Patient and physician radiation exposure during minimally invasive lumbar decompression: A prospective assessment of X-ray exposure risks.

INTRODUCTION: Minimally invasive lumbar decompression (mild®) is becoming a popular procedure for treating lumbar spinal stenosis (LSS) secondary to hypertrophic ligamentum flavum (LF). The mild® procedure is commonly performed under live fluoroscopic guidance and carries a risk of radiation exposure to the patient and healthcare. METHODS: One physician performed mild® on 41 patients at the Cleveland Clinic Department of Pain Management from October 2019 to December 2021, while wearing a radiation exposure monitor (Mirion Technologies). Mean fluoroscopy time, mean exposure per case, and mean exposure per unilateral level decompressed were the primary outcomes measured. The secondary outcome was to provide a comparison of radiation exposure during similar fluoroscopically guided procedures. RESULTS: Mean patient fluoroscopy exposure time was 2.1 min ±0.9 (range: 1.1-5.6) fluoroscopy time per unilateral level decompressed. The mean patient radiation skin exposure from mild® was 1.1 ± 0.9 mGym2, and the mean total dose was 142.3 ± 108.6 mGy per procedure. On average, the physician was exposed to an average deep tissue exposure of 4.1 ± 3.2 mRem, 2.9 ± 2.2 mRem estimated eye exposure, and 14.7 ± 11.0 mRem shallow tissue exposure per unilateral level decompressed. An individual physician would exceed the annual exposure limit of 5 Rem after approximately 610 mild® procedures per year. CONCLUSIONS: This study is an attempt to quantify the radiation exposure to the physician and patient during the mild® procedure. Compared with other fluoroscopically guided pain management procedures, patient and physician radiation exposure during mild® was low.

The MOTION study: Two-year results of a real-world randomized controlled trial of the mild® procedure for treatment of lumbar spinal stenosis.

OBJECTIVE: The MOTION study is designed to measure the impact of percutaneous image-guided lumbar decompression as a first-line therapy on patients otherwise receiving real-world conventional medical management for lumbar spinal stenosis with neurogenic claudication secondary to hypertrophic ligamentum flavum. This prospective, multicenter randomized controlled trial uses objective and patient-reported outcome measures to compare the combination of the mild® percutaneous treatment and nonsurgical conventional medical management (CMM) to CMM-Alone. METHODS: Test group patients received the mild procedure after study enrollment. Test and control groups were allowed conventional conservative therapies and low-risk interventional therapies as recommended by their physicians. Subjective outcomes included the Oswestry Disability Index, Numeric Pain Rating Scale, and Zurich Claudication Questionnaire. Objective outcomes included a validated Walking Tolerance Test, the rate of subsequent lumbar spine interventions, and safety data. RESULTS: Two-year follow-up included 64 mild + CMM and 67 CMM-Alone patients. All outcome measures showed significant improvement from baseline for mild + CMM, whereas the majority of CMM-Alone patients had elected to receive mild treatment or other lumbar spine interventions by 2 years, precluding valid 2-year between-group comparisons. Neither group reported any device- or procedure-related adverse events. CONCLUSIONS: The durability of mild + CMM for this patient population was demonstrated for all efficacy outcomes through 2 years. Improvements in walking time from baseline to 2 years for patients treated with mild + CMM were significant and substantial. The lack of reported device or procedure-related adverse events reinforces the strong safety profile of the mild procedure. These results provide support for early interventional treatment of symptomatic LSS with the mild procedure.

Impact of Long-Term Evoked Compound Action Potential Controlled Closed-Loop Spinal Cord Stimulation on Sleep Quality in Patients With Chronic Pain: An EVOKE Randomized Controlled Trial Study Subanalysis.

