Pharmacological Treatment in the Management of Glenohumeral Osteoarthritis.

Glenohumeral osteoarthritis (GH-OA) is a common cause of shoulder pain and is characterized by articular cartilage thinning, glenoid bone loss and deformity, osteophytosis, and other associated changes. The prevalence is estimated to be between 85 and 94% in men and women over the age of 80 years. A diagnosis of GH-OA is established based on clinical history, physical examination, and radiographic assessments. Non-pharmacological treatment options may serve as adjuvants to other therapies and should be incorporated for a more holistic approach to management. Pharmacological treatments include oral agents such as acetaminophen, non-steroidal anti-inflammatory drugs (NSAIDs), opioids, corticosteroids and antidepressants. The National Institute for Health and Care Excellence (NICE) UK guidelines recommend NSAIDS as the first-line drugs for OA; topical forms of some of these agents can also be used. However, clinical evidence is largely lacking for its use in GH-OA, although patients with other types of OA, especially the knee and hip, are using these products in efforts to relieve joint pain. Intra-articular injections such as platelet-rich plasma, cortisone, and hyaluronic acid are usually used to control symptoms in moderate to advanced arthritis or in non-surgical candidates. Other non-surgical treatment options include suprascapular nerve block and radiofrequency ablation, and these options have been studied on different levels of evidence. Furthermore, all these treatments have their own indications, contraindications, and adverse effects profiles. Surgical treatment of GH-OA is reserved for patients who do not respond to conservative management or who suffer from debilitating symptoms that severely impair their quality of life.Level of Evidence IV, review article.

Randomized control trial of ultrasound-guided erector spinae block versus shoulder periarticular anesthetic infiltration for pain control after arthroscopic shoulder surgery: Study protocol clinical trial (SPIRIT compliant).

INTRODUCTION: Moderate to severe postoperative pain and associated opioid use may interfere with patients' well-being and course of recovery. Regional anesthetic techniques provide an opportunity for opioid sparing and improved patient outcomes. A new regional technique called the erector spinae plane (ESP) block has the potential to provide effective analgesia after shoulder arthroscopy with minimal risks and decreased opioid consumption. Our primary objective is to determine whether, in patients who undergo arthroscopic shoulder surgery, a preoperative ESP block reduces pain scores as compared to periarticular infiltration at the end of surgery. Additionally, we will also examine other factors such as opioid consumption, sensory block, adverse events, patient satisfaction, and persistent pain. METHODS: This is a 2-arm, single-center, parallel-design, double-blind randomized controlled trial of 60 patients undergoing arthroscopic shoulder surgery. Eligible patients will be recruited in the preoperative clinic. Using a computer-generated randomization, with a 1:1 allocation ratio, patients will be randomized to either the ESP or periarticular infiltration group. Patients will be followed in hospital in the postanesthesia care unit, at 24 hours, and at 1 month. The study with be analyzed as intention-to-treat. DISCUSSION: This study will inform an evidence-based choice in recommending ESP block for shoulder arthroscopy, as well as providing safety data. The merits of the study include its double dummy blinding to minimize observer bias, and its assessment of patient important outcomes, including pain scores, opioid consumption, and patient satisfaction. This study will also help provide an estimate of the incidence of side effects and complications of the ESP block. TRIAL REGISTRATION NUMBER: NCT03691922; Recruited Date of registration: October 2, 2018.

A case report of a thalamic stroke associated with sudden disappearance of severe chronic low back pain.

BACKGROUND: Chronic pain conditions are associated with neuroplasticity within the central nervous system. In most patients the maladaptive consequence of neuroplasticity supports prolonged course of chronic pain, despite the absence of a commensurate etiology. From a pain neuromatrix perspective it can involve three different circuits within the central nervous system; the classical sensory pathway, the limbic system pathway, and the associative pathways involving the parietal cortical connections. Although this can be conceptualized as a fluid system composed of several interacting networks, it can be broadly separated into a nociceptive specific network of spino-thalamic neurons and second order neurons beyond thalamus that are not nociceptor specific. Thalamus acts as an important relay station that conveys nociceptive signaling to higher centres. Neuroplastic changes can potentially involve any parts within this neuromatrix. It is very uncommon to observe the sudden disappearance of such a chronic pain condition. METHODS AND RESULTS: In this case report, the author describes the clinical course of a patient with severe chronic low back pain (CLBP), whose pain suddenly disappeared after a stroke involving his left thalamus. Although extremely rare, existing case reports of such disappearance of pain with a secondary stroke in patients suffering from central post stroke pain (CPSP) are reviewed. The author further postulates hypotheses that could potentially explain this phenomenon based on the existing knowledge. CONCLUSIONS AND IMPLICATIONS: Although extremely rare and unpredictable, a thalamic stroke involving areas that are involved in chronic pain signaling can potentially lead to disappearence of an existing chronic pain condition. This is the first case report of such sudden disappearence of CLBP with well established nociceptive pathology supported by clinical and imaging findings. This unique case report could potentially generate ideas for future research and clinical treatment in the field of neuromodulation and brain stimulation.

