A Single-center Experience with a Shear Thinning Conformable Embolic.

The purpose of this study was to evaluate the technical success, effectiveness, and safety of transarterial embolization for acute bleeding management with a shear-thinning conformable embolic. This single-center retrospective study evaluated outcomes following embolization using Obsidio(OCE). Technical success was defined as performing transarterial embolization within the target vessel to complete stasis of antegrade flow. Treatment effectiveness was defined as cessation of bleeding for patients. 11 patients underwent 11 embolization procedures. A total of 16 arteries were embolized. Indications for embolization were spontaneous tumor bleeding (6/11), hematuria (2/11), active duodenal bleeding (1/11), portal hypertensive bleeding (1/11), and rectus sheath hematoma (1/11). Technical success was 100%. The median vessel diameter was 2 mm (range 1-3). There were no adverse events as per SIR adverse event criteria or off-target embolization. OCE demonstrated technical success and treatment effectiveness with a short-term safety profile for transarterial embolization interventions.

Current and future directions in interventional neuro-oncology-are we there yet?

Advancements in technology and technical expertise increasingly enable neurointerventionalists to deliver safer and more effective endovascular treatments to cancers of the brain, spine, head, and neck. In addition to established neuro-oncological interventions such as pre-surgical tumor embolization and percutaneous ablation, newer modalities focused on direct arterial infusion of chemotherapy, radioisotopes, and radiosensitizers continue to gain traction as complementary treatment options, while stem cell-mediated delivery of theranostic nanoparticles and oncolytic virus are being explored for even greater specificity in targeting cancers across the blood-brain barrier. This article aims to provide an overview of the current state of the art and future directions for the field of interventional neuro-oncology, as well as opportunities and challenges presented by this emerging treatment modality.

Modified Clavien-Dindo-Sink Classification System for operative complications in adult spine surgery.

OBJECTIVE: Currently there is no standardized mechanism to describe or compare complications in adult spine surgery. Thus, the purpose of the present study was to modify and validate the Clavien-Dindo-Sink complication classification system for applications in spine surgery. METHODS: The Clavien-Dindo-Sink complication classification system was evaluated and modified for spine surgery by four fellowship-trained spine surgeons using a consensus process. A distinct group of three fellowship-trained spine surgeons completed a randomized electronic survey grading 71 real-life clinical case scenarios. The survey was repeated 2 weeks after its initial completion. Fleiss' and Cohen's kappa (κ) statistics were used to evaluate interrater and intrarater reliabilities, respectively. RESULTS: Overall, interobserver reliability during the first and second rounds of grading was excellent with a κ of 0.847 (95% CI 0.785-0.908) and 0.852 (95% CI 0.791-0.913), respectively. In the first round, interrater reliability ranged from good to excellent with a κ of 0.778 for grade I (95% CI 0.644-0.912), 0.698 for grade II (95% CI 0.564-0.832), 0.861 for grade III (95% CI 0.727-0.996), 0.845 for grade IV-A (95% CI 0.711-0.979), 0.962 for grade IV-B (95% CI 0.828-1.097), and 0.960 for grade V (95% CI 0.826-1.094). Intraobserver reliability testing for all three independent observers was excellent with a κ of 0.971 (95% CI 0.944-0.999) for rater 1, 0.963 (95% CI 0.926-1.001) for rater 2, and 0.926 (95% CI 0.869-0.982) for rater 3. CONCLUSIONS: The Modified Clavien-Dindo-Sink Classification System demonstrates excellent interrater and intrarater reliability in adult spine surgery cases. This system provides a useful framework to better communicate the severity of spine-related complications.

MicroRNA-29a: a novel target for non-operative management of symptomatic lumbar spinal stenosis.