OBJECTIVE: Spinal cord stimulation (SCS) is considered an effective interventional nonpharmacologic treatment option for several chronic pain conditions. Here we present the effects of the novel evoked compound action potential (ECAP) controlled closed-loop (ECAP-CL) SCS system on long-term sleep quality outcomes from the EVOKE study. MATERIALS AND METHODS: The EVOKE study is a double-blind, randomized, controlled clinical trial conducted at 13 sites in the United States (N = 134 patients). The clinical trial utilized SCS to manage chronic pain and compared novel ECAP-CL technology to open-loop SCS. Additionally, sleep quality data was collected using the Pittsburgh Sleep Quality Index (PSQI) at baseline and all study visits. RESULTS: The mean PSQI global score for ECAP-CL patients at baseline was 14.0 (n = 62; ± 0.5, SD 3.8), indicating poor sleep quality. Clinically meaningful and statistically significant reductions (p < 0.001) in the global PSQI scores were noted at 12 months (n = 55; 5.7 ± 0.6, SD 4.2). A total of 76.4% of ECAP-CL patients met or exceeded Minimal Clinically Important Difference from baseline in PSQI at 12 months. Additionally, 30.9% of ECAP-CL patients achieved "good sleep quality" scores (PSQI ≤ 5), and 29.1% achieved sleep quality remission. "Normative" sleep scores were observed in 29.6% of ECAP-CL patients at 12 months, and these scores were better than the US general population. Additionally, ECAP-CL patients achieved statistically significant changes from baseline (p < 0.01) across all seven subcomponent scores of PSQI at 12 months. CONCLUSIONS: ECAP-CL SCS elicits consistent neural activation of the target leading to less variability in long-term therapy delivery. In the EVOKE study, this resulted in ECAP-CL patients demonstrating clinically superior and sustained pain relief. Results from this study provide new evidence of long-term improvement in sleep quality and quantity in patients with chronic pain resulting from the use of this novel ECAP-CL SCS technology. CLINICAL TRAIL REGISTRATION: The Clinicaltrials.gov registration number for the study is NCT02924129.

The MOTION Study: A Randomized Controlled Trial with Objective Real-World Outcomes for Lumbar Spinal Stenosis Patients Treated with the mild® Procedure: One-Year Results.

OBJECTIVE: The purpose of this study is to provide Level-1 objective, real-world outcome data for patients with lumbar spinal stenosis suffering from neurogenic claudication secondary to hypertrophic ligamentum flavum. DESIGN: The MOTION Study is a prospective, multicenter, randomized controlled trial comparing the mild® Procedure (minimally invasive lumbar decompression; Vertos Medical, Aliso Viejo, CA, USA) as a first-line therapy in combination with nonsurgical conventional medical management (CMM) vs CMM alone as the active control. METHODS: Patients in the test group received the mild Procedure at baseline. Both the mild+CMM group and the control group were allowed unrestricted access to conventional real-world therapies. Patient-reported outcomes included the Oswestry Disability Index, the Zurich Claudication Questionnaire, and the Numeric Pain Rating Scale. A validated Walking Tolerance Test, the incidence of subsequent lumbar spine interventions, and the occurrence of adverse events were used to measure objective outcomes. RESULTS: Sixty-nine patients in each group were analyzed at 1-year follow-up. No device- or procedure-related adverse events were reported in either group. Results from all primary and secondary outcome measures showed statistical significance in favor of mild+CMM. CONCLUSIONS: One-year results of this Level-1 study demonstrated superiority of mild+CMM over CMM alone for patients with lumbar spinal stenosis who were suffering from neurogenic claudication secondary to hypertrophic ligamentum flavum. Use of the validated Walking Tolerance Test to objectively measure increased ability to walk without severe symptoms provided evidence of statistically significantly better outcomes for mild+CMM than for CMM alone. With no reported device or procedure-related adverse events, the long-standing safety profile of the mild Procedure was reaffirmed. mild is a safe, durable, minimally invasive procedure that has been shown to be effective as an early interventional therapy for patients suffering from symptomatic lumbar spinal stenosis.

Impact of biological sex on the outcomes of spinal cord stimulation in patients with chronic pain.

