STUDY DESIGN.Retrospective review.
OBJECTIVE.Develop a simplified frailty index for cervical deformity (CD) patients.
SUMMARY OF BACKGROUND DATA.To improve preoperative risk stratification for ...surgical CD patients, a CD frailty index (CD-FI) incorporating 40 health deficits was developed. While novel, the CD-FI is clinically impractical due to the large number of factors needed for its calculation. To increase clinical utility, a simpler, modified CD-FI (mCD-FI) is necessary.
METHODS.CD patients (C2-C7 Cobb>10°, CL>10°, cSVA>4 cm, or CBVA>25°) >18 year with preoperative CD-FI component factors. Pearson bivariate correlation assessed relationships between component deficits of the CD-FI and overall CD-FI score. Top deficits contributing to CD-FI score were included in multiple stepwise regression models. Deficits from model with largest R were dichotomized, and the mean score of all deficits calculated, resulting in mCD-FI score from 0 to 1. Patients were stratified by mCD-FINot Frail (NF, <0.3), Frail (0.3–0.5), Severely Frail (SF, >0.5). Means comparison tests established correlations between frailty category and clinical outcomes.
RESULTS.Included121 CD patients (61 ± 11 yr, 60%F). Multiple stepwise regression models identified 15 deficits as responsible for 86% of the variation in CD-FI; these factors were used to construct the mCD-FI. Overall, mean mCD-FI was 0.31 ± 0.14. Breakdown of patients by mCD-FI categoryNF47.9%, Frail46.3%, SF5.8%. Compared with NF and Frail, SF patients had the longest inpatient hospital stays (P = 0.042), as well as greater baseline neck pain (P = 0.033), inferior Neck Disability Index scores (P<0.001) and inferior EQ-5D scores (P < 0.001). Frail patients had higher odds of superficial infection (OR:1.11.0–1.2), and SF patients had increased odds of mortality (OR:8.31.3–53.9).
CONCLUSION.Increased frailty, assessed by mCD-FI, correlated with increased length of stay, neck pain, and decreased health-related quality of life. Frail patients were at greater risk for infection, and severely frail patients had greater odds of mortality. This relationship between frailty and clinical outcomes suggests that mCD-FI offers clinical utility as a preoperative risk stratification tool.Level of Evidence3
STUDY DESIGN.Retrospective review of prospectively-collected, multicenter adult spinal deformity (ASD) database.
OBJECTIVE.The aim of this study was to evaluate the rate of patients who accrue ...catastrophic cost (CC) with ASD surgery utilizing direct, actual costs, and determine the feasibility of predicting these outliers.
SUMMARY OF BACKGROUND DATA.Cost outliers or surgeries resulting in CC are a major concern for ASD surgery as some question the sustainability of these surgical treatments.
METHODS.Generalized linear regression models were used to explain the determinants of direct costs. Regression tree and random forest models were used to predict which patients would have CC (>$100,000).
RESULTS.A total of 210 ASD patients were included (mean age of 59.3 years, 83% women). The mean index episode of care direct cost was $70,766 (SD = $24,422). By 90 days and 2 years following surgery, mean direct costs increased to $74,073 and $77,765, respectively. Within 90 days of the index surgery, 11 (5.2%) patients underwent 13 revisions procedures, and by 2 years, 26 (12.4%) patients had undergone 36 revision procedures. The CC threshold at the index surgery and 90-day and 2-year follow-up time points was exceeded by 11.9%, 14.8%, and 19.1% of patients, respectively. Top predictors of cost included number of levels fused, surgeon, surgical approach, interbody fusion (IBF), and length of hospital stay (LOS). At 90 days and 2 years, a total of 80.6% and 64.0% of variance in direct cost, respectively, was explained in the generalized linear regression models. Predictors of CC were number of fused levels, surgical approach, surgeon, IBF, and LOS.
CONCLUSION.The present study demonstrates that direct cost in ASD surgery can be accurately predicted. Collectively, these findings may not only prove useful for bundled care initiatives, but also may provide insight into means to reduce and better predict cost of ASD surgery outside of bundled payment plans.Level of Evidence3
The impact of ethnicity on the surgery outcomes of adolescent idiopathic scoliosis in the adult (AISA) is poorly understood. This study aimed to compare the surgery outcomes for AISA between the ...United States (US) and Japan (JP).
171 surgically treated AISA (20-40y) were consecutively collected from 2 separate multicenter databases. Patients were propensity-score matched for age, gender, curve type, levels fused, and 2y postop spinal alignment. Demographic and radiographic parameters were compared between the US and JP at baseline and 2y post-op.