PURPOSE: Lumbar spinal stenosis (LSS) is the most common reason for spinal surgery in patients over the age of 65, and there are few effective non-surgical treatments. Therefore, the development of novel treatment or preventative modalities to decrease overall cost and morbidity associated with LSS is an urgent matter. The cause of LSS is multifactorial; however, a significant contributor is ligamentum flavum hypertrophy (LFH) which causes mechanical compression of the cauda equina or nerve roots. We assessed the role of a novel target, microRNA-29a (miR-29a), in LFH and investigated the potential for using miR-29a as a therapeutic means to combat LSS. METHODS: Ligamentum flavum (LF) tissue was collected from patients undergoing decompressive surgery for LSS and assessed for levels of miR-29a and pro-fibrotic protein expression. LF cell cultures were then transfected with either miR-29a over-expressor (agonist) or inhibitor (antagonist). The effects of over-expression and under-expression of miR-29a on expression of pro-fibrotic proteins was assessed. RESULTS: We demonstrated that LF at stenotic levels had a loss of miR-29a expression. This was associated with greater LF tissue thickness and higher mRNA levels of collagen I and III. We also demonstrated that miR29-a plays a direct role in the regulation of collagen gene expression in ligamentum flavum. Specifically, agents that increase miR-29a may attenuate LFH, while those that decrease miR-29a promote fibrosis and LFH. CONCLUSION: This study demonstrates that miR-29a may potentially be used to treat LFH and provides groundwork to initiate the development of a therapeutic product for LSS.

Development of a rabbit human glioblastoma model for testing of endovascular selective intra-arterial infusion (ESIA) of novel stem cell-based therapeutics.

BACKGROUND: Endovascular selective intra-arterial (ESIA) infusion of cellular oncotherapeutics is a rapidly evolving strategy for treating glioblastoma. Evaluation of ESIA infusion requires a unique animal model. Our goal was to create a rabbit human GBM model to test IA infusions of cellular therapies and to test its usefulness by employing clinical-grade microcatheters and infusion methods to deliver mesenchymal stem cells loaded with an oncolytic adenovirus, Delta-24-RGD (MSC-D24). METHODS: Rabbits were immunosuppressed with mycophenolate mofetil, dexamethasone, and tacrolimus. They underwent stereotactic xenoimplantation of human GBM cell lines (U87, MDA-GSC-17, and MDA-GSC-8-11) into the right frontal lobe. Tumor formation was confirmed on magnetic resonance imaging, histologic, and immunohistochemistry analysis. Selective microcatheter infusion of MSC-D24 was performed via the ipsilateral internal carotid artery to assess model utility and the efficacy and safety of this approach. RESULTS: Twenty-five rabbits were implanted (18 with U87, 2 MDA-GSC-17, and 5 MDA-GSC-8-11). Tumors formed in 68% of rabbits (77.8% for U87, 50.0% for MDA-GSC-17, and 40.0% for MDA-GSC-8-11). On MRI, the tumors were hyperintense on T2-weighted image with variable enhancement (evidence of blood brain barrier breakdown). Histologically, tumors showed phenotypic traits of human GBM including varying levels of vascularity. ESIA infusion into the distal internal carotid artery of 2 ml of MSCs-D24 (107 cells) was safe in the model. Examination of post infusion specimens documented that MSCs-D24 homed to the implanted tumor at 24 hours. CONCLUSIONS: The intracranial immunosuppressed rabbit human GBM model allows testing of ESIA infusion of novel therapeutics (eg, MSC-D24) in a clinically relevant fashion.

Image-Guided Deployment and Monitoring of a Novel Tungsten Nanoparticle-Infused Radiopaque Absorbable Inferior Vena Cava Filter in a Swine Model.

PURPOSE: To improve radiopacity of radiolucent absorbable poly-p-dioxanone (PPDO) inferior vena cava filters (IVCFs) and demostrate their effectiveness in clot-trapping ability. MATERIALS AND METHODS: Tungsten nanoparticles (WNPs) were incorporated along with polyhydroxybutyrate (PHB), polycaprolactone (PCL), and polyvinylpyrrolidone (PVP) polymers to increase the surface adsorption of WNPs. The physicochemical and in vitro and in vivo imaging properties of PPDO IVCFs with WNPs with single-polymer PHB (W-P) were compared with those of WNPs with polymer blends consisting of PHB, PCL, and PVP (W-PB). RESULTS: In vitro analyses using PPDO sutures showed enhanced radiopacity with either W-P or W-PB coating, without compromising the inherent physicomechanical properties of the PPDO sutures. W-P- and W-PB-coated IVCFs were deployed successfully into the inferior vena cava of pig models with monitoring by fluoroscopy. At the time of deployment, W-PB-coated IVCFs showed a 2-fold increase in radiopacity compared to W-P-coated IVCFs. Longitudinal monitoring of in vivo IVCFs over a 12-week period showed a drastic decrease in radiopacity at Week 3 for both filters. CONCLUSIONS: The results highlight the utility of nanoparticles (NPs) and polymers for enhancing radiopacity of medical devices. Different methods of incorporating NPs and polymers can still be explored to improve the effectiveness, safety, and quality of absorbable IVCFs.