BACKGROUND: Spinal cord stimulation (SCS) continues to gain increasing popularity in the pain management field for the treatment of different painful conditions; however, to-date, the correlation between the SCS effectiveness and biological sex has not been fully established. We aimed to investigate the correlation between the biological sex and SCS outcomes. METHODS: Following Institutional Review Board approval, a retrospective cohort study was performed by collecting data for patients treated with SCS at a tertiary academic center between the years 2002 and 2019. Data was assessed with multivariable linear regression to investigate the association between biological sex and pain scores at baseline, 6-, and 12- months following SCS implantation. Propensity score matching (PSM) was performed based on a set of covariates including age, duration of pain, time since implant, BMI, opioid medications use, smoking, depression and history of alcohol, or substance abuse. RESULTS: Of the patients treated with SCS implants, 418 patients fit the inclusion and exclusion criteria, out of which the majority were females (272, 65%). The pre-matching data reported a significant difference in history of diabetes and depression and was also significant for greater opioid use in male patients at baseline, 6-, and 12-months post-SCS implant. Propensity score matching (PSM) was performed based on the above mentioned covariant. After matching, no statistical difference was found among the variables, in both groups. Furthermore, after matching no significant differences in the pain scores at baseline, 6-, and 12-months post-SCS implant were observed. CONCLUSION: No biological sex-based differences in the analgesic response to SCS therapy was detected at 6- and 12-months post-SCS implant between groups with similar demographics, biomedical, and psychological values.

The durability of minimally invasive lumbar decompression procedure in patients with symptomatic lumbar spinal stenosis: Long-term follow-up.

BACKGROUND: Minimally invasive lumbar decompression (mild® ) has been shown to be safe and effective for the treatment of lumbar spinal stenosis patients with hypertrophic ligamentum flavum as a contributing factor. This study examines the long-term durability of the mild procedure through 5-year follow-up. Pain relief and opioid medications utilization during 12-month follow-up were also assessed. METHODS: All patients diagnosed with lumbar spinal stenosis secondary to ligamentum flavum hypertrophy who underwent mild from 2010 through 2015 at the Cleveland Clinic Department of Pain Management were included in this retrospective longitudinal observational cohort study. The primary outcome measure was the incidence of open lumbar decompression surgery at the same level(s) as the mild intervention during 5-year follow-up. Secondary outcome measures were the change in pain levels using the Numeric Rating Scale and opioid medications utilization using Morphine Milligram Equivalent dose per day from baseline to 3, 6, and 12 months post-mild procedure. Postprocedural complications (minor or major) were also collected. RESULTS: Seventy-five patients received mild during the protocol-defined time period and were included in the study. Only 9 out of 75 patients required lumbar surgical decompression during the 5-year follow-up period. Subjects experienced statistically significant pain relief and reduction of opioid medications utilization at 3, 6, and 12 months compared to baseline. CONCLUSION: Based on our analysis, the mild procedure is durable over 5 years and may allow elderly patients with symptomatic lumbar spinal stenosis to avoid lumbar decompression surgery while providing significant symptomatic relief.

Diagnosis of Sacroiliac Joint Pain: Predictive Value of Three Diagnostic Clinical Tests.

INTRODUCTION: To date, there have been no acceptable and accurate diagnostic criteria or standards of care for the management of sacroiliac joint (SIJ) pain. Several studies have yielded different contributions of clinical presentation, history, and physical examination in the diagnosis of SIJ pain. Our goal in this study was to assess the sensitivity and specificity of the diagnostic clinical tests and their predictive value in accurately diagnosing SIJ pain. METHODOLOGY: Upon enrolling 200 eligible patients with SIJ pain as their primary diagnosis, they were re-evaluated and their verbal rating scale (VRS) pain scores and demographic data were obtained. Thereafter, three SIJ diagnostic tests were performed: the thigh thrust test, the Patrick test, and a modified version of the Gaenslen test that is referred to as the Mekhail test. Subsequently, the patients were taken to the procedure room to undergo SIJ injection, for which a confirmative result was ≥50% pain relief. The physicians performing the procedure were blinded of the results of the 3 tests performed. Results from the 3 tests were incorporated with the procedure results, from which we drew statistical and medical conclusions determining their predictive value and degree of aid to physicians in diagnosing SIJ pain. RESULTS: We found that the cumulative effect of adding simultaneous tests increased the sensitivity of the testing but decreased the specificity, which generates a powerful screening tool. The combination of the Patrick and Mekhail tests demonstrated the best accuracy, with 94% sensitivity, 17% specificity, 81% positive predictive value, and 44% negative predictive value. The Patrick test was better than other tests for differentiating patients with SIJ pain from those with non-SIJ pain. No combination yielded both significant sensitivity and specificity. Generally, the overall predictive value of any of the tests on their own or their combination did not vary significantly from the predictive value of baseline demographics, including pre-injection pain score and pain referral diagram. CONCLUSION: In conclusion, our study results were similar to those of previous investigators who found that physical examination plays a limited role in diagnosing SIJ pain. Specifically, we found that the clinical tests and/or their combinations added no significant predictive capacity compared to patients' baseline characteristics in predicting the response to diagnostic SIJ injection, albeit the combination of the Mekhail and Patrick tests yielded high sensitivity (94%), making them viable for consecutive screening, possibly reducing the unnecessary costs of diagnostic SIJ injection procedures.