A total of 108 patients were matched by propensity score (age; US vs. JP: 29 ± 6 vs. 29 ± 7y, females: 76 vs. 76%, curve type Schwab-SRS TypeT; TypeD; TypeL; TypeN: 35; 35; 30; 0 vs. 37; 33; 30; 0%) levels fused: 10 ± 4 vs. 10 ± 4, 2y thoracic curve:17 ± 13 vs. 17 ± 12°, 2y CSVL: 10 ± 8 vs. 11 ± 9 mm). Similar clinical improvement was achieved between US and JP (function; 4.2 ± 0.9 vs 4.3 ± 0.6, p = 0.60, pain; 3.8 ± 0.9 vs 4.1 ± 0.8, p = 0.13, satisfaction; 4.3 ± 0.9 vs 4.2 ± 0.7, p = 0.61, total; 4.0 ± 0.8 vs 4.1 ± 0.5, p = 0.60). The correlation analyzes indicated that postoperative SRS-22 subdomains correlated differently with satisfaction (all subdomains moderately correlated with satisfaction in the US while only pain and mental health correlated moderately with satisfaction in JP (function: r = 0.61 vs 0.29, pain: r = . 72 vs 0.54, self-image: r = 0.72 vs 0.37, mental health: r = 0.64 vs 0.55).
Surgery for AISA was similarly effective in the US and JP. Satisfaction for spinal surgery among patients in different countries may not be different unless the procedure limits an individual's unique lifestyle that the patient expected to resume.
Three-column osteotomies (3COs), usually in the form of pedicle subtraction or vertebral column resection, have become common in adult spinal deformity surgery. Although a powerful tool for deformity ...correction, 3COs can increase the risks of perioperative morbidity.
Operative patients with adult spinal deformity (Cobb angle of >20°, sagittal vertical axis SVA of >5 cm, pelvic tilt of >25°, and/or thoracic kyphosis of >60°) with available baseline and 2-year radiographic and health-related quality-of-life (HRQoL) data were included. Patients were stratified into 2 groups by surgical year: Group I (2008 to 2013) and Group II (2014 to 2018). Patients with 3COs were then isolated for outcomes analysis. Severe sagittal deformity was defined by an SVA of >9.5 cm. Best clinical outcome (BCO) was defined as an Oswestry Disability Index (ODI) of <15 and Scoliosis Research Society (SRS)-22 of >4.5. Multivariable regression analyses were used to assess differences in surgical, radiographic, and clinical parameters.
Seven hundred and fifty-two patients with adult spinal deformity met the inclusion criteria, and 138 patients underwent a 3CO. Controlling for baseline SVA, PI-LL (pelvic incidence minus lumbar lordosis), revision status, age, and Charlson Comorbidity Index (CCI), Group II was less likely than Group I to have a 3CO (21% versus 31%; odds ratio OR = 0.6; 95% confidence interval CI = 0.4 to 0.97) and more likely to have an anterior lumbar interbody fusion (ALIF; OR = 1.6; 95% CI = 1.3 to 2.3) and a lateral lumbar interbody fusion (LLIF; OR = 3.8; 95% CI = 2.3 to 6.2). Adjusted analyses showed that Group II had a higher likelihood of supplemental rod usage (OR = 21.8; 95% CI = 7.8 to 61) and a lower likelihood of proximal junctional failure (PJF; OR = 0.23; 95% CI = 0.07 to 0.76) and overall hardware complications by 2 years (OR = 0.28; 95% CI = 0.1 to 0.8). In an adjusted analysis, Group II had a higher likelihood of titanium rod usage (OR = 2.7; 95% CI = 1.03 to 7.2). Group II had a lower 2-year ODI and higher scores on Short Form (SF)-36 components and SRS-22 total (p < 0.05 for all). Controlling for baseline ODI, Group II was more likely to reach the BCO for the ODI (OR = 2.8; 95% CI = 1.2 to 6.4) and the SRS-22 total score (OR = 4.6; 95% CI = 1.3 to 16).
Over a 10-year period, the rates of 3CO usage declined, including in cases of severe deformity, with an increase in the usage of PJF prophylaxis. A better understanding of the utility of 3CO, along with a greater implementation of preventive measures, has led to a decrease in complications and PJF and a significant improvement in patient-reported outcome measures.
Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.
Purpose
Health-related quality of life (HRQL) instruments are essential in value-driven health care, but patients often have more specific, personal priorities when seeking surgical care. The ...Scoliosis Research Society-22R (SRS-22R), an HRQL instrument for spinal deformity, provides summary scores spanning several health domains, but these may be difficult for patients to utilize in planning their specific care goals. Our objective was to create preoperative predictive models for responses to individual SRS-22R questions at 1 and 2 years after adult spinal deformity (ASD) surgery to facilitate precision surgical care.
