Trends in Lumbar Fusion Procedure Rates and Associated Hospital Costs for Degenerative Spinal Diseases in the United States, 2004 to 2015

The Minimal Clinically Important Difference for the Oswestry Disability Index Substantially Varies Based on Calculation Method: Implications to Value-Based Care

STUDY DESIGN

Retrospective study.

OBJECTIVE

Evaluate differences in the minimal clinically important difference (MCID) threshold value based on various acceptable statistical methods and how these differences may influence the interpretation of surgical benefit following elective 1- and 2-level lumbar fusion.

SUMMARY OF BACKGROUND DATA

The MCID is a statistically determined threshold value to evaluate if a patient has received benefit from a medical procedure. In the era of value-based medicine, the MCID has become increasingly important. However, there is substantial ambiguity surrounding the interpretation of this value, given that it can be influenced by both demographic and methodological factors.

METHODS

A total of 371 patients who underwent 1- or 2-level elective lumbar fusions between June 2021 and June 2023 were included in this study. All patients completed both their preoperative and 6-month postoperative Oswestry Disability Index (ODI), as well as 2 anchor questions concerning satisfaction with their surgical procedure. The MCID values were calculated using 16 accepted statistical methods, and the resulting MCID values were applied to the cohort to determine how many patients reached MCID by 6 months postfusion.

RESULTS

Results demonstrated significant variability in the MCID value. The average MCID value for all 16 methods was 10.5±7.0 points in the in the range (0.8 to 25). Distribution methods provided lower threshold MCID values but had greater variability while the Anchor methods resulted in higher threshold values but had lower variability. Depending on the method used 30% to 83% of the cohort reached MCID by 6 months.

CONCLUSION

The statistical method used to calculate the MCID resulted in significantly different threshold values and greatly affected the number of patients meeting MCID. The results demonstrates the complexity surrounding the interpretation of MCID values and calls into question the utility of a single statistically determined value to assess surgical success.

Ropivacaine-epinephrine-clonidine-ketorolac is an effective opioid-sparing local anesthetic for patients undergoing posterior spinal fusion

BACKGROUND CONTEXT

Ropivacaine-Epinephrine-Clonidine-Ketorolac (RECK) cocktail can improve pain control in patients undergoing lumbar decompression. Given the aging population, rising healthcare costs, the opioid epidemic, and associations of acute pain control with long-term opioid use, effective opioid-sparing analgesia following spinal fusion surgery may impart societal benefits.

PURPOSE

We aimed to investigate whether RECK was an effective local anesthetic for patients undergoing posterior spinal fusion.

STUDY DESIGN/SETTING

Single-center retrospective cohort study.

PATIENT SAMPLE

Patients who underwent posterior spinal fusion surgery from June 2019 to June 2021.

OUTCOME MEASURES

Primary outcomes of interest were postoperative pain levels as determined by Visual Analog Scale, in-hospital opioid consumption, length-of-stay <4 days, and long-term opioid utilization at three months postoperatively. Secondary outcomes of interest were rates of discharge to home, complication rates, readmissions within 90 days.

METHODS

We analyzed whether opioid exposure, patient-specific or surgery-specific factors, and administration of RECK (versus another local anesthetic) were associated with postoperative pain levels, in-hospital opioid consumption, length-of-stay, home discharge, long-term opioid utilization, complications, and readmissions within 90 days using multivariable regression.

RESULTS

Of the 162 patients meeting study criteria, 49 (30.2%) received RECK. RECK was significantly associated with decreased pain levels at 2-, 4-, 6-, and 12-hours postoperatively (p≤.001-.01). RECK was associated with decreased total and daily inpatient opioid utilization (as measured by oral morphine equivalents) in multivariable linear regression (B=-159.6, 95% CI:-255.5- -63.6, p=.002 and B=-27.9, 95% CI:-48.9- -7.0, p=.01, respectively). Length-of-stay duration of <4 days was associated with RECK administration (OR 4.1, 95% CI:1.4-13.2, p=.01) and was negatively associated with levels fused (OR 0.4, 95% CI:0.2-0.7, p=.005) and durotomy (OR 0.02, 95% CI:0.0009-0.1, p<.001). Prolonged postoperative opioid utilization was associated with preoperative opioid prescription (OR 3.6, 95% CI:1.7-7.8, p=.001) and was negatively associated with RECK (OR 0.4, 95% CI:0.2-0.9, p=.04). RECK was not associated with readmissions, complications, or home discharge.

CONCLUSIONS

In patients undergoing posterior spinal fusion, RECK was superior to other local anesthetics as it improved pain control, decreased length-of-stay, and decreased opioid utilization. RECK was not associated with increased complications, readmissions, or rates of discharge to home.

Impact of Lumbar Degenerative Changes on Vertebral Bone Strength: A Finite Element Analysis

Assessing the bone condition in patients with spinal disease is clinically valuable. However, evaluating bone strength in the presence of spine degenerative changes is challenging. Quantitative computed tomography (QCT) and finite element analysis (FEA) have been proposed as methods for more accurate bone quality assessment. This study investigates the relationship between bone strength predicted by FEA and other relevant biological parameters. This retrospective cross-sectional study included 127 patients with spinal disease who underwent preoperative CT scans between 2014 and 2020. Baseline patient characteristics, volumetric bone mineral density (vBMD) measured by QCT, and vertebral bone strength predicted by FEA were collected. The degree of degeneration was evaluated by classifying osteophyte formation, disc height narrowing, vertebral sclerosis, and spondylolisthesis into a grading scale ranging from 0 to 2. Multiple linear regression analysis was conducted to assess the effect of each factor on bone strength predicted by FEA. Of 127 patients, 120 patients (median age was 62 years) were included. The median vBMD and vertebral strength were 114.3 mg/cm3 and 7892.9 N, respectively. After adjusting for age, sex, body mass index, smoking status, diabetes mellitus, vBMD, and degenerative changes, multiple linear regression analysis revealed that sex, vBMD, and degree of degeneration independently increased the vertebral strength measured by FEA. This study suggests that in patients with spinal disease, vertebral bone strength is affected not only by sex and bone mineral density but also by degenerative changes. Thus, bone strength could be predicted more accurately in patients with spinal disease using FEA.

Risk Factors of 90-Day Unplanned Readmission After Lumbar Spine Surgery for Degenerative Lumbar Disk Disease: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVE

With the increasing aging population, the number of patients undergoing lumbar spinal surgery for degenerative changes is rising. In the United States, spinal fusion surgery ranked sixth in operating room procedures, accounting for 3.2% of all such procedures, with an aggregate cost for stays amounting to $14.1 billion, making it the most expensive operating room procedure in 2018. The aim of this study was to identify valid risk factors of 90-day unplanned readmissions after lumbar spine surgery through a meta-analysis, with the goal of saving insurance finances and improving patient clinical outcomes.

METHODS

We searched PubMed, Embase, Web of Science, and Cochrane Library databases using the search terms "90-day readmission" and "lumbar spine surgery." Eleven eligible studies were included. Characteristic differences between readmitted and nonreadmitted patients were identified and analyzed using Review Manager software.

RESULTS

This meta-analysis included 11 studies with a total of 648 415 patients; 50 047 were readmitted unplanned after lumbar spine surgery. The incidence of unplanned readmission after lumbar spine surgery was 7.72%. Among demographic risk factors, older age and higher body mass index were significantly associated with unplanned readmission after lumbar spine surgery. Patient characteristics, such as depression, diabetes mellitus, hypertension, renal failure, and an American Society of Anesthesiologists grade greater than 2 were also significantly associated with unplanned readmission after lumbar spine surgery.

CONCLUSION

The meta-analysis revealed a 7.72% incidence of unplanned readmission after lumbar spine surgery. These findings suggest the need for enhanced preoperative optimization and careful patient selection for lumbar spine surgery, particularly in elderly patients and those with multiple comorbidities. Implementation of targeted preventive strategies for high-risk patients may help reduce unplanned readmissions and improve healthcare resource utilization.

Prediction of Primary Admission Total Charges Following Single-Level Lumbar Arthrodesis Utilizing Machine Learning

Study DesignRetrospective analysis utilizing machine learning.ObjectivesThis study aims to identify the key factors influencing total charges during the primary admission period following single-level lumbar arthrodesis, using machine learning models to enhance predictive accuracy.MethodsData were extracted from the National Inpatient Sample (NIS) database and analyzed using various machine learning models, including random forest, gradient boosting trees, and logistic regression. A total of 78,022 unweighted cases of patients who underwent single-level lumbar arthrodesis were identified using the NIS database from 2016 to 2020. Variables included hospital size, region, patient-specific factors, and procedural details. Multivariate linear regression was also used to identify charge-related variables.ResultsThe average total charge for single-level lumbar arthrodesis was $145,600 ± $102,500. Significant predictors of charge included length of stay, hospital size, hospital ownership, and region. Private investor-owned hospitals and procedures performed in the Western U.S. were associated with higher charges. Random forest models demonstrated superior predictive accuracy with an AUC of .866, outperforming other models.ConclusionsHospital characteristics, regional factors, and patient-specific variables significantly influence the charges of single-level lumbar arthrodesis. Machine learning models, particularly random forest, provide robust tools for predicting healthcare costs, enabling better resource allocation and decision-making. Future research should explore these dynamics further to optimize cost management and improve care quality.

Polyetheretherketone vs Titanium Cages in Spinal Fusion: Spin Bias in Abstracts of Systematic Reviews and Meta-Analyses

Study DesignCross sectional.ObjectiveSpin bias, where authors distort findings to overstate efficacy, is prevalent in the medical literature. The comparative superiority of polyetheretherketone (PEEK) and titanium (Ti) cages in spinal fusion remains controversial. This study aims to assess the prevalence of spin bias in meta-analyses and systematic reviews comparing PEEK vs Ti cages in spinal fusion.MethodsThe PubMed, Embase, and Web of Science databases were searched to identify meta-analyses and systematic reviews comparing PEEK and titanium cages in spinal fusion. Included studies were assessed for the presence of the 9 most severe types of spin bias. This study also graded the quality of these articles using A Measurement Tool to Assess systematic Reviews 2 (AMSTAR 2) criteria.ResultsThe search resulted in 2352 articles, of which 13 met the inclusion criteria. Spin bias was identified in 8/13 (61.54%) of the included studies, with the most prevalent types being Type 3 (38.46%) and Type 5 (30.77%). Using AMSTAR 2, 1/13 (7.69%) studies were rated as critically low quality, 4/13 (30.77%) as low, 8/13 (61.54%) as moderate, with none rated as high.ConclusionsSpin was found in 61.54% of the reviews comparing PEEK and Ti cages in spinal fusion, with none achieving a high-quality rating. Surgeons must critically evaluate these articles for bias prior to utilizing them in clinical decision making.

Does incidental durotomy affect clinical outcome in patients with lumbar degenerative diseases after posterior open lumbar interbody fusion? a multicenter observational study

BACKGROUND

Incidental durotomy (ID) during spinal surgery is common during spinal surgery. This study aimed to determine whether intraoperative ID affects the perioperative and long-term clinical outcomes in patients with degenerative lumbar disease (DLD) undergoing posterior open lumbar interbody fusion (POLIF).