The Impact of Tobacco Smoking on Spinal Cord Stimulation Effectiveness in Complex Regional Pain Syndrome Patients.

OBJECTIVES: We aim to investigate the correlation of smoking and spinal cord stimulation (SCS) effectiveness for pain relief in complex regional pain syndrome (CRPS) patients while controlling for possible confounding factors including opioid intake. MATERIALS AND METHODS: Following Institutional Review Board approval, a retrospective cohort study was performed by collecting data for all CRPS patients treated with SCS at Cleveland Clinic between 1998 and 2013. We divided patients into three groups based on their smoking status at the time of SCS device implant: Current smokers, former smokers, or nonsmokers. We used a linear mixed modeling to assess the association between smoking status and pain score at baseline and at 3, 6, and 12 months. We then used pairwise t-tests for post hoc comparisons of pain scores. RESULTS: Of the 420 CRPS patients treated with SCS implants, the reduction in pain score was highest among nonsmokers. Nonsmokers demonstrated a consistent and steady decrease in pain scores over time, whereas the current and former smoker cohorts showed an initial reduction in pain at three months compared to baseline which was not sustained to the 12-months benchmark. Nonetheless, former smokers continued to report slightly lower pain scores than current smokers, although not statistically significant. The baseline opioid consumption was least among nonsmokers (30 [0, 62] oral mg morphine sulfate equivalent). We also found a statistically significant association between time postimplant and reported pain score (χ2 = 508.88, p < 0.001). The overall mean pain score for all three cohorts was highest at baseline (7.6 ± 1.7) and showed a decrease at the 3, 6, and 12 months postimplant time points with mean score of 5.7 ± 2.0, 5.6 ± 2.3, and 5.4 ± 2.5, respectively. CONCLUSION: Tobacco cigarette smoking was associated with reduced SCS effectiveness for pain relief.

Longevity and Utilization Cost of Rechargeable and Non-Rechargeable Spinal Cord Stimulation Implants: A Comparative Study.

INTRODUCTION: Despite major advancements in features and capabilities of the implantable pulse generator (IPG), real-life longevity and cost-effectiveness studies to guide pain specialists to make the appropriate choice between rechargeable and non-rechargeable IPG are limited. Our study aimed to compare the longevity and cost effectiveness of rechargeable vs. non-rechargeable IPG and SCS systems. METHODS: Data were collected for all SCS implantations performed between 1994 and 2018. The primary goal was to determine IPG longevity, defined as the time interval between IPG implantation and elective replacement due to IPG end of life (EOL). On the other hand, SCS system longevity was defined as the time between SCS implantation and its removal or revision for any reason other than IPG EOL. Kaplan-Meier and log-rank tests were used to assess IPG and SCS system longevities. Cost analysis was performed for cost effectiveness. RESULTS: The median IPG longevity was significantly higher for rechargeable SCS devices than for non-rechargeable SCS devices (7.20 years and 3.68 years, respectively). The median cost per day was similar for both IPGs, $13.90 and $13.81 for non-rechargeable and rechargeable, respectively. The median cost for SCS systems was higher for the rechargeable group ($60.70) compared with the non-rechargeable group ($31.38). CONCLUSIONS: Rechargeable IPG had increased longevity compared to their non-rechargeable counterparts, yet there was no significant difference in the actual longevity due to premature revisions or explantations between both SCS systems. Furthermore, non-rechargeable SCS systems were found to be the more cost-effective option when compared with rechargeable SCS systems.

Multicenter Retrospective Study of Neurostimulation With Exit of Therapy by Explant.

