Compounded Topical Pain Creams to Treat Localized Chronic Pain: A Randomized Controlled Trial.

Background: The use of compounded topical pain creams has increased dramatically, yet their effectiveness has not been well evaluated. Objective: To determine the efficacy of compounded creams for chronic pain. Design: Randomized controlled trials of 3 interventions. (ClinicalTrials.gov: NCT02497066). Setting: Military treatment facility. Participants: 399 patients with localized pain classified by each patient's treating physician as neuropathic (n = 133), nociceptive (n = 133), or mixed (n = 133). Intervention: Pain creams compounded for neuropathic pain (ketamine, gabapentin, clonidine, and lidocaine), nociceptive pain (ketoprofen, baclofen, cyclobenzaprine, and lidocaine), or mixed pain (ketamine, gabapentin, diclofenac, baclofen, cyclobenzaprine, and lidocaine), or placebo. Measurements: The primary outcome measure was average pain score 1 month after treatment. A positive categorical response was a reduction in pain score of 2 or more points coupled with a score above 3 on a 5-point satisfaction scale. Secondary outcomes included Short Form-36 Health Survey scores, satisfaction, and categorical response. Participants with a positive outcome were followed through 3 months. Results: For the primary outcome, no differences were found in the mean reduction in average pain scores between the treatment and control groups for patients with neuropathic pain (-0.1 points [95% CI, -0.8 to 0.5 points]), nociceptive pain (-0.3 points [CI, -0.9 to 0.2 points]), or mixed pain (-0.3 points [CI, -0.9 to 0.2 points]), or for all patients (-0.3 points [CI, -0.6 to 0.1 points]). At 1 month, 72 participants (36%) in the treatment groups and 54 (28%) in the control group had a positive outcome (risk difference, 8% [CI, -1% to 17%]). Limitations: Generalizability is limited by heterogeneity among pain conditions and formulations of the study interventions. Randomized follow-up was only 1 month. Conclusion: Compounded pain creams were not better than placebo creams, and their higher costs compared with approved compounds should curtail routine use. Primary Funding Source: Centers for Rehabilitation Sciences Research, Defense Health Agency, U.S. Department of Defense.

Radiofrequency techniques to treat chronic knee pain: a comprehensive review of anatomy, effectiveness, treatment parameters, and patient selection.

BACKGROUND: The use of radiofrequency ablation (RFA) procedures to treat chronic knee pain has surged in the past decade, though many questions remain regarding anatomical targets, selection criteria, and evidence for effectiveness. METHODS: A comprehensive literature review was performed on anatomy, selection criteria, technical parameters, results of clinical studies, and complications. Databases searched included MEDLINE and Google Scholar, with all types of clinical and preclinical studies considered. RESULTS: We identified nine relevant clinical trials, which included 592 patients, evaluating knee RFA for osteoarthritis and persistent postsurgical pain. These included one randomized, placebo-controlled trial, one randomized controlled trial evaluating RFA as add-on therapy, four comparative-effectiveness studies, two randomized trials comparing different techniques and treatment paradigms, and one non-randomized, controlled trial. The results of these studies demonstrate significant benefit for both reduction and functional improvement lasting between 3 and 12 months, with questionable utility for prognostic blocks. There was considerable variation in the described neuroanatomy, neural targets, radiofrequency technique, and selection criteria. CONCLUSION: RFA of the knee appears to be a viable and effective treatment option, providing significant benefit to well-selected patients lasting at least 3 months. More research is needed to better identify neural targets, refine selection criteria to include the use of prognostic blocks, optimize treatment parameters, and better elucidate relative effectiveness compared to other treatments.

Effectiveness of Lumbar Facet Joint Blocks and Predictive Value before Radiofrequency Denervation: The Facet Treatment Study (FACTS), a Randomized, Controlled Clinical Trial.

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: WHAT THIS ARTICLE TELLS US THAT IS NEW: BACKGROUND:: With facet interventions under scrutiny, the authors' objectives were to determine the effectiveness of different lumbar facet blocks and their ability to predict radiofrequency ablation outcomes. METHODS: A total of 229 participants were randomized in a 2:2:1 ratio to receive intraarticular facet injections with bupivacaine and steroid, medial branch blocks, or saline. Those with a positive 1-month outcome (a 2-point or more reduction in average pain score) and score higher than 3 (positive satisfaction) on a 5-point satisfaction scale were followed up to 6 months. Participants in the intraarticular and medial branch block groups with a positive diagnostic block (50% or more relief) who experienced a negative outcome proceeded to the second phase and underwent radiofrequency ablation, while all saline group individuals underwent ablation. Coprimary outcome measures were average reduction in numerical rating scale pain score 1 month after the facet or saline blocks, and average numerical rating scale pain score 3 months after ablation. RESULTS: Mean reduction in average numerical rating scale pain score at 1 month was 0.7 ± 1.6 in the intraarticular group, 0.7 ± 1.8 in the medial branch block group, and 0.7 ± 1.5 in the placebo group; P = 0.993. The proportions of positive blocks were higher in the intraarticular (54%) and medial branch (55%) groups than in the placebo group (30%; P = 0.01). Radiofrequency ablation was performed on 135 patients (45, 48, and 42 patients from the intraarticular, medial branch, and saline groups, respectively). The average numerical rating scale pain score at 3 months was 3.0 ± 2.0 in the intraarticular, 3.2 ± 2.5 in the medial branch, and 3.5 ± 1.9 in the control group (P = 0.493). At 3 months, the proportions of positive responders in the intraarticular, medial branch block, and placebo groups were 51%, 56%, and 24% for the intraarticular, medial branch, and placebo groups, respectively (P = 0.005). CONCLUSIONS: This study establishes that facet blocks are not therapeutic. The higher responder rates in the treatment groups suggest a hypothesis that facet blocks might provide prognostic value before radiofrequency ablation.

