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

Retrieval analysis of PEEK rods pedicle screw system: three cases analysis

PURPOSE

To analyze the characteristics of PEEK rods retrieved in vivo, specifically their wear and deformation, biodegradability, histocompatibility, and mechanical properties.

METHOD

Six PEEK rods were retrieved from revision surgeries along with periprosthetic tissue. The retrieved PEEK rods were evaluated for surface damage and internal changes using Micro-CT, while light and electron microscopy were utilized to determine any histological changes in periprosthetic tissues. Patient history was gathered from medical records. Two intact and retrieved PEEK rods were used for fatigue testing analysis by sinusoidal load to the spinal construct.

RESULTS

All implants showed evidence of plastic deformation around the screw-rod interface, while the inner structure of PEEK rods appeared unchanged with no visible voids or cracks. Examining images captured through light and electron microscopy indicated that phagocytosis of macrophages around PEEK rods was less severe in comparison to the screw-rod interface. The results of an energy spectrum analysis suggested that the distribution of tissue elements around PEEK rods did not differ significantly from normal tissue. During fatigue testing, it was found that the retrieved PEEK rods cracked after 1.36 million tests, whereas the intact PEEK rods completed 5 million fatigue tests without any failure.

CONCLUSION

PEEK rods demonstrate satisfactory biocompatibility, corrosion resistance, chemical stability, and mechanical properties. Nevertheless, it is observed that the indentation at the junction between the nut and the rod exhibits relatively weak strength, making it susceptible to breakage. As a precautionary measure, it is recommended to secure the nut with a counter wrench, applying the preset torque to prevent overtightening.

Lumbar Facet Arthroplasty Versus Fusion for Grade-I Degenerative Spondylolisthesis with Stenosis: A Prospective Randomized Controlled Trial

BACKGROUND

The comparative effectiveness of decompression plus lumbar facet arthroplasty versus decompression plus instrumented lumbar spinal fusion in patients with lumbar spinal stenosis and grade-I degenerative spondylolisthesis is unknown.

METHODS

In this randomized, controlled, Food and Drug Administration Investigational Device Exemption trial, we assigned patients who had single-level lumbar spinal stenosis and grade-I degenerative spondylolisthesis to undergo decompression plus lumbar facet arthroplasty (arthroplasty group) or decompression plus fusion (fusion group). The primary outcome was a predetermined composite clinical success score. Secondary outcomes included the Oswestry Disability Index (ODI), visual analog scale (VAS) back and leg pain, Zurich Claudication Questionnaire (ZCQ), Short Form (SF)-12, radiographic parameters, surgical variables, and complications.

RESULTS

A total of 321 adult patients were randomized in a 2:1 fashion, with 219 patients assigned to undergo facet arthroplasty and 102 patients assigned to undergo fusion. Of these, 113 patients (51.6%) in the arthroplasty group and 47 (46.1%) in the fusion group who had either reached 24 months of postoperative follow-up or were deemed early clinical failures were included in the primary outcome analysis. The arthroplasty group had a higher proportion of patients who achieved composite clinical success than did the fusion group (73.5% versus 25.5%; p < 0.001), equating to a between-group difference of 47.9% (95% confidence interval, 33.0% to 62.8%). The arthroplasty group outperformed the fusion group in most patient-reported outcome measures (including the ODI, VAS back pain, and all ZCQ component scores) at 24 months postoperatively. There were no significant differences between groups in surgical variables or complications, except that the fusion group had a higher rate of developing symptomatic adjacent segment degeneration.

CONCLUSIONS

Among patients with lumbar spinal stenosis and grade-I degenerative spondylolisthesis, lumbar facet arthroplasty was associated with a higher rate of composite clinical success than fusion was at 24 months postoperatively.

LEVEL OF EVIDENCE

Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

Lumbar Decompression With and Without Fusion for Lumbar Stenosis With Spondylolisthesis: A Cost Utility Analysis

STUDY DESIGN

Markov model.

OBJECTIVE

To compare the cost-effectiveness of lumbar decompression alone (DA) with lumbar decompression with fusion (DF) for the management of adults undergoing surgery for lumbar stenosis with associated degenerative spondylolisthesis.

SUMMARY OF BACKGROUND DATA

Rates of lumbar fusion have increased for all indications in the United States over the last 20 years. Recent randomized controlled trial data, however, have suggested comparable functional outcomes and lower reoperation rates for lumbar decompression and fusion as compared with DA in the treatment of lumbar stenosis with degenerative spondylolisthesis.

MATERIALS AND METHODS

A multistate Markov model was constructed from the US payer perspective of a hypothetical cohort of patients with lumbar stenosis with associated spondylolisthesis requiring surgery. Data regarding clinical improvement, costs, and reoperation were generated from contemporary randomized trial evidence, meta-analyses of recent prospective studies, and large retrospective cohorts. Base case, one-way sensitivity analysis, and probabilistic sensitivity analyses were conducted, and the results were compared with a WTP threshold of $100,000 (in 2022 USD) over a two-year time horizon. A discount rate of 3% was utilized.

RESULTS

The incremental cost and utility of DF relative to DA were $12,778 and 0.00529 aggregated quality adjusted life years. The corresponding incremental cost-effectiveness ratio of $2,416,281 far exceeded the willingness to pay threshold of $100,000. In sensitivity analysis, the results varied the most with respect to rate of improvement after DA, rate of improvement after lumbar decompression and fusion, and odds ratio of reoperation between the two groups. Zero percent of one-way and probabilistic sensitivity analyses achieved cost-effectiveness at the willingness-to-pay threshold.

CONCLUSIONS

Within the context of contemporary surgical data, DF is not cost-effective compared with DA in the surgical management of lumbar stenosis with associated spondylolisthesis over a two-year time horizon.

The hemostatic and anti-inflammatory effects of intravenous single-dose of tranexamic acid in double-segment posterior lumbar interbody fusion: a case control study

This study aims to observe the hemostatic and anti-inflammatory effects of intravenous administration of tranexamic acid (TXA) in dual segment posterior lumbar interbody fusion (PLIF). The data of 53 patients with lumbar disease treated with double-segment PLIF were included in this study. The observation group was received a single-dose intravenous of TXA (1 g/100 mL) 15 min before skin incision after general anesthesia. The control group was not received TXA. The observation indicators included postoperative activated partial prothrombin time (APTT), thrombin time (PT), thrombin time (TT), fibrinogen (FIB), platelets (PLT), and postoperative deep vein thrombosis in the lower limbs, surgical time, intraoperative bleeding volume, postoperative drainage volume, transfusion rate, postoperative hospital stay, red blood cell (RBC), hemoglobin (HB), hematocrit (HCT), C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) on the 1st, 4th, 7th, and last tested day after surgery. All patients successfully completed the operation, and there was no deep vein thrombosis after operation. There was no statistically significant difference in postoperative APTT, PT, TT, FIB, PLT, surgical time, and postoperative hospital stay between the two groups (p > 0.05). The intraoperative bleeding volume, postoperative drainage volume, and transfusion rate in the observation group were lower than those in the control group, and the differences were statistically significant (p < 0.05). There was no statistically significant difference in RBC, HB, HCT, CRP, and ESR between the two groups on the 1st, 4th, 7th, and last tested day after surgery (p > 0.05). Intravenous administration of TXA in dual segment PLIF does not affect coagulation function and can reduce bleeding volume, postoperative drainage volume, and transfusion rate. Moreover, it does not affect the postoperative inflammatory response.

Longitudinal Analysis of the Care Pathway of Patients with Lumbar Spinal Stenosis in the US

Background

Evidence regarding the frequency and timing of treatment for lumbar spinal stenosis (LSS) fails to offer clear consensus. We describe the LSS care journey from initial diagnosis to first surgical intervention.

Methods

Using Medicare claims database from 2009 through 2020, we identified patients who were diagnosed with LSS. The use and timing of conservative and surgical treatments during the entire follow-up from the initial diagnosis were reported.

Results

Of the 143,849 patients identified, 68% received conservative care within 8.4 months and 25.3% received a surgical or minimally invasive intervention over 5.7 years following initial diagnosis, with 12.6% undergoing open decompression alone, 10.2% undergoing open decompression with fusion, and 5.1% undergoing fusion surgery alone. Fewer than 1% were provided with interspinous spacers or a percutaneous image-guided lumbar decompression.

Conclusion

Approximately three-quarters of patients in the study received no surgical or non-invasive interventions for approximately six years following diagnosis with LSS.

Diabetes increases risk of lumbar spinal fusion complications: association with altered structure of newly formed bone at the fusion site

Diabetes predisposes to spine degenerative diseases often requiring surgical intervention. However, the statistics on the prevalence of spinal fusion success and clinical indications leading to the revision surgery in diabetes are conflicting. The purpose of the presented retrospective observational study was to determine the link between diabetes and lumbar spinal fusion complications using a database of patients (n = 552, 45% male, age 54 ± 13.7 years) residing in the same community and receiving care at the same health care facility. Outcome measures included clinical indications and calculated risk ratio (RR) for revision surgery in diabetes. Paravertebral tissue recovered from a non-union site of diabetic and nondiabetic patients was analyzed for microstructure of newly formed bone. Diabetes increased the RR for revision surgery due to non-union complications (2.80; 95% CI, 1.12-7.02) and degenerative processes in adjacent spine segments (2.26; 95% CI, 1.45-3.53). In diabetes, a risk of revision surgery exceeded the RR for primary spinal fusion surgery by 44% (2.36 [95% CI, 1.58-3.52] vs 1.64 [95% CI, 1.16-2.31]), which was already 2-fold higher than diabetes prevalence in the studied community. Micro-CT of bony fragments found in the paravertebral tissue harvested during revision surgery revealed structural differences suggesting that newly formed bone in diabetic patients may be of compromised quality, as compared with that in nondiabetic patients. In conclusion, diabetes significantly increases the risk of unsuccessful lumbar spine fusion outcome requiring revision surgery. Diabetes predisposes to the degeneration of adjacent spine segments and pseudoarthrosis at the fusion sites, and affects the structure of newly formed bone needed to stabilize fusion.