INTRODUCTION: Spinal cord stimulation (SCS) devices are cost effective and improve function as well as quality of life. Despite the demonstrated benefits of SCS, some patients have the device explanted. We are interested in exploring the patient characteristics of those explanted. METHODS: This is a retrospective chart review of neurostimulation patients who underwent explantation at 18 centers across the United States within the previous five years. RESULTS: Data from 352 patients were collected and compiled. Failed Back Surgery syndrome was the most common diagnosis (38.9%; n = 136/350) and over half of the patients reported numerical rating scale (NRS) scores ≥8 prior to implant (64.3%; n = 207/322). All patients reported changes in NRS scores across time, with an initial decrease after implant followed by a pre-explant increase (F (2, 961) = 121.7, p < 0.001). The most common reason for device explant was lack or loss of efficacy (43.9%; 152/346) followed by complications (20.2%; 70/346). Eighteen percent (18%; 62/343) of patients were explanted by a different physician than the implanting one. Rechargeable devices were explanted at a median of 15 months, whereas primary cell device explants occurred at a median of 36 months (CI 01.434, 2.373; median endpoint time ratio = 2.40). DISCUSSION: Loss or lack of efficacy and complications with therapy represent the most frequent reasons for neurostimulation explantation. Of the devices that were explanted, therapy was terminated earlier when devices were rechargeable, when complications occurred, or when pain relief was not achieved or maintained. Furthermore, in nearly 20% of the cases, a different provider than the implanting physician performed device removal. CONCLUSIONS: SCS is largely a safe and efficacious strategy for treating select chronic refractory pain syndromes. Further prospective data and innovation are needed to improve patient selection, maintain SCS therapeutic efficacy and reduce the reasons that lead to device explant.

Spinal Cord Stimulator Implant Infection Rates and Risk Factors: A Multicenter Retrospective Study.

OBJECTIVES: Spinal cord stimulation is an evidence-based treatment for a number of chronic pain conditions. While this therapy offers improvement in pain and function it is not without potential complications. These complications include device failure, migration, loss of therapeutic paresthesia, and infection. This article looked to establish a modern infection rate for spinal cord stimulators, assess the impact of known risk factors for surgical site infections and to determine the impact of certain preventative measures on the rate of infection. METHODS: After institutional review board approval, a multisite, retrospective review was conducted on 2737 unique implants or revisions of SCS systems. Patient demographics, risk factors including diabetes, tobacco use, obesity, revision surgery, trial length, implant location, implant type, surgeon background, prophylactic antibiotic use, utilization of a occlusive dressing, and post-operative antibiotic use were recorded and analyzed. RESULTS: The overall infection rate was 2.45% (n = 67). Diabetes, tobacco use, and obesity did not independently increase the rate of infection. Revision surgeries had a trend toward higher infection rate; however, this did not meet statistical significance. There was no difference in the rate of infection between implants performed by physicians of different base specialties, cylinder leads vs. paddle leads, or between different prophylactic antibiotics. Implants performed at academic centers had a higher rate of infection when compared to implants performed in nonacademic settings. When patients received an occlusive dressing or post-operative antibiotics they had a lower rate of infection. CONCLUSIONS: The infection rate (2.45%) reported in this study is lower than the previously reported rates (3-6%) and are on par with other surgical specialties. This study did not show an increased rate of infection for patients that used tobacco, had diabetes or were obese. It's possible that given the low overall infection rate a larger study is needed to establish the true impact of these factors on infection. In addition, this study did not address the impact of poorly controlled diabetes mellitus (elevated hemoglobin A1c) vs. well-controlled diabetes. It can be concluded from this study that utilizing an occlusive dressing over the incision in the post-operative period decreases the rate of infection and should become the standard of care. This study also demonstrated the positive impact of post-operative antibiotics in decreasing the rate of infection. Studies in other surgical specialties have not shown this impact which would suggest that further research is needed.

Spinal Cord Stimulator Related Infections: Findings From a Multicenter Retrospective Analysis of 2737 Implants.

