Hydrogel Augmentation of the Lumbar Intervertebral Disc: An Early Feasibility Study of a Treatment for Discogenic Low Back Pain.

PURPOSE: To assess the safety and effectiveness of intradiscal hydrogel in patients with chronic low back pain (CLBP) due to degenerative disc disease (DDD) refractory to conventional medical management. MATERIALS AND METHODS: Twenty patients aged 22-69 years with numerical rating scale (NRS) pain of ≥4 were enrolled. All patients with CLBP resulting from DDD confirmed by imaging and discography received injections of hydrogel (Hydrafil Intervertebral Disc Augmentation; ReGelTec, Baltimore, Maryland) at 1 or 2 lumbar levels (29 levels treated) from August to December 2020. The primary safety end point was freedom from serious adverse events (SAEs). The primary performance end point was successful gel delivery into the desired disc. Patients were also assessed on the NRS as well as the Oswestry disability index (ODI). RESULTS: Nineteen patients were followed up at a mean of 131 days, and 1 patient was lost to follow-up. Preliminary results showed significant reductions in median NRS back pain from 7 (range 4-10) to 1 (range 0-8) (P <.0001) and median ODI scores from 54 (range 22-58) to 2 (range 0-58) (P <.0001) at 6 months of follow-up. There were 5 SAEs, and 4 of the 2 were determined to be associated with treatment. CONCLUSIONS: This early feasibility study showed that the hydrogel implant was safe with no persistently symptomatic SAEs, and demonstrated effectiveness with significant reduction in pain and improvement in function when used to treat painful DDD and CLBP.

Advanced Interventional Procedures for Knee Osteoarthritis: What Is the Current Evidence?

The prevalence of knee osteoarthritis (OA) is the highest among all joints and likely to increase over the coming decades. Advances in the repertoire of diagnostic capabilities of imaging and an expansion in the availability and range of image-guided interventions has led to development of more advanced interventional procedures targeting pain related to OA pain while improving the function of patients presenting with this debilitating condition. We review the spectrum of established advanced interventional procedures for knee OA, describe the techniques used to perform these procedures safely, and discuss the clinical evidence supporting each of them.

An Interim Analysis of the First 102 Patients Treated in the Prospective Vertebral Augmentation Sacroplasty Fracture Registry.

PURPOSE: To evaluate the efficacy of sacroplasty for treating sacral insufficiency fractures, including the effect on pain relief, patient function and adverse event rates in an as-treated on-label prospective data registry. MATERIALS AND METHODS: Observational data including patient reported outcomes (PROs), patient characteristics, osteoporosis treatment, fracture duration, cause of sacral fractures and image guidance used for treatment were collected for patients undergoing sacroplasty. The PROs were collected at baseline then at one, three, and at six months following the procedure. The primary outcomes were pain as measured by the Numerical Rating Scale (NRS) and function as measured by the Roland Morris Disability Questionnaire (RMDQ). Secondary outcomes included adverse events, cement leakage, new neurologic events, readmissions and death. RESULTS: The interim results for the first 102 patients included significant pain reduction with mean pain improvement scores at six months decreasing from 7.8 to 0.9 (P < .001) and significant improvement in function with mean RMDQ scores improving from 17.7 to 5.2 (P < .001). Most procedures were performed under fluoroscopy (58%). There was cement leakage in 17.7% of the subjects but only one adverse event which was a new neurologic deficit related to cement extravasation. The readmission rate was 16% mostly due to additional back pain and fractures and there were no subject deaths. CONCLUSIONS: Sacroplasty with cement augmentation for acute, subacute and chronic painful sacral insufficiency fractures caused by osteoporosis or neoplastic disorders results in highly significant improvements in pain and function with very low rate of procedural related adverse events.

Vertebral augmentation: an overview.