Osteoimmunological Principles Adapted to Achieve Mechanically Superior Posterolateral Fusion in a New Zealand White Rabbit Model Using Antigen-Coated, Electrospun Beta-Tricalcium Phosphate

Introduction Triggering the immune system via antigenic stimulation at the time of spinal fusion surgery may enhance bone morphogenesis and result in successful bony arthrodesis. We sought to demonstrate that bone morphogenesis could be enhanced via antigenic immunologic stimulation of a surgical fusion site. Methods New Zealand white rabbits underwent non-instrumented posterolateral fusion of L5-6 with implantation of either an immunologically activated graft (inert beta-tricalcium phosphate) or harvested autograft. Fusion was evaluated using plain radiographs, micro-computed tomography (CT), mechanical palpation, and biomechanical testing. The final evaluation was carried out at 12 weeks postoperatively. Results Eight rabbits received immunologically activated grafts; 10 received autografts and served as historical controls. Fusion rates were identical between groups (both 50%). Radiographs and micro CT of the fusion mass showed no significant difference between groups, and both showed good incorporation of the transverse processes into the fusion masses with radiographic evidence confirming trabeculation and bone remodeling. However, mechanical testing of the fusion sites showed superior fusion strength in the rabbits that received immunologically activated grafts, approaching a factor of two on flexion/extension, lateral bending, and axial rotation. Little to no graft material was appreciable in the non-fused antigen-treated specimens. Conclusions There is a long-standing need for a graft material that can replace autograft bone, due to the negative clinical consequences and financial costs pertaining to autologous bone harvesting. No allograft bone substitute to date has been able to reliably replicate the success of harvested autograft bone. This study suggests that immunological enhancement of inert beta-tricalcium phosphate can potentially be a substitute for allograft bone that can meet and even exceed the success of harvested autograft bone.

Preference Sensitive Care and Shared Decision-Making in Lumbar Spinal Stenosis: A Scoping Review

STUDY DESIGN

Scoping review.

OBJECTIVE

The objective of this study was to conduct a scoping review exploring the extent to which preference sensitivity has been studied in treatment decisions for lumbar spinal stenosis (LSS), utilizing shared decision-making (SDM) as a proxy.

BACKGROUND

Preference-sensitive care involves situations where multiple treatment options exist with significant tradeoffs in cost, outcome, recovery time, and quality of life. LSS has gained research focus as a preference-sensitive care scenario.

MATERIALS AND METHODS

A scoping review protocol in accordance with "Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews" regulations was registered with the Open Science Framework (ID: 9ewup) and conducted across multiple databases from January 2000 to October 2022. Study selection and characterization were performed by 3 independent reviewers and an unbiased moderator.

RESULTS

The search resulted in the inclusion of 16 studies varying in design and sample size, with most published between 2016 and 2021. The studies examined variables related to SDM, patient preferences, surgeon preferences, and decision aids (DAs). The outcomes assessed included treatment choice, patient satisfaction, and patient understanding. Several studies reported that SDM influenced treatment choice and patient satisfaction, while the impact on patient understanding was less clear. DAs were used in some studies to facilitate SDM.

CONCLUSION

The scoping review identified a gap in comprehensive studies analyzing the preference sensitivity of treatment for LSS and the role of DAs. Further research is needed to better understand the impact of patient preferences on treatment decisions and the effectiveness of DAs in LSS care. This review provides a foundation for future research in preference-sensitive care and SDM in the context of lumbar stenosis treatment.

Comparative Review of the Socioeconomic Burden of Lower Back Pain in the United States and Globally

Internationally, the United States (U.S.) cites the highest cost burden of low back pain (LBP). The cost continues to rise, faster than the rate of inflation and overall growth of health expenditures. We performed a comprehensive literature review of peer-reviewed and non- peer-reviewed literature from PubMed, Scopus, and Google Scholar for contemporary data on prevalence, cost, and projected future costs. Policymakers in the U.S. have long attempted to address the high-cost burden of LBP through limiting low-value services and early imaging. Despite these efforts, costs (~$40 billion; ~$2,000/patient/yr) continue to rise with increasing rates of unindicated imaging, high rates of surgery, and subsequent revision surgery without proper trial of non-pharmacologic measures and no corresponding reduction in LBP prevalence. Globally, the overall prevalence of LBP continues to rise largely secondary to a growing aging population. Cost containment methods should focus on careful and comprehensive clinical assessment of patients to better understand when more resource-intensive interventions are indicated.

Socioeconomic disparities in lumbar fusion rates were exacerbated during the COVID-19 pandemic

Background

The COVID-19 pandemic disrupted healthcare access and utilization throughout the US, with variable impact on patients of different socioeconomic status (SES) and race. We characterize pre-pandemic and pandemic demographic and SES trends of lumbar fusion patients in the US.

Methods

Adults undergoing first-time lumbar fusion 1/1/2004-3/31/2021 were assessed in Clinformatics® Data Mart for patient age, geographical location, gender, race, education level, net worth, and Charlson Comorbidity Index (CCI). Multivariable regression models were used to evaluate the significance of trends over time, with a focus on pandemic trends 2020-2021 versus previous trends 2004-2019.

Results

The total 217,204 patients underwent lumbar fusions, 1/1/2004-3/31/2021. The numbers and per capita rates of lumbar fusions increased 2004-2019 and decreased in 2020 (first year of COVID-19 pandemic), with large variation in geographic distribution. There was overall a significant decrease in proportion of White patients undergoing lumbar fusion over time (OR=0.997, p<.001), though they were more likely to undergo surgery during the pandemic (OR=1.016, p<.001). From 2004-2021, patients were more likely to be educated beyond high school. Additionally, patients in the highest (>$500k) and lowest (<$25k) net worth categories had significantly more fusions over time (p<.001). During the pandemic (2020-2021), patients in higher net worth groups were more likely to undergo lumbar fusions ($150k-249k & $250k-499k: p<.001) whereas patients in the lowest net worth group had decreased rate of surgeries (p<.001). Lastly, patients' CCI increased significantly from 2004 to 2021 (coefficient=0.124, p<.001), and this trend held true during the pandemic (coefficient=0.179, p<.001).

Conclusions

To the best of our knowledge, our work represents the most comprehensive and recent characterization of SES variables in lumbar fusion rates. Unsurprisingly, lumbar fusions decreased overall with the onset of the COVID-19 pandemic. Importantly, disparities in fusion patients across patient race and wealth widened during the pandemic, reversing years of progress, a lesson we can learn for future public health emergencies.

The influence of osteoporosis on mechanical complications in lumbar fusion surgery: a systematic review

Background

Adults undergoing spine surgery often have underlying osteoporosis, which may be a risk factor for postoperative complications. Although these associations have been described, osteoporosis remains profoundly underdiagnosed and undertreated in the spine surgery population. A thorough, comprehensive systematic review summarizing the relationships between bone mineral density (BMD) and specific complications of lumbar fusion surgery could be a valuable resource for raising awareness and supporting clinical practice changes.

Methods

PubMed, Embase, and Web of Science databases were searched for original clinical research articles reporting on BMD, or surrogate measure, as a predictor of complications in adults undergoing elective lumbar fusion for degenerative disease or deformity. Endpoints included cage subsidence, screw loosening, pseudarthrosis, vertebral fracture, junctional complications, and reoperation.

Results

A total of 71 studies comprising 12,278 patients were included. Overall, considerable heterogeneity in study populations, methods of bone health assessment, and definition and evaluation of clinical endpoints precluded meta-analysis. Nevertheless, low BMD was associated with higher rates of implant failures like cage subsidence and screw loosening, which were often diagnosed with concomitant pseudarthrosis. Osteoporosis was also a significant risk factor for proximal junctional kyphosis, particularly due to fracture. Many studies found surgical site-specific BMD to best predict focal complications. Functional outcomes were inconsistently addressed.

Conclusions

Our findings suggest osteoporosis is a significant risk factor for mechanical complications of lumbar fusion. These results emphasize the importance of preoperative osteoporosis screening, which allows for medical and surgical optimization of high-risk patients. This review also highlights current practical challenges facing bone health evaluation in patients undergoing elective surgery. Future prospective studies using standardized methods are necessary to strengthen existing evidence, identify optimal predictive thresholds, and establish specialty-specific practice guidelines. In the meantime, an awareness of the surgical implications of osteoporosis and utility of preoperative screening can provide for more informed, effective patient care.

Using Machine Learning Models to Identify Factors Associated With 30-Day Readmissions After Posterior Cervical Fusions: A Longitudinal Cohort Study

OBJECTIVE

Readmission rates after posterior cervical fusion (PCF) significantly impact patients and healthcare, with complication rates at 15%-25% and up to 12% 90-day readmission rates. In this study, we aim to test whether machine learning (ML) models that capture interfactorial interactions outperform traditional logistic regression (LR) in identifying readmission-associated factors.

METHODS

The Optum Clinformatics Data Mart database was used to identify patients who underwent PCF between 2004-2017. To determine factors associated with 30-day readmissions, 5 ML models were generated and evaluated, including a multivariate LR (MLR) model. Then, the best-performing model, Gradient Boosting Machine (GBM), was compared to the LACE (Length patient stay in the hospital, Acuity of admission of patient in the hospital, Comorbidity, and Emergency visit) index regarding potential cost savings from algorithm implementation.

RESULTS

This study included 4,130 patients, 874 of which were readmitted within 30 days. When analyzed and scaled, we found that patient discharge status, comorbidities, and number of procedure codes were factors that influenced MLR, while patient discharge status, billed admission charge, and length of stay influenced the GBM model. The GBM model significantly outperformed MLR in predicting unplanned readmissions (mean area under the receiver operating characteristic curve, 0.846 vs. 0.829; p < 0.001), while also projecting an average cost savings of 50% more than the LACE index.

CONCLUSION

Five models (GBM, XGBoost [extreme gradient boosting], RF [random forest], LASSO [least absolute shrinkage and selection operator], and MLR) were evaluated, among which, the GBM model exhibited superior predictive performance, robustness, and accuracy. Factors associated with readmissions impact LR and GBM models differently, suggesting that these models can be used complementarily. When analyzing PCF procedures, the GBM model resulted in greater predictive performance and was associated with higher theoretical cost savings for readmissions associated with PCF complications.

A prospective study of lumbar facet arthroplasty in the treatment of degenerative spondylolisthesis and stenosis: cost-effective assessment from the Total Posterior Spine system (TOPSTM) IDE Study: 2-year model revision and sensitivity analyses based on 305 subjects

BACKGROUND CONTEXT

A previous cost-effectiveness analysis published in 2022 found that the Total Posterior Spine (TOPSTM) system was dominant over transforaminal lumbar interbody fusion (TLIF). This analysis required updating to reflect a more complete dataset and pricing considerations.

PURPOSE

To evaluate the cost-effectiveness of TOPSTM system as compared with TLIF based on an updated and complete FDA investigational device exemption (IDE) data set.

STUDY DESIGN/SETTING

Cost-utility analysis of the TOPSTM system compared to TLIF.