INTRODUCTION: Surgical site infection is a potential complication of spinal cord stimulator (SCS) implantation. Current understanding of the epidemiology, diagnosis, and treatment of these infections is based largely on small clinical studies, many of which are outdated. Evidence-based guidelines for management of SCS-related infections thus rely instead on expert opinion, case reports, and case series. In this study, we aim to provide a large scale retrospective study of infection management techniques specifically for SCS implantation. METHODS: A multicenter retrospective study of SCS implants performed over a seven-year period at 11 unique academic and non-academic institutions in the United States. All infections and related complications in this cohort were analyzed. RESULTS: Within our study of 2737 SCS implant procedures, we identified all procedures complicated by infection (2.45%). Localized incisional pain and wound erythema were the most common presenting signs. Laboratory studies were performed in the majority of patients, but an imaging study was performed in less than half of these patients. The most common causative organism was Staphylococcus aureus and the IPG pocket was the most common site of an SCS-related infection. Explantation was ultimately performed in 52 of the 67 patients (77.6%). Non-explantation salvage therapy was attempted in 24 patients and was successful in resolving the infection in 15 patients without removal of SCS hardware components. DISCUSSION: This study provides current data regarding SCS related infections, including incidence, diagnosis, and treatment.

A Comprehensive Outcome-Specific Review of the Use of Spinal Cord Stimulation for Complex Regional Pain Syndrome.

BACKGROUND: Complex regional pain syndrome (CRPS) is a painful, debilitating affliction that is often difficult to treat. It has become common international practice to use spinal cord stimulation (SCS) for the treatment of CRPS as other therapies fail to provide adequate relief, quality of life, or improvement in function. This comprehensive outcome-specific systematic review of the use of SCS for CRPS was performed to elucidate the available evidence with focus on clinically relevant patient-specific outcomes. METHODS: A systematic review of the literature was conducted to evaluate the effects of SCS on patients with CRPS for the following outcomes and provide summary levels of evidence in regard to each outcome: perceived pain relief, pain score, resolution of CRPS signs, functional status, quality of life, psychological impact, sleep hygiene, analgesic medication utilization, and patient satisfaction with SCS therapy. Search terms included "complex regional pain syndrome," "spinal cord stimulation," and "reflex sympathetic dystrophy," without restriction of language, date, or type of publication, albeit only original data were included in analyses. Of 30 studies selected, seven systematic reviews were excluded, as were four studies reporting combination therapy that included SCS and other therapies (ie, concurrent peripheral nerve stimulation, intrathecal therapy) without clear delineation to the effect of SCS alone on outcomes. A total of 19 manuscripts were evaluated. RESULTS: Perceived pain relief, pain score improvement, quality of life, and satisfaction with SCS were all rated 1B+, reflecting positive high-level (randomized controlled trial) evidence favoring SCS use for the treatment of CRPS. Evidence for functional status improvements and psychological effects of SCS was inconclusive, albeit emanating from a randomized controlled trial (evidence level 2B±), and outcomes evidence for both sleep hygiene and resolution of CRPS signs was either nonexistent or of too low quality from which to draw conclusions (evidence level 0). An analgesic sparing effect was observed in nonrandomized reports, reflecting an evidence level of 2C+. CONCLUSIONS: Spinal cord stimulation remains a favorable and effective modality for treating CRPS with high-level evidence (1B+) supporting its role in improving CRPS patients' perceived pain relief, pain score, and quality of life. A paucity of evidence for functional improvements, resolution of CRPS signs, sleep hygiene, psychological impact, and analgesic sparing effects mandate further investigation before conclusions can be drawn for these specific outcomes.

Optimal Temperature for Radiofrequency Ablation of Lumbar Medial Branches for Treatment of Facet-Mediated Back Pain.

BACKGROUND: Radiofrequency ablation (RFA) of the medial branch nerves that innervate the facet joints is a well-established treatment modality; however, studies to determine the optimal radiofrequency ablation temperature are lacking. A wide range (70 to 90°C) has been used. This study aimed to compare outcomes with two set temperatures for the lumbar facet medial branch ablation, 90 and 80°C. METHODS: This retrospective study compared the degree of patient self-reported functional improvement relief, postoperative opioid dose changes, as well as duration among lumbar facet medial branch (RFA) patients who had the procedures performed at 80 or 90°C. RESULTS: Patients who underwent the procedure at 90°C had 3.1 (95% CI 1.7, 6.5) times the odds (P = 0.0004) of reporting functional improvement of at least 50% when compared to those who underwent neurotomy at 80°C. For self-reported functional improvement greater or equal to 75%, the results were sustained with an odds ratio of 2.8 (95% CI 1.2, 5.7) favoring those with 90°C temperature neurotomy (P = 0.002). CONCLUSION: There seems to be significant functional improvement associated with temp of 90°C compared to 80°C, with no added risk of complications. Randomized controlled studies are warranted.