Methods
Two prospective observational cohorts were queried for ASD patients with SRS-22R data at baseline and 1 and 2 years after surgery. In total, 150 covariates were used in training machine learning models, including demographics, surgical data and perioperative complications. Validation was accomplished via an 80%/20% data split for training and testing, respectively. Goodness of fit was measured using area under receiver operating characteristic (AUROC) curves.
Results
In total, 561 patients met inclusion criteria. The AUROC ranged from 56.5 to 86.9%, reflecting successful fits for most questions. SRS-22R questions regarding pain, disability and social and labor function were the most accurately predicted. Models were less sensitive to questions regarding general satisfaction, depression/anxiety and appearance.
Conclusions
To the best of our knowledge, this is the first study to explicitly model the prediction of individual answers to the SRS-22R questionnaire at 1 and 2 years after deformity surgery. The ability to predict individual question responses may prove useful in preoperative counseling in the age of individualized medicine.
Graphic abstract
These slides can be retrieved under Electronic Supplementary Material.
Abstract
BACKGROUND: Although adult cervical spine deformity (ACSD) is associated with pain and disability, its health impact has not been quantified in comparison to other chronic diseases.
...OBJECTIVE: To perform a comparative analysis of the health impact of symptomatic ACSD to US normative and chronic disease values using EQ-5D (EuroQuol-5 Dimensions questionnaire) scores.
METHODS: ACSD patients presenting for surgical treatment were identified from a prospectively collected multicenter database. Baseline demographics and EQ-5D scores were collected and compared with US normative and disease state values.
RESULTS: Of 121 ACSD patients, 115 (95%) completed the EQ-5D (60% women, mean age 61 years, previous spine surgery in 44%). Diagnoses included kyphosis with mid-cervical (63.4%), cervico-thoracic (23.5%), or thoracic (8.7%) apex and primary coronal deformity (4.3%). The mean ACSD EQ-5D index was 0.511 (standard definition = 0.224), which is 34% below the bottom 25th percentile (0.780) for similar age- and gender-matched US normative populations. Mean ACSD EQ-5D index values were worse than the bottom 25th percentile for several other disease states, including chronic ischemic heart disease (0.708), malignant breast cancer (0.708), and malignant prostate cancer (0.708). ACSD mean index values were comparable to the bottom 25th percentile values for blindness/low vision (0.543), emphysema (0.508), renal failure (0.506), and stroke (0.463). EQ-5D scores did not significantly differ based on cervical deformity type (P = .66).
CONCLUSION: The health impact of symptomatic ACSD is substantial, with negative impact across all EQ-5D domains. The mean ACSD EQ-5D index was comparable to the bottom 25th percentile values for blindness/low vision, emphysema, renal failure, and stroke.
Purpose
To assess the ability of the recently developed adult spinal deformity frailty index (ASD-FI) to predict odds of perioperative complications, odds of reoperation, and length of hospital stay ...after adult spinal deformity (ASD) surgery using a database other than the one used to create the index.
Methods
We used the ASD-FI to calculate frailty scores for 266 ASD patients who had minimum postoperative follow-up of 2 years in the European Spine Study Group (ESSG) database. Patients were enrolled from 2012 through 2013. Using ASD-FI scores, we categorized patients as not frail (NF) (< 0.3 points), frail (0.3–0.5 points), or severely frail (SF) (> 0.5 points). Multivariable logistic regression, adjusted for preoperative and surgical factors such as operative time and blood loss, was performed to determine the relationship between ASD-FI category and odds of major complications, odds of reoperation, and length of hospital stay.
Results
We categorized 135 patients (51%) as NF, 90 patients (34%) as frail, and 41 patients (15%) as SF. Overall mean ASD-FI score was 0.29 (range 0–0.8). The adjusted odds of experiencing a major intraoperative or postoperative complication (OR 4.5, 95% CI 2.0–10) or having a reoperation (OR 3.9, 95% CI 1.7–8.9) were higher for SF patients compared with NF patients. Mean hospital stay was 2.1 times longer (95% CI 1.8–2.4) for SF patients compared with NF patients.
Conclusions
Greater patient frailty, as measured by the ASD-FI, is associated with longer hospital stays and greater odds of major complications and reoperation.
Graphical abstract
These slides can be retrieved under Electronic Supplementary Material.
prospective, multicenter.
To determine if models for predicting outcome and complications in the setting of adult deformity surgery can be constructed.
A classification of adult spinal deformity has ...been established. The latter categorizes patients radiographically and ties to disability as well as most likely treatment approach. Classification by radiographs alone is insufficient to guide treatment and models for predicting outcome are necessary to establish algorithms.
This is a longitudinal study of adult patients with spinal deformity. All subjects were drawn from a prospective multicenter database. Baseline, 1-year and 2-year radiographic and health related quality of life measures were obtained (SRS, ODI, SF-12). Any peri- or postoperative complications were tabulated. Binary and logistic regressions were applied to create models of outcome and complications.
