Innovative technologies in thoracolumbar and lumbar spine surgery failing to reach standard of care: state-of-art review.

PURPOSE: To evaluate previously popular technologies in the field of spine surgery, and to better understand their advantages and limitations to the current standards of care. Spine surgery is an ever-evolving field that serves to resolve various spinal pathologies in patients of all ages. While there are established treatments for various conditions, such as lumbar spinal stenosis, idiopathic scoliosis, and degenerative lumbar disease, there is always further research and development in these areas to produce innovative technologies that can lead to better outcomes. As this process progresses, we must remind ourselves of previously tried and tested inventions and their outcomes that have fallen short of becoming a standard to ensure we are able to learn lessons from the past. METHODS: A thorough literature review was conducted with the aim of compiling literature of previously utilized technologies in spine surgery. Biomedical databases were utilized to gather relevant articles including PubMed, MEDLINE, and EMBASE. Emphasis was placed on gathering articles with technologies or therapeutics aimed at treating common spinal pathologies including lumbar spinal stenosis (LSS), adolescent idiopathic scoliosis (AIS), and other degenerative lumbar spine diseases. The keywords used were: "failed technologies", "historical technologies", "spine surgery", "spinal stenosis", "adolescent idiopathic scoliosis", and "degenerative lumbar spine disease". A total of 47 articles were gathered after initial review. RESULTS: Different technologies pertaining to spine surgery were identified and critically evaluated. Some of these technologies included X-STOP, Vertiflex, Vertebral Body Stapling, and Dynesys. These technologies were evaluated for their strengths and limitations across their spinal pathology applications. While each type of technology had their benefits, the data tended to be mixed with various limitations across studies. CONCLUSION: These technologies have been trialed in the field of spine surgery across various spinal pathologies, but still prove of limited efficacy and shortcomings to the current standards of care.

Preoperative rehabilitation optimization for spinal surgery: a narrative review of assessment, interventions, and feasibility.

PURPOSE: Postoperative physical therapy (PT) is a cornerstone of orthopedic and musculoskeletal rehabilitation, proven to provide various positive clinical benefits. However, there is a paucity of literature evaluating the utility of preoperative rehabilitation specific to spine surgery. Thus, this review article aims to provide an overview of previously published studies discussing the efficacy of preoperative rehabilitation programs and its role in spinal surgery. Special emphasis was given to preoperative frailty assessments, physical performance tests, interventional strategies, feasibility, and future directions. METHODS: We performed a literature review using PubMed, Google Scholar, EMBASE, and PubMed Central (PMC) using directed search terms. Articles that examined preoperative rehabilitation in adult spine surgery were compiled for this review. Prehabilitation programs focused on exercise, flexibility, and behavioral modifications have been shown to significantly improve pain levels and functional strength assessments in patients undergoing elective spine surgery. In addition, studies suggest that these programs may also decrease hospital stays, return to work time, and overall direct health care expenditure costs. Screening tools such as the FRAIL scale can be used to assess frailty while physical function tests like the timed-up-and go (TUGT), 5 repetition sit-to-stand test (5R-STST), and hand grip strength (HGS) can help identify patients who would most benefit from prehabilitation. CONCLUSIONS: This review illustrates that prehabilitation programs have the potential to increase quality of life, improve physical function and activity levels, and decrease pain, hospital stays, return to work time, and overall direct costs. However, there is a paucity of literature in this field that requires further study and investigation.

Characteristics of Spinal Morphology According to the "Current" and "Theoretical" Roussouly Classification Systems in a Diverse, Asymptomatic Cohort: Multi-Ethnic Alignment Normative Study (MEANS).