Predictive factors associated with success and failure for Calmare (Scrambler) therapy: a multicenter analysis.

OBJECTIVE: Calmare (Scrambler) therapy is a novel therapeutic modality that purports to provide pain relief by "scrambling" afferent pain signals and replacing them with "non-pain" information through conventional lines of neural transmission. The goal of this study is to identify which factors are associated with treatment outcome for Calmare therapy. METHODS: Data were garnered from 3 medical centers on 147 patients with various pain conditions who underwent a minimum of either 3 Calmare therapies on consecutive days or 5 therapies overall. A successful outcome was predefined as ≥50% pain relief on a 0 to 10 numerical rating scale that persisted for longer than 1 month after the last treatment. Variables evaluated for their association with outcome included age, sex, study site, baseline pain score, etiology, type of pain, diagnosis, treatment compliance, coexisting psychopathology, opioid use, antidepressant use, and membrane stabilizer use. RESULTS: Overall, the success rate was 38.1%. Variables found to be associated with a positive outcome in multivariate logistic regression included the presence of neuropathic (OR=24.78; 95% CI, 2.47-248.97; P=0.006) or mixed (OR=10.52; 95% CI, 1.09-101.28; P=0.042) pain, and treatment at either Walter Reed (OR=6.87; 95% CI, 1.60-29.51; P=0.010) or Seoul National University (OR=12.29; 95% CI, 1.73-87.43; P=0.012). Factors that correlated with treatment failure were disease (OR=0.04; 95% CI, 0.002-0.59; P=0.020) or traumatic/surgical etiologies (OR=0.05; 95% CI, 0.005-0.56; P=0.015) and antidepressant use (OR=0.47; 95% CI, 0.18-1.02; P=0.056). CONCLUSIONS: A neuropathic or mixed neuropathic-nociceptive pain condition was associated with a positive treatment outcome. Investigators should consider these findings when developing selection criteria in clinical trials designed to determine the efficacy of Calmare therapy.

The effect of sedation on the accuracy and treatment outcomes for diagnostic injections: a randomized, controlled, crossover study.

BACKGROUND AND OBJECTIVE: Diagnostic injections are used to diagnose myriad pain conditions, but are characterized by a high false-positive rate. One potential cause of inaccurate diagnostic blocks is the use of sedation. We sought to determine the effect of sedation on the validity of diagnostic injections. DESIGN: Randomized, crossover study in which 73 patients were allocated to receive a diagnostic sacroiliac joint or sympathetic nerve block performed either with or without sedation using midazolam and fentanyl. Those who obtained equivocal relief, good relief lasting less than 3 months, or who were otherwise deemed good candidates for a repeat injection, received a subsequent crossover injection within 3 months (N = 46). SETTING AND PATIENTS: A tertiary care teaching hospital and a military treatment facility. RESULTS: In the primary crossover analysis, blocks performed with sedation resulted in a larger mean reduction in pain diary score than those done without sedation (1.2 [2.6]; P = 0.006), less procedure-related pain (difference in means 2.3 [2.5]; P < 0.0001), and a higher proportion of patients who obtained > 50% pain relief on their pain diaries (70% vs. 54%; P = 0.039). The increased pain reduction was not accompanied by increased satisfaction (sedation mean 3.9 [1.1] vs. 3.7 [1.3]; P = 0.26). Similar findings were observed for the parallel group (N = 73) and omnibus (all sedation vs. no sedation blocks, N = 110) analyses. No differences in outcomes were noted between the use and non-use of sedation at 1-month. CONCLUSIONS: The use of sedation during diagnostic injections may increase the rate of false-positive blocks and lead to misdiagnoses and unnecessary procedures, but has no effect on satisfaction or outcomes at 1-month.

Epidural lysis of adhesions.

As our population ages and the rate of spine surgery continues to rise, the use epidural lysis of adhesions (LOA) has emerged as a popular treatment to treat spinal stenosis and failed back surgery syndrome. There is moderate evidence that percutaneous LOA is more effective than conventional ESI for both failed back surgery syndrome, spinal stenosis, and lumbar radiculopathy. For cervical HNP, cervical stenosis and mechanical pain not associated with nerve root involvement, the evidence is anecdotal. The benefits of LOA stem from a combination of factors to include the high volumes administered and the use of hypertonic saline. Hyaluronidase has been shown in most, but not all studies to improve treatment outcomes. Although infrequent, complications are more likely to occur after epidural LOA than after conventional epidural steroid injections.