Lumbar spinal stenosis: therapeutic options review.

Lumbar spinal stenosis (LSS) functionally impacts significant numbers of Americans per year. Current estimates place the number of Americans suffering from senescent lumbar spinal stenosis at 400,000. The prevalence of this disorder in patients ranging from 60 to 69 years of age is very high. Forty-seven percent of this age group have mild to moderate stenosis, and 19.7% have severe stenosis. As the baby boomer generation gets older, 10,000 individuals attain the age of 65 years every day in United States. LSS is becoming very common and will be a major healthcare issue as the population ages. Although LSS is not life threatening, it can cause substantial disability with limitations to performing daily activities, and thus, the associated negative impact on quality of life (QOL). This article reviews the pathophysiology and current treatment options for LSS, focusing on evidence-based treatment options.

The 2-year cost-effectiveness of 3 options to treat lumbar spinal stenosis patients.

Lumbar spinal stenosis (LSS) may result from degenerative changes of the spine, which lead to neural ischemia, neurogenic claudication, and a significant decrease in quality of life. Treatments for LSS range from conservative management including epidural steroid injections (ESI) to laminectomy surgery. Treatments vary greatly in cost and success. ESI is the least costly treatment may be successful for early stages of LSS but often must be repeated frequently. Laminectomy surgery is more costly and has higher complication rates. Minimally invasive lumbar decompression (mild(®) ) is an alternative. Using a decision-analytic model from the Medicare perspective, a cost-effectiveness analysis was performed comparing mild(®) to ESI or laminectomy surgery. The analysis population included patients with LSS who have moderate to severe symptoms and have failed conservative therapy. Costs included initial procedure, complications, and repeat/revision or alternate procedure after failure. Effects measured as change in quality-adjusted life years (QALY) from preprocedure to 2 years postprocedure. Incremental cost-effectiveness ratios were determined, and sensitivity analysis conducted. The mild(®) strategy appears to be the most cost-effective ($43,760/QALY), with ESI the next best alternative at an additional $37,758/QALY. Laminectomy surgery was the least cost-effective ($125,985/QALY).

Kyphoplasty increases vertebral height, decreases both pain score and opiate requirements while improving functional status.

Vertebral compression fractures can result from advanced osteoporosis, or less commonly from metastatic or traumatic insults to the vertebral column, and result in disabling pain and decreased functional capacity. Various vertebral augmentation options including kyphoplasty aim at preventing the sequelae of pain and immobility that can develop as the result of the vertebral fractures. The mechanism for pain relief following kyphoplasty is not entirely understood, and the restoration of a portion of the lost vertebral height is a subject of debate. We retrospectively reviewed radiographic imaging, pain relief, analgesic intake and functional outcomes in 67 consecutive patients who underwent single- or multilevel kyphoplasty with the primary goal of quantifying the restoration of lost vertebral height. We observed a mean of 45% of the lost vertebral height restored postprocedurally. Secondarily, kyphoplasty was associated with significant decreases in pain scores, daily morphine consumption and improvement in patient-reported functional measures.

Factors that might impact intrathecal drug delivery (IDD) dose escalation: a longitudinal study.

BACKGROUND: Intrathecal drug delivery (IDD) system with implantable pumps has been used to treat cancer-related pain as well as noncancer-related chronic pain. Opioids, including morphine and hydromorphone, are the most commonly used intrathecal (IT) agents. Although technology, techniques, and knowledge of IDD have improved, dose escalation occurs relatively rapidly in noncancer pain. METHODS: Retrospective chart review of IDD pump patients, implanted for a minimum of 2 years, was designed to investigate possible existing predictors that might impact IDD dose escalation, such as patient's demographic risk factors, duration of the treatment, and diagnosis of the patient's pain correlates with increase in medication requirement. Primary outcome was defined as the annual percent escalation in daily opioid dosage, and secondary outcome was the average annual percent reduction in VRS pain scores. RESULTS: Median dosage escalation was 17% per year for patients with neuropathic pain compared with 12% per year for patients with other pain modalities. Mean opioid dosage increased 30.4% more rapidly for patients with neuropathic pain than for other pain modalities. The adjusted difference in means was 28.8% (P = 0.001). None of the secondary exposures were statistically significant after the Bonferroni adjustment. No association was found between pain modality and annual percent change in VRS pain score. CONCLUSION: Annual increases in daily opioid dosage were higher among patients with neuropathic pain than among patients with other modalities; we also found no evidence of difference in annual pain reduction.