STUDY DESIGN: Cross-sectional cohort study. OBJECTIVE: To classify spinal morphology using the "current" and "theoretical" Roussouly systems and assess sagittal alignment in an asymptomatic cohort. METHODS: 467 asymptomatic volunteers were recruited from 5 countries. Radiographic parameters were measured via the EOS imaging system. "Current" and "theoretical" Roussouly classification was assigned with sagittal whole spine imaging using sacral slope (SS), pelvic incidence (PI), and the lumbar apex. One-way analysis of variance (ANOVA) was performed to compare subject characteristics across Roussouly types, followed by post hoc Bonferroni correction. RESULTS: Volunteers were categorized into 4 groups (Types 1-4) and 1 subgroup (Type 3 AP) using the "current" and "theoretical" Roussouly systems. The mean PI in "current" Roussouly groups was 40.8° (Type 1), 43.6° (Type 2), 52.4° (Type 3), 62.4° (Type 4), and 43.7° (Type 3AP). The mean PI in "theoretical" Roussouly groups was 36.5° (Type 1), 39.1°(Type 2), 52.5° (Type 3), 67.3° (Type 4), and 51.0° (Type 3AP). The difference in PI between "current" and "theoretical" Roussouly types was significant for Type 1 (P = .02), Type 2 (P < .001), Type 4 (P < .001), and Type 3AP (P < .001). 34.7% of subjects had a "current" Roussouly type different from the "theoretical" type. Type 3 theoretical shape had the most frequent mismatch, constituting 61.1% of the mismatched subjects. 51.5% of mismatched Type 3 become "current" Type 4. CONCLUSION: The distribution of Roussouly types differs depending on whether the "current" or "theoretical" classification are employed. A sizeable proportion of volunteers exhibited current and theoretical type mismatch, highlighting the need to interpret sagittal alignment cautiously when utilizing the Roussouly system.

Prospective Validation of the Spinal Cord Shape Classification System in the Prediction of Intraoperative Neuromonitoring Data Loss: Assessing the Risk of Spinal Cord Data Loss During Spinal Deformity Correction.

BACKGROUND: The Spinal Cord Shape Classification System (SCSCS) class has been associated with spinal cord monitoring data loss during spinal deformity surgery. The objective of the current study was to prospectively validate the SCSCS as a predictor of spinal cord monitoring data loss during spinal deformity surgery. METHODS: A prospective cohort study of consecutive patients who were undergoing primary deformity surgery at a single institution from 2018 to 2023 and whose major curve was in the spinal cord region was undertaken. Spinal cord morphology at the apex of the major curve on preoperative axial T2-weighted magnetic resonance imaging was used to categorize patients into 3 spinal cord shape types based on the SCSCS. The primary outcome was intraoperative neuromonitoring (IONM) data loss related to spinal cord dysfunction. Demographics and surgical and radiographic variables were compared between patients with IONM data loss and those without loss. Predictors of IONM loss were determined using bivariate and multivariable logistic regression analyses. RESULTS: A total of 256 patients (168 adult, 88 pediatric) were included and were separated into 3 SCSCS types: 110 (43.0%) with Type I, 105 (41.0%) with Type II, and 41 (16.0%) with Type III. IONM loss was observed in 30 (11.7%) of the 256 patients, including 7 (6.4%) of 110 with SCSCS Type I, 7 (6.7%) of 105 with Type II, and 16 (39.0%) of 41 with Type III. IONM loss was associated with SCSCS Type III, the preoperative deformity angular ratio, performance of 3-column osteotomies, greater operative time, greater transfusion volume, and greater postoperative sagittal corrections. SCSCS type was the strongest independent predictor of IONM data loss. SCSCS Type III had the greatest odds of IONM loss (odds ratio [OR] = 6.68, 95% confidence interval [CI] = 2.45 to 18.23 compared with Types I and II combined). The overall predictive performance with respect to IONM loss (area under the receiver operating characteristic curve = 0.827) was considered excellent. CONCLUSIONS: This prospective cohort study of patients undergoing spinal deformity correction confirmed that patients with a Type-III spinal cord shape had greater odds of IONM loss. Inclusion of the SCSCS in preoperative risk stratification and intraoperative management of spinal deformity corrective surgery is recommended. LEVEL OF EVIDENCE: Prognostic Level II . See Instructions for Authors for a complete description of levels of evidence.

Comparison of the Odontoid and Orbital-Coronal Vertical Axis Lines in Evaluating Coronal Alignment and Outcomes in Adult Spinal Deformity Surgery.

