Background: Instrumented spinal fusions can be used in the treatment of vertebral fractures, spinal instability, and scoliosis or kyphosis. Construct-level selection has notable implications on postoperative recovery, alignment, and mobility. This study sought to project future trends in the implementation rates and associated costs of single-level versus multilevel instrumentation procedures in US Medicare patients aged older than 65 years in the United States. Methods: Data were acquired from the Centers for Medicare & Medicaid Services from January 1, 2000, to December 31, 2019. Procedure costs and counts were abstracted using Current Procedural Terminology codes to identify spinal level involvement. The Prophet machine learning algorithm was used, using a Bayesian Inference framework, to generate point forecasts for 2020 to 2050 and 95% forecast intervals (FIs). Sensitivity analyses were done by comparing projections from linear, log-linear, Poisson and negative-binomial, and autoregressive integrated moving average models. Costs were adjusted for inflation using the 2019 US Bureau of Labor Statistics' Consumer Price Index. Results: Between 2000 and 2019, the annual spinal instrumentation volume increased by 776% (from 7,342 to 64,350 cases) for single level, by 329% (from 20,319 to 87,253 cases) for two-four levels, by 1049% (from 1,218 to 14,000 cases) for five-seven levels, and by 739% (from 193 to 1,620 cases) for eight-twelve levels (P < 0.0001). The inflation-adjusted reimbursement for single-level instrumentation procedures decreased 45.6% from $1,148.15 to $788.62 between 2000 and 2019, which is markedly lower than for other prevalent orthopaedic procedures: total shoulder arthroplasty (−23.1%), total hip arthroplasty (−39.2%), and total knee arthroplasty (−42.4%). By 2050, the number of single-level spinal instrumentation procedures performed yearly is projected to be 124,061 (95% FI, 87,027 to 142,907), with associated costs of $93,900,672 (95% FI, $80,281,788 to $108,220,932). Conclusions: The number of single-level instrumentation procedures is projected to double by 2050, while the number of two-four level procedures will double by 2040. These projections offer a measurable basis for resource allocation and procedural distribution.

Systematic review and meta-analysis. To conduct a literature review on outcomes of discectomy for upper lumbar disc herniations (ULDH), estimate pooled rates of satisfactory outcomes, compare open laminectomy/microdiscectomy (OLM) versus minimally invasive surgical (MIS) techniques, and compare results of disc herniations at L1-3 versus L3-4. A systematic review of articles reporting outcomes of nonfusion surgical treatment of L1-2, L2-3, and/or L3-4 disc herniations was performed. The inclusion and exclusion of studies was performed according to the latest version of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A total of 20 articles were included in the quantitative meta-analysis. Pooled proportion of satisfactory outcome (95% CI) was 0.77 (0.70, 0.83) for MIS and 0.82 (0.78, 0.84) for OLM. There was no significant improvement with MIS techniques compared with standard OLM, odds ratio (OR) = 0.86, 95% CI (0.42, 1.74), P = .66. Separating results by levels revealed a trend of higher satisfaction with L3-4 versus L1-3 with OLM surgery, OR = 0.46, 95% CI (0.19, 1.12), P = .08. Our analysis reveals that discectomy for ULDH has an overall success rate of approximately 80% and has not improved with MIS. Discectomy for herniations at L3-4 trends toward better outcomes compared with L1-2 and L2-3, but was not significant.

Prediction of blood transfusion after adult spinal deformity (ASD) surgery can identify at-risk patients and potentially reduce its utilization and the complications associated with it. The use of artificial neural networks (ANNs) offers the potential for high predictive capability. A total of 1173 patients who underwent surgery for ASD were identified in the 2017–2019 NSQIP databases. The data were split into 70% training and 30% testing cohorts. Eighteen patient and operative variables were used. The outcome variable was receiving RBC transfusion intraoperatively or within 72 h after surgery. The model was assessed by its sensitivity, positive predictive value, F1-score, accuracy (ACC), and area under the curve (AUROC). Average patient age was 56 years and 63% were female. Pelvic fixation was performed in 21.3% of patients and three-column osteotomies in 19.5% of cases. The transfusion rate was 50.0% (586/1173 patients). The best model showed an overall ACC of 81% and 77% on the training and testing data, respectively. On the testing data, the sensitivity was 80%, the positive predictive value 76%, and the F1-score was 78%. The AUROC was 0.84. ANNs may allow the identification of at-risk patients, potentially decrease the risk of transfusion via strategic planning, and improve resource allocation.

Background: Disparities among patients with cancer are well documented. Recent studies suggest these disparities also affect patients undergoing metastatic spinal tumor surgery. However, it is unclear whether social factors are associated with ambulatory outcomes or overall survival. Questions/purposes: In patients undergoing metastatic spinal tumor surgery, (1) Are race, Social Vulnerability Index (SVI) score, or insurance status associated with a lower likelihood of postoperative ambulation? (2) Are race, SVI score, or insurance status associated with shorter overall survival? Methods: Between April 2012 and June 2021, we surgically treated 148 patients for metastatic cord compression or spinal mechanical instability because of cancer. Inclusion criteria were patients with complete demographic, social, oncologic, and follow-up data and patients who were followed until death or for at least 3 months postoperatively. Based on these criteria, 12% (18 of 148) were excluded because they had incomplete data and another 7% (11 of 148) were excluded because they were lost before the minimum study follow-up interval, leaving 80% (119) for analysis. Collected social data included self-reported race (White, Black, Hispanic or Latino, or other), SVI score, and primary insurance (Medicare, Medicaid, or private). The median age of the group was 62 years (interquartile range [IQR] 53 to 70 years), and 58% of patients were men (69 of 119). The race distribution was 45% Black (54 of 119), 32% Hispanic or Latino (38 of 119), 16% White (19 of 119), and 7% other (eight of 119). The median SVI score was 89.8 (IQR 73.8 to 98.5), and 74% of patients (88) were categorized as having high vulnerability. The insurance distribution was as follows: Medicare: 43%, Medicaid: 36%, and private insurance: 21%. The primary outcome variable was complete inability to ambulate postoperatively and the secondary outcome was median overall survival. Exploratory data analysis, univariate and multivariate logistic regression, and univariate and multivariate Cox regression analyses were performed. Results: After controlling for race, SVI score, insurance status, primary cancer, and modified Bauer score, the only factor independently associated with postoperative nonambulation was preoperative nonambulatory status (odds ratio 59.3 [95% confidence interval (CI) 13.2 to 266.1]; p < 0.001). After controlling for variables such as performance status, BMI, primary cancer, modified Bauer score, and insurance status, factors independently associated with survival included Eastern Cooperative Oncology Group performance status (hazard ratio [HR] 1.4 [95% CI 1.1 to 2.0]; p = 0.03), prostate cancer (HR 0.4 [95% CI 0.1 to 0.9]; p = 0.03), and hematologic cancer (HR 0.3 [95% CI 0.1 to 0.8]; p = 0.02). Race, SVI score, and insurance status were not associated with overall survival. Conclusion.: In this study, we found no difference in ambulatory outcome for patients based on their race, SVI score, or insurance status. Likewise, no differences in postoperative survival were found. These findings suggest that despite differences in presentation or short-term outcome reported in other investigations, the social factors we explored were not associated with the likelihood of a patient being nonambulatory postoperatively or shorter survival after spinal tumor surgery. Research studies that analyze race as a covariate of interest should take care to explore metrics of socioeconomic deprivation (such as the SVI score) to avoid drawing misleading conclusions. Level of Evidence: Level III, therapeutic study.