Impact of temperature on the magnitude and duration of relief after lumbar facets medial branch nerves radiofrequency ablation: a randomized double-blinded study.

INTRODUCTION: There are numerous studies appraising the variables that may influence the clinical outcomes after lumbar thermal radiofrequency ablation (RFA). Expanding the lesion size may increase the likelihood of capturing the target nerves in the lesion, thereby increasing the technical success rate of RFA. However, our literature search has failed to identify a consensus on the optimal target temperature. A retrospective study demonstrated that there seems to be significant functional improvement associated with the temperature of 90°C compared with 80°C. The authors prospectively studied the subject in a double-blinded randomized fashion. METHODS: Patients undergoing RFA for lumbar facetogenic pain were randomized in two cohorts (80°C and 90°C). Physicians and patients were blinded to the temperature used. The primary outcome was self-reported pain scores up to 12 months. Secondary outcomes included: self-reported functional improvement, duration of relief as measured by the time before repeat ablation of the same medial branches nerves, opioids' consumption, and patient satisfaction. RESULTS: Both groups reported pain improvement in all follow-up time points. Overall, both groups achieved statistically significant pain reduction (p<0.05). The median time to repeat RFA in the 80°C group was 112 (49-252) days, while it was 217 (198-348) days in the 90°C group (p<0.04). The univariate analysis emphasized that the RFA temperature is a statistically significant factor for pain improvement of more than 50%, OR 2.7 (1.1 to 6.6) p value=0.031. CONCLUSION: RFA has been demonstrated as an effective therapeutic modality for lumbar facetogenic back pain. Yet, the several factors involved in determining a favorable outcome of this procedure require further research and optimization. This prospective double-blinded randomized trial demonstrated that RFA at both temperatures (80°C, 90°C) provided significance at all the time periods examined. However, RFA at 90°C was superior to 80°C in regard to the duration of relief.

Durable multimodal and holistic response for physiologic closed-loop spinal cord stimulation supported by objective evidence from the EVOKE double-blind randomized controlled trial.

INTRODUCTION: Chronic pain patients may experience impairments in multiple health-related domains. The design and interpretation of clinical trials of chronic pain interventions, however, remains primarily focused on treatment effects on pain intensity. This study investigates a novel, multidimensional holistic treatment response to evoked compound action potential-controlled closed-loop versus open-loop spinal cord stimulation as well as the degree of neural activation that produced that treatment response. METHODS: Outcome data for pain intensity, physical function, health-related quality of life, sleep quality and emotional function were derived from individual patient level data from the EVOKE multicenter, participant, investigator, and outcome assessor-blinded, parallel-arm randomized controlled trial with 24 month follow-up. Evaluation of holistic treatment response considered whether the baseline score was worse than normative values and whether minimal clinical important differences were reached in each of the domains that were impaired at baseline. A cumulative responder score was calculated to reflect the total minimal clinical important differences accumulated across all domains. Objective neurophysiological data, including spinal cord activation were measured. RESULTS: Patients were randomized to closed-loop (n=67) or open-loop (n=67). A greater proportion of patients with closed-loop spinal cord stimulation (49.3% vs 26.9%) were holistic responders at 24-month follow-up, with at least one minimal clinical important difference in all impaired domains (absolute risk difference: 22.4%, 95% CI 6.4% to 38.4%, p=0.012). The cumulative responder score was significantly greater for closed-loop patients at all time points and resulted in the achievement of more than three additional minimal clinical important differences at 24-month follow-up (mean difference 3.4, 95% CI 1.3 to 5.5, p=0.002). Neural activation was three times more accurate in closed-loop spinal cord stimulation (p<0.001 at all time points). CONCLUSION: The results of this study suggest that closed-loop spinal cord stimulation can provide sustained clinically meaningful improvements in multiple domains and provide holistic improvement in the long-term for patients with chronic refractory pain. TRIAL REGISTRATION NUMBER: NCT02924129.