METHODS

This multicenter observational study was conducted at two spinal centers between January 2020 and December 2022. The patients were divided into ID and non-ID groups according to whether ID occurred intraoperatively. Primary outcome measure was the length of hospital stay (LOS), while secondary outcome measures were 30-day readmission rate; hospital costs; postoperative visual analog scale (VAS) scores for low back pain (LBP) and leg pain (LP) at 1 day, 3, 7, and 15 days, 1 month, 3, 6, and 12 months; and Oswestry Disability Index (ODI) at 1 month, 3, 6, and 12 months.

RESULTS

Intraoperative ID occurred in 8.7% (36/415) patients. LOS, operative time, estimated blood loss, 30-day readmission rate, and hospital costs were significantly higher in the ID group. On average, the LOS increased by 2.9 days and hospital costs increased by 4800.2 yuan per patient. The ID group had significantly higher baseline VAS scores for LBP 15 days and 1 month postoperatively than the non-ID group. The ODI was significantly higher in the ID group than in the non-ID group 1 month postoperatively. No significant differences were noted in the VAS scores and ODI between the two groups at 3, 6, and 12 months postoperatively. Finally, we found that a higher BMI (P = 0.035, OR: 1.195, 95%CI: 1.012-1.412) and revision surgery (P = 0.022, OR: 2.901, 95%CI: 1.164-7.233) were risk factors for intraoperative ID.

CONCLUSIONS

Although ID does not significantly affect the long-term outcomes in patients with DLD after POLIF, it can lead to poorer perioperative clinical outcomes. Lumbar fusion surgery should be performed meticulously to minimize the incidence of intraoperative ID.

Health literacy and patient-reported outcomes in preoperative patients undergoing lumbar spine surgery: a cross-sectional study

BACKGROUND CONTEXT

Health literacy (HL) plays an important role in health outcomes (e.g., Activities of Daily Living and Quality of Life) among patients with chronic diseases and elderly persons. The association between functional HL and health outcomes in patients with lumbar degenerative disease has also been revealed. Comprehensive HL includes three levels of functional, communicative, and critical HL that may affect the health outcomes of patients undergoing lumbar spine surgery. However, the association between comprehensive HL and health outcomes in patients undergoing lumbar spine surgery has not yet been investigated.

PURPOSE

To examine the impact of comprehensive HL on patient-reported outcomes (PROs) of pain-related disabilities and health-related quality of life in patients undergoing lumbar spine surgery.

STUDY DESIGN/SETTING

Cross-sectional study.

PATIENT SAMPLE

Patients aged 18 years or older who presented to a general hospital-based spine center for the surgical treatment of lumbar degenerative disease.

OUTCOME MEASURES

Oswestry Disability Index 2.0 (ODI), EuroQol-5D-5L (EQ-5D-5L).

METHODS

Between June 2023 and May 2024, consecutive patients aged 18 years or older presenting to the spine center were approached for participation in this cross-sectional study. Patients completed a questionnaire concerning sociodemographic characteristics; Functional, Communicative, and Critical Health Literacy (FCCHL); and PROs, including ODI and EQ-5D-5L. A multivariable linear regression analysis with potential confounders was performed to examine the relationship between FCCHL and PROs.

RESULTS

Of 128 eligible patients, 124 (97%) were included in the statistical analysis. Higher total FCCHL score was significantly associated with better PROs (ODI (regression coefficient, -10.6; [95% confidence interval, -17.6, -3.6]), EQ-5D-5L (0.093 [0.022, 0.165])) in a linear dose-response manner. Functional HL was not associated with PROs; however, communicative and critical HL were both associated with PROs.

CONCLUSIONS

Higher comprehensive HL, including functional, communicative, and critical HL, was associated with better PROs, characterized by lower ODI and higher EQ-5D-5L scores, in a linear dose-response manner in patients undergoing lumbar spine surgery. Our study suggests that comprehensive HL is important to prevent disabilities in daily life due to lumbar degenerative disease.

Sickle Cell Disease Has No Impact on 10-Year Cumulative Incidence and Indications for Revision Lumbar Fusion

Study DesignRetrospective Cohort Study.ObjectivesPatients with sickle cell disease (SCD) experience distinct physiological challenges that may alter surgical outcomes. There has been no research establishing 10-year lumbar fusion (LF) implant survivorship rates among individuals with SCD. This study aims to determine the 10-year cumulative incidence and indications for revision LF between patients with and without SCD.MethodsA national database was queried to identify patients with and without SCD who underwent primary LF. SCD patients undergoing LF were propensity-score matched in a 1:4 ratio by age, gender, and Charlson Comorbidity Index (CCI) to a matched LF control. In total, 246 SCD patients were included along with 981 and 100,000 individuals in the matched and unmatched control cohorts, respectively. Kaplan-Meier survival analysis was utilized to determine the 10-year cumulative incidence rates of revision LF. Furthermore, multivariable analysis using Cox proportional hazard modeling was performed to compare indications for revisions and surgical complications between cohorts including hardware removal, drainage and evacuation, pseudoarthrosis, and mechanical failure.ResultsNo significant differences were found in the cumulative incidence of 10-year all-cause revision LF between patients in the SCD cohort and either of the control cohorts (P > .05 for each). Additionally, there were no significant differences between the SCD cohort and either of the control cohorts in regards to the indications for revision or surgical complications in LF (P > .05 for each).ConclusionsThis study indicates that SCD patients do not have increased risk for revision LF, nor any of its indications.

Optimizing Wound Healing Following Cervical Spine Surgery

INTRODUCTION

The volume of cervical spine procedures continues to grow. Plastic and reconstructive surgeons (PRSs) commonly address complex wound-related issues in such cases. The present study investigates whether routine PRS closure of cervical spinal wounds improves outcomes compared with those performed without.

METHODS

Data of patients operated on for cervical spine procedures by the senior author (P.J.T.) between January 2016 and June 2023 were analyzed. Only posterior surgical approaches were included. Demographics, medical status, procedure indication, and surgical characteristics were reviewed. Wound-related and medical complications were examined within a 30-day postoperative period, along with incidences of unplanned reoperation or readmission. Outcomes were compared with 12,943 CPT-matched cases reported by the American College of Surgeons National Surgical Quality Improvement Program.

RESULTS

Five hundred eighty-eight cases were included: 511 (87%) were performed for degenerative spine conditions, 60 (10%) for traumatic injuries, 7 (1%) for neoplasms, 7 (1%) for congenital conditions, and 3 (0.5%) for infected cyst management. The PRS group demonstrated a greater prevalence of diabetes (27% vs 22%, P = 0.016) and chronic obstructive pulmonary disease (10% vs 6%, P < 0.001). Those who received PRS closure were less likely to return to the operating room (1% vs 3%, P = 0.005) or experience a wound-related readmission (2% vs 5%, P < 0.001).

CONCLUSION

PRS closure of cervical spine cases minimizes the risk of reoperation and readmission, even among a population with comorbidities known to be associated with wound-related complications. Improved outcomes were especially observed for more complex wounds requiring local flap closure. Thus, there is strong evidence to support PRS involvement in cervical spine surgery.

Optimizing wound healing following lumbar spine surgery

The prevalence of open lumbar spine procedures has increased due to surgical advancements and an aging population. This study examined prophylactic closure by the plastic and reconstructive surgery (PRS) service compared to similar procedures from the National Surgical Quality Improvement Program (NSQIP) database. Patients who underwent lumbar spine surgery closed primarily by the PRS service at a large academic surgical center between January 2016 and June 2023 were included, while grafts or flaps were excluded. Charts were reviewed for demographics, preoperative risk factors, operative course, superficial surgical site infection (SSI), deep SSI, organ/space SSI, wound dehiscence, seroma, hematoma, cerebrospinal fluid leak, and medical complications. Unplanned readmission and revision surgeries related to the procedure were noted. Outcomes were assessed 30 days postoperatively. Outcomes within 30 days postoperatively were recorded in 46,006 NSQIP cases after matching by Current Procedural Terminology (CPT) and International Classification of Diseases - 10 (ICD-10) codes. A total of 888 consecutive lumbar surgery patients closed by PRS were reviewed. Wound-related revisional surgeries (1.2% vs. 2.6%, p = 0.013) and wound-related readmissions (1.5% vs. 4.2%, p < 0.001) were significantly lower for the PRS group than the NSQIP group. Transfusion (2.7% vs. 4.4%, p = 0.013) and urinary tract infection rates (0.2% vs. 1.3%, p = 0.005) were also lower for the PRS group. PRS closure also showed significantly decreased odds of revisional surgery (ß = 0.587, p = 0.021) and any wound infection (ß = 0.503, p = 0.026) after logistic regression. Thus, PRS closure of lumbar spine procedures may decrease the risk of wound-related revisional surgeries, readmissions, and infections. Therefore, this study supports the use of prophylactic PRS closure in such cases.

FDA regulatory considerations for innovative orthopedic devices: A review

Novel and innovative orthopedic devices are needed to address clinical challenges in orthopedic practice. Obtaining regulatory authorization for such devices, however, can prove challenging. An inherent dilemma exists between innovation to address unmet needs and imitation to demonstrate substantial equivalence to a predicate device, which is required for the less burdensome 510(k) pathway. This article provides both an overview of highly innovative orthopedic devices over the last 10 years as well as considerations for FDA regulatory pathways and programs available to manufacturers of such devices. A review of 20 innovative orthopedic devices receiving Breakthrough Device Designation and/or a De Novo classification found that devices had diverse features and applications, but did possess shared technological trends including bioresorption, flexible components, and new substance/material use. A review of all new orthopedic devices authorized through the three major regulatory pathways in the last 10 years was also conducted. Spinal devices represented the largest share of recent orthopedic devices (38 % of 510(k) clearances and 25 % of De Novo classifications). Across all three pathways, decision time was on average around 30 % shorter for orthopedic devices with a Breakthrough Device Designation versus those without, though differences were not significant. New orthopedic devices authorized in the last 10 years were found to be highly reliant on the 510(k) pathway, with a 99 % utilization rate. However, the FDA Breakthrough Devices Program and De Novo pathway offer opportunities specific to innovative technologies, such as expedited review and potential market competition protection, as demonstrated through specific case studies in this review. As these FDA initiatives continue to evolve and manufacturers continue to take advantage of these opportunities, orthopedic device development, which has primarily prioritized incremental innovation, may too evolve to produce more breakthrough innovations.

The influence of psychological factors on postoperative clinical outcomes in patients undergoing lumbar spine surgery: a systematic review and meta-analysis

PURPOSE

The rate of lumbar spine surgeries has increased and the postoperative course is influenced not only by physical but also psychological factors. Patients with pre-existing psychological disorders appear to be more likely to develop anxiety and depression, these factors could negatively affect pain perception, disability, and quality of life. A systematic review and metanalysis were performed to determinate which psychological factors impact on spinal postoperative clinical outcomes and how it can influence postoperative clinical outcomes in patients undergoing spinal surgery.

METHODS

A Systematic literature review was performed on the following databases: PubMed/ MEDLINE, Scopus, Psychinfo and Web of Science on October 2022. The quality of the included studies was assessed using the ROBINS-E tool (Risk Of Bias In Non-randomized Studies - of Exposures). This review was registered at Prospero CRD42022380777. Meta-analysis was performed to compare back pain, leg pain disability, quality of life between the group of patients with psychological issues and control groups as continuous outcomes.

RESULTS

Of the identified 1756 studies, eventually 13 studies were included with a total of 5364 patients. Our results suggest that patients affected by anxiety and depression report worse back pain (MD 0.40, 95% CI 0.20 to 0.62, p = 0.0001) and disability (MD 9.58 95% CI 2.67 to 16.48, p = 0.007) levels after spine surgery than patients with healthy mental status. Instead quality of life and leg pain don't show significant differences between the two groups.