PATIENT SAMPLE

A multicenter, FDA IDE, randomized control trial (RCT) investigated the efficacy of TOPSTM compared to TLIF with a current population of n=305 enrolled and n=168 with complete 2-year follow-up.

OUTCOME MEASURES

Cost and quality adjusted life years (QALYs) were calculated to determine our primary outcome measure, the incremental cost-effectiveness ratio. Secondary outcome measures included: net monetary benefit as well at willingness-to-pay (WTP) thresholds.

METHODS

The primary outcome of cost-effectiveness is determined by incremental cost-effectiveness ratio. A Markov model was used to simulate the health outcomes and costs of patients undergoing TOPSTM or TLIF over a 2-year period. alternative scenario sensitivity analysis, one-way sensitivity analysis, and probabilistic sensitivity analysis were conducted to assess the robustness of the model results.

RESULTS

The updated base case result demonstrated that TOPSTM was immediately and longitudinally dominant compared with the control with an incremental cost-effectiveness ratio of -9,637.37 $/QALY. The net monetary benefit was correspondingly $2,237, both from the health system's perspective and at a WTP threshold of 50,000 $/QALY at the 2-year time point. This remained true in all scenarios tested. The Alternative Scenario Sensitivity Analysis suggested cost-effectiveness irrespective of payer type and surgical setting. To remain cost-effective, the cost difference between TOPSTM and TLIF should be no greater than $1,875 and $3,750 at WTP thresholds of $50,000 and 100,000 $/QALY, respectively.

CONCLUSIONS

This updated analysis confirms that the TOPSTM device is a cost-effective and economically dominant surgical treatment option for patients with lumbar stenosis and degenerative spondylolisthesis compared to TLIF in all scenarios examined.

Discharge within 1 day following elective single-level transforaminal lumbar interbody fusion: a propensityscore-matched analysis of predictors, complications, and readmission

STUDY DESIGN

This was a retrospective case-control study using 8 years of data from a nationwide database of surgical outcomes in the United States.

PURPOSE

This study aimed to improve our understanding of the risk factors associated with a length of stay (LOS) >1 day and aid in reducing postoperative hospitalization and complications.

OVERVIEW OF LITERATURE

Despite the proven safety of transforaminal lumbar interbody fusion (TLIF), some patients face prolonged postoperative hospitalization.

METHODS

Data were collected from the American College of Surgeons National Surgical Quality Improvement Program dataset from 2011 to 2018. The cohort was divided into patients with LOS up to 1 day (LOS ≤1 day), defined as same day or next-morning discharge, and patients with LOS >1 day (LOS >1 day). Univariable and multivariable regression analyses were performed to evaluate predictors of LOS >1 day. Propensity-score matching was performed to compare pre- and postdischarge complication rates.

RESULTS

A total of 12,664 eligible patients with TLIF were identified, of which 14.8% had LOS ≤1 day and 85.2% had LOS >1 day. LOS >1 day was positively associated with female sex, Hispanic ethnicity, diagnosis of spondylolisthesis, American Society of Anesthesiologists classification 3, and operation length of >150 minutes. Patients with LOS >1 day were more likely to undergo intraoperative/postoperative blood transfusion (0.3% vs. 4.5%, p<0.001) and reoperation (0.1% vs. 0.6%, p=0.004). No significant differences in the rates of postdischarge complications were found between the matched groups.

CONCLUSIONS

Patients with worsened preoperative status, preoperative diagnosis of spondylolisthesis, and prolonged operative time are more likely to require prolonged hospitalization and blood transfusions and undergo unplanned reoperation. To reduce the risk of prolonged hospitalization and associated complications, patients indicated for TLIF should be carefully selected.

Comparing Metal Artifact Severity and Ability to Assess Near-Metal Anatomy Between 0.55 T and 1.5 T MRI in Patients with Metallic Spinal Implants-A Scanner Comparison Study

RATIONALE AND OBJECTIVES

To compare image quality and metal artifact severity at 0.55 T and 1.5 T MRI in patients with spinal implants following posterior fusion surgery.

MATERIALS AND METHODS

50 consecutive patients (mean age: 69 ± 12 years) who underwent 0.55 T and 1.5 T MRI following posterior fusion surgery of the lumbar or thoracolumbar spine were included. Examinations used metal artifact reduction protocols from clinical routine. Images were rated by two fellowship-trained musculoskeletal radiologists for image quality, ability to assess the spinal canal and the neural foramina, and artifact severity on 5-point Likert scales. Additionally, differences in artifact severity and visibility of near-metal anatomy among implant sizes (1-level vs. 2-level vs. >2-levels) were evaluated.

RESULTS

Signal/contrast (mean: 4.0 ± 0.3 [0.55 T] vs. 4.4 ± 0.6 [1.5 T]; p < .001) and resolution (3.8 ± 0.5 vs. 4.2 ± 0.7; p < .001) were rated lower at 0.55 T. The ability to assess the spinal canal (4.4 ± 0.5 vs. 4.2 ± 0.9; p = .69) and the neural foramina (3.8 ± 0.5 vs. 3.8 ± 0.9; p = .19) were however rated equally good with excellent interrater agreement (range: 0.84-0.94). Susceptibility artifacts were rated milder at 0.55 T (1.8 ± 0.5 vs. 3.0 ± 0.6; p < .001). For implant size-based subgroups, the visibility of near-metal anatomy decreased with implant length at 1.5 T, but remained unchanged at 0.55 T. In consequence, the spinal canal and neural foramina could be better assessed at 0.55 T in patients with multi-level implants (4.4 ± 0.5 vs. 3.6 ± 1.1; p < .001).

CONCLUSION

Metal artifacts of spinal implants are substantially less pronounced at 0.55 T MRI. When examining patients with multi-level posterior fusion, this translates into a superior ability to assess near-metal anatomy, where 1.5 T MRI reaches diagnostic limitations.

Predictors of Admission to Post-Acute Rehabilitation Following Multi-Level Spinal Decompression and Fusion Surgery and Its Associated Outcomes

OBJECTIVE

To investigate predictive factors and outcomes in those admitted to post-acute rehabilitation (PAR) versus those that discharged home following multi-level spinal decompression and fusion surgery.

METHODS

Retrospective case review study of adults that underwent multi-level spinal decompression and fusion surgery between 2016 and 2022 at an academic institution. Preoperative, perioperative, postoperative, and outcomes variables were compared between those discharged home versus PAR. Finally, multiple logistic regression was used to determine factors contributing to PAR admission.

RESULTS

Of 241 total patients, 89 (37%) discharged home and 152 (63%) discharged to PAR. Among home discharge patients, 45.9% used an assistive device, while among PAR patients, 61.5% used 1 (P = 0.041). Mean pre-operative Oswestry Disability Index score was significantly lower in the home discharge group compared to the PAR discharge group (40.3 vs. 45.3 respectively, P = 0.044). Females were 2.43 times more likely to be discharged to PAR compared to males (95% CI: 1.06, 5.54, P = 0.04). Patients with a mood disorder had 2.81 times higher odds of being discharged to PAR compared to those without (95% CI: 1.20, 6.60, P = 0.02). Other variables evaluated were not statistically significant.

CONCLUSIONS

Female sex and presence of a mood disorder increase the likelihood to PAR discharge following multi-level spinal decompression surgery.

Characterizing Negative Online Reviews of Spine Surgeons

DESIGN

Retrospective review.

OBJECTIVE

Characterize negative reviews of spine surgeons in the United States.

SUMMARY

Physician rating websites significantly influence the selection of doctors by other patients. Negative experiences are impacted by various factors, both clinical and nonclinical, geography, and practice structure. The purpose of this study was to evaluate and categorize negative reviews of spine surgeons in the United States, with a focus on surgical versus nonsurgical reviewers.

METHODS

Spine surgeons were selected from available online professional society membership directories. A search for reviews was performed on Healthgrades.com, Vitals.com, and RateMDs.com for the past 10 years. Free response reviews were coded by complaint, and qualitative analysis was performed. χ 2 and Fisher exact tests were used to compare categorical variables, and multiple comparisons were adjusted with Benjamini-Hochberg correction. A binary logistic regression model was performed for the top three most mentioned nonclinical and clinical complaint labels. A P -value <0.05 was considered statistically significant.

RESULTS

A total of 16,695 online reviews were evaluated, including 1690 one-star reviews (10.1%). Among one-star reviews, 64.7% were written by nonsurgical patients and 35.3% by surgical patients. Nonclinical and clinical comments constituted 54.9% and 45.1% of reviews, respectively. Surgeons in the South had more "bedside manner" comments (43.3%, P <0.0001), while Northeast surgeons had more "poor surgical outcome" remarks compared with all other geographic regions (14.4%, P <0.001). Practicing in the South and Northeast were independent predictors of having complaints about "bedside manner" and "poor surgical outcome," respectively.

CONCLUSION

Most one-star reviews of spine surgeons were attributed to nonsurgical patients, who tended to be unsatisfied with nonclinical factors, especially "bedside manner." However, there was substantial geographic variation. These results suggest that spine surgeons could benefit from focusing on nonclinical factors (bedside manner), especially among nonoperative patients, and that regional nuances should be considered in delivering spine care.

LEVEL OF EVIDENCE

Level- 5.

The effect of preoperative use of anticoagulants on the hemostatic effect of intravenous application of tranexamic acid in PLIF: a case control study

Intravenous application of tranexamic acid (TXA) in posterior lumbar interbody fusion (PLIF) can effectively reduce blood loss without affecting coagulation function. However, it has not been reported whether preoperative use of anticoagulants may affect the efficacy of TXA in PLIF. The purpose of this study is to observe the effect of preoperative use of anticoagulants on coagulation indicators and blood loss after PLIF receiving intravenous unit dose TXA. A retrospective analysis was conducted on data from 53 patients with PLIF between 2020.11 and 2022.9, who received intravenous application of a unit dose of TXA (1 g/100 mL) 15 min before the skin incision after general anesthesia. Those who used anticoagulants within one week before surgery were recorded as the observation group, while those who did not use anticoagulants were recorded as the control group. The main observation indicators include surgical time, intraoperative blood loss, postoperative drainage volume, blood transfusion, and red blood cell (RBC), hemoglobin (HB), and hematocrit (HCT) measured on the 1st, 4th, 7th, and last-test postoperative days. Secondary observation indicators included postoperative incision healing, deep vein thrombosis of lower limbs, postoperative hospital stay, and activated partial thrombin time (APTT), prothrombin time (PT), thrombin time (TT), fibrinogen (FIB), and platelets (PLT) on the 1st and 4th days after surgery. The operation was successfully completed in both groups, the incision healed well after operation, and no lower limb deep vein thrombosis occurred. There was no significant difference in surgical time, intraoperative blood loss, postoperative drainage volume, and blood transfusion between the two groups (p > 0.05). There was no significant difference in the RBC, HB, and HCT measured on the 1st, 4th, 7th, and last-test postoperative days between the two groups (p > 0.05). There was no statistically significant difference in APTT, PT, TT, FIB and PLT between the two groups on the 1st and 4th postoperative days (p > 0.05). There was no significant difference in postoperative hospital stay between the two groups (p > 0.05). The use of anticoagulants within one week before surgery does not affect the hemostatic effect of intravenous unit dose TXA in PLIF.

