age Related and Independently Associated to Personal Reported Outcome Measurement Scores in the Nonfused Spine.

OBJECTIVE: To evaluate Obeid-coronal malalignment (O-CM) modifiers according to age, sagittal alignment, and patient-reported outcome measures (PROMs), in the mobile spine. METHODS: Retrospective review of a prospective multicenter adult spinal deformity (ASD) database with 1,243 (402 nonoperative, 841 operative) patients with no prior fusion surgery. Patients were included if they were aged over 18 years and were affected by spinal deformity defined by one of: Cobb angle ≥ 20°, pelvic tilt ≥ 25°, sagittal vertical axis ≥ 5 cm, thoracic kyphosis ≥ 60°. Patients were classified according to the O-CM classification and compared to coronally aligned patients. Multivariate analysis was performed on the relationship between PROMs and age, global tilt (GT) and coronal malalignment (CM). RESULTS: Four hundred forty-three patients had CM of more than 2 cm compared to 800 who did not. The distribution of these modifiers was correlated to age. After multivariate analysis, using age and GT as confounding factors, we found that before the age of 50 years, 2A1 patients had worse sex life and greater satisfaction than patients without CM. After 50 years of age, patients with CM (1A1, 1A2) had worse self-image and those with 2A2, 2B had worse self-image, satisfaction, and 36-item Short Form Health Survey physical function. Self-image was the consistent determinant of patients opting for surgery for all ages. CONCLUSION: CM distribution according to O-CM modifiers is age dependent. A clear correlation between the coronal malalignment and PROMs exists when using the O-CM classification and in the mobile spine, this typically affects self-image and satisfaction. Thus, CM classified according to O-CM modifiers is correlated to PROMs and should be considered in ASD.