CONCLUSION

Our findings demonstrate a correlation between presence of mental disease and the worsening of post-surgical clinical outcomes. Anxiety and depressive symptoms can influence pain and disability symptoms during the postoperative phase.

Frailty and malnutrition as predictors of major complications following posterior thoracolumbar fusion in elderly patients: a retrospective cohort study

BACKGROUND CONTEXT

The number of elderly patients with degenerative spinal deformity (DSD) is increasing, and posterior thoracolumbar fusion surgery is an effective treatment option, but there are often postoperative major complications, which may hinder the benefit for elderly patients. Currently, there is no consensus on the best risk assessment technique for predicting major complications in elderly patients undergoing long-segment fusion surgery.

PURPOSE

This study constructs a risk assessment model using the Modified 5-Item Frailty Index (mFI-5) and serum albumin and evaluates its predictive value.

STUDY DESIGN

This is a retrospective analysis of a prospectively established database of DSD.

PATIENT SAMPLE

Consecutive patients (aged 65 and older) who underwent open posterior thoracolumbar fusion surgery for DSD between April 2018 and December 2023 were included.

OUTCOME MEASURES

Outcome measures included postoperative major complications, length of hospital stay (LOS), readmission and reoperation within 30 days, discharge disposition, physiological function recovery.

METHODS

The study reviewed consecutive patients who underwent open posterior thoracolumbar fusion surgery for DSD. Patients were divided into three groups based on the presence or absence of frailty or frailty combined with malnutrition. Spearman ρ analysis was used to assess the correlation between mFI-5 and serum albumin levels. Univariate analyses and multivariate logistic regression were conducted to explore the relationship between frailty and malnutrition defined by mFI-5 and serum albumin and major postoperative complications. Finally, the Receiver Operating Characteristic (ROC) curve was used to evaluate the predictive value of this model for major complications.

RESULTS

Compared to the Normal group (n=59), both the Frailty group (n=121) and the Frailty and Malnutrition group (n=50) had higher rates of major complications (21.5% vs 8.5%, p=.035; 28% vs 8.5%, p=.002). Multivariate logistic regression showed that frailty and malnutrition status, higher ASA score, and more bleeding were independent predictors of major postoperative complications. The ROC curve demonstrated that frailty combined with malnutrition defined by mFI-5 and serum albumin had a larger area under the curve compared to mFI-5 or serum albumin alone (AUC: 0.676; 95% CI: 1.101-14.129; p<.001).

CONCLUSIONS

Compared to considering frailty or malnutrition alone, the combined assessment of frailty and malnutrition using mFI-5 and serum albumin is valuable in predicting major complications in elderly patients undergoing posterior thoracolumbar fusion surgery.

There is no "Value Penalty" for revision spine surgery: an application of the operative value index for primary versus revision lumbar fusions

The increasing prevalence of elective lumbar fusions has been accompanied by a steady rise in revision procedures. Few studies have identified the relative cost-effectiveness of revision lumbar fusion using detailed costing methodology. Here, we aim to compare the "value" (outcomes achieved per dollar spent) of primary versus revision lumbar fusion by integrating time-driven activity-based costing (TDABC) with patient-reported outcomes (PROs). 292 patients were prospectively enrolled to undergo elective lumbar fusion. Revision surgery was defined as any case of lumbar fusion after a previous lumbar spine surgery. TDABC was employed to identify intraoperative costs for all cases. Oswestry Disability Index (ODI) scores were collected both preoperatively and at 6-months postoperatively. "Value" was measured through the Operative Value Index (OVI), defined as the percent improvement in ODI per $1,000 spent intraoperatively. Multivariable linear regression, accounting for confounders, was performed to assess whether revision surgery was significantly associated with total cost and OVI. Secondary analyses were performed to compare costs and OVI between primary fusions, revisions for prior decompression and fusion, and revisions for prior decompression alone. The average total cost of a revision fusion was $18,252 +/- $8,496, compared to $18,073 +/- $8,894 for a primary fusion. The average OVI for these groups were 1.79 and 1.65, respectively. On multivariable regression analysis, there were no significant differences in OVI (p = 0.423) or total cost (p = 0.841) between primary and revision cohorts.In the era of value-based care, it is increasingly important for hospitals to identify drivers of variation in the cost-effectiveness of neurosurgical care. By integrating PROs with detailed cost data, we demonstrate that revision lumbar fusions may not significantly differ in cost or value compared to primary fusions.

Utility of Routine Preoperative Urinalysis in Elective Lumbar Spine Fusion Surgery

Study DesignA retrospective cohort study.ObjectiveTo evaluate the utility of routine preoperative urinalysis as a predictor of postoperative complications following elective lumbar fusion surgery (ELFS).MethodsThis study included a retrospective review of patients aged ≥18 years-old who underwent ELFS for degenerative pathology between 2018 to 2022 at a single academic institution. Patients were categorized into 3 groups: No Urinalysis (No-UA), Negative Urinalysis (Negative-UA), and Positive Urinalysis (Positive-UA). A retrospective review of medical records was conducted including patient characteristics and clinical factors of interest. Emergency department (ED) visits and return to the operating room (OR) within 3-months postoperatively were recorded. Statistical analyses were performed using bivariate and multivariate analysis.ResultsA total of 493 patients were included. Despite having higher rates of preoperative antibiotics administered, patients with a positive urinalysis were significantly more likely to present with postoperative urinary tract infections (UTIs) than the No-UA and Negative-UA groups. No significant differences were seen in other types of complications including pneumonia, bacteremia, superficial wound infections, deep wound infections, and wound dehiscence between the 3 groups. Additionally, rates of return to OR, return to ED, reinsertion of foley catheters, duration of indwelling catheterization, and hospital length of stay had no significant differences between the groups.ConclusionThis study suggests there may be a limited role in performing routine preoperative urinalysis prior to ELFS. This study may help further improve preoperative assessment guidelines and assist with patient counseling and considerations prior to elective lumbar fusion surgery.

Evaluating surgical interventions for low-grade degenerative lumbar spondylolisthesis: a network meta-analysis of decompression alone, fusion, and dynamic stabilization

OBJECTIVE

This study aimed to investigate which of the decompression alone (DA), decompression with fusion (DF), and decompression with dynamic stabilization (DS) produced the most favorable outcome for patients with low-grade degenerative lumbar spondylolisthesis (LDLS).

MATERIAL AND METHOD

Pubmed, Embase, Cochrane, and Web of Science were searched for all studies published before October 1, 2023. A review and data analysis of all randomized controlled trials (RCTs) of three interventions was performed by Stata (version 17.0) and Review Manager (version 5.4).

RESULT

21 RCT studies with 3192 patients were included in the network meta-analysis. DA was superior to DF (MD = -92.05, P < 0.05; MD = -295.57, P < 0.05; MD = -2.19, P < 0.05; RR = 0.54, P < 0.05, respectively) and DS (MD = -35.69, P < 0.05; MD = -100.7, P < 0.05; MD = -295.57, P < 0.05; MD = -2.19, P < 0.05; RR = 0.54, P < 0.05, respectively) in reducing operative time, intraoperative blood loss, length of hospital stay, and postoperative adverse events. DS was superior to DF in reducing operative time, intraoperative blood loss, and length of hospital stay (MD = -56.35, P < 0.05; MD = -194.84, P < 0.05; MD = -1.12, P < 0.05, respectively). DF was superior to DA in reducing reoperations (RR = 0.55, p < 0.05). DF was superior to DA (MD = -1.44, p < 0.05) and DS (MD = -0.41, p < 0.05) in controlling the progression of olisthesis.

CONCLUSION

DA was the most favorable treatment for LDLS, reducing operative time, bleeding, hospital stay, and postoperative complications. DF outperformed DA in reducing reoperation rates. Although DS showed benefits in operative time and bleeding compared to DF, it did not offer a significant advantage over DA.

Effects of prehabilitation on outcomes following elective lumbar spine surgery: A systematic review and meta-analysis

Background

Elective lumbar spine surgery is increasingly being implemented to treat patients with specific low back pain. However, approximately 30% of patients continue to have long-term pain and disability after surgery.

Objective

The aim of this study was to systematically review the literature on the effectiveness of pre-surgical rehabilitation (prehab) alone or in combination with usual care versus usual care on patient-oriented outcomes and health-related costs following elective lumbar spine surgery.

Data sources

Electronic databases from MEDLINE, CINAHL, EMBASE, and AMED were systematically searched from their inception to November 2022.

Study selection

Randomized controlled trials that examined adult (age >18 years) prehab programs and evaluated one or more outcomes of interest were included in this review.

Data extraction

In pairs, six reviewers independently conducted a risk-of-bias assessment and extracted outcome data from included studies, in accordance with the Template for Intervention Description and Replication (TIDieR). A meta-analysis was conducted when trials were homogeneous.

Data synthesis

A total of eight trials (n = 739 participants), reported in 13 different manuscripts, were eligible for inclusion. Exercise prehab interventions are superior to usual care for disability at 3-month (MD: -2.56, 95% CI -4.98 to -0.15), back pain at 6-month (MD: -6.65, 95% CI -13.25 to -0.05), and health-related costs (MD: €2572.8, 95% CI: €1963.0 to €3182.5). CBT prehab interventions seem to be superior to usual care for back pain at 3-month (MD: -7.3, 95% CI: -14.5 to -0.05). Individual trials showed that education prehab interventions may be superior to usual for back pain at 1-month post-operative (MD: 12.3, 95% CI: 0.9 to 23.7).

Limitations

Overall, the inclusion of heterogeneous trials (e.g., diagnosis, types of surgery, dosage, content, and duration of interventions) with small sample sizes leads to inconclusive and very low certainty of effect estimates.

Conclusion

The present systematic review has brought to light the dearth of high-quality evidence in support of prehab interventions for patients undergoing lumbar spine surgery. Given the uncertainty surrounding the results obtained from low-quality randomized controlled trials, it is currently not feasible to provide recommendations for clinical practice.

Models of care for managing non-specific low back pain

BACKGROUND

Alternative care models seek to improve the quality or efficiency of care, or both, and thus optimise patient health outcomes. They provide the same health care but change how, when, where, or by whom health care is delivered and co-ordinated. Examples include care delivered via telemedicine versus in-person care or care delivered to groups versus individual patients.

OBJECTIVES

To assess the effects of alternative models of evidenced-based care for people with non-specific low back pain on the quality of care and patient self-reported outcomes and to summarise the availability and principal findings of economic evaluations of these alternative models.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and trial registries up to 14 June 2024, unrestricted by language.

SELECTION CRITERIA

We included randomised controlled trials comparing alternative care models to usual care or other care models. Eligible trials had to investigate care models that changed at least one domain of the Cochrane EPOC delivery arrangement taxonomy and provide the same care as the comparator arm. Participants were individuals with non-specific low back pain, regardless of symptom duration. Main outcomes were quality of care (referral for/receipt of lumbar spine imaging, prescription/use of opioids, referral to a surgeon/lumbar spine surgery, admission to hospital for back pain), patient health outcomes (pain, back-related function), and adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion, extracted data, and assessed risk of bias and the certainty of evidence using GRADE. The primary comparison was alternative models of care versus usual care at closest follow-up to 12 months.