Optimizing Dual Antiplatelet Therapy in the Perioperative Period for Spine Surgery After Recent Percutaneous Coronary Intervention: A Comprehensive Review, Synthesis, and Catalyst for Protocol Formulation

The increased incidence of spine surgery within the past decade has highlighted the importance of robust perioperative management to improve patient outcomes overall. Coronary artery disease is a common medical comorbidity present in the population of individuals who receive surgery for spinal pathology that is often treated with dual antiplatelet therapy (DAPT) after percutaneous coronary intervention. Discontinuation of DAPT before surgical intervention is typically indicated; however, contradictory evidence exists in the literature regarding the timing of DAPT use and discontinuation in the perioperative period. We review the most recent cardiac and spine literature on the intricacies of percutaneous coronary intervention and its associated risks in the postoperative period. We further propose protocols for DAPT use after both elective and urgent spine surgery to optimize perioperative care.

Intraoperative clonidine in endometriosis and spine surgery: A protocol for two randomised, blinded, placebo-controlled trials

BACKGROUND

A high proportion of patients who undergo surgery continue to suffer from moderate to severe pain in the early postoperative period despite advances in pain management strategies. Previous studies suggest that clonidine, an alpha2 adrenergic agonist, administered during the perioperative period could reduce acute postoperative pain intensity and opioid consumption. However, these studies have several limitations related to study design and sample size and hence, further studies are needed.

AIM

To investigate the effect of a single intravenous (IV) dose of intraoperative clonidine on postoperative opioid consumption, pain intensity, nausea, vomiting and sedation after endometriosis and spine surgery.

METHODS

Two separate randomised, blinded, placebo-controlled trials are planned. Patients scheduled for endometriosis (CLONIPAIN) will be randomised to receive either 150 μg intraoperative IV clonidine or placebo (isotonic saline). Patients undergoing spine surgery (CLONISPINE) will receive 3 μg/kg intraoperative IV clonidine or placebo. We aim to include 120 patients in each trial to achieve power of 90% at an alpha level of 0.05.

OUTCOMES

The primary outcome is opioid consumption within the first three postoperative hours. Secondary outcomes include pain intensity at rest and during coughing, nausea, vomiting and sedation within the first two postoperative hours and opioid consumption within the first six postoperative hours. Time to discharge from the PACU will be registered.

CONCLUSION

This study is expected to provide valuable information on the efficacy of intraoperative clonidine in acute postoperative pain management in patients undergoing endometriosis and spine surgery.

Optimization of radiation doses for open lumbar spinal fusion using C-arm fluoroscopy and impact on radiation-induced cancer: a pilot study

PURPOSE

Intraoperative fluoroscopy use is essential during spinal fusion procedures. The amount of radiation dose should always be minimized. This study aimed to determine the feasibility of halving the frame rate from 12.5 to 6.25 frames per second (fps) and to quantify the reduction in the risk of developing radiation-induced cancer.

METHODS

This pilot study included 34 consecutive patients operated for open lumbar posterolateral fusion (PLF) with or without transforaminal lumbar interbody fusion (TLIF). C-arm modes were changed from half-dose (12.5 frames per second (fps), group I) to quarter-dose (6.25 fps, group II). Age, body mass index, surgical procedure, number of treated levels, and complications were collected. Kerma area product (KAP), cumulative air kerma (CAK), and fluoroscopy time were compared. Effective dose and radiation-induced cancer risk were estimated.

RESULTS

Eighteen and 16 patients were, respectively, included in group I and II. Demographic, surgical data, and fluoroscopy time were similar in both groups. However, CAK, KAP, and effective dose were significantly lower in group II, respectively, 0.56 versus 0.41 mGy (p = 0.03), 0.09 versus 0.06 Gy cm2 (p = 0.04), and 0.03 versus 0.02 mSv (p = 0.04). Radiation-induced cancer risk decreased by 47.7% from 1.49 × 10-6 to 7.77 × 10-7 after optimization. No complications were recorded in either group.

CONCLUSION

This study demonstrates the feasibility of setting 6.25 fps for TLIF with and without PLF. By halving the fps, radiation-induced cancer risk could be almost divided by two, without compromising surgical outcome. Finally, after optimization, the risk of developing radiation-induced cancer was less than one in a million.

Preoperative nutritional status and postoperative health outcomes in older adults undergoing spine surgery: Electronic health records analysis

AIM

To examine whether a high nutritional risk status, assessed via the Geriatric Nutritional Risk Index (GNRI), is independently associated with postoperative health outcomes, including unplanned intensive care unit (ICU) admissions, infectious complications, and prolonged length of stay in older patients undergoing spine surgery.

METHODS

We conducted a retrospective descriptive study analyzing electronic health records from a tertiary hospital, including data from 1,014 patients aged ≥70 undergoing elective spine surgery between February 2013 and March 2023.

RESULTS

High nutritional risk patients had significantly higher odds of unplanned ICU admission, infectious complications, and prolonged length of stay compared to low-risk patients. For each one-point increase in GNRI, there was a significant 0.91- and 0.95-fold decrease in the odds of unplanned ICU admission and infectious complications, respectively.

CONCLUSION

GNRI screening in older patients before spine surgery may have potential to identify those at elevated risk for postoperative adverse outcomes.

Biomechanical Comparison of Subsidence Between Patient-Specific and Non-Patient-Specific Lumbar Interbody Fusion Cages

STUDY DESIGN

Biomechanical study.

OBJECTIVES

Several strategies to improve the surface of contact between an interbody device and the endplate have been employed to attenuate the risk of cage subsidence. 3D-printed patient-specific cages have been presented as a promising alternative to help mitigate that risk, but there is a lack of biomechanical evidence supporting their use. We aim to evaluate the biomechanical performance of 3D printed patient-specific lumbar interbody fusion cages in relation to commercial cages in preventing subsidence.

METHODS

A cadaveric model is used to investigate the possible advantage of 3D printed patient-specific cages matching the endplate contour using CT-scan imaging in preventing subsidence in relation to commercially available cages (Medtronic Fuse and Capstone). Peak failure force and stiffness were analyzed outcomes for both comparison groups.

RESULTS

PS cages resulted in significantly higher construct stiffness when compared to both commercial cages tested (>59%). PS cage peak failure force was 64% higher when compared to Fuse cage (P < .001) and 18% higher when compared to Capstone cage (P = .086).

CONCLUSIONS

Patient-specific cages required higher compression forces to produce failure and increased the cage-endplate construct' stiffness, decreasing subsidence risk.

Incidental Durotomy Repair in Lumbar Spine Surgery: Institutional Experience and Review of Literature

STUDY DESIGN

: Retrospective Chart Review.

OBJECTIVES

Incidental durotomies (IDs) are common spine surgery complications. In this study, we present a review on the most commonly utilized management strategies, report our institutional experience with case examples, and describe a stepwise management algorithm.

METHODS

A retrospective review was performed of the electronic medical records of all patients who underwent a thoracolumbar or lumbar spine surgery between March 2017 and September 2019. Additionally, a literature review of the current management approaches to treat IDs and persistent postoperative CSF leaks following lumbar spine surgeries was performed.

RESULTS

We looked at 1133 patients that underwent posterior thoracolumbar spine surgery. There was intraoperative evidence of ID in 116 cases. Based on our cohort and the current literature, we developed a progressive treatment algorithm for IDs that begins with a primary repair, which can be bolstered by dural sealants or a muscle patch. If this fails, the primary repair can be followed by a paraspinal muscle flap, as well as a lumbar drain. If the patient cannot be weaned from temporary CSF diversion, the final step in controlling postoperative leak is longterm CSF diversion via a lumboperitoneal shunt. In our experience, these shunts can be weaned once the patient has no further clinical or radiographic signs of CSF leak.

CONCLUSIONS

There is no standardized management approach of IDs and CSF leaks in the literature. This article intends to provide a progressive treatment algorithm and contribute to the development process of a treatment consensus.

Safety and benefit of ambulation within 24 hours in elderly patients undergoing lumbar fusion: propensity score matching study of 882 patients

BACKGROUND CONTEXT

Elderly patients are less likely to recover from lumbar spine fusion (LSF) as rapidly compared with younger patients. However, there is still a lack of research on the effect of early ambulation on elderly patients undergoing LSF surgery for lumbar degenerative disorders.

PURPOSE

To evaluate the safety and benefit of ambulation within 24 hours in elderly patients who underwent LSF.

STUDY DESIGN

A retrospective study.

PATIENT SAMPLE

Consecutive patients (aged 65 and older) who underwent elective transforaminal lumbar interbody fusion surgery for degenerative disorders from January 2019 to October 2022.

OUTCOME MEASURES

Outcome measures included postoperative complications, postoperative drainage (mL), laboratory test data, length of hospital stay (LOS), readmission and reoperation within 3 months.

METHODS

Early ambulation patients (ambulation within 24 hours after surgery) were propensity-score matched 1:1 to a delayed ambulation patients (ambulation at a minimum of 48 hours postoperatively) based on age, intraoperative blood loss, and number of fused segments. The incidence of postoperative adverse events (AEs, including rates of complications, readmission, and prolonged LOS) and the average LOS were used to assess the safety and benefit of early ambulation, respectively. Multivariable regression analysis was performed to assess the association between early ambulation and postoperative AEs. The risk factors for delayed ambulation were also determined using multivariable logistic analyses.

RESULTS

A total of 998 patients with LSF surgery were reviewed in this study. After excluding 116 patients for various reasons, 882 patients (<24 hours: N=350, 24-48 hours: N=230, and >48 hours: N= 302) were included in the final analysis. After matching, sex, BMI, preoperative comorbidities, laboratory test data and surgery-related variables were comparable between the groups. The incidence of postoperative AEs was significantly lower in the EA group (44.3% vs 64.0%, p<.001). The average postoperative LOS of the EA group was 2 days shorter than the DA group (6.5 days vs 8.5 days, p<.001). Patients in the EA group had a significantly lower rate of prolonged LOS compared with the DA group (35.1% vs 55.3%, p<.001). There was no significant difference in postoperative drainage volumes between the two groups. Multivariable analysis identified older age (odds ratio [OR] 1.07, p<.001), increased intraoperative EBL (OR 1.002, p=.001), and higher international normalization ratio (OR 10.57, p=.032) as significant independent risk factors for delayed ambulation.