Dual Mini-Fragment Plate Fixation of Midshaft Clavicle Fractures Reduces Risk of Reoperation Compared With Single-Plate Fixation Techniques.

BACKGROUND: Recent studies have highlighted dual plating as a method of reducing high rates of postoperative complication after operative management of displaced midshaft clavicular fractures. However, few studies have reliably characterized reoperation rates and magnitude of risk reduction achieved when using dual versus anterior and superior single-plate techniques. HYPOTHESIS: There would be lower rates of reoperation among patients who underwent open reduction and internal fixation (ORIF) of displaced midshaft clavicular fractures via dual plating. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: This was a retrospective analysis of patients who underwent ORIF for a displaced midshaft clavicular fracture between 2010 and 2021 at a level 1 trauma center with a minimum 12-month follow-up. Patients were separated into 3 cohorts based on fixation type: (1) orthogonal dual mini-fragment plate fixation, (2) superior plate fixation, and (3) anterior plate fixation. Data on patient characteristics, fracture pattern, and reoperations were documented. All-cause reoperation rates and hazard ratio (HR) estimates of dual, superior, and anterior plating were calculated using a multivariate multilevel mixed-effects parametric survival model. Significant confounders including high-risk fracture morphology and smoking status were controlled for in the final model. RESULTS: A final cohort of 256 patients was identified with mean follow-up of 4.9 ± 3.8 years. In total, 101 patients underwent superior plating, 92 underwent anterior plating, and 63 underwent dual plating. Overall, 31 reoperations took place (18 in superior, 12 in anterior, 1 in dual plating) among 22 patients. Major contributors to reoperation included symptomatic hardware (n = 11), nonunion (n = 8), deep infection (n = 7), and wound dehiscence (n = 2). Superior plating revealed the highest reoperation rate of 0.031 per person-years, followed by anterior plating with 0.026 per person-years and dual plating with 0.005 per person-years. Overall, single plating (either anterior or superior placement) had a nearly 8-fold greater risk of reoperation than dual plating (HR, 7.62; 95% CI, 1.02-56.82; P = .048). Further broken down by technique, superior plating had an 8-fold greater risk of reoperation than dual plating (HR, 8.36; 95% CI, 1.10-63.86; P = .041), but anterior plating did not demonstrate a statistically significant difference compared with dual plating (HR, 6.79; 95% CI, 0.87-52.90; P = .068). CONCLUSION: Dual-plate fixation represents an excellent treatment for displaced midshaft clavicular fractures, with low rates of nonunion and reoperation. When compared with single locked superior or anterior plate fixation, dual mini-fragment plate fixation has a nearly 8-fold lower risk of reoperation.

Carotid blowout into the trachea: unusual entity with unexpected management outcome.

We present a case report of a patient with a history of aggressive thyroid cancer managed by surgery, chemotherapy, and radiation to the neck. A year later, he presented with hemoptysis. Endobronchial ultrasound showed a pulsatile vessel; however, a CT scan and conventional angiogram were negative. Three days later, a repeat angiogram revealed a pseudoaneurysm arising from the right common carotid artery. Carotid sacrifice was performed after passing balloon test occlusion. Three years later the patient presented with coil herniation into the trachea. The carotid stump was closed with a vascular plug to prevent rebleeding from coil removal. Four months later the patient experienced an intractable cough and underwent laryngoscopy-assisted removal of the residual coil mass. This case report discusses the rare scenario of a carotid blowout into the trachea and the subsequent course of events.

Imaging in Interventional Radiology: 2043 and Beyond.