STUDY DESIGN: Asymptomatic Multi-Ethnic Alignment Normative Study (MEANS) cohort: cross-sectional, multi-center. Symptomatic cohort: retrospective, multi-surgeon, single-center. OBJECTIVE: To assess the association of odontoid-coronal vertical axis (OD-CVA) and orbital-coronal vertical axis (ORB-CVA) with radiographic parameters, patient-reported outcomes (PROs), and clinical outcomes. SUMMARY OF BACKGROUND DATA: Previous literature studied the OD-CVA in an asymptomatic cohort and ORB-CVA in a symptomatic cohort, demonstrating their correlations with radiographic parameters and ORB-CVA with outcomes. METHODS: 468 asymptomatic adult participants were prospectively enrolled in the MEANS cohort. 174 symptomatic ASD patients with 6 fused levels and 2-year follow-ups were retrospectively enrolled in the symptomatic cohort. The association between OD-CVA and ORB-CVA, and radiographic parameters, perioperative variables, PROs, and outcomes were analyzed. Pearson's correlation was used to assess correlation and logistic regression odds of outcomes. RESULTS: In the MEANS cohort, the ORB-CVA correlated with C7-CVA (r=0.58) and OD-CVA (r=0.74). In the symptomatic cohort, preoperative ORB-CVA correlated better with leg length discrepancy (LLD) (r=0.17, P=0.029) while preoperative OD-CVA correlated better with C7-CVA (r=0.90, P<0.001). Postoperative ORB-CVA correlated with postoperative C7-CVA (r=0.66, P<0.001) and postoperative OD-CVA correlated stronger with postoperative C7-CVA (r=0.81, P<0.001). Both preoperative OD-CVA (r=0.199) and ORB-CVA (r=0.208) correlated with preoperative Oswestry Disability Index (ODI). ORB-CVA correlated better than OD-CVA in the preoperative SRS-22r pain category but worse in total and other subcategories. Preoperative ORB-CVA was associated with increased odds of intraoperative complication (OR=1.28, 1.01-1.22), like OD-CVA (OR=1.30, 1.12-1.53). Neither preoperative ORB-CVA nor OD-CVA was associated with reoperations and readmissions after multivariate analysis. Preoperative OD-ORB mismatch >1.5 cm was not associated with increased odds of intraoperative and postoperative complications, reoperations, or readmissions. CONCLUSION: ORB-CVA and OD-CVA correlated with radiographic parameters, PROs, and intraoperative complications. ORB-CVA and OD-CVA can be used interchangeably as cranial coronal parameters in ASD surgery.

The Thoracolumbar Inflection Point in a Population of Asymptomatic Volunteers: A Multi-Ethnic Alignment Normative Study Cohort Study.

STUDY DESIGN: Prospective cohort study. OBJECTIVES: To show population variance in the Inflection Point (IP) and its role in defining maximum Thoracic Kyphosis (TK) and Lumbar Lordosis (LL). METHODS: 468 asymptomatic adult volunteers were included in the Multi-Ethnic Normative Alignment Study (MEANS). To find parameters correlating with IP, the vertebrae and discs were numbered such that C7 was 0, T1 was 1, with T1-T2 disc being 1.5, etc. Statistical analysis was performed by a correlation matrix for IP and the 9 other selected parameters along with linear regressions. RESULTS: The overall mean IP was 12.44 approximately corresponding to T12-L1 disc with the median being 12.50, range was T8-L4. The cohort was then stratified by sex and ethnicity, but there was no significant difference in IP between groups. IP in younger subjects was 13 (L1), compared to 12.5 (T12-L1 disc) in older subjects (P < .05). IP was moderately correlated with the TK apex (r = .66). No strong correlation was found between IP and LL magnitude or apex, TK magnitude, sacral slope, or Pelvic Incidence (PI). In terms of other sagittal parameters, PI and LL demonstrated a significant positive correlation. PI and TK did not have a strong association. CONCLUSIONS: The mean IP was at the T12-L1 disc, however IP ranged from T8 to L4. Older subjects tended to have a relatively more cephalad IP. No radiographic variable was found to be a strong predictor of the IP. TK apex was found to have a moderate correlation.