CONCLUSIONS

Ambulation within 24 hours after LSF surgery is independently associated fewer AEs and shorter hospital stays in elderly patients. Implementing the goal of ambulation within 24 hours after LSF surgery into enhanced recovery after surgery protocols for elderly patients seems appropriate. Older age, increased intraoperative blood loss and worse coagulation function are associated with delayed ambulation.

Clinical Improvement After Lumbar Fusion: Using PROMIS to Assess Recovery Kinetics

STUDY DESIGN

Retrospective review of a single institution cohort.

OBJECTIVE

The goal of this study is to identify features that predict delayed achievement of minimum clinically important difference (MCID) following elective lumbar spine fusion using Patient-Reported Outcomes Measurement Information System (PROMIS) surveys.

SUMMARY OF BACKGROUND DATA

Preoperative prediction of delayed recovery following lumbar spine fusion surgery is challenging. While many studies have examined factors impacting the achievement of MCID for patient-reported outcomes in similar cohorts, few studies have assessed predictors of early functional improvement.

METHODS

We retrospectively reviewed patients undergoing elective one-level posterior lumbar fusion for degenerative pathology. Patients were subdivided into two groups based on achievement of MCID for each respective PROMIS domain either before six months ("early responders") or after six months ("late responders") following surgical intervention. Multivariable logistic regression analysis was used to determine features associated with odds of achieving distribution-based MCID before or after six months follow up.

RESULTS

147 patients were included. The average age was 64.3±13.0 years. At final follow-up, 57.1% of patients attained MCID for PI and 72.8% for PF. However, 42 patients (49.4%) reached MCID for PI by six months, compared to 44 patients (41.1%) for PF. Patients with severe symptoms had the highest probability of attaining MCID for PI (OR 10.3; P =0.001) and PF (OR 10.4; P =0.001) Preoperative PROMIS symptomology did not predict early achievement of MCID for PI or PF. Patients who received concomitant iliac crest autograft during their lumbar fusion had increased odds of achieving MCID for PI (OR 8.56; P =0.001) before six months.

CONCLUSION

Our study demonstrated that the majority of patients achieved MCID following elective one-level lumbar spine fusion at long-term follow-up, although less than half achieved this clinical benchmark for each PROMIS metric by six months. We also found that preoperative impairment was not associated with when patients would achieve MCID. Further prospective investigations are warranted to characterize the trajectory of clinical improvement and identify the risk factors associated with poor outcomes more accurately.

MRI phenotypes of herniated discs associated with adjacent disc degeneration

Adjacent segment degeneration is commonly observed in patients after fusion surgery. Among the associated risk factors is the preoperative presence of adjacent disc degeneration (ADD). The risk factors and other spine phenotypes associated with preoperative ADD is critical to understand the pathological process and better prognosis postsurgery. Current study aims to assess and compare the magnetic resonance imaging (MRI) spinal phenotype of herniated level with and without ADD. Preoperative T2W sagittal lumbar MRI images of 155 lumbar disc herniated patients were analyzed for the presence of ADD (Pfirrmann grade III and above). The herniated disc level was assessed for the presence and absence of vertebral endplate (VEP) defects, Modic changes, and high intensity zone (HIZ). Mean age of patients was 38 ± 2 years, almost 62% were males. ADD was found in 57%, VEP defects were seen in 62% of the herniated level, 24.5% showed Modic changes, 3.8% showed spondylolishthesis, and 15.5% revealed HIZ. Age and other demographic factors did not have any significant effect on the presence of ADD, the patients with extruded and sequestered discs had more ADD (p = 0.02). VEP defects were significantly higher in levels with ADD (p = 0.02). Patients with ADD had significantly VEP defect scores (p = 0.01), Modic score (p = 0.002), HIZ score (0.02), and posterior bulge score (p < 0.001). Findings suggest that affected levels with VEP defects and severe grade of disc herniation have the greater likelihood of having ADD. Once developed this ADD may also affect the other spinal levels, and also can affect postoperative prognosis.

Mesenchymal Stem Cell Exosomes Enhance Posterolateral Spinal Fusion in a Rat Model

Spinal fusion, a common surgery performed for degenerative lumbar conditions, often uses recombinant human bone morphogenetic protein 2 (rhBMP-2) that is associated with adverse effects. Mesenchymal stromal/stem cells (MSCs) and their extracellular vesicles (EVs), particularly exosomes, have demonstrated efficacy in bone and cartilage repair. However, the efficacy of MSC exosomes in spinal fusion remains to be ascertained. This study investigates the fusion efficacy of MSC exosomes delivered via an absorbable collagen sponge packed in a poly Ɛ-caprolactone tricalcium phosphate (PCL-TCP) scaffold in a rat posterolateral spinal fusion model. Herein, it is shown that a single implantation of exosome-supplemented collagen sponge packed in PCL-TCP scaffold enhanced spinal fusion and improved mechanical stability by inducing bone formation and bridging between the transverse processes, as evidenced by significant improvements in fusion score and rate, bone structural parameters, histology, stiffness, and range of motion. This study demonstrates for the first time that MSC exosomes promote bone formation to enhance spinal fusion and mechanical stability in a rat model, supporting its translational potential for application in spinal fusion.

Graded exercise with motion style acupuncture therapy for a patient with failed back surgery syndrome and major depressive disorder: a case report and literature review

Effective treatment of failed back surgery syndrome (FBSS) remains challenging despite urgent medical attention requirements. Depression is a contributing factor to the development and poor prognosis of FBSS, and vice versa. We report the case of a patient with FBSS and major depressive disorder (MDD) treated with graded exercise combined with motion-style acupuncture therapy (MSAT). A 53-year-old male veteran who had undergone lumbar discectomy and laminectomy with instrumented fusion was admitted to the hospital with re-current back pain and radiative pain in the left leg. The effects of failed surgery triggered MDD as a comorbidity. After a six-week routine treatment without remarkable improvement, a three-week program of graded exercise with MSAT was applied. The numeric rating scale (NRS) and short form-36 (SF-36) were used to assess low back pain with radiating leg pain, and daily functioning levels, respectively. The voluntary walking distance of the patients was measured. To analyze the therapeutic effects and other applications of the intervention, we surveyed clinical trials using MSAT or graded exercise therapy (GET). Three weeks of graded exercise with MSAT reduced physical and mental functional disabilities (SF-36, physical component: 15.0 to 37.2, mental component: 21.9 to 30.1) as well as the intensity of low back pain and/or radiative leg pain (NRS: 50 to 30). Furthermore, as the therapeutic intensity gradually increased, there was a significant corresponding increase in daily walking distance (mean daily walking distance, the first week vs. baseline, second, and third week, 3.05 ± 0.56: 2.07 ± 0.79, 4.27 ± 0.96, and 4.72 ± 1.04 km, p = 0.04, p = 0.02, and p = 0.003, respectively). Three randomized controlled trials of GET were included, all showing statistically significant antidepressant effects in the diseased population. Graded exercise with MSAT may be an effective rehabilitative therapy for patients with FBSS and MDD who have impaired daily routines.

A Novel Intraoperative CT Navigation System for Spinal Fusion Surgery in Lumbar Degenerative Disease: Accuracy and Safety of Pedicle Screw Placement

Background: In recent years, intraoperative computed tomography (CT) navigation has become widely used for the insertion of pedicle screws in spinal fusion surgery. However, conventional intraoperative CT navigation may be impaired by infrared interference between the infrared camera and surgical instruments, which can lead to the misplacement of pedicle screws. Recently, a novel intraoperative CT navigation system, NextAR, has been developed. It uses a small infrared camera mounted on surgical instruments within the surgical field. NextAR navigation can minimize the problem of infrared interference and be expected to improve the accuracy of pedicle screw placement. Methods: This study investigated the accuracy of pedicle screw insertion under NextAR navigation in spinal fusion surgery for lumbar degenerative diseases. The accuracy of pedicle screw placement was evaluated in 15 consecutive patients using a CT grading scale. Results: Screw perforation occurred in only 1 of the total 70 screws (1.4%). Specifically, there was one grade 1 perforation within 2 mm, but no perforations larger than 2 mm. There were no reoperations or neurological complications due to screw misplacement. Conclusions: NextAR navigation can provide high accuracy for pedicle screw insertion and help ensure safe spinal fusion surgery for lumbar degenerative diseases.

Addressing the Impact of Race and Ethnicity on Musculoskeletal Spine Care in the United States

➤ Despite being a social construct, race has an impact on outcomes in musculoskeletal spine care.➤ Race is associated with other social determinants of health that may predispose patients to worse outcomes.➤ The musculoskeletal spine literature is limited in its understanding of the causes of race-related outcome trends.➤ Efforts to mitigate race-related disparities in spine care require individual, institutional, and national initiatives.

Developing Mixed-Effects Models to Compare the Predictive Ability of Various Comorbidity Indices in a Contemporary Cohort of Patients Undergoing Lumbar Fusion

BACKGROUND AND OBJECTIVE

As incidence of operative spinal pathology continues to grow, so do the rates of lumbar spinal fusion procedures. Comorbidity indices can be used preoperatively to predict potential complications. However, there is a paucity of research defining the optimal comorbidity indices in patients undergoing spinal fusion surgery. We aimed to use modeling strategies to evaluate the predictive validity of various comorbidity indices and combinations thereof.

METHODS

Patients who underwent spinal fusion were queried using data from the Nationwide Readmissions Database for the years 2016 through 2019. Using comorbidity indices as predictor variables, receiver operating characteristic curves were developed for pertinent complications such as mortality, nonroutine discharge, top-quartile cost, top-quartile length of stay, and 30-day readmission.

RESULTS

A total of 750 183 patients were included. Nonroutine discharges occurred in 161 077 (21.5%) patients. The adjusted all-payer cost for the procedure was $37 616.97 ± $27 408.86 (top quartile: $45 409.20), and the length of stay was 4.1 ± 4.4 days (top quartile: 8.1 days). By comparing receiver operating characteristics of various models, it was found that models using Frailty + Elixhauser Comorbidity Index (ECI) as the primary predictor performed better than other models with statistically significant P -values on post hoc testing. However, for prediction of mortality, the model using Frailty + ECI was not better than the model using ECI alone ( P = .23), and for prediction of all-payer cost, the ECI model outperformed the models using frailty alone ( P < .0001) and the model using Frailty + ECI ( P < .0001).