Since its inception in the early 20th century, interventional radiology (IR) has evolved tremendously and is now a distinct clinical discipline with its own training pathway. The arsenal of modalities at work in IR includes x-ray radiography and fluoroscopy, CT, MRI, US, and molecular and multimodality imaging within hybrid interventional environments. This article briefly reviews the major developments in imaging technology in IR over the past century, summarizes technologies now representative of the standard of care, and reflects on emerging advances in imaging technology that could shape the field in the century ahead. The role of emergent imaging technologies in enabling high-precision interventions is also briefly reviewed, including image-guided ablative therapies.

The Effects of Cervical Orthoses on Head and Intervertebral Range of Motion.

STUDY DESIGN: Prospective Cohort. OBJECTIVE: Quantify and compare the effectiveness of cervical orthoses in restricting intervertebral kinematics during multiplanar motions. SUMMARY OF BACKGROUND DATA: Previous studies evaluating the efficacy of cervical orthoses measured global head motion and did not evaluate individual cervical motion segment mobility. Prior studies focused only on the flexion/extension motion. METHODS: Twenty adults without neck pain participated. Vertebral motion from the occiput through T1 was imaged using dynamic biplane radiography. Intervertebral motion was measured using an automated registration process with validated accuracy better than 1 degree. Participants performed independent trials of maximal flexion/extension, axial rotation, and lateral bending in a randomized order of unbraced, soft collar (foam), hard collar (Aspen), and cervical thoracic orthosis (CTO) (Aspen) conditions. Repeated-measures ANOVA was used to identify differences in the range of motion (ROM) among brace conditions for each motion. RESULTS: Compared with no collar, the soft collar reduced flexion/extension ROM from occiput/C1 through C4/C5, and reduced axial rotation ROM at C1/C2 and from C3/C4 through C5/C6. The soft collar did not reduce motion at any motion segment during lateral bending. Compared with the soft collar, the hard collar reduced intervertebral motion at every motion segment during all motions, except for occiput/C1 during axial rotation and C1/C2 during lateral bending. The CTO reduced motion compared with the hard collar only at C6/C7 during flexion/extension and lateral bending. CONCLUSIONS: The soft collar was ineffective as a restraint to intervertebral motion during lateral bending, but it did reduce intervertebral motion during flexion/extension and axial rotation. The hard collar reduced intervertebral motion compared with the soft collar across all motion directions. The CTO provided a minimal reduction in intervertebral motion compared with the hard collar. The utility in using a CTO rather than a hard collar is questionable, given the cost and little or no additional motion restriction.

Association Between Industry Sponsorship of Spine-Related Clinical Trials, Publication Status, and Research Outcomes.

STUDY DESIGN: Observational Database Study. OBJECTIVES: Prospective clinical trials in spinal surgery are expensive to conduct, especially when randomized, appropriately powered, and/or multicentered. Industry collaborations generate symbiotic relationships promoting technological advancement; however, they also allow for bias. To the authors' knowledge, there is no known analysis of correlations between industry sponsorship and publication rates of spine-related clinical trials. This observational work evaluates such potential associations. METHODS: The ClinicalTrials.gov database was queried with terms spine, spinal, spondylosis, spondylolysis, cervical, lumbar, and compression fracture over an 11-year period. Design characteristics and outcomes were recorded from 822 spine surgery-related trials. Trials were stratified based on funding source and intervention class. Groups were compared via two-tailed chi-square test of independence or Fisher's exact test (α = .05), based on completion status and publication rates of positive vs negative results. RESULTS: Industry-sponsored spine-related clinical trials were more likely to be terminated than their non-industry-sponsored counterparts (P < .001). Of the trials achieving publication, industry-sponsored trials reported positive results at a higher rate than did trials without industry funding (P = .037). Clinical trials examining devices were more likely to be terminated than those studying other intervention classes (P = .001). CONCLUSIONS: High termination rates and positive result publication rates among industry-sponsored clinical trials in spinal surgery likely reflect industry's influence on the research community. Such partnership alleviates financial burden and provides accessibility to cutting-edge innovation. It is essential that all parties remain mindful of the significant bias that funding source may impart on study outcome.

Increasing Quality and Frequency of Goals-of-Care Documentation in the Highest-Risk Surgical Candidates: One-Year Results of the Surgical Pause Program.