MAIN RESULTS

Fifty-seven trials (29,578 participants) met our inclusion criteria. Trials were primarily set within primary care (18 trials) or physiotherapy practices (15 trials) in high-income countries (51 trials). Forty-eight trials compared alternative models of care to usual care. There was substantial clinical diversity across alternative care models. Alternative care models most commonly differed from usual care by altering the co-ordination/management of care processes (18 trials), or by utilising information and communication technology (10 trials). Moderate-certainty evidence indicates that alternative care models probably result in little difference in referral for or receipt of any lumbar spine imaging at follow-up closest to 12 months compared to usual care (risk ratio (RR) 0.92, 95% confidence interval (CI) 0.86 to 0.98; I2 = 2%; 18 trials, 16,157 participants). In usual care, 232/1000 people received lumbar spine imaging compared to 213/1000 people who received alternative care models. We downgraded the certainty of the evidence by one level due to serious indirectness (diversity in outcome measurement). Moderate-certainty evidence suggests that alternative care models probably result in little or no difference in the prescription or use of opioid medication at follow-up closest to 12 months compared to usual care (RR 0.95, 95% CI 0.89 to 1.03; I2 = 0%; 15 trials, 13,185 participants). In usual care, 349 out of 1000 people used opioid medication compared to 332 out of 1000 people in alternative care models. We downgraded the certainty of the evidence by one level due to serious indirectness (diversity in outcome measurement). We are uncertain if alternative care models alter referral for or use of lumbar spine surgery at follow-up closest to 12 months compared to usual care as the certainty of the evidence was very low (odds ratio (OR) 1.04, 95% CI 0.79 to 1.37; I2 = 0%; 10 trials, 4189 participants). We downgraded the certainty of the evidence by three levels due to very serious imprecision (wide CIs) and serious indirectness (diversity in outcome measurement). We are uncertain if alternative care models alter hospital admissions for non-specific low back pain at follow-up closest to 12 months compared to usual care as the certainty of evidence was very low (OR 0.86, 95% CI 0.67 to 1.11; I2 = 8%; 12 trials, 10,485 participants). We downgraded the certainty of the evidence by three levels due to serious indirectness (diversity in outcome measurement), serious publication bias (asymmetry of results), minor imprecision (wide CIs), and minor risk of bias (blinding of participants/personnel). High-certainty evidence indicates that alternative care models result in a small but clinically unimportant improvement in pain on a 0 to 10 scale (mean difference -0.24, 95% CI -0.43 to -0.05; I2 = 68%; 36 trials, 9403 participants). Mean pain at follow-up closest to 12 months was 2.4 points on a 0 to 10 rating scale (lower score indicates less pain) with usual care compared to 2.2 points with alternative care models, a difference of 0.2 points better (95% CI 0.4 better to 0.0 better; minimal clinically important difference (MCID) 0.5 to 1.5 points). High-certainty evidence indicates that alternative care models result in a small, clinically unimportant improvement in back-related function compared with usual care (standardised mean difference -0.12, 95% CI -0.20 to -0.04; I2 = 66%; 44 trials, 13,688 participants). Mean back-related function at follow-up closest to 12 months was 6.4 points on a 0 to 24 rating scale (lower score indicates less disability) with usual care compared to 5.7 points with alternative care models, a difference of 0.7 points better (95% CI 1.2 better to 0.2 better; MCID 1.5 to 2.5 points). We are uncertain of the effect of alternative care models on adverse events compared to usual care as the certainty of the evidence was very low (OR 0.81, 95% CI 0.45 to 1.45; I2 = 43%; 10 trials, 2880 participants). We downgraded the certainty of the evidence by three levels due to serious risk of bias (blinding of participants/personnel), serious indirectness (variation in assumed risk), and serious inconsistency (substantial between-study heterogeneity).

AUTHORS' CONCLUSIONS

Compared to usual care, alternative care models for non-specific low back pain probably lead to little or no difference in the quality of care and result in small but clinically unimportant improvements in pain and back-related function. Whether alternative care models result in a difference in total adverse events compared to usual care remains unresolved.

Transforaminal Versus Lateral Interbody Fusions for Treatment of Adjacent Segment Disease in the Lumbar Spine

STUDY DESIGN

Retrospective comparative study.

OBJECTIVE

This study compared outcomes for patients managed with a lateral approach to interbody fusion [lateral (LLIF) or oblique (OLIF)] versus a posterior (PLIF) or transforaminal interbody fusion (TLIF) for treatment of adjacent segment disease (ASD) above or below a prior lumbar fusion construct.

SUMMARY OF BACKGROUND DATA

No study has compared outcomes of lateral approaches to more traditional posterior approaches for the treatment of ASD.

METHODS

Retrospective review was performed of patients who underwent single-level lateral or posterior approaches for lumbar interbody fusion for symptomatic ASD between January 2010 and December 2021. Exclusion criteria included skeletal immaturity (age below 18 y old) and surgery indication for malignancy or infection. Patient demographics, medical comorbidities, operative details, postoperative complications, and revision surgery profiles were collected for all patients. Standard descriptive statistics were used to summarize data. Comparative statistical analyses were performed using Statistical Package for the Social Sciences (Version 28.0.1.0; Chicago, IL).

RESULTS

A total of 152 patients (65±10 y) were included in the study with a mean duration of follow-up of 1.6±1.4 years. The cohort included 123 PLIF/TLIF (81%), 18 LLIF (12%), 11 OLIF (7%). TLIF/PLIF experienced greater mean operative time (210±62 min vs. 184±80 OLIF/105±64 LLIF, P <0.001) and estimated blood loss (414±254 mL vs. 49±29 OLIF/36±33 LLIF, P <0.001). No significant difference in rate of postoperative complications. Postoperative radicular pain was significantly greater in OLIF (7, 64%) and LLIF (7, 39%) compared with PLIF/TLIF (16, 13%), P <0.001. No statistically significant difference in health care utilization was noted between the groups.

CONCLUSION

Lateral fusions to treat ASD demonstrated no significantly different risk of complication compared with posterior approaches. Our study demonstrated significantly increased operative time and estimated blood loss for the posterior approach and an increased risk of radicular pain from manipulation/retraction of psoas following lateral approaches.

LEVEL OF EVIDENCE

Level III.

Undetected low bone mineral density in patients undergoing lumbar fusion surgery-prevalence and risk factors

Background

Sufficient bone quality is a prerequisite for low complication rates and satisfactory outcomes in lumbar fusion surgery (LFS). Low bone mineral density (BMD), including osteoporosis and osteopenia, is linked to adverse postoperative outcomes. Despite reports of a high prevalence of undiagnosed osteoporosis, it is uncertain which risk factors should guide preoperative BMD screening in LFS.

Methods

This secondary cross-sectional analysis of a prospective institutional database at an academic spine center included adult patients undergoing LFS for degenerative conditions between 2014 and 2023. Opportunistic quantitative CT (qCT) at the L1/2 level was performed before surgery, and demographic and medical history data were extracted. Descriptive and comparative statistics, univariable and multivariable logistic regression were performed to determine risk factors for present and undiagnosed osteoporosis.

Results

Of the 675 patients screened, 578 (54% female) were included after excluding those with preoperative lumbar CT scans not suitable for qCT. The median age was 65 years (IQR 58-72), and the median BMI of 28.9 kg/m2 (IQR 25.2-32.9). Osteoporosis was identified in 182 patients (31%), with 114 previously diagnosed and 68 newly detected via preoperative qCT. Undiagnosed osteoporosis was found in 12% of all patients and 37% of those with osteoporosis. Osteopenia was present in 199 patients (34%), leading to an overall impaired bone quality prevalence of 66%. Multivariable analysis revealed that age and female sex were independent risk factors for osteoporosis, while undiagnosed cases were more common in males, patients with higher BMI, and older individuals.

Conclusions

This study found a high prevalence of abnormal BMD in LFS patients, with a significant proportion of undiagnosed osteoporosis. While osteoporosis was more common in females, male patients with osteoporosis were more frequently undiagnosed. Spine surgeons must remain vigilant about metabolic bone disease in LFS patients to ensure preoperative optimization and prevent complications.

Evaluation of GPT-4 concordance with north American spine society guidelines for lumbar fusion surgery

Background

Concordance with evidence-based medicine (EBM) guidelines is associated with improved clinical outcomes in spine surgery. The North American Spine Society (NASS) has published coverage guidelines on indications for lumbar fusion surgery, with a recent survey demonstrating a 60% concordance rate across its members. GPT-4 is a popular deep learning model that receives knowledge training across public databases including those containing EBM guidelines. There is prior research exploring the potential utility of artificial intelligence (AI) software in adherence with spine surgery practices and guidelines, inviting opportunity to further investigate application in the setting of lumbar fusion surgery with current AI models.

Methods

Seventeen well-validated clinical vignettes with specific indications for or against lumbar fusion based on NASS criteria were obtained from a prior published research study. Each case was transcribed into a standardized prompt and entered into GPT-4 to obtain a decision whether fusion is indicated. Interquery reliability was assessed with serial identical queries utilizing the Fleiss' Kappa statistic. Majority response among serial queries was considered as the final GPT-4 decision. Queries were all entered in separate strings. The investigator entering the prompts was blinded to the NASS-concordant decisions for the cases prior to complete data collection. Decisions by GPT-4 and NASS guidelines were compared with Chi-square analysis.

Results

GPT-4 responses for 15/17 (88.2%) of the clinical vignettes were in concordance with NASS EBM lumbar fusion guidelines. There was a significant association in clinical decision-making when determining indication for spine fusion surgery between GPT-4 and NASS guidelines (χ² = 9.75; p<.01). There was substantial agreement among the sets of responses generated by GPT-4 for each clinical case (K = 0.71; p<.001).

Conclusions

There is significant concordance between GPT-4 responses and NASS EBM indications for lumbar fusion surgery. AI and deep learning models may prove to be an effective adjunct tool for clinical decision-making within modern spine surgery practices.

L3-L4 Hyperlordosis and Decreased Lower Lumbar Lordosis Following Short-Segment L4-L5 Lumbar Fusion Surgery is Associated With L3-L4 Revision Surgery for Adjacent Segment Stenosis

STUDY DESIGN

Retrospective review of prospective cohort.

OBJECTIVES

Reoperation at L3-L4 for adjacent segment disease (ASD) is common after L4-L5 spine fusion. L4-S1 lower lumbar lordosis (LLL) accounts for the majority of global lumbar lordosis (GLL) and is modifiable during surgery. We sought to determine if a reduction in LLL leads to an increase in L3-L4 focal lumbar lordosis (L3-L4 FLL) and resulting risk of ASD at L3-L4.

METHODS

We reviewed the records of a prospective cohort with lumbar spinal stenosis who underwent L4-L5 or L4-L5-S1 fusion between 2006 and 2012. Radiographic parameters-GLL, LLL, L3-L4 FLL, upper lumbar lordosis, lordosis distribution index, pelvic tilt, and pelvic incidence-were extracted from preoperative and postoperative lumbar spine radiographs. Statistical comparisons were made between those who underwent revision for post-fusion adjacent level stenosis at L3-L4 (REVISION) and those who did not (NO REVISION).