Vertebral compression fractures (VCFs) are a common pathologic process seen in 30-50% of individuals over the age of 50 years. Historically, VCFs were first treated with nonsurgical management while vertebral augmentation was reserved for severe cases resulting in deformity or significant disability. Current treatment algorithms based on established appropriateness criteria have changed recommendations towards supporting early vertebral augmentation for the VCFs causing the most clinically difficulty and taking into account the degree of vertebral body height loss, kyphotic deformity, and the degree of clinical progression. Percutaneous vertebroplasty (PVP) involves injecting primarily polymethacrylate (PMMA) bone cement directly into the cancellous bone of the vertebral body. There is recent literature showing the effectiveness of PVP including data comparing vertebroplasty to sham treatment. Vertebroplasty evolved into balloon kyphoplasty (BKP) where a balloon is first inserted into the vertebral body to create a cavity and reduce the fracture followed by an injection of bone cement. Both PVP and BKP have been shown to be significantly more effective at treatment of VCFs compared to nonsurgical management. The benefits shown in the literature have been demonstrated randomized control trials, cohort matched trials, post-market trials, registries, and many other data sources with approximately 250 manuscripts produced per year dedicated to the topic of vertebral augmentation.

Vertebral Augmentation: Is It Time to Get Past the Pain? A Consensus Statement from the Sardinia Spine and Stroke Congress.

Vertebral augmentation has been used to treat painful vertebral compression fractures and metastatic lesions in millions of patients around the world. An international group of subject matter experts have considered the evidence, including but not limited to mortality. These considerations led them to ask whether it is appropriate to allow the subjective measure of pain to so dominate the clinical decision of whether to proceed with augmentation. The discussions that ensued are related below.

Cooled radiofrequency ablation of genicular nerves provides 24-Month durability in the management of osteoarthritic knee pain: Outcomes from a prospective, multicenter, randomized trial.

OBJECTIVE: To assess long-term outcomes of cooled radiofrequency ablation (CRFA) of genicular nerves for chronic knee pain due to osteoarthritis (OA). METHODS: A prospective, observational extension of a randomized, controlled trial was conducted on adults randomized to CRFA. Subjects were part of a 12-month clinical trial comparing CRFA of genicular nerves to a single hyaluronic injection for treatment of chronic OA knee pain, who then agreed to visits at 18- and 24-months post CRFA and had not undergone another knee procedure since. The subjects were evaluated for pain using the Numeric Rating Scale (NRS) function using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), subjective benefit using the Global Perceived Effect (GPE) scale, quality of life using the EuroQol-5-Dimensions-5 Level (EQ-5D-5L) questionnaire, and safety. RESULTS: Of 57 subjects eligible, 36 enrolled; 32 completed the 18-month visit with a mean NRS score of 2.4 and 22 (69%) reporting ≥50% reduction in pain from baseline (primary endpoint); 27 completed the 24-month visit, with a mean NRS of 3.4 and 17 (63%) reporting ≥50% pain relief. Functional and quality of life improvements persisted similarly, with mean changes from baseline of 53.5% and 34.9% in WOMAC total scores, and 24.8% and 10.7% in EQ-5D-5L Index scores, at 18- and 24-months, respectively. There were no identified safety concerns in this patient cohort. CONCLUSION: In this subset of subjects, CRFA of genicular nerves provided durable pain relief, improved function, and improved quality of life extending to 24 months post procedure, with no significant safety concerns.

Vertebral augmentation with spinal implants: third-generation vertebroplasty.

This article is to review the different types of vertebral augmentation implants recently becoming available for the treatment of benign and malignant spinal compression fractures. After a detailed description of the augmentation implants, we review the available clinical data. We will conclude with a summary of the advantages and disadvantages of vertebral implants and how they can affect the future treatment options of compression fractures.

Cooled radiofrequency ablation provides extended clinical utility in the management of knee osteoarthritis: 12-month results from a prospective, multi-center, randomized, cross-over trial comparing cooled radiofrequency ablation to a single hyaluronic acid injection.