Patient values may be obscured when decisions are made under the circumstances of constrained time and limited counseling. The objective of this study was to determine if a multidisciplinary review aimed at ensuring goal-concordant treatment and perioperative risk assessment in high-risk orthopaedic trauma patients would increase the quality and frequency of goals-of-care documentation without increasing the rate of adverse events. Methods: We prospectively analyzed a longitudinal cohort of adult patients treated for traumatic orthopaedic injuries that were neither life- nor limb-threatening between January 1, 2020, and July 1, 2021. A rapid multidisciplinary review termed a "surgical pause" (SP) was available to those who were ≥80 years old, were nonambulatory or had minimal ambulation at baseline, and/or resided in a skilled nursing facility, as well as upon clinician request. Metrics analyzed include the proportion and quality of goals-of-care documentation, rate of return to the hospital, complications, length of stay, and mortality. Statistical analysis utilized the Kruskal-Wallis rank and Wilcoxon rank-sum tests for continuous variables and the likelihood-ratio chi-square test for categorical variables. Results: A total of 133 patients were either eligible for the SP or referred by a clinician. Compared with SP-eligible patients who did not undergo an SP, patients who underwent an SP more frequently had goals-of-care notes identified (92.4% versus 75.0%, p = 0.014) and recorded in the appropriate location (71.2% versus 27.5%, p < 0.001), and the notes were more often of high quality (77.3% versus 45.0%, p < 0.001). Mortality rates were nominally higher among SP patients, but these differences were not significant (10.6% versus 5.0%, 5.1% versus 0.0%, and 14.3% versus 7.9% for in-hospital, 30-day, and 90-day mortality, respectively; p > 0.08 for all). Conclusions: The pilot program indicated that an SP is a feasible and effective means of increasing the quality and frequency of goals-of-care documentation in high-risk operative candidates whose traumatic orthopaedic injuries are neither life- nor limb-threatening. This multidisciplinary program aims for goal-concordant treatment plans that minimize modifiable perioperative risks. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Dynamic Changes in Lumbar Spine Kinematics During Gait May Explain Improvement in Back Pain and Disability in Patients With Hip-Spine Syndrome.

STUDY DESIGN: Prospective cohort. OBJECTIVE: Determine if total hip arthroplasty (THA) changes lumbar spine kinematics during gait in a manner that explains the improvements in back pain seen in patients with hip-spine syndrome. SUMMARY OF BACKGROUND DATA: For patients with hip-spine syndrome, improvements in both hip and back pain have been demonstrated after THA; however, the exact mechanism of improvement in back pain remains unknown, as no corresponding changes in lumbar spine static radiographic parameters have been identified. METHODS: Thirteen patients with severe, unilateral hip osteoarthritis scheduled to undergo THA with concomitant back pain and disability were tested at baseline and 6 months after THA. Harris Hip Score (HHS) and Oswestry Disability Index questionnaires were completed; the static orientation of the spine and pelvis were measured on standing radiographs, and lumbar spine kinematics were measured during treadmill walking using a validated measurement system that matched subject-specific bone models created from CT scans to dynamic biplane radiographs. RESULTS: After THA, both the Oswestry Disability Index (36.3-11.3, P <0.001) and Harris Hip Score (55.7-77.9, P <0.001) improved; however, there were no changes in static intervertebral or pelvis orientation. During gait after THA, the overall lumbar spine (L1 to L5) was less lordotic from heel strike to contralateral toe off ( P <0.001), the L4 and L5 vertebra were less anteriorly tilted by 3.9° ( P =0.038) from midstance to contralateral heel strike and by 3.9° ( P =0.001) during stance, respectively. CONCLUSION: The decreased anterior tilt of the 2 lowest lumbar vertebrae and the corresponding loss of lumbar lordosis may reduce facet loading during the stance phase of gait after THA. This change in lumbar spine kinematics during gait is a potential mechanism to explain the observed improvements in back pain and disability after THA. LEVEL OF EVIDENCE: 4.

Image-guided deployment and monitoring of a novel tungsten nanoparticleâ€"infused radiopaque absorbable inferior vena cava filter in pigs.