RESULTS

Inclusion criteria were met by 104 patients. The REVISION cohort included 19 individuals. No significant differences in baseline demographics or operative details for the index procedure were found between groups. Postoperatively, when compared to the NO REVISION cohort, the REVISION cohort had a decrease in LLL (-2.6° vs + 1.5°, P = .011) and LDI (-5.1% vs + 1.3%, P = .039), and an increase in L3-L4 FLL (+2.6° vs -.6°, P = .001).

CONCLUSIONS

A reduction in LLL and compensatory increase in L3-L4 FLL after initial lower lumbar fusion surgery resulted in more reoperation at L3-L4 for post-fusion adjacent level spinal stenosis.

Obesity and Clinical, Radiographic, and Surgical Outcomes After Minimally Invasive Single-Level Transforaminal versus Lateral Lumbar Interbody Fusion

OBJECTIVE

To determine the effect of obesity on clinical, radiographic, and surgical outcomes after lateral lumbar interbody fusion (LLIF) versus minimally invasive surgery (MIS) transforaminal lumbar interbody fusion (TLIF) and compare the effectiveness of LLIF versus MIS TLIF in treating obese patients.

METHODS

A retrospective comparative analysis of patients who underwent single-level L4-5 LLIF or MIS TLIF over a 7-year period was performed. Spinopelvic parameters were compared based on preoperative and postoperative radiographs. Body mass index (BMI) ≥30 was deemed "high"; BMI <30 was deemed "low."

RESULTS

In total, 154 patients underwent LLIF or MIS TLIF during the study period (33 TLIF high BMI, 45 TLIF low BMI, 28 LLIF high BMI, and 48 LLIF low BMI). Compared with TLIF high BMI patients, TLIF low BMI patients experienced superior posterior disc height restoration (P = 0.05), shorter operative duration (P = 0.01), decreased revision surgery rate (P = 0.02), reduced estimated blood loss (P = 0.04), and shorter hospital length of stay (P = 0.03). No differences in outcomes were seen in LLIF high BMI versus LLIF low BMI cohorts. Among obese patients, LLIF provided superior restoration in anterior disc height (P < 0.001), posterior disc height (P = 0.003), and neuroforaminal height (P = 0.002); shorter operative duration (P < 0.001); and decreased estimated blood loss (P = 0.008), compared with MIS TLIF.

CONCLUSIONS

Obesity was associated with poorer overall radiographic and surgical outcomes after MIS TLIF but not LLIF. In obese patients in our cohort, LLIF provided superior improvements in spinopelvic parameters and surgical characteristics. BMI should be considered when deciding between LLIF and MIS TLIF.

Deep Learning for Lumbar Disc Herniation Diagnosis and Treatment Decision-Making Using Magnetic Resonance Imagings: A Retrospective Study

BACKGROUND

Lumbar disc herniation (LDH) is a common cause of back and leg pain. Diagnosis relies on clinical history, physical exam, and imaging, with magnetic resonance imaging (MRI) being an important reference standard. While artificial intelligence (AI) has been explored for MRI image recognition in LDH, existing methods often focus solely on disc herniation presence.

METHODS

We retrospectively analyzed MRI images from patients assessed for surgery by specialists. We then trained deep learning convolutional neural networks to detect LDH on MRI images. This study compared pure AI, pure human, and AI-assisted approaches for diagnosis accuracy and decision time. Statistical analysis evaluated each method's effectiveness.

RESULTS

Our approach demonstrated the potential of deep learning to aid LDH diagnosis and treatment. The AI-assisted group achieved the highest accuracy (94.7%), outperforming both pure AI and pure human approaches. AI integration reduced decision time without compromising accuracy.

CONCLUSIONS

Convolutional neural networks effectively assist specialists in initial LDH diagnosis and treatment decisions based on MRI images. This synergy between AI and human expertise improves diagnostic accuracy and efficiency, highlighting the value of AI-assisted diagnosis in clinical practice.

Low-Virulent Colonialization in Patients with Screw Loosening After Spondylodesis: A Single-Center Experience

OBJECTIVE

Screw loosening is one of the most frequent complications after instrumented spine surgery, which constitutes a heavy burden for patients and the health care system. Low-virulent colonialization with biofilm formation has been identified as a possible cause for screw loosening. The aim of this study was to investigate the rate of low virulent infections in recurrent screw loosening after revision surgery.

METHODS

Seventy-nine patients from January 2015-July 2018 undergoing revision surgery due to clinically aseptic implant loosening were included in our observational study. Sonication of the loosened implant was performed. All identified patients received clinical and radiographic follow-up. Screw loosening was evaluated in computed tomography scans carried out at least 12 months after revision surgery. Patients were differentiated into the following 3 groups: 1) all patients with low virulent colonialization, who received antibiotic treatment (Co + ABX); 2) all patients with colonialization without postoperative antibiotic treatment (Co-ABX); and 3) reference cohort containing all patients without colonialization (noCo).

RESULTS

Seventy-nine patients (51 females; mean age, 65.12 years) were identified. Forty-two patients (51.2%) received radiologic follow-up with computed tomography scan for implant control. These patients were assigned to 3 groups (Co + ABX: n = 5 [12%]; Co-ABX: n = 8 [19%]; noCo: n = 29 [69%]). In 10 of 13 patients with positive sonication results (Co + ABX and Co-ABX), recurrent screw loosening occurred (76.9%). Antibiotic administration had no influence on screw loosening rates (4 of 5 patients [80%] in Co + ABX and 6 of 8 [75%] patients in Co-ABX; P > 0.05). In the reference group, noCo, in 11 of 29 patients (37.9%), recurrent screw loosening was identified (P = 0.043).

CONCLUSIONS

In patients with screw revision surgery, incidence of low-virulent microorganism colonialization is high and may play a role in the incidence of screw loosening. New therapeutic approaches addressing low-virulent infections and biofilm formation may be helpful.

Matrix stiffness regulates nucleus pulposus cell glycolysis by MRTF-A-dependent mechanotransduction

Increased matrix stiffness of nucleus pulposus (NP) tissue is a main feature of intervertebral disc degeneration (IVDD) and affects various functions of nucleus pulposus cells (NPCs). Glycolysis is the main energy source for NPC survival, but the effects and underlying mechanisms of increased extracellular matrix (ECM) stiffness on NPC glycolysis remain unknown. In this study, hydrogels with different stiffness were established to mimic the mechanical environment of NPCs. Notably, increased matrix stiffness in degenerated NP tissues from IVDD patients was accompanied with impaired glycolysis, and NPCs cultured on rigid substrates exhibited a reduction in glycolysis. Meanwhile, RNA sequencing analysis showed altered cytoskeleton-related gene expression in NPCs on rigid substrates. Myocardin-related transcription factor A (MRTF-A) is a transcriptional coactivator in mechanotransduction mainly responding to cytoskeleton remodeling, which was activated and translocated to the nucleus under rigid substrate and was upregulated during IVDD progression. Furthermore, gas chromatography-mass spectrometry (GC-MS) analysis revealed that MRTF-A overexpression reduced NPC glycolytic metabolite abundance and identified a correlation with AMPK pathway. Mechanistically, rigid substrates and MRTF-A overexpression inhibited Kidins220 expression and AMPK phosphorylation in NPCs, whereas MRTF-A inhibition, treated with the MRTF-A inhibitor CCG, partially rescued NP tissue degeneration and glycolytic enzyme expression. Our data demonstrate that MRTF-A is a critical regulator that responds to increased matrix stiffness in IVDD, and MRTF-A activation reduces NPC glycolysis by down-regulating Kidins220 and inhibiting AMPK phosphorylation.

Rapid preparation of bioactive composites for transforaminal lumbar interbody fusion

The current stem cell tissue engineering always requires in vitro cell culture. To solve this problem, the bone mesenchymal stem cells (MSCs) screen-enrich-combine circulating system (SECCS) was created to rapidly enrich stem cells and combined with β-tricalcium phosphate (β-TCP) to immediately produce bioactive MSCs/β-TCP composites. 37 patients who underwent transforaminal lumbar interbody fusion (TLIF) surgery were included in this study and randomly divided into two groups. One group uses laminal bone grafts (LBG) for intervertebral fusion, and another group uses MSCs/β-TCP composites. The new technique could quickly and selectively enrich stem cells from the bone marrow and simultaneously implant them into the intervertebral space during operation. The cells eluted from the β-tricalcium phosphate were confirmed to be stem cells based on their characteristics. Higher early fusion rates, similar intervertebral height decreases, and functional improvement tendencies were observed in the SECCS group when compared to the LBG group. The bioactive scaffold prepared by SECCS showed better osteogenic efficiency at the early stage of intervertebral fusion compared to autologous LBG, which provided a new bone scaffold substitute for autologous bone.

Imaging of the postoperative spine

There has been a significant increase in the number of spinal surgical procedures performed over the last few decades, resulting in a proportionate increase in the number of postoperative imaging studies.An exhaustive literature search was performed along with consideration of various guidelines and expert opinions regarding postoperative spine imaging. Complications are divided into early (in the first few weeks) and delayed, depending on the time of onset. Some complications occurring in the early postoperative period are common for both the instrumented and non-instrumented spine. Delayed complications are specific to the type of surgery performed and have been described as such. This review discusses the normal postoperative appearance and the various early and delayed complications.An understanding of the normal postoperative appearance is pertinent to distinguish normal from abnormal. A plain radiograph is the primary imaging modality for immediate postoperative assessment and long-term follow-up after spinal instrumentation. MRI with or without contrast is the imaging modality of choice for the evaluation of the postoperative spine. CT is the best modality for the assessment of the instrumented spine and status of bony fusion. Imaging assessment of the postoperative spine is complex and requires knowledge of key factors for interpretation like indications for the initial surgical procedure, type and approach of the surgical procedure, instrumentation used, time elapsed since surgery, and clinical complaints. · For proper interpretation of the postoperative spine, it is very important to understand the indication and type of spinal procedure involved. · Baseline postoperative radiographs are important to detect any change in the position of metalwork and implant integration.. · Computed tomography is the modality of choice to evaluate bony fusion and metalwork-specific complications. · Postoperative fluid collection is the most common early complication and MRI is the imaging modality of choice for the identification of the same.. · Intravenous gadolinium is helpful to differentiate between scar/vascularized granulation tissue and recurrent or residual disc.. · Kaur S, Lalam R, Trivedi R. Imaging of the postoperative spine. Rofo 2025; DOI 10.1055/a-2507-8347.

Synthesis and Preclinical Evaluation of a Novel Oxy133-Infused Biomimetic Bone Graft Using a Rat Model of Posterolateral Spinal Fusion

OBJECTIVE

To 1) create a novel tissue-engineered bone graft comprising the osteoinductive oxysterol Oxy133 and 2) compare the osteogenic capability of this novel bone graft with bone graft substitutes previously examined.

METHODS

Oxy133 was homogeneously incorporated into a biomimetic (BioMim) bone graft substitute comprising extracellular matrix and calcium phosphates. Two iterations of the graft were created: one corresponding to an implant-dose of 2.0 mg Oxy133 (BioMim-Oxy133-Lo) and the other corresponding to an implant-dose of 20 mg Oxy133 (BioMim-Oxy133-Hi). Thirty-two male Sprague-Dawley rats were allocated randomly to 4 equally sized groups: 1) BioMim-Oxy133-Lo, 2) BioMim-Oxy133-Hi, 3) absorbable collagen sponge (ACS) with topically applied Oxy133 dissolved in dimethyl sulfoxide (ACS-Oxy133; 20 mg Oxy133/graft), and 4) ACS with topically applied recombinant human bone morphogenetic protein-2 (rhBMP-2) dissolved in water (ACS-rhBMP-2; 5.0 μg rhBMP-2/graft). All animals underwent L4-L5 posterolateral spinal fusion. Spines were harvested 8 weeks postoperatively and analyzed using micro-computed tomography imaging.