CONCLUSION

This investigation is the first to use big data and modeling strategies to delineate the relative predictive utility of the ECI and Johns Hopkins Adjusted Clinical Groups comorbidity indices for the prognostication of patients undergoing lumbar fusion surgery. With the knowledge gained from our models, spine surgeons, payers, and hospitals may be able to identify vulnerable patients more effectively within their practice who may require a higher degree of resource utilization.

The effect of perioperative sequential application of multiple doses of tranexamic acid on postoperative blood loss after PLIF: a prospective randomized controlled trial

BACKGROUND

Tranexamic acid (TXA) has been utilized in spinal surgery to effectively reduce intraoperative blood loss (IBL) and allogeneic blood transfusion rates. However, the traditional TXA regimen might last the entire duration of hyperfibrinolysis caused by surgical trauma, resulting in its limited ability to reduce postoperative blood loss (PBL). Therefore, the aim of this study was to investigate the effectiveness of perioperative sequential administration of multiple doses of TXA in reducing PBL in patients who underwent posterior lumbar interbody fusion (PLIF).

METHODS

From October 2022 to June 2023, 231 patients who were diagnosed with lumbar degenerative disease and scheduled to undergo PLIF were prospectively enrolled in the present study. The patients were randomly divided into three groups. Moreover, all patients received an intravenous injection of TXA at a dose of 15 mg/kg 15 min before the surgical skin incision. Patients in Group A received a placebo of normal saline after surgery, while patients in Group B received three additional intravenous injections of TXA at a dose of 15 mg/kg every 24 h. Patients in Group C received three additional intravenous injections of TXA at a dose of 15 mg/kg every 5 h. The primary outcome measure was PBL. In addition, this study assessed total blood loss (TBL), IBL, routine blood parameters, liver and kidney function, coagulation parameters, fibrinolysis indexes, inflammatory indicators, drainage tube removal time (DRT), length of hospital stay (LOS), blood transfusion rate, and incidence of complications for all subjects.

RESULTS

The PBL, TBL, DRT, and LOS of Group B and Group C were significantly lower than those of Group A ( P <0.05). The level of D-dimer (D-D) in Group C was significantly lower than that in Group A on the first day after the operation ( P =0.002), and that in Group B was significantly lower than that in Group A on the third day after the operation ( P =0.003). The interleukin-6 levels between the three groups from 1 to 5 days after the operation were in the order of Group A > Group B > Group C. No serious complications were observed in any patient. The results of multiple stepwise linear regression analysis revealed that PBL was positively correlated with incision length, IBL, smoking history, history of hypertension, preoperative fibrinogen degradation product level, and blood transfusion. It was negatively correlated with preoperative levels of fibrinogen, red blood cells, blood urea nitrogen, and age. Compared to female patients, male patients had an increased risk of PBL. Finally, the incidence of PBL was predicted.

CONCLUSIONS

Sequential application of multiple doses of TXA during the perioperative period could safely and effectively reduce PBL and TBL, shorten DRT and LOS, reduce postoperative D-D generation, and reduce the postoperative inflammatory response. In addition, this study provided a novel prediction model for PBL in patients undergoing PLIF.

Systematic Review of Prophylactic Plastic Surgery Closure to Prevent Postoperative Wound Complications Following Spine Surgery

Spinal surgeries are increasingly performed in the United States, but complication rates can be unacceptably high at up to 26%. Consequently, plastic surgeons (PS) are sometimes recruited by spine surgeons (SS) for intraoperative assistance with soft tissue closures. An electronic multidatabase literature search was systematically conducted to determine whether spinal wound closure performed by PS minimizes postoperative wound healing complications when compared to closure by SS (neurosurgical or orthopedic), with the hypothesis that closures by PS minimizes incidence of complications. All published studies involving patients who underwent posterior spinal surgery with closure by PS or SS at index spine surgery were identified. Filtering by exclusion criteria identified 10 studies, 4 of which were comparative in nature and included both closures by PS and SS. Of these 4, none reported significant differences in postoperative outcomes between the groups. Across all studies, PS were involved in cases with higher baseline risk for wound complications and greater comorbidity burden. Closures by PS were significantly more likely to have had prior chemotherapy in 2 of the 4 (50%) studies (P = 0.014, P < 0.001) and radiation in 3 of the 4 (75%) studies (P < 0.001, P < 0.01, P < 0.001). In conclusion, closures by PS are frequently performed in higher risk cases, and use of PS in these closures may normalize the risk of wound complications to that of the normal risk cohort, though the overall level of evidence of the published literature is low.

Impact of unplanned readmissions on lumbar surgery outcomes: a national study of 33,447 patients

BACKGROUND CONTEXT

Unplanned readmissions following lumbar spine surgery have immense clinical and financial implications. However, little is known regarding the impact of unplanned readmissions on patient-reported outcomes (PROs) following lumbar spine surgery.

PURPOSE

To evaluate the impact of unplanned readmissions, including specific readmission reasons, on patient reported outcomes 12 months after lumbar spine surgery.

STUDY DESIGN/SETTING

A retrospective cohort study of prospectively collected data was conducted using patients included in the lumbar module of the Quality and Outcomes Database (QOD), a national, multicenter spine registry.

PATIENT SAMPLE

A total of 33,447 patients who underwent elective lumbar spine surgery for degenerative diseases were included. Mean age was 59.8 (SD=14.04), 53.6% were male, 89.5% were white, 45.9% were employed, and 47.5% had private insurance.

OUTCOME MEASURES

Unplanned 90-day readmissions and 12-month patient-reported outcomes (PROs) including numeric rating scale (NRS) scores for back and leg pain, Oswestry Disability Index (ODI) scores, EuroQol-5 Dimension (EQ-5D) scores, and North American Spine Society (NASS) patient-satisfaction scores.

METHODS

The lumbar module of the QOD was queried for adults undergoing elective lumbar spine surgery for degenerative disease. Unplanned 90-day readmissions were classified into 4 groups: medical, surgical, pain-only, and no readmissions. Medical and surgical readmissions were further categorized into primary reason for readmission. 12-month PROs assessing patient back and leg pain (NRS), disability (ODI), quality of life (EQ-5D), and patient satisfaction were collected. Multivariable models predicting 12-month PROs were built controlling for covariates.

RESULTS

A total of 31,430 patients (94%) had no unplanned readmission while 2,017 patients (6%) had an unplanned readmission within 90 days following lumbar surgery. Patients with readmissions had significantly worse 12-month PROs compared with those with no unplanned readmissions in covariate-adjusted models. Using Wald-df as a measure of predictor importance, surgical readmissions were associated with the worst 12-month outcomes, followed by pain-only, then medical readmissions. In separate covariate adjusted models, we found that readmissions for pain, SSI/wound dehiscence, and revisions were among the most important predictors of worse outcomes at 12-months.

CONCLUSIONS

Unplanned 90-day readmissions were associated with worse pain, disability, quality of life, and greater dissatisfaction at 12-months, with surgical readmissions having the greatest impact, followed by pain-only readmissions, then medical readmissions. Readmissions for pain, SSI/wound dehiscence, and revisions were the most important predictors of worse outcomes. These results may help providers better understand the factors that impact outcomes following lumbar spine surgery and promote improved patient counseling and perioperative management.

Assessing performance of Geriatric Surgery Verification Program preoperative communication standards in spine surgery

BACKGROUND

To assess performance of the American College of Surgeons Geriatric Surgery Verification (GSV) Program preoperative communication standards in older patients undergoing high risk spine surgery.

METHODS

We performed an external validation of a natural language processing (NLP) method for identifying documentation meeting GSV communication standards. We then applied this method to a retrospective cohort of patients aged 65 and older who underwent spinal fusion procedures between January 2018-December 2020 in a large healthcare system in Massachusetts. Our primary outcome of interest was fulfillment of GSV communication domains: overall health goals, treatment goals, and patient-centered outcomes. Factors associated with the fulfillment of at least one domain were assessed using Poisson regression to adjust for confounding.

RESULTS

External validation of the NLP method had a sensitivity of 88.6% and specificity of 99.0%. Our study population included 1294 patients, of whom only 0.8% (n = 10) patients contained documentation of all three GSV domains, and 33.7% (n = 436) had documentation fulfilling at least one GSV domain. The GSV domain with lowest frequency of documentation was overall health goals, with only 35 (2.7%) of patients meeting this requirement. Adjusted analysis suggested that patients with a Charlson comorbidity score of one or more had higher fulfillment of GSV criteria (CCI 1-3: prevalence rate ratio (PRR) 1.8, 95% confidence interval (CI) 1.5-2.1; CCI >3: PRR 1.5, 95% CI 1.2-1.9).

CONCLUSION

A paucity of geriatric patients undergoing spine surgery had preoperative documentation consistent with GSV standards. Given that spine surgery is one of the highest risk surgeries in older adults and GSV standards are relevant to all surgical specialties, wider promulgation of these standards is warranted.

Advances in Imaging (Intraop Cone-Beam Computed Tomography, Synthetic Computed Tomography, Bone Scan, Low-Dose Protocols)

Spine surgery has seen a rapid advance in the refinement and development of 3-dimensional and nuclear imaging modalities in recent years. Cone-beam CT has proven to be a valuable tool for improving the accuracy of pedicle screw placement. The use of synthetic CT and low-dose CT have also emerged as modalities which allow for little to no radiation while streamlining imaging workflows. Bone scans also serve to provide functional information about bone metabolism in both the preoperative and postoperative monitoring phases.

Transdural retrieval of retropulsed transforaminal lumbar interbody fusion cages

Transforaminal lumbar interbody fusions (TLIFs) are performed for various lumbar spine pathologies. Posterior migration of an interbody cage is a complication that may result in neurologic injury and require reoperation. Sparse information exists regarding the safety and efficacy of a transdural approach for cage retrieval. We describe a surgical technique, in which centrally retropulsed cages were safely retrieved transdurally. A patient with prior L3-S1 posterior lumbar fusion and L4-S1 TLIFs presented with radiculopathy and weakness in dorsiflexion. Imaging revealed posterior central migration of TLIF cages causing compression of the traversing L5 nerve root. Cages were removed transdurally; the correction was performed with an all-posterior T10-pelvis fusion. Aside from temporary weakness in right-sided dorsiflexion, the patient experienced complete resolution in their radiculopathy and strength returned to its presurgical state by 3 months. The transdural approach for interbody removal can be safely performed and should be a tool in the spine surgeon's armamentarium.