Predictive models of reaching a minimal clinically important difference had an area under the ROC curve above 0.82 and correct classification from 75% to 81%. Development of a complication was correctly classified in 71% of cases. Patients most likely to reach threshold improvement through surgery: older, lower apex deformity, greater disability, higher deformity score by classification. Patients most likely to develop complications: high sagittal balance grade and fusion to sacrum.
By applying the classification of adult deformity and considering baseline health status, models for predicting outcome can be established. Further work will refine these models and permit clinical validation. This effort will help establish reliable clinical models such that treatment algorithms can be established for the challenging patients suffering from adult spinal deformity.
ABSTRACT
BACKGROUND
Distal junctional kyphosis (DJK) development after cervical deformity (CD)-corrective surgery is a growing concern for surgeons and patients. Few studies have investigated risk ...factors that predict the occurrence of DJK.
OBJECTIVE
To predict DJK development after CD surgery using predictive modeling.
METHODS
CD criteria was at least one of the following: C2-C7 Coronal/Cobb > 10°, C2-7 sagittal vertical axis (cSVA) > 4 cm, chin-brow vertical angle > 25°. DJK was defined as the development of an angle <−10° from the end of fusion construct to the second distal vertebra, and change in this angle by <−10° from baseline to postoperative. Baseline demographic, clinical, and surgical information were used to predict the occurrence of DJK using generalized linear modeling both as one overall model and as submodels using baseline demographic and clinical predictors or surgical predictors.
RESULTS
One hundred seventeen CD patients were included. At any postoperative visit up to 1 yr, 23.1% of CD patients developed DJK. DJK was predicted with high accuracy using a combination of baseline demographic, clinical, and surgical factors by the following factors: preoperative neurological deficit, use of transition rod, C2-C7 lordosis (CL)<−12°, T1 slope minus CL > 31°, and cSVA > 54 mm. In the model using only baseline demographic/clinical predictors of DJK, presence of comorbidities, presence of baseline neurological deficit, and high preoperative C2-T3 angle were included in the final model (area under the curve = 87%). The final model using only surgical predictors for DJK included combined approach, posterior upper instrumented vertebrae below C4, use of transition rod, lack of anterior corpectomy, more than 3 posterior osteotomies, and performance of a 3-column osteotomy.
CONCLUSION
Preoperative assessment and consideration should be given to these factors that are predictive of DJK to mitigate poor outcomes.
Retrospective cohort study.
Assess whether modifying spinal alignment goals to accommodate frailty considerations will decrease mechanical complications and maximize clinical outcomes.
The Global ...Alignment and Proportion (GAP) score was developed to assist in reducing mechanical complications, but has had less success predicting such events in external validation. Higher frailty and many of its components have been linked to the development of implant failure. Therefore, modifying the GAP score with frailty may strengthen its ability to predict mechanical complications.
We included 412 surgical ASD patients with two-year follow-up. Frailty was quantified using the modified Adult Spinal Deformity Frailty Index (mASD-FI). Outcomes: proximal junctional kyphosis and proximal junctional failure (PJF), major mechanical complications, and "Best Clinical Outcome" (BCO), defined as Oswestry Disability Index<15 and Scoliosis Research Society 22-item Questionnaire Total>4.5. Logistic regression analysis established a six-week score based on GAP score, frailty, and Oswestry Disability Index US Norms. Logistic regression followed by conditional inference tree analysis generated categorical thresholds. Multivariable logistic regression analysis controlling for confounders was used to assess the performance of the frailty-modified GAP score.
Baseline frailty categories: 57% not frail, 30% frail, 14% severely frail. Overall, 39 of patients developed proximal junctional kyphosis, 8% PJF, 21% mechanical complications, 22% underwent reoperation, and 15% met BCO. The mASD-FI demonstrated a correlation with developing PJF, mechanical complications, undergoing reoperation, and meeting BCO at two years (all P <0.05). Regression analysis generated the following equation: Frailty-Adjusted Realignment Score (FAR Score)=0.49×mASD-FI+0.38×GAP Score. Thresholds for the FAR score (0-13): proportioned: <3.5, moderately disproportioned: 3.5-7.5, severely disproportioned: >7.5. Multivariable logistic regression assessing FAR score demonstrated associations with mechanical complications, reoperation, and meeting BCO by two years (all P <0.05), whereas the original GAP score was only significant for reoperation.
This study demonstrated adjusting alignment goals in adult spinal deformity surgery for a patient's baseline frailty status and disability may be useful in minimizing the risk of complications and adverse events, outperforming the original GAP score in terms of prognostic capacity.
III.