BACKGROUND: Safe and effective non-surgical treatments are an important part of the knee osteoarthritis (OA) treatment algorithm. Cooled radiofrequency ablation (CRFA) and hyaluronic acid (HA) injections are two commonly used modalities to manage symptoms associated with knee OA. METHODS: A prospective 1:1 randomized study was conducted in 177 patients comparing CRFA to HA injection with follow-ups at 1, 3, 6 and 12 months. HA subjects with unsatisfactory outcomes at 6-months were allowed to crossover and receive CRFA. Knee pain (numeric rating scale = NRS), WOMAC Index (pain, stiffness and physical function), overall quality of life (global perceived effect = GPE, EQ-5D-5 L), and adverse events were measured. RESULTS: At 12-months, 65.2% of subjects in the CRFA cohort reported ≥50% pain relief from baseline. Mean NRS pain score was 2.8 ± 2.4 at 12 months (baseline 6.9 ± 0.8). Subjects in the CRFA cohort saw a 46.2% improvement in total WOMAC score at the 12-month timepoint. 64.5% of subjects in the crossover cohort reported ≥50% pain relief from baseline, with a mean NRS pain score of 3.0 ± 2.4 at 12 months (baseline 7.0 ± 1.0). After receiving CRFA, subjects in the crossover cohort had a 27.5% improvement in total WOMAC score. All subjects receiving CRFA reported significant improvement in quality of life. There were no serious adverse events related to either procedure and overall adverse event profiles were similar. CONCLUSION: A majority of subjects treated with CRFA demonstrated sustained knee pain relief for at least 12-months. Additionally, CRFA provided significant pain relief for HA subjects who crossed over 6 months after treatment. TRIAL REGISTRATION: This trial was registered on ClinicalTrials.gov, NCT03381248. Registered 27 December 2017.

Spine Intervention-An Update on Injectable Biomaterials.

Back pain is the second most common reason for primary-care physician visits after the common cold. New understanding of the spine pathophysiology and biomechanics led to the development of novel injectable biomaterials to treat those pain generators. Although not all biomaterials are currently ready for common use, there is significant interest by the medical community to invest time, resources, and energy to optimize these injectables. This review introduces basic concepts and advancements in the field of bioinjectables tailored for the vertebral body. Also, we highlight advances in injectable biomaterials which were presented at the Groupe de Recherche Interdisciplinaire sur les Biomatériaux Ostéoarticulaires Injectables (GRIBOI) (Interdisciplinary Research Society for Injectable Osteoarticular Biomaterials) meeting in March 2018 in Los Angeles, CA. Indeed, multidisciplinary translational research and international meetings such as GRIBOI bring together scientists and clinicians with different backgrounds/expertise to discuss injectable biomaterials innovations tailored for the interventional pain management field.

Optimizing success with lumbar disc arthroplasty.

PURPOSE: This study aimed at determining the variables that may prove useful in predicting clinical outcomes following lumbar disc arthroplasty. METHODS: Pre- and post-operative imaging assessments were obtained for 99 single-level lumbar disc arthroplasty patients from a prospective IDE study. The assessments and patient demographics were tested to identify variables that were significantly associated with clinical outcomes. RESULTS: Clinical outcome data were available for 85 % of patients at the 5-year follow-up. Numerous assessments made from the pre-operative imaging were found to have statistically significant associations with clinical outcomes at 2 and 5 years. The most notable factors were related to the amount of degeneration at the index level, with patients achieving better outcome scores at 5 years if they have higher grades of degeneration preoperatively. CONCLUSIONS: Several variables may prove effective at optimizing clinical outcomes including a preoperative disc height <8 mm, Modic type 2 changes adjacent to the target disc, a low amount of lordosis present at the treatment level, low levels of fatty replacement of the paraspinal musculature, a prominent amount of facet joint or disc degeneration, and the presence of flat or convex vertebral endplates. There were also post-operative findings associated with better patient outcomes including a larger percent of the endplate covered with the implant, larger implant heights, greater increases in disc space heights, and a larger increase in index level lumbar lordosis. These variables could be explored in other clinical studies to facilitate meta-analyses that could identify effective strategies to optimize clinical outcomes with lumbar disc arthroplasty.