RESULTS

Successful fusion was achieved in all animals. Grafts containing Oxy133 had significantly greater bone volume, percent of bone volume per tissue volume (%BV), bone surface density (BSD), and trabecular number (TbN) compared to ACS-rhBMP-2 (P < 0.01 for each). Animals treated with BioMim-Oxy133-Lo had the greatest %BV, BSD, and TbN (P < 0.001 for each), whereas animals treated with ACS-rhBMP-2 had the lowest %BV, BSD, TbN, and trabecular thickness (P < 0.001 for each).

CONCLUSIONS

BioMim-Oxy133 is a novel bone graft that led to superior bone volume and quality compared to ACS-rhBMP-2 in a clinically translatable rat model of spinal fusion. Future work is needed to further evaluate this material as a safe and efficacious bone graft substitute.

American College of Surgeons National Surgical Quality Improvement Program Surgical Risk Calculator as a Predictor of Postoperative Outcomes After Adult Spinal Deformity Surgery: A Retrospective Cohort Analysis

BACKGROUND AND OBJECTIVES

In recent years, there has been an outpouring of scoring systems that were built to predict outcomes after various surgical procedures; however, research validating these studies in spinal surgery is quite limited. In this study, we evaluated the predictability of the American College of Surgeons National Surgical Quality Improvement Program Surgical Risk Calculator (ACS NSQIP SRC) for various postoperative outcomes after spinal deformity surgery.

METHODS

A retrospective chart review was conducted to identify patients who underwent spinal deformity surgery at our hospital between January 1, 2014, and December 31, 2022. Demographic and clinical data necessary to use the ACS NSQIP SRC and postoperative outcomes were collected for these patients. Predictability was analyzed using the area under the curve (AUC) of receiver operating characteristic curves and Brier scores.

RESULTS

Among the 159 study patients, the mean age was 64.5 ± 9.5 years, mean body mass index was 31.9 ± 6.6, and 95 (59.7%) patients were women. The outcome most accurately predicted by the ACS NSQIP SRC was postoperative pneumonia (observed = 5.0% vs predicted = 3.2%, AUC = 0.75, Brier score = 0.05), but its predictability still fell below the acceptable threshold. Other outcomes that were underpredicted by the ACS NSQIP SRC were readmission within 30 days (observed = 13.8% vs predicted = 9.0%, AUC = 0.63, Brier score = 0.12), rate of discharge to nursing home or rehabilitation facilities (observed = 56.0% vs predicted = 46.6%, AUC = 0.59, Brier = 0.26), reoperation (observed 11.9% vs predicted 5.4%, AUC = 0.60, Brier = 0.11), surgical site infection (observed 9.4% vs predicted 3.5%, AUC = 0.61, Brier = 0.05), and any complication (observed 33.3% vs 19%, AUC = 0.65, Brier = 0.23). Predicted and observed length of stay were not significantly associated (β = 0.132, P = .47).

CONCLUSION

The ACS NSQIP SRC is a poor predictor of outcomes after spinal deformity surgery.

Evaluation of the Therapeutic Effect of Decompression with or without Fusion on Lumbar Spinal Stenosis Caused by Degenerative Lumbar Spondylolisthesis: A Systematic Review and Meta-Analysis

OBJECTIVE

As a common clinical disease, lumbar spinal stenosis (LSS) is currently the preferred surgical treatment, and there are various opinions. We conducted a study on whether fusion should be performed simultaneously with decompression for LSS caused by low-grade degenerative lumbar spondylolisthesis and compared the efficacy and safety of the 2 surgeries.

METHODS

We conducted literature searches on Cochrane Library, Embase, PubMed, Scopus, and China National Knowledge Infrastructure databases to search for randomized controlled trials and observational studies that compared decompression alone and decompression plus fusion in the treatment of LSS with low-grade lumbar spondylolisthesis. We conducted a meta-analysis on surgical duration, hospital stay, incidence of complications, intraoperative blood loss, lower back and leg pain scores, and Oswestry Disability Index scores.

RESULTS

We ultimately included 8 articles, including 2 randomized controlled trials and 6 observational studies. Additional fusion did not benefit patients in relieving lower back pain (P = 0.05) and leg pain (P = 0.12), and there was no significant difference in Oswestry Disability Index (P = 0.12) and perioperative complication rate (P = 0.10) between the 2. However, decompression alone was significantly better than the decompression plus fusion group in terms of surgical time (P = 0.0008), hospital stay (P < 0.0001), and intraoperative blood loss (P < 0.00001).

CONCLUSIONS

In this article, decompression alone has shorter surgical and hospitalization time and less intraoperative bleeding compared to decompression plus fusion. And there was no significant difference in pain score and disability index between the 2 surgeries during follow-up. Therefore, we can say that for patients with LSS caused by low-grade lumbar spondylolisthesis, decompression alone is not inferior to decompression plus fusion.

Synergistic enhancement of spinal fusion in preclinical models using low-dose rhBMP-2 and stromal vascular fraction in an injectable hydrogel composite

Spinal fusion surgery remains a significant challenge due to limitations in current bone graft materials, particularly in terms of bioactivity, integration, and safety. This study presents an innovative approach using an injectable hydroxyapatite/β-tricalcium phosphate (HA/β-TCP) hydrogel combined with stromal vascular fraction (SVF) and low-dose recombinant human BMP-2 (rhBMP-2) to enhance osteodifferentiation and angiogenesis. Through a series of in vitro studies and preclinical models involving rats and minipigs, we demonstrated that the hydrogel system enables the sustained release of rhBMP-2, resulting in significantly improved bone density and integration, alongside reduced inflammatory responses. The combination of rhBMP-2 and SVF in this injectable formulation yielded superior spinal fusion outcomes, with enhanced mechanical properties and increased bone mass in both small and large animal models. These findings suggest that this strategy offers a promising and safer alternative for spinal fusion, with strong potential for clinical application.

3D printed titanium banana interbody cages versus titanium-coated PEEK bullet cages for TLIF

INTRODUCTION

Lumbar degenerative spinal disease is a common, major cause of pain and disability. Titanium and polyetheretherketone (PEEK) are popular materials for interbody implants although evidence is mixed on which material is superior in terms of fusion and subsidence. The purpose of this study was to evaluate the clinical outcome of 3D printed titanium (3DPT) cages in patients undergoing TLIFs, as well as complication profiles based on widely used outcome metrics and reoperation events.

METHODS

A retrospective review was conducted for patients receiving 1- or 2-level TLIF at an academic medical center between January 2018 and May 2022. Patients were divided into two cohorts according to the material of interbody cage(s), either 3DPT banana or titanium-coated PEEK bullet. Radiographs, patient-reported outcome measures (PROMs), and complications were analyzed and compared. All included patients had radiographic and clinical follow-up of at least one year.

RESULTS

200 patients with 277 interbody cage-implanted levels were included. Patients received either 3DPT (n = 140) or PEEK (n = 60) interbody cages with 202 and 75 instrumented vertebral levels per cohort, respectively. At one year, the 3DPT cohort demonstrated a higher fusion rate of 93.3 % compared to the PEEK cohort's fusion rate of 73.2 % (p < 0.0001). Subsidence rates were 6.0 % and 25.0 % for the 3DPT and PEEK groups, respectively (p < 0.0001).

CONCLUSION

While 3DPT and PEEK interbody cages demonstrated few adverse events at short- and long-term follow-up, 3DPT exhibited a higher rate of fusion and lower rate of subsidence at one year.

A prospective evaluation of cellular bone matrix for posterolateral lumbar fusion

INTRODUCTION

Autograft bone is the gold standard graft used in posterolateral lumbar intertransverse fusion (PLF) but can be limited by supply and donor site morbidity. Cadaveric cellular allografts represent an alternative source of graft material that avoids these limitations.

OBJECTIVE

To assess the safety and efficacy of ViviGenRCellular Bone Matrix in comparison to autograft bone in PLF.

METHODS

We performed a prospective study of 20 subjects who underwent PLF including 55 segmental levels. Each patient received ViviGen over the decorticated posterolateral gutter on one side an autograft bone on the other side. Fusion grading was assigned by a blinded independent neuroradiologist using a CT-based modified Lenke radiographic classification at 12 months.

RESULTS

There was a nonsignificant increase in surgical levels showing grade A fusion for ViviGen as compared to autograft bone (62 % vs. 44 %, p = 0.056). There was a nonsignificant decrease for Vivigen compared to autograft bone in grade B (16.4 % vs 25.5 %, p = 0.241) and fusion failure (21.8 % vs 30.9 %, p = 0.279). 69 % of subjects had significant improvement in back pain numeric rating and Oswestry scores. 73 % of patients had improvement in their leg pain scores. There were no significant changes in lumbar lordosis (p = 0.611) or mean segmental lordosis (p = 0.417). At 12 months, 35 % of all levels had a > 2-degree change on flexion versus extension views while 21 % of all levels had a > 3-degree change.

CONCLUSION

ViviGen cellular bone matrix demonstrates its theoretical bone-generative properties by showing non-inferiority relative to autograft with regards to fusion rates and similarity regarding patient reported outcome measures. Cellular bone matrix agents may represent a safe and noninferior alternative to autograft bone while circumventing potential drawbacks of the latter.

Patients With a History of Lumbar Fusion Have a Greater Risk of Revision Arthroscopy and Conversion to Total Hip Arthroplasty After Primary Hip Arthroscopy

PURPOSE

To characterize the risk of revision hip arthroscopy or conversion to total hip arthroplasty (THA) among patients with a history of lumbar fusion undergoing primary hip arthroscopy.

METHODS

We used the Statewide Planning and Research Cooperative System, an administrative database including all ambulatory and inpatient surgery encounters in New York, to identify all patients who underwent hip arthroscopy for femoroacetabular impingement between 2010 and 2020. Patients with previous lumbar fusion were identified using Current Procedural Terminology and International Classification of Diseases, Ninth and Tenth Revision, coding definitions. Patients with and without previous fusion were matched in a 1:5 ratio according to age and comorbidity burden. The number of levels fused was defined in the following fashion: (1) no fusion, (2) 1-2 levels, or (3) ≥3 levels. Patients were followed for 2 years to evaluate the rate of revision hip arthroscopy or conversion to THA. Multivariable logistic regression models were used to measure the association between number of levels fused and revision hip arthroscopy or conversion to THA.

RESULTS

Between 2010 and 2020, there were 23,277 patients who underwent primary hip arthroscopy in New York state. Of these, 348 (1.4%) had a previous lumbar fusion. After matching for age and comorbidities, the composite rate of revision hip arthroscopy or conversion to THA was greater in patients with previous lumbar fusion compared with patients without (16.5% vs 8.5%; P < .001). This risk increased with the number of levels fused (1-2 levels: 15.1%; adjusted odds ratio, 1.8; 95% confidence interval 1.3-2.6; vs ≥3 levels: 26.3%; adjusted odds ratio, 3.4; 95% confidence interval 1.7-7.0).

CONCLUSIONS

Patients with a history of lumbar fusion had significantly greater rates of revision hip arthroscopy and conversion to THA compared with patients without previous fusion. The risk of revision hip arthroscopy or conversion to THA was increased approximately 2-fold in patients with 1 to 2 levels fused and 3-fold in patients with 3 or more levels fused.