The use of absorbable inferior vena cava filters (IVCFs) constructed with poly-p-dioxanone (PPDO) eliminates risks and complications associated with the use of retrievable metallic filters. Radiopacity of radiolucent PPDO IVCFs can be improved with the incorporation of nanoparticles (NPs) made of high-atomic number materials such as gold and bismuth. In this study, we focused on incorporating tungsten NPs (WNPs), along with polyhydroxybutyrate (PHB), polycaprolactone (PCL), and polyvinylpyrrolidone (PVP) polymers to increase the surface adsorption of the WNPs. We compared the imaging properties of WNPs with single-polymer PHB (W-P) and WNPs with polymer blends consisting of PHB, PCL, and PVP (W-PB). Our in vitro analyses using PPDO sutures showed enhanced radiopacity with either W-P or W-PB coating, without compromising the inherent physico-mechanical properties of the PPDO sutures. We observed a more sustained release of WNPs from W-PB-coated sutures than W-P-coated sutures. We successfully deployed W-P- and W-PB-coated IVCFs into the inferior vena cava of pig models, with monitoring by fluoroscopy. At the time of deployment, W-PB-coated IVCFs showed a 2-fold increase in radiopacity compared to W-P-coated IVCFs. Longitudinal monitoring of in vivo IVCFs over a 12-week period showed a drastic decrease in radiopacity at week 3 for both filters. Results of this study highlight the utility of NPs and polymers for enhancing radiopacity of medical devices; however, different methods of incorporating NPs and polymers can still be explored to improve the efficacy, safety, and quality of absorbable IVCFs.

Technical Trick: Supplemental Medial Column Screw Fixation of Distal Femur Fractures Treated With a Laterally Based Locked Plate.

SUMMARY: Given known failure rates after lateral plating of distal femur fractures, there is an increasing interest in augmenting fixation to improve outcomes. The addition of medial plates or intramedullary nails have been described with promising results, decreasing nonunion and varus collapse rates. However, the use of dual implants increases implant costs, adds surgical complexity, and requires a second surgical approach that may increase morbidity. A supplemental, percutaneously placed, medial column screw may provide a less invasive means of improving stability and achieving fracture union compared with lateral plating alone.

In Vivo Evidence of Early Instability and Late Stabilization in Motion Segments Immediately Superior to Anterior Cervical Arthrodesis.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: The aim was to identify patient factors that affect adjacent segment kinematics after anterior cervical discectomy and fusion (ACDF) as measured by biplane radiography. SUMMARY OF BACKGROUND DATA: The etiology of adjacent segment disease (ASD) may be multifactorial. Previous studies have investigated associations between patient factors and ASD, although few attempted to link patient factors with mechanical changes in the spine that may explain ASD development. Previous studies manually measured intervertebral motion from static flexion/extension radiographs, however, manual measurements are unreliable, and those studies failed to measure intervertebral motion during rotation. METHODS: Patients had continuous cervical spine flexion/extension and axial rotation movements captured at 30 images per second in a dynamic biplane radiography system preoperatively and 1 year after ACDF. Digitally reconstructed radiographs generated from subject-specific computed tomography scans were matched to the biplane radiographs using a validated tracking process. Dynamic kinematics and preoperative disc height were calculated from this tracking process. Preoperative magnetic resonance imagings were evaluated for disc bulge. Patient age, sex, body mass index, smoking status, diabetes, psychiatric history, presence of an inciting event, and length of symptoms were collected. Multivariate linear regression was performed to identify patient factors associated with 1-year postoperative changes in adjacent segment kinematics. RESULTS: Sixty-three patients completed preoperative and postoperative testing. Superior adjacent segment disc height and disc bulge predicted the change in superior adjacent segment range of motion after surgery. Inferior adjacent segment disc bulge, smoking history, and the use of psychiatric medications predicted the change in inferior adjacent segment flexion/extension range of motion after surgery. CONCLUSIONS: Preexisting adjacent segment disc degeneration, as indicated by disc height and disc bulge, was associated with reduced adjacent segment motion after ACDF, while lack of preexisting adjacent disc degeneration was associated with increased adjacent segment motion after ACDF. These findings provide in vivo evidence supporting early instability and late stabilization in the pathophysiology of disc degeneration.

Percutaneous lumbar annular puncture: A rat model to study intervertebral disc degeneration and pain-related behavior.