Reducing residual forces in spinal fusion using a custom-built rod bending machine

BACKGROUND AND OBJECTIVE

As part of spinal fusion surgery, shaping the rod implant to align with the anatomy is a tedious, error-prone, and time-consuming manual process. Inadequately contoured rod implants introduce stress on the screw-bone interface of the pedicle screws, potentially leading to screw loosening or even pull-out.

METHODS

We propose the first fully automated solution to the rod bending problem by leveraging the advantages of augmented reality and robotics. Augmented reality not only enables the surgeons to intraoperatively digitize the screw positions but also provides a human-computer interface to the wirelessly integrated custom-built rod bending machine. Furthermore, we introduce custom-built test rigs to quantify per screw absolute tensile/compressive residual forces on the screw-bone interface. Besides residual forces, we have evaluated the required bending times and reducer engagements, and compared our method to the freehand gold standard.

RESULTS

We achieved a significant reduction of the average absolute residual forces from for the freehand gold standard to (p=0.0015) using the bending machine. Moreover, our bending machine reduced the average time to instrumentation per screw from to . Reducer engagements per rod were significantly decreased from an average of 1.00±1.14 to 0.11±0.32 (p=0.0037).

CONCLUSION

The combination of augmented reality and robotics has the potential to improve surgical outcomes while minimizing the dependency on individual surgeon skill and dexterity.

Addressing the Challenge of Spine Patient Triage: Development of a Simple Algorithm for Identification of Potential Surgical Candidates

INTRODUCTION

Given that most spine conditions do not require surgical intervention, using surgeons to manage the subset of patients potentially requiring surgery is the most efficient resource allocation strategy. The purpose of this study was to develop a simple algorithm for identifying patients most likely to require spine surgery that could be used to appropriately triage this population to surgeons.

METHODS

A retrospective review of 5,886 consecutive new patients presenting to a multidisciplinary spine clinic from March 2021 to September 2022 was conducted. The primary outcome was whether a patient underwent spine surgery during the study period. A total of 64 independent variables were recorded from patient intake and the first visit. A gradient boosted model was generated to identify the independent variables most associated with undergoing surgery. The five most important variables were entered into a multiple logistic regression model, and a simplified decision support tool was generated and assessed.

RESULTS

Overall, 440 of 5886 patients (7.5%) underwent surgery during the study period. The following variables were identified as the top five predictors of spine surgery: patient goal of interest in learning about spine surgery, history of spine injections, difficulty walking a mile, radicular symptoms greater than axial symptoms, and increased age. Each of these variables was confirmed to be independently associated with undergoing surgery (all P < 0.001). The decision support tool yielded a sensitivity of 60.0%, specificity of 76.6%, likelihood ratio of 2.56, positive predictive value of 17.2%, and negative predictive value of 96.0% for predicting surgery. An AUC of 0.683 was achieved.

CONCLUSION

A simple 5-question algorithm incorporating patient demographics, symptoms, treatment history, physical function, and patient goals may improve the ability of practices to identify potential spine surgery candidates before their first visit. Prospective application and evaluation of the algorithm to evaluate whether it improves the triage of appropriate patients to spine surgeons is warranted.

Targeted Delivery of Abaloparatide to Spinal Fusion Site Accelerates Fusion Process in Rats

Spinal fusions are performed to treat congenital skeletal malformations, spondylosis, degenerative disk diseases, and other pathologies of the vertebrae that can be resolved by reducing motion between neighboring vertebrae. Unfortunately, up to 100,000 fusion procedures fail per year in the United States, suggesting that efforts to develop new approaches to improve spinal fusions are justified. We have explored whether the use of an osteotropic oligopeptide to target an attached bone anabolic agent to the fusion site might be exploited to both accelerate the mineralization process and improve the overall success rate of spinal fusions. The data presented below demonstrate that subcutaneous administration of a modified abaloparatide conjugated to 20 mer of D-glutamic acid not only localizes at the spinal fusion site but also outperforms the standard of care (topically applied BMP2) in both speed of mineralization (p < 0.05) and overall fusion success rate (p < 0.05) in a posterior lateral spinal fusion model in male and female rats, with no accompanying ectopic mineralization. Because the bone-localizing conjugate can be administered ad libitum post-surgery, and since the procedure appears to improve on standard of care, we conclude that administration of a bone-homing anabolic agent for improvement of spinal fusion surgeries warrants further exploration.

Comparative outcomes of awake spine surgery under spinal versus general anesthesia: a comprehensive systematic review and meta-analysis

BACKGROUND

Awake surgery, under spinal anesthesia (SA), is an alternative to surgery under general anesthesia (GA), in neurological and spine surgery. In the literature, there seem to be some evidence supporting benefits associated with the use of this anesthetic modality, as compared to GA. Currently, there is a notable lack of updated and comprehensive review addressing the complications associated with both awake SA and GA in spine surgery. We hence aimed to perform a systematic review of the literature and meta-analysis on the topic.

METHODS

A systematic search was conducted to identify studies that assessed SA in spine surgery from database inception to April 14, 2023, in PubMed, Medline, Embase, and Cochrane databases. Outcomes of interest included estimated blood loss, length of hospital stay, operative time, and overall complications. Meta-analysis was conducted using random effects models.

RESULTS

In total, 38 studies that assessed 7820 patients were included. The majority of the operations that were treated with SA were single-level lumbar cases. Awake patients had significantly shorter lengths of hospital stay (Mean difference (MD): - 0.40 days; 95% CI - 0.64 to - 0.17) and operative time (MD: - 19.17 min; 95% CI - 29.68 to - 8.65) compared to patients under GA. The overall complication rate was significantly higher in patients under GA than SA (RR, 0.59 [95% CI 0.47-0.74]). Patients under GA had significantly higher rates of postoperative nausea/vomiting RR, 0.60 [95% CI 0.39-0.90]) and urinary retention (RR, 0.61 [95% CI 0.37-0.99]).

CONCLUSIONS

Patients undergoing awake spine surgery under SA had significantly shorter operations and hospital stays, and fewer rates of postoperative nausea and urinary retention as compared to GA. In summary, awake spine surgery offers a valid alternative to GA and added benefits in terms of postsurgical complications, while being associated with relatively low morbidity.

Risk of noise-induced hearing loss in the spine surgeon

Background

Occupation-related noise-induced hearing loss (NIHL) has both negative economic and quality of life implications. The risk spine surgeons undertake in regards to NIHL during operative intervention is unknown. Governing bodies, including the National Institute for Occupational Safety and Health, have recommended exposure limits not to exceed 85 decibels (dB) over 8 hours. The purpose of this study is to characterize noise exposure to spine surgeons in the operating room (OR).

Methods

Prospective collection of intraoperative recordings of spinal surgeries (cervical and thoracic/lumbar) was undertaken. Data gathered included procedure, operative duration, presence of background music, and noise information. Noise information included maximum decibel level (MDL), Peak level (LCPeak), Equivalent continuous sound pressure level, time weighted average (TWA), dose, and projected dose. Noise measurements were compared with baseline controls with and without music (empty ORs).

Results

Two hundred seven noise recordings were analyzed. One hundred eighteen of those being spinal surgeries, 49 baseline recordings without music, and 40 with music. Maximum decibel level reached a maximum value of 111.5 dBA, with an average amongst surgical recordings of 103 dBA. Maximum decibel level exceeded 85 dBA in 100% of cases and was greater than 100 dBA in 78%. The maximum LCPeak recorded was 132.9 dBC with an average of 120 dBC. Furthermore, the average dose was 7.8% with an average projected dose of 26.5%. The highest dose occurred during a laminectomy at 72.9% of daily allowable noise. Maximum projected dose yielded 156% during a 3-level anterior cervical discectomy and fusion.

Conclusions

Spine surgeons are routinely exposed to damaging noise levels (>85 dBA) during operative intervention. With spine surgeons often performing multiple surgeries a day, the cumulative risk of noise exposure cannot be ignored. The synergistic effects of continuous and impact noise places spine surgeons at risk for the development of occupation-related NIHL.

The Re-Evaluation of Frailty in Predicting Complications after Long-Segment Spinal Fusion for Adult Spinal Deformity

OBJECTIVE

To evaluate on a national scale how frailty status (stratified using the 5-item Modified Frailty Index (mFI-5)) affects the operative characteristics of and complications after long-segment spinal fusion (LSF) for adult spinal deformity (ASD).

METHODS

Adults undergoing LSF of ≥3 vertebrae in the National Surgical Quality Improvement Program database years 2015-2020 were split into 2 cohorts: nonfrail with mFI = 0 or 1; frail with mFI ≥2. Demographics, operative characteristics, and 30-day complications were contrasted between the cohorts using the Student's t-test, the Fisher's exact test, or a multivariate analysis when appropriate.

RESULTS

In the 340 LSF cases collected, 268 fell into the nonfrail cohort and 72 into the frail cohort. The frail cohort constituted a high rate of geriatric age (65.3% vs. 38.1%; P < 0.001), higher body mass index (32.9 ± 0.86 vs. 30.2 ± 0.39; P = 0.005), and more comorbidities in 9 of 14 measures. After surgery, the frail cohort experienced more urinary tract infections (odds ratio [OR], 3.33; confidence interval [CI], 1.01-10.94; P = 0.04). However, the frail cohort shared similarities with the nonfrail cohort in terms of length of stay (5.11 ± 0.51 vs. 6.01 ± 1.62 days; P = 0.60), home discharge (OR, 0.76; CI, 0.42-1.39; P = 0.38), readmission (OR, 2.45; CI, 0.87-6.89; P = 0.09), and overall rate of complications (OR, 0.89; CI, 0.50-1.59; P = 0.70).

CONCLUSIONS

Despite trends found in past studies of ASD, this analysis showed that the frailty status of mFI ≥2 is a poor predictor of surgical and hospitalization course and overall complications in LSF when examined up to 30 days postoperatively.

Intraoperative Cone-Beam Computed Tomography Navigation Versus 2-Dimensional Fluoroscopy in Single-Level Lumbar Spinal Fusion: A Comparative Analysis

OBJECTIVE

Several studies have advocated for the higher accuracy of transpedicular screw placement under cone-beam computed tomography (CBCT) compared to conventional 2-dimensional (2D) fluoroscopy. The superiority of navigation systems in perioperative and postoperative outcomes remains a topic of debate. This study aimed to compare operative time, screw placement time and accuracy, total radiation dose, perioperative and postoperative outcomes in patients who underwent transpedicular screw fixation for degenerative lumbar spondylolisthesis (DLS) using intraoperative CBCT navigation versus 2D fluoroscopy.