LEVEL OF EVIDENCE

Level III, prognostic retrospective matched comparative case series.

A Pilot Study of the Gut Microbiota in Spine Fusion Surgery Patients

Background

The microbiome has been identified as a contributor to bone quality. As skeletal health is critical to success of orthopedic surgery, the gut microbiome may be a modifiable factor associated with postoperative outcomes. For spine fusion surgery in particular, de novo bone formation and sufficient bone mineral density are essential for successful outcomes. Given the prevalence and complexity of these procedures, the identification of novel factors that may be related to operative success is important.

Questions/purposes

We sought to investigate how the composition of the microbiota related to bone health in a focused spinal fusion surgery cohort.

Methods

We investigated the composition of the microbiome in a cohort of 31 patients prior to spinal fusion surgery, as well as changes in the microbiome over 6 weeks postoperatively. Preoperative areal bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry.

Results

Composition of gut microbiota differed among spinal fusion patients with low bone mass (T-score ≤ -1.0) and those with normal BMD (P = .03). There was no significant change in composition of the gut microbiota between preoperative evaluation and 6 weeks postoperatively.

Conclusions

Our findings in this small sample suggest there may be a relationship between BMD and composition of the gut microbiome in patients who undergo spinal fusion surgery. Further work is needed to investigate these relationships as well as potential interventions to foster a favorable microbial composition in spinal fusion surgery patients.

Benefits of early recovery after surgery (ERAS) protocols on perioperative outcomes in patients undergoing elective lumbar spinal fusion: a prospective study

BACKGROUND CONTEXT

Enhanced Recovery After Surgery (ERAS) protocols have been shown to accelerate patient recovery across various surgical fields. There are growing reports of the benefits of ERAS for lumbar fusion, but the majority rely on retrospective analysis.

PURPOSE

This study aimed to prospectively assess the impact of an ERAS protocol on perioperative outcomes in patients undergoing lumbar spinal fusion.

STUDY DESIGN/SETTING

Prospective comparative cohort study conducted at a tertiary medical center in Taipei, Taiwan, between November 2020 and May 2023.

PATIENT SAMPLE

The study included 242 patients undergoing lumbar spinal fusion for degenerative spinal conditions divided into ERAS and non-ERAS groups.

OUTCOME MEASURES

Main outcomes measured included operative duration, estimated blood loss (EBL), postoperative nausea and vomiting (PONV), analgesic use, and visual analog scale (VAS) pain score.

METHODS

Propensity score matching (PSM) was used to minimize confounders between the 2 groups. Differences between the 2 groups were assessed using the 2-sample independent t-test or nonparametric Mann-Whitney U test for continuous variables, and the chi-square test or Fisher's exact test for categorical variables.

RESULTS

The ERAS group had significantly shorter operative time (202±68 min vs. 255±85 min) and EBL (480±302 ml vs. 641±387 ml) compared to the non-ERAS group. The ERAS group had significantly less total morphine-sulfate-equivalent (MSE) consumption (27±24 mg vs. 42±42 mg) and used patient-controlled analgesia (PCA) (97% vs. 41%) more frequently compared to the non-ERAS group. Notably, the ERAS group had a shorter time to ambulation and shorter time to removal of Foley catheters.

CONCLUSIONS

These data suggest that the employed ERAS protocol significantly enhances recovery trajectories and the need for analgesics in patients undergoing lumbar spinal fusion.

Surgeon Recommendation and Outcomes of Decompression With vs Without Fusion in Patients With Degenerative Spondylolisthesis

Importance

The ability of surgeons to choose the right patient for fusion in addition to decompression when operating for degenerative spondylolisthesis with symptomatic spinal stenosis is debated. The addition of fusion increases risk, morbidity, and costs but has been claimed to give better results for selected patients.

Objective

To investigate whether following surgeons' opinions regarding fusion was associated with clinical outcomes.

Design, Setting, and Participants

This cohort study was conducted alongside the Norwegian Degenerative Spondylolisthesis and Spinal Stenosis randomized clinical trial, which showed noninferiority for decompression alone compared with decompression with fusion. From February 12, 2014, to December 18, 2017, trial surgeons from 16 Norwegian departments denoted their preferred treatment for 222 of 267 patients with symptomatic spinal stenosis and degenerative spondylolisthesis. For this analysis, the clinical outcomes of the patients who were and were not randomized to the recommended treatment were compared.

Main Outcome and Measures

The primary outcome was a reduction of at least 30% from baseline to 2 years after surgery on the Oswestry Disability Index, ranging from 0 (no impairment) to 100 (maximum impairment). Secondary outcomes included the Zürich Claudication Questionnaire, leg and back pain scores, and the EuroQol 5-Dimension score.

Results

Among 222 patients (155 [70%] female; mean [SD] age, 66.2 [7.7] years), decompression alone was recommended for 112 patients, of whom 59 received only decompression, and additional fusion for 110 patients, of whom 57 received fusion. At 2-year follow-up, 87 of 116 patients (75%) who received surgery in agreement with the surgeons' recommendations and 77 of 106 (73%) who received surgery in disagreement with the surgeons' recommendations reached the primary outcome (difference, 2.4 percentage points; 95% CI, -9.1 to 13.9 percentage points). All secondary outcomes were in the same direction as the primary outcome.

Conclusions and Relevance

In this cohort study of 222 patients with degenerative spondylolisthesis who participated in a randomized clinical trial, surgeons' recommendations were not associated with better outcomes than a random allocation when deciding between decompression alone and decompression with instrumented fusion. The results suggest that surgeons performing degenerative spondylolisthesis surgery could rely safely on evidence of operating with decompression alone, despite the conflict of expert opinion.

The spinopelvic alignment in patients with prior knee or hip arthroplasty undergoing elective lumbar surgery

BACKGROUND CONTEXT

Concurrent degeneration of the lumbar spine, hip, and knee can cause significant disability and lower quality of life. Osteoarthritis in the lower extremities can lead to movement limitations, possibly requiring total knee arthroplasty (TKA) or total hip arthroplasty (THA). These procedures often impact spinal posture, causing alterations in spinopelvic alignment and lumbar spine degeneration. It is unclear if patients with a history of prior total joint arthroplasty (TJA) have different spinopelvic alignment compared to patients without.

PURPOSE

To assess the relationship between a history of previous THA or TKA, as well as combined THA and TKA, and the spinopelvic alignment in patients undergoing elective lumbar surgery for degenerative conditions.

STUDY DESIGN

A retrospective analysis was conducted on patients who underwent lumbar surgery for degenerative conditions. The patients were stratified based on a history of TKA, THA, or both TKA and THA.

PATIENT SAMPLE

A total of 632 patients (63% female) with an average age of 64±11 years and an average BMI of 30±6 kg/m2 were included.

OUTCOME MEASURES

Patients were stratified based on a history of THA, TKA, or combined THA and TKA. Spinopelvic parameters (lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), and pelvic incidence (PI)) were assessed. The relationship between spinopelvic alignment and prior TKA, THA or TKA and THA was analyzed.

METHODS

The data was tested for normal distribution using the Shapiro-Wilk test. We analyzed the relationship between the spinopelvic parameters and the different arthroplasty groups. Differences in scores between groups were examined using ANOVA. Tukey's Honestly Significant Difference test was used for pairwise comparison for significant ANOVA test results. Multivariable linear regression was applied, adjusted for age, sex and BMI.

RESULTS

A total of 632 patients (63% female) were included in the study. Of these patients, 74 (12%) had a history of isolated TKA, 40 (6%) had prior isolated THA, and 15 (2%) had TKA and THA prior to lumbar surgery. Patients with prior arthroplasty were predominantly female (59%) and significantly older (68±7 years vs 63±12 years, p<.001) with a significantly higher BMI (31±6 kg/m2 vs 29±6 kg/m2, p<.001). The LL was significantly lower (45.0°±13 vs 50.9°±14 p=.011) in the arthroplasty group compared to the nonarthroplasty group. A history of isolated TKA was significantly associated with lower LL (Est=-3.8, 95% CI -7.3 to -0.3, p=.031) and SS (Est=-2.6, 95% CI -5.0 to -0.2, p=.012) compared to patients without TJA. Prior combined THA and TKA was found to be significantly associated with a higher PT compared to the nonarthroplasty group (Est=5.1, 95% CI 0.4-9.8, p=.034).

CONCLUSIONS

The spinopelvic alignment differs between patients with and without prior TJA who undergo elective lumbar surgery. The study shows that a history of TKA is significantly associated with a lower LL and SS. The combination of THA and TKA was associated with a significantly higher PT. These findings highlight the complex relationship between the hip, spine, and knee. Moreover, the results could aid in enhancing preoperative planning of lumbar surgery in patients with known TJA.

Comparison of reoperation incidence after fusion versus decompression for lumbar degenerative disease: A propensity score-weighted study

BACKGROUND

Reoperation after lumbar spine surgery is a major issue for both patients and physicians. It is uncertain whether fusion is superior to decompression alone for lumbar degenerative disease regarding reoperation rate. We aim to evaluate the reoperation rate after fusion surgery for lumbar degenerative disease compared with decompression alone.

METHODS

This study was conducted under a retrospective cohort design in patients undergoing fusion or decompression alone in one or two levels for lumbar degenerative disease using a Japanese claims-based database. Primary outcome was reoperation incidence during the follow-up period, and secondary outcome was reoperation incidence within 90 days postoperatively. Confounding factors were handled using propensity score overlap weighting. Cumulative incidence of reoperation was calculated from the Kaplan-Meier curve and hazard ratios (HRs) and 95% confidence intervals (CIs) for reoperation were estimated using Cox proportional hazards regression models.

RESULTS

8497 patients (2051 patients in the fusion group and 6446 in the decompression alone group) were included in the study. There was no difference in reoperation rate between fusion and decompression alone (weighted HR 0.85 [95% CI 0.69 to 1.04]; p = 0.11).

CONCLUSIONS

Among patients with lumbar degenerative disease who underwent fusion or decompression alone, no significant difference was observed between the two groups.

Outpatient Neurosurgery: ASCs and the Medicolegal Landscape

The purpose of this work is to provide an understanding of the medicolegal landscape with regards to ambulatory surgery centers and physician owned hospitals, trends in our healthcare system, the benefits of facility ownership for both outpatient and inpatient spine surgery, and the effect of each on physicians and patients.

Distal Lumbar Lordosis is Associated With Reoperation for Adjacent Segment Disease After Lumbar Fusion for Degenerative Conditions

STUDY DESIGN

A single centre retrospective review.

OBJECTIVE

Recent studies have suggested that distal lordosis (L4-S1, DL) remains constant across all pelvic incidence (PI) subgroups, whilst proximal lordosis (L1-L4, PL) varies. We sought to investigate the impact of post-operative DL on adjacent segment disease (ASD) requiring reoperation in patients undergoing lumbar fusion for degenerative conditions.

METHODS

Patients undergoing 1-3 level lumbar fusion with the two senior authors between 2007-16 were included. Demographic and radiographic data were recorded. Univariate, multivariate binary logistic regression, and Kaplan Meier survivorship analyses were performed.