Background: Previous animal models of intervertebral disc degeneration (IDD) rely on open surgical approaches, which confound the degenerative response and pain behaviors due to injury to surrounding tissues during the surgical approach. To overcome these challenges, we developed a minimally invasive percutaneous puncture procedure to induce IDD in a rat model. Methods: Ten Fischer 344 male rats underwent percutaneous annular puncture of lumbar intervertebral discs (IVDs) at L2-3, L3-4, and L4-5. Ten unpunctured rats were used as controls. Magnetic resonance imagings (MRIs), serum biomarkers, and behavioral tests were performed at baseline and 6, 12, and 18 weeks post puncture. Rats were sacrificed at 18 weeks and disc histology, immunohistochemistry, and glycosaminoglycan (GAG) assays were performed. Results: Punctured IVDs exhibited significant reductions in MRI signal intensity and disc volume. Disc histology, immunohistochemistry, and GAG assay results were consistent with features of IDD. IVD-punctured rats demonstrated significant changes in pain-related behaviors, including total distance moved, twitching frequency, and rearing duration. Conclusions: This is the first reported study of the successful establishment of a reproducible rodent model of a percutaneous lumbar annular puncture resulting in discogenic pain. This model will be useful to test therapeutics and elucidate the basic mechanisms of IDD and discogenic pain.

Risk factors for complications and reoperation following operative management of displaced midshaft clavicle fractures.

BACKGROUND: Optimal management of a displaced midshaft clavicle fracture remains controversial. This study assessed demographic factors, fracture pattern, and surgical technique as potential predictors of surgical complications. Smoking, diabetes, obesity, polytrauma, high-energy mechanism, inpatient status, transverse or comminuted fractures, and single-plating technique were hypothesized to be associated with an increased risk of complications following clavicle fracture open reduction internal fixation (ORIF). METHODS: Consecutive patients with minimum 12-week follow-up from the trauma and sports medicine divisions at a single tertiary institution who presented with a midshaft clavicle fracture and underwent ORIF between 2007 and 2020 were retrospectively identified. Patient demographics, fracture pattern, plating technique, and postoperative complications were recorded. Postoperative complications were classified into major (reoperation) and minor (no reoperation) complications. Chi-squared statistics, Fisher's exact test, analysis of variance, Kruskal-Wallis test, and multivariate logistic regression modeling were utilized with a significance level set to P < .05. RESULTS: One hundred ninety-eight patients (average = 39.5 ± 14.6 years) were identified with an average follow-up of 9.1 ± 10.7 months. The cohort consisted of 155 males (78.3%), 62 smokers (31.3%), and 12 diabetics (6.1%). Injury characteristics revealed 80 transverse fractures (40.4%), 87 oblique fractures (43.9%), and 31 Z-type fractures (15.7%). Seventy-nine patients (39.9%) underwent superior plating, 72 (36.4%) underwent anterior plating, and 47 (23.7%) underwent dual plating. Overall, postoperative complications occurred in 47 patients (23.7%), 29 minor (14.6%) and 18 major (9.1%). Major complications requiring reoperation were symptomatic hardware, nonunion, deep infection, wound dehiscence, and broken hardware. Minor complications consisted of sensory deficit or paresthesia beyond peri-incisional numbness, superficial infections, postoperative pain and/or stiffness, and delayed union. Smoking status (P = .008), obesity (P = .009), and transverse or Z-type fractures (P = .002) were significant prognostic factors for overall complication risk. Only manual labor was predictive of minor complications (P = .019). Transverse or Z-type fractures and single plating were predictive of major complications (P = .004 and P = .008, respectively). No reoperations occurred in patients who underwent dual plating. Smokers (P = .027) with transverse/Z-type fractures (P = .022) were at the highest risk of reoperation with single plating. CONCLUSION: The overall rate of complications following ORIF of displaced midshaft clavicle fracture was 27.3%, with 9.1% requiring reoperation. Given relatively high complication rates, in instances when nonoperative vs. operative management is equivocal, nonoperative management should be strongly considered in obese patients, smokers, and patients who present with transverse or Z-type fracture. If operative management is indicated, use of dual plating may decrease reoperation rates.