A Self-Polymerizing Mesh of Nano-Tethers for the Mechanical Constraint of Degraded Intervertebral Discs-A Review of 25 Years of Pre-Clinical and Early Clinical Research.

Genipin polymers are self-forming tensile-load-carrying oligomers, derived from the gardenia fruit, that covalently bond to amines on collagen. The potential therapeutic mechanical benefits of a non-discrete in situ forming mesh of genipin oligomers for degraded spinal discs were first conceived in 1998. Over more than two decades, numerous studies have demonstrated the immediate mechanical effects of this injectable, intra-annular polymeric mesh including an early demonstration of an effect on clinical outcomes for chronic or recurrent discogenic low back pain. This literature review focused on articles investigating mechanical effects in cadaveric animal and human spinal discs, biochemical mechanism of action studies, articles describing the role of mechanical degradation in the pathogenesis of degenerative disc disease, initial clinical outcomes and articles describing current discogenic low back pain treatment algorithms. On the basis of these results, clinical indications that align with the capabilities of this novel injectable polymer-based treatment strategy are discussed. It is intended that this review of a novel nano-scale material-based solution for mechanical deficiencies in biologically limited tissues may provide a helpful example for other innovations in spinal diseases and similarly challenging musculoskeletal disorders.

Computed Tomographic Characterization for Basivertebral Nerve Ablation Utilizing a Radiofrequency Multitined Expandable Electrode.

Background: A growing body of clinical evidence has demonstrated that intraosseous minimally invasive basivertebral nerve (BVN) ablation results in significant and durable improvements in vertebrogenic back pain. Thus, it is important to develop, refine and validate new and additional devices to accomplish this procedure. Methods: Using reconstructions of 31 patient computed tomography (CT) scans of the lumbosacral spine (L1-S1), the primary objective was to simulate the intravertebral placement of a novel multitined expandable electrode in bipolar configuration at the targeted ablation site and determine if the proper trajectories could be achieved in order for the device tips to be in the correct position for lesion formation at the BVN plexus. Successful device deployment required that the distance between tips was between 10 mm and 20 mm. Results: The mean distances between device tips ranged from 11.35 mm (L5) to 11.87 mm (L3), and there were no statistically significance differences across the six vertebral levels (F = 0.72, p = 0.61). The percentage of successful intraosseous device placements within the tip distance acceptable range (≥ 10 mm to ≤ 20 mm) was 90% (162 of 180), with no tip-to-tip distances > 20 mm. There was a notable association between decreasing vertebral level and mean degree of angulation between contralateral devices ranging from 50.90° at L1 to 91.51° at S1, and the difference between across the six vertebral levels was significant (F = 89.5, p < 0.01). Conclusion: Feasibility evidence is provided from real world CT imaging data that validates using the multitined electrode for proper intraosseous placement within the vertebral body to effectively ablate the BVN plexus.

Perspective on Intradiscal Therapies for Lumbar Discogenic Pain: State of the Science, Knowledge Gaps, and Imperatives for Clinical Adoption.

Specific clinical diagnostic criteria have established a consensus for defining patients with lumbar discogenic pain. However, if conservative medical management fails, these patients have few treatment options short of surgery involving discectomy often coupled with fusion or arthroplasty. There is a rapidly-emerging research effort to fill this treatment gap with intradiscal therapies that can be delivered minimally-invasively via fluoroscopically guided injection without altering the normal anatomy of the affected vertebral motion segment. Viable candidate products to date have included mesenchymal stromal cells, platelet-rich plasma, nucleus pulposus structural allograft, and other cell-based compositions. The objective of these products is to repair, supplement, and restore the damaged intervertebral disc as well as retard further degeneration. In doing so, the intervention is meant to eliminate the source of discogenic pain and avoid surgery. Methodologically rigorous studies are rare, however, and based on the best clinical evidence, the safety as well as the magnitude and duration of clinical efficacy remain difficult to estimate. Further, we summarize the US Food and Drug Administration's (FDA) guidance regarding the interpretation of the minimal manipulation and homologous use criteria, which is central to designating these products as a tissue or as a drug/device/biologic. We also provide perspectives on the core evidence and knowledge gaps associated with intradiscal therapies, propose imperatives for evaluating effectiveness of these treatments and highlight several new technologies on the horizon.