Benefits and safety of gabapentinoids in chronic low back pain: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND AND OBJECTIVE: Chronic Low Back Pain (CLBP) is very common, with a lifetime prevalence between 51% and 80%. In majority, it is nonspecific in nature and multifactorial in etiology. Pregabalin (PG) and Gabapentin (GB) are gabapentinoids that have demonstrated benefit in neuropathic pain conditions. Despite no clear rationale, they are increasingly used for nonspecific CLBP. They necessitate prolonged use and are associated with adverse effects and increased cost. Recent guidelines from the National Health Service (NHS), England, expressed concerns on their off-label use, in addition to the risk of misuse. We aimed to assess the effectiveness and safety of gabapentinoids in adult CLBP patients. METHODS: Electronic databases of MEDLINE, EMBASE, and Cochrane were searched from their inception until December 20th, 2016. We included randomized control trials reporting the use of gabapentinoids for the treatment of CLBP of >3 months duration, in adult patients. Study selection and data extraction was performed independently by paired reviewers. Outcomes were guided by Initiative on Methods, Measurement and Pain Assessment in Clinical Trials guidelines, with pain relief and safety as the primary outcomes. Meta-analyses were performed for outcomes reported in 3 or more studies. Outcomes were reported as mean differences (MDs) or risk ratios (RRs) with their corresponding 95% confidence intervals (CIs), and I2 in percentage representing the percentage variability in effect estimates that could be explained by heterogeneity. GRADE (Grading of Recommendations Assessment, Development, and Evaluation) was used to assess the quality of evidence. RESULTS: Out of 1,385 citations, eight studies were included. Based on the interventions and comparators, studies were analyzed in 3 different groups. GB compared with placebo (3 studies, n = 185) showed minimal improvement of pain (MD = 0.22 units, 95% CI [-0.5 to 0.07] I2 = 0%; GRADE: very low). Three studies compared PG with other types of analgesic medication (n = 332) and showed greater improvement in the other analgesic group (MD = 0.42 units, 95% CI [0.20 to 0.64] I2 = 0; GRADE: very low). Studies using PG as an adjuvant (n = 423) were not pooled due to heterogeneity, but the largest of them showed no benefit of adding PG to tapentadol. There were no deaths or hospitalizations reported. Compared with placebo, the following adverse events were more commonly reported with GB: dizziness-(RR = 1.99, 95% CI [1.17 to 3.37], I2 = 49); fatigue (RR = 1.85, 95% CI [1.12 to 3.05], I2 = 0); difficulties with mentation (RR = 3.34, 95% CI [1.54 to 7.25], I2 = 0); and visual disturbances (RR = 5.72, 95% CI [1.94 to 16.91], I2 = 0). The number needed to harm with 95% CI for dizziness, fatigue, difficulties with mentation, and visual disturbances were 7 (4 to 30), 8 (4 to 44), 6 (4 to 15), and 6 (4 to 13) respectively. The GRADE evidence quality was noted to be very low for dizziness and fatigue, low for difficulties with mentation, and moderate for visual disturbances. Functional and emotional improvements were reported by few studies and showed no significant improvements. CONCLUSIONS AND RELEVANCE: Existing evidence on the use of gabapentinoids in CLBP is limited and demonstrates significant risk of adverse effects without any demonstrated benefit. Given the lack of efficacy, risks, and costs associated, the use of gabapentinoids for CLBP merits caution. There is need for large high-quality trials to more definitively inform this issue. TRIAL REGISTRATION: PROSPERO CRD42016034040.