METHODS

A retrospective analysis was conducted on patients affected by single-level DLS who underwent posterior lumbar instrumentation with transpedicular screw fixation using surgical CBCT navigation (NV group) or 2D fluoroscopy-assisted freehand technique (FH group). Demographics, screw placement time and accuracy, operative time, total radiation dose, intraoperative blood loss, screw revision rate, complications, and length of stay (LOS) were assessed.

RESULTS

The study included a total of 30 patients (NV group: n = 15; FH group: n = 15). The mean screw placement time, operative time, and LOS were significantly reduced in the NV group compared to the FH group (p < 0.05). The total radiation dose was significantly higher in the NV group (p < 0.0001). No significant difference was found in terms of blood loss and postoperative complications.

CONCLUSION

This study suggests that intraoperative CBCT-navigated single-level lumbar transpedicular screw fixation is superior in terms of mean screw placement time, operative time, and LOS compared to 2D fluoroscopy, despite a higher intraoperative radiation exposure.

Pre-operative bone quality deficits and risk of complications following spine fusion surgery among postmenopausal women

Poor bone quality is a risk factor for complications after spinal fusion surgery. This study investigated pre-operative bone quality in postmenopausal women undergoing spine fusion and found that those with small bones, thinner cortices and surgeries involving more vertebral levels were at highest risk for complications.

PURPOSE

Spinal fusion is one of the most common surgeries performed worldwide. While skeletal complications are common, underlying skeletal deficits are often missed by pre-operative DXA due to artifact from spinal pathology. This prospective cohort study investigated pre-operative bone quality using high resolution peripheral CT (HRpQCT) and its relation to post-operative outcomes in postmenopausal women, a population that may be at particular risk for skeletal complications. We hypothesized that women with low volumetric BMD (vBMD) and abnormal microarchitecture would have higher rates of post-operative complications.

METHODS

Pre-operative imaging included areal BMD (aBMD) by DXA, cortical and trabecular vBMD and microarchitecture of the radius and tibia by high resolution peripheral CT. Intra-operative bone quality was subjectively graded based on resistance to pedicle screw insertion. Post-operative complications were assessed by radiographs and CTs.

RESULTS

Among 50 women enrolled (age 65 years), mean spine aBMD was normal and 35% had osteoporosis by DXA at any site. Low aBMD and vBMD were associated with "poor" subjective intra-operative quality. Skeletal complications occurred in 46% over a median follow-up of 15 months. In Cox proportional models, complications were associated with greater number of surgical levels (HR 1.19 95% CI 1.06-1.34), smaller tibia total area (HR 1.67 95% CI1.16-2.44) and lower tibial cortical thickness (HR 1.35 95% CI 1.05-1.75; model p < 0.01).

CONCLUSION

Women with smaller bones, thinner cortices and procedures involving a greater number of vertebrae were at highest risk for post-operative complications, providing insights into surgical and skeletal risk factors for complications in this population.

Weekend Admission Increases Risk of Readmissions Following Elective Thoracolumbar Spinal Fusion

STUDY DESIGN

Retrospective database study.

OBJECTIVES

The goal of this study was to assess the influence of weekend admission on patients undergoing elective thoracolumbar spinal fusion by investigating hospital readmission outcomes and analyzing differences in demographics, comorbidities, and postoperative factors.

METHODS

The 2016-2018 Nationwide Readmission Database was used to identify adult patients who underwent elective thoracolumbar spinal fusion. The sample was divided into weekday and weekend admission patients. Demographics, comorbidities, complications, and discharge status data were compiled. The primary outcomes were 30-day and 90-day readmission. Univariate logistic regression analyzed the relationship between weekday or weekend admission and 30- or 90-day readmission, and multivariate regression determined the impact of covariates.

RESULTS

177,847 patients were identified in total, with 176,842 in the weekday cohort and 1005 in the weekend cohort. Multivariate regression analysis found that 30-day readmissions were significantly greater for the weekend cohort after adjusting for sex, age, Medicare or Medicaid status, and comorbidity status (OR 2.00, 95% CI: 1.60-2.48; P < .001), and 90-day readmissions were also greater for the weekend cohort after adjustment (OR 2.01, 95% CI: 1.68-2.40, P < .001).

CONCLUSIONS

Patients undergoing elective thoracolumbar spinal fusion surgery who are initially admitted on weekends are more likely to experience hospital readmission. These patients have increased incidence of deep vein thrombosis, postoperative infection, and non-routine discharge status. These factors are potential areas of focus for reducing the impact of the "weekend effect" and improving outcomes for elective thoracolumbar spinal fusion.

The Effect of Preoperative Marijuana Use on Surgical Outcomes, Patient-Reported Outcomes, and Opioid Consumption Following Lumbar Fusion

STUDY DESIGN

Retrospective Cohort Study.

OBJECTIVES

To (1) investigate the effect of marijuana use on surgical outcomes following lumbar fusion, (2) determine how marijuana use affects patient-reported outcomes measures (PROMs), and (3) determine if marijuana use impacts the quantity of opioids prescribed.

METHODS

Patients > 18 years of age who underwent primary one- or two-level lumbar fusion with preoperative marijuana use at our institution were identified. A 3:1 propensity match incorporating patient demographics and procedure type was conducted to compare preoperative marijuana users to non-marijuana users. Patient demographics, surgical characteristics, surgical outcomes (90-day all-cause and 90-day surgical readmissions, reoperations, and revision surgeries), pre- and postoperative narcotic usage, and PROMs were compared between groups. Multivariate regression models were created to determine the effect of marijuana on surgical reoperations patient-reported outcomes (PROMs) 1-year postoperatively.

RESULTS

Of the 259 included patients, 65 used marijuana preoperatively. Multivariate logistic regression analysis demonstrated that marijuana use (OR = 2.28, P = .041) significantly increased the likelihood of having a spine reoperation. No other surgical outcome was found to be significantly different between groups. Multivariate linear regression analysis showed that marijuana use was not significantly associated with changes in 1-year postoperative PROMs (all, P > .05). The quantity of pre- and postoperative opioids prescriptions was not significantly different between groups (all, P > .05).

CONCLUSIONS

Preoperative marijuana use increased the likelihood of a spine reoperation for any indication following lumbar fusion, but it was not associated with 90-day all cause readmission, surgical readmission, the magnitude of improvement in PROMs, or differences in opioid consumption.

LEVEL OF EVIDENCE

III.

Development and external validation of a predictive model for prolonged length of hospital stay in elderly patients undergoing lumbar fusion surgery: comparison of three predictive models

PURPOSE

This study aimed to develop a predictive model for prolonged length of hospital stay (pLOS) in elderly patients undergoing lumbar fusion surgery, utilizing multivariate logistic regression, single classification and regression tree (hereafter, "classification tree") and random forest machine-learning algorithms.

METHODS

This study was a retrospective review of a prospective Geriatric Lumbar Disease Database. The primary outcome measure was pLOS, which was defined as the LOS greater than the 75th percentile. All patients were grouped as pLOS group and non-pLOS. Three models (including logistic regression, single-classification tree and random forest algorithms) for predicting pLOS were developed using training dataset and internal validation using testing dataset. Finally, online tool based on our model was developed to assess its validity in the clinical setting (external validation).

RESULTS

The development set included 1025 patients (mean [SD] age, 72.8 [5.6] years; 632 [61.7%] female), and the external validation set included 175 patients (73.2 [5.9] years; 97[55.4%] female). Multivariate logistic analyses revealed that older age (odds ratio [OR] 1.06, p < 0.001), higher BMI (OR 1.08, p = 0.002), number of fused segments (OR 1.41, p < 0.001), longer operative time (OR 1.02, p < 0.001), and diabetes (OR 1.05, p = 0.046) were independent risk factors for pLOS in elderly patients undergoing lumbar fusion surgery. The single-classification tree revealed that operative time ≥ 232 min, delayed ambulation, and BMI ≥ 30 kg/m2 as particularly influential predictors for pLOS. A random forest model was developed using the remaining 14 variables. Intraoperative EBL, operative time, delayed ambulation, age, number of fused segments, BMI, and RBC count were the most significant variables in the final model. The predictive ability of our three models was comparable, with no significant differences in AUC (0.73 vs. 0.71 vs. 0.70, respectively). The logistic regression model had a higher net benefit for clinical intervention than the other models. The nomogram was developed, and the C-index of external validation for PLOS was 0.69 (95% CI, 0.65-0.76).

CONCLUSION

This investigation produced three predictive models for pLOS in elderly patients undergoing lumbar fusion surgery. The predictive ability of our three models was comparable. Logistic regression model had a higher net benefit for clinical intervention than the other models. Our predictive model could inform physicians about elderly patients with a high risk of pLOS after surgery.

Intraoperative and Postoperative Management of Incidental Durotomies During Open Degenerative Lumbar Spine Surgery: A Systematic Review

SUMMARY OF BACKGROUND DATA

Incidental durotomy is a common intraoperative complication of lumbar spine surgery. Intra and postoperative protocols in the management of this common complication vary considerably, with no consensus in the literature.

OBJECTIVE

To systematically review (1) lumbar dural repair techniques for open degenerative procedures; (2) review described postoperative protocols after lumbar dural repairs.

STUDY DESIGN

Systematic review.

MATERIALS AND METHODS

A systematic review of the literature was performed for all articles published from inception until September 2022 using Pubmed, EMBASE, Medline, and Cochrane databases to identify articles assessing the management of durotomy in open surgery for degenerative diseases of the lumbar spine. Two independent reviewers assessed the articles for inclusion criteria, and disagreements were resolved by consensus. Outcomes included persistent leaks, return to the operating room, recurrent symptoms, medical complications, or patient satisfaction.

RESULTS

A total of 10,227 articles were initially screened. After inclusion criteria were applied, 9 studies were included (n=1270 patients) for final review. Repair techniques included; no primary repair, suture repair in running or interrupted manner with or without adjunctive sealants, sealants alone, or patch repair with muscle, fat, epidural blood patch, or synthetic graft. Postoperative protocols included the placement of a subfascial drain with varying durations of bed rest. Notable findings included no benefit of prolonged bedrest compared with early ambulation ( P =0.4), reduced cerebrospinal fluid leakage with fat graft compared with muscle grafts ( P <0.001), and decreased rates of revision surgery in studies that used subfascial drains (1.7%-2.2% vs 4.34%-6.66%).

CONCLUSIONS

Significant variability in intraoperative durotomy repair techniques and postoperative protocols exists. Primary repair with fat graft augmentation seems to have the highest success rate. Postoperatively, the use of a subfascial drain with early ambulation reduces the risk of pseudomenignocele formation, medical complications, and return to the operating room. Further research should focus on prospective studies with the goal to standardize repair techniques and postoperative protocols.