Treatment Gaps and Emerging Therapies in Lumbar Disc Herniation.

BACKGROUND: Lumbar disc herniation (LDH) occurs when the central disc material, primarily the nucleus pulposus, is displaced beyond the outer annulus, compressing the spinal nerve roots. LDH symptoms, including radicular leg pain, radiculopathy, and low back pain, are associated with considerable disease burden and the significant utilization of health care resources. OBJECTIVES: Provide overview of the current treatment landscape for LDH, identify unmet needs, and describe emerging treatments. STUDY DESIGN: Narrative literature review. METHODS: A review of literature concerning available LDH treatments and associated outcomes was conducted in PubMed to identify areas of unmet need. Some key words included "lumbar disc herniation," "radicular leg pain," "sciatica," "treatment," "therapy," and "burden." RESULTS: For patients who do not respond to conservative therapy, epidural steroid injections (ESIs) are widely used for persistent LDH symptoms. While ESIs provide short-term improvements in radicular pain, evidence that ESIs bestow sustained benefits is limited. ESIs are not approved by the US Food and Drug Administration (FDA) and, in rare cases, carry risks of infection and neurological injury, as well as the potential for long-term systemic effects of glucocorticoids. In cases when nonsurgical treatment fails to relieve symptoms, lumbar discectomy can provide rapid pain relief; however, in addition to the risk of intraoperative complications, the long-term consequences of lumbar discectomy may include recurrent pain or herniation, revision discectomy, loss of disc height, and Modic changes. Treatments for LDH in late-stage clinical development include sustained-release ESI formulations and a novel agent for chemonucleolysis, a nonsurgical method of minimizing the volume of the displaced nucleus pulposus. Emerging minimally invasive therapies that address the underlying pathophysiology of the disease have the potential to bridge the gap between symptomatic treatments and surgery. LIMITATIONS: Because this paper was a narrative review, literature search and selection processes were not systematic in nature. The evidence regarding the long-term efficacy of some treatments, such as discectomy, was limited by the high rates of crossover between the treatment groups. CONCLUSIONS: The lack of sustained benefits associated with ESIs and the risks associated with surgery underscore the unmet need for novel, minimally invasive interventional therapies able to address the underlying nerve root compression in LDH.

Intradiscal Steroid Injections for Degenerative Disc Disease With Modic Changes: A Retrospective Study of Therapeutic and Diagnostic Features.

PURPOSE: Anterior column pain refers to axial low back pain (LBP) originating from the intervertebral disc or vertebral endplates (discogenic or vertebrogenic pain). We sought to assess the safety and effectiveness of intradiscal steroid injection (IDSI) in diagnosing and treating patients with LBP arising from the anterior column. PATIENTS AND METHODS: This is a retrospective chart review of 66 patients who underwent 77 injections in an outpatient, private practice setting for the treatment of chronic lower back with history and physical exam findings indicating an origin within the anterior column and magnetic resonance imaging (MRI) findings of Modic changes associated with disc degeneration of grade 4 or above on the modified Pfirrmann scale. Patients reported pain as measured by the numerical rating scale (NRS) before the injection, at the time of their follow-up, and their maximum pain relief. The primary outcome was the change in NRS before and after the injections. The secondary outcome determined if the changes in the subjects' NRS met the minimal clinically important change (MCIC) criteria for LBP. We conducted a statistical analysis using a paired sample t-test. RESULTS: There was a statistically significant difference between the pre-injection and follow-up NRS scores (p < 0.001) and a significant difference between pre-injection and maximum relief NRS scores (p < 0.001). Most subjects (55/77, 71.4%) met the MCIC to relieve their chronic LBP at the time of the follow-up evaluation. CONCLUSION: For patients with chronic LBP and degenerative endplate changes, IDSIs provided these patients with significant short-term pain relief from pain arising from the anterior column.