RESULTS

335 patients were included in the final analysis. Most had single (67%) or two (31%) level fusions. The mean follow-up was 64-month. Fifty-seven patients (17%) underwent reoperation for ASD at an average of 78-month post-operatively (R group). The R group had a significantly lower mean post-operative DL (27.3 vs 31.1 deg, P < .001) and mean PI (55.5 vs 59.2 deg, P < .05). On univariate analysis, patients with a post-operative DL of <35 deg had higher odds of reoperation for ASD than those with a post-operative DL of ≥35 deg (OR 2.7, P = .016). In the multivariate model, post-operative DL, low/average PI, and spondylolisthesis were all significantly associated with reoperation for ASD.

CONCLUSION

This study provides preliminary support to an association between post-operative distal lumbar lordosis and risk of reoperation for ASD in patients undergoing fusions for degenerative conditions. Further multicentre prospective study is needed to independently confirm this association and identify the impact of restoration of physiological distal lumbar lordosis on long term patient outcomes.

Do TLIF and PLIF Techniques Differ in Perioperative Complications? - Comparison of Complications Rates of Two High Volume Centers

STUDY DESIGN

Retrospective bicentric Cohort Study.

OBJECTIVE

Posterior (PLIF) and transforaminal lumbar interbody fusion (TLIF) have been clinically proven for the surgical treatment of degenerative spinal disorders. Despite many retrospective studies, the superiority of either technique has not been proven to date. In the literature, the complication rate of the conventional PLIF technique is reported to be significantly higher, but with inconsistent complication recording. In this retrospective bicentric study, a less invasive PLIF technique was compared with the conventional TLIF technique and complications were recorded using the validated SAVES V2 classification system.

METHODS

1142 patients underwent PLIF (702) or TLIF (n = 440) up to 3 levels in two specialized centers. Epidemiological data, intra- and postoperative complications during hospitalization and after discharge were analyzed according to SAVES V2.

RESULTS

The overall complication rate was 13.74%. TLIF-patients had slightly significant more complications than PLIF-patients (TLIF = 16.6%/PLIF = 11.9%, P = .0338). Accordingly, complications during revision surgeries were more frequent in the first cohort (TLIF = 20.9%/PLIF = 12.6%; P = .03252). In primary interventions, the surgical technique did not correlate with the complication rate (TLIF = 12.4%/PLIF = 11.7%). There were no significant differences regarding severity of complications.

CONCLUSIONS

An important component of this work is the complication recording according to a uniform classification system (SAVES V2). In contrast to previous literature, we could demonstrate that there is not a significant difference between the two surgical techniques.

Risk factors for deep surgical site infection following open posterior lumbar fusion: A retrospective case-control study

This study aimed to identify risk factors for deep surgical site infection (SSI) following open posterior lumbar fusion (OPLF). We retrospectively analyzed the clinical data of patients who underwent OPLF between January 2014 and December 2022. Patients were divided into SSI and non-SSI groups according to whether deep SSI occurred following OPLF. Patient's sex, age, body mass index (BMI), history of diabetes mellitus and smoking, American Society of Anesthesiologists score, surgical segment, surgical time, preoperative albumin level, local use of vancomycin, and cerebrospinal fluid (CSF) leakage were compared between the 2 groups. Univariate and multivariate logistic regression analyses were used to identify risk factors for postoperative deep SSI. The deep SSI rate was 5.0% (63/1256). Among them, age (P < .001), BMI (P = .008), surgical segment (P < .001), surgical time (P < .001), prevalence of diabetes mellitus (P = .036), and CSF leakage (P < .001) were significantly higher in the SSI group, whereas the preoperative albumin level (P < .001) and proportion of local use of vancomycin (P = .046) were significantly lower in the SSI group than those in the non-SSI group. Multivariate analysis indicated that higher age (P = .046, odds ratio [OR]: 1.036, 95% confidence interval [CI]: 1.001-1.073), BMI (P = .038, OR: 1.113, 95% CI: 1.006-1.232), lower preoperative albumin level (P = .041, OR: 0.880, 95% CI: 0.778-0.995), higher surgical segment (P = .004, OR: 2.241, 95% CI: 1.297n3.871), and CSF leakage (P = .046, OR: 2.372, 95% CI: 1.015-5.545) were risk factors, and the local use of vancomycin (P < .001, OR: 0.093, 95% CI: 0.036-0.245) was the protective factor for deep SSI following OPLF. We identified 5 risk factors (older age and BMI, lower preoperative albumin level, higher surgical segment, and CSF leakage) and 1 protective factor (local use of vancomycin powder) for deep SSI following OPLF. To address these risk and protective factors, comprehensive evaluations and recommendations should be provided to patients to reduce SSI rates.

A curved compliant spinal bone anchor to enhance fixation strength

Pedicle screws have long been established as the gold standard for spinal bone fixation. However, their fixation strength can be compromised in cases of low bone density, particularly in osteoporotic bone, due to the reliance on a micro-shape lock between the screw thread and the surrounding bone. To address this challenge, we propose augmenting conventional pedicles screws with a curved compliant anchor. This anchor integrates a curved super-elastic nitinol rod that is advanced through a canulated pedicle screw, forming a macro-shape lock within the vertebral body to aid the fixation strength. Both placement safety and fixation strength of this novel spinal bone anchor were validated on tissue phantoms (Sawbones). The radius of the curved compliant anchor's path demonstrates high precision while exhibiting strong dependence on the bone density in which the anchor is placed. When the curved compliant anchor is combined with a conventional pedicle screw, the mean maximum pull-out force elevated to 290 N, marking a 14% enhancement in pull-out resistance compared to using pedicle screw alone. Further augmentation with multiple curved compliant anchors holds promise for even greater fixation. The application of a curved compliant spinal bone anchor offers a promising means of increasing the fixation strength of pedicles screws, which is especially relevant in challenging clinical scenarios such a patient suffering from osteoporosis.

The Smokeless Paradox: Nontobacco Nicotine Use and Complications in Anterior Cervical Discectomy and Fusion

INTRODUCTION

Cervical fusion surgeries are commonly performed to stabilize the spine and relieve pain from various conditions. Recent increases in nontobacco nicotine product use, such as electronic cigarettes, present new challenges because of their unknown effects on spinal fusion outcomes. Our study aims to explore the effect of nontobacco nicotine dependence (NTND) on the success of cervical spinal fusions.

METHODS

We analyzed TriNetX database data for patients undergoing primary anterior cervical diskectomy and fusion, identified by specific Current Procedural Terminology codes, and categorized into cohorts based on a preoperative diagnosis of nicotine dependence, excluding those with tobacco use or dependence. Propensity matching in the ratio of 1:1 was done to control for demographics and body mass index. We analyzed 90-day medical and 2-year implant complications using chi-squared exact tests and univariate regressions within the matched cohorts.

RESULTS

The NTND and control cohorts comprised 5,331 and 43,033 patients, respectively. Five thousand two hundred thirty-two matched pairs of patients were included from each cohort as shown in Table 1. Our results indicate notable disparities in complications within 90 days postoperation between the cohorts. The NTND cohort had higher risks for opioid use (85.6% vs. 80.3%, P < 0.001), emergency department visits (13.0% vs. 8.40%, P < 0.001), opioid abuse (0.4% vs. 0.2%, P < 0.001), inpatient hospitalizations (20.0% vs. 17.4%, P < 0.001), and sepsis (1.40% vs. 0.80%, P = 0.01). At the 2-year follow-up, increases were observed in pseudarthrosis (14.0% vs. 9.60%, P < 0.001), adjacent segment disease (3.70% vs. 2.20%, P < 0.001), dysphagia (8.90% vs. 6.3%, P = 0.001), and revision surgery (2.00% vs. 1.40%, P = 0.02).

CONCLUSION

This study highlights notable postoperative complications in patients with NTND undergoing cervical spinal fusion.

Multimodal prehabilitation combined with perioperative enhanced recovery after surgery care for older patients undergoing spinal fusion surgery in China: protocol for a multicentre randomised controlled trial (PRACTICE trial)

INTRODUCTION

Besides the comorbid risk factors shared by older and younger patients, older individuals may also experience malnutrition, as well as cognitive or functional impairments. The accumulation of frailty and various geriatric syndromes in older individuals results in decreased physiological reserves, which makes the recovery process after spine surgery particularly challenging. Theoretically, combining the presurgery optimisation provided by a multimodal prehabilitation programme with the reduction of surgical stress provided by an enhanced recovery after surgery (ERAS) programme could improve postoperative recovery of older patients.

METHODS AND ANALYSIS

This is a prospective, multicentre, assessor-blinded, randomised controlled study. Patients who are 75 years of age or older and are scheduled for spinal fusion surgery will be enrolled on three academic medical centres. Regular preadmission education and perioperative ERAS care will be given to participants who were randomised to the control group. Participants randomised to the intervention group will receive multimodal prehabilitation combined with ERAS (PREERAS) management. We will include 164 patients with spinal fusion in three hospitals in China. All included patients will be followed for 90 days after surgery or until death. The primary outcome is the Comprehensive Complication Index (CCI), which ranges from 0 to 100, where a score of 100 indicates death due to complications. Secondary outcomes include length of stay and non-home discharge, rates of postoperative complications and unplanned readmission, North American Spine Society satisfaction, and Oswestry Disability Index/Neck disability index. Ninety-day CCI will be compared between groups using linear regression. Other continuous or categorical outcomes will be compared using linear or logistic regression.

ETHICS AND DISSEMINATION

This study has received ethical approval from the Xuanwu Hospital of Capital Medical University Ethics Committees (2024-088-001). The findings will be submitted to a peer-reviewed journal for publication.

TRIAL REGISTRATION NUMBER

NCT06140797.

Lumbar Spinal Fusion Outcomes in Patients With Cancer Compared to Matched Peers Without Cancer

STUDY DESIGN

Retrospective Matched Cohort Study.

OBJECTIVES

Optimization of medical comorbidities is an essential part of preoperative management. However, the isolated effects of individual comorbidities have not been evaluated within a homogenous spine surgery population. This exact matching study aims to assess the independent effects of cancer on outcomes following single-level lumbar fusions for non-cancer surgery.

METHODS

4680 consecutive patients undergoing single-level posterior-only lumbar fusion were retrospectively enrolled. Univariate statistics and coarsened exact matching (CEM) were computed to evaluate outcomes between cancer patients and those without comorbidities.

RESULTS

By logistic regression, malignancy conferred a higher risk of surgical complication (P = 0.016, OR = 2.64, CI = [1.200,5.790]), 30- and 90- day readmission (P = 0.012, OR = 2.025, CI = [1.170-3.510]; P < 0.001, OR = 2.34, CI = [1.430, 3.830], respectively), 90-day reoperation (P < 0.001, OR = 2.16, [1.110, 4.200]), and death at 90-days (P = 0.032, OR = 8.27, CI = [1.200, 56.850]). After matching, malignancy was associated with increased odds of incidental durotomy (6 vs 0 cases, P = 0.048) and death at both 30 and 90 days (both: OR = 8.0, P = 0.020, CI = [1.00, 63.960]). No cases of durotomy occurred in cases with mortality in the matched sample, suggesting independent relationships. There were no differences in length of stay, non-home discharge, ED evaluation, readmission, or reoperations.

CONCLUSION

Among otherwise exact-matched patients undergoing single level lumbar fusion, history of malignancy conferred a higher risk of short-term mortality, but not other outcomes suggestive of surgical failure. Increased mortality after lumbar fusion should be studied further and may play a role in surgical decision-making and patient discussions.