Posterior Lateral Arthrodesis as a Treatment Option for Lumbar Spinal Stenosis: Safety and Early Clinical Outcomes.

Introduction: Lumbar spinal stenosis (LSS) is a common condition caused by degenerative changes in the lumbar spine with age. LSS is caused by a variety of factors, including degenerative spondylosis and spondylolisthesis. People suffering with LSS experience neurogenic claudication, which causes severe physical limitations, discomfort, and a decrease in quality of life. Less invasive procedures are now being researched to improve the prognosis, success rate, and safety of LSS treatments. Posterior lateral spinal arthrodesis (PLSA) is a new surgical treatment for LSS. This study looks at the procedural and patient safety of PLSA. Materials and methods: This study is a multicenter retrospective analysis of the safety of PLSA who met the clinical indications for PLSA and underwent the procedure at eight interventional spine practices. Data was collected on demographical information, pre-procedural numeric rating scale score (NRS), post-procedural NRS, and complication reporting. Patients who were included had LSS with or without spondylolisthesis and had failed conservative treatments. A descriptive statistical analysis was performed to report the outcomes. Results were reported as mean and standard deviations for continuous outcomes, and frequency (%) for categorical outcomes. Results: This retrospective analysis involved 191 patients and 202 PLSA implants. The majority of patients were male Caucasians with a mean age of 69.2 years and a BMI of 31.1. A large majority of implants were placed at the L4-5 level, and the average pre-procedural NRS was 6.3 while the average post-procedural NRS was 3.1, indicating a 50.8% reduction in pain (p < 0.0001). Two patients reported complications, but they were unrelated to the device or surgical procedure; no infections, device malfunctions, or migrations were reported in the patient cohort. Conclusion: Preliminary results with PLSA implants indicate that it is a safe treatment option for patients with moderate LSS who do not respond to conservative management.

Cooled radiofrequency ablation versus standard medical management for chronic sacroiliac joint pain: a multicenter, randomized comparative effectiveness study.

INTRODUCTION: Low back pain is the leading cause of disability worldwide, with sacroiliac joint pain comprising up to 30% of cases of axial lower back pain. Conservative therapies provide only modest relief. Although placebo-controlled trials show efficacy for sacral lateral branch cooled radiofrequency ablation, there are no comparative effectiveness studies. METHODS: In this randomized, multicenter comparative effectiveness study, 210 patients with clinically suspected sacroiliac joint pain who obtained short-term benefit from diagnostic sacroiliac joint injections and prognostic lateral branch blocks were randomly assigned to receive cooled radiofrequency ablation of the L5 dorsal ramus and S1-S3 lateral branches or standard medical management consisting of pharmacotherapy, injections and integrative therapies. The primary outcome measure was mean reduction in low back pain score on a 0-10 Numeric Rating Scale at 3 months. Secondary outcomes included measures of quality of life and function. RESULTS: 3 months post-treatment, the mean Numeric Rating Scale pain score for the cooled radiofrequency ablation group was 3.8±2.4 (mean reduction 2.5±2.5) compared with 5.9±1.7 (mean reduction 0.4±1.7) in the standard medical management group (p<0.0001). 52.3% of subjects in the cooled radiofrequency ablation group experienced >2 points or 30% pain relief and were deemed responders versus 4.3% of standard medical management patients (p<0.0001). Comparable improvements favoring cooled radiofrequency ablation were noted in Oswestry Disability Index score (mean 29.7±15.2 vs 41.5+13.6; p<0.0001) and quality of life (mean EuroQoL-5 score 0.68±0.22 vs 0.47±0.29; p<0.0001). CONCLUSIONS: In patients with sacroiliac joint pain, cooled radiofrequency ablation provided statistically superior improvements across the spectrum of patient outcomes compared with standard medical management. TRIAL REGISTRATION NUMBER: NCT03601949.