Accepted

Degenerative disc disease is a common cause of chronic low back pain. Surgical intervention is an invasive treatment associated with high costs. There is growing interest in regenerative medicine as a less invasive but direct disc treatment for chronic discogenic low back pain.

The psychological flexibility model can be seen as a basis for an integrated and progressive psychological approach to chronic pain management. Some researchers suggest that psychological flexibility and inflexibility represent distinct processes and constructs. This meta-analysis is the first to provide a summary estimate of the overall effect size for the relationship between psychological (in)flexibility and common outcomes among chronic pain patients. The research protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO, https://www.crd.york.ac.uk/PROSPERO/), registration number CRD42021285705. Four databases were searched (PsycINFO; PubMed; Web of Science, CINAHL) along with reference lists. Thirty-six cross-sectional studies were included (7,779 participants). Meta-analyses (random effects model) indicated a significant medium negative association between psychological flexibility and pain intensity or functional impairment. The present study also indicated a significant small to medium association between psychological inflexibility and pain intensity, a nearly large association between psychological inflexibility and functional impairment as well as the quality of life, and a large association between psychological inflexibility and anxiety/depression. Due to the limited number of included studies, the relationship between risk behavior and psychological inflexibility may not be significant. Types of countries and instruments measuring psychological inflexibility may explain part of the heterogeneity. These findings may carry significant implications for chronic pain patients regarding the potential relationship between psychological inflexibility or flexibility and these outcomes. It may consequently form the basis for more robust testing of causal and manipulable relationships.

The term 'opioids' refers to both the natural compounds ('opiates') which are extracted from the opium poppy plant () and their semi-synthetic and synthetic derivatives. They all possess relatively similar biochemical profiles and interact with the opioid receptors within the human body to produce a wide range of physiological effects. They have historically been used for medicinal purposes, their analgesic and sedative effects, and in the management of chronic and severe pain. They have also been used for non-medicinal and recreational purposes to produce feelings of relaxation, euphoria and well-being. Over the last decade, the emergence of an illegal market in new synthetic opioids has become a major global public health issue, associated with a substantial increase in unintentional overdoses and drug-related deaths. Synthetic opioids include fentanyl, its analogues and emerging non-fentanyl opioids. Their popularity relates to changes in criminal markets, pricing, potency, availability compared to classic opioids, ease of transport and use, rapid effect and lack of detection by conventional testing technologies. This article expands on our previous review on new psychoactive substances. We now provide a more in-depth review on synthetic opioids and explore the current challenges faced by people who use drugs, healthcare professionals, and global public health systems.

Opioids have been commonly used to treat chronic pain, but they are associated with significant morbidity and mortality. Cannabis has been advocated as an alternative; however, a growing number of patients are now using a combination of opioid and cannabis and the impact of this combination is not well-studied.

With the wide acceptance of acupuncture, many papers and guidelines recommend that acupuncture is effective for chronic pain (CP). In this study, we applied bibliometric methods to analyze the current research situation of acupuncture intervention in CP, to gain insight into the current situation and future development trend of this field.

Osteoarthritis is a very disabling disease that can be treated with both non-pharmacological and pharmacological approaches. In the last years, pharmaceutical-grade chondroitin sulfate (CS) and glucosamine emerged as symptomatic slow-acting molecules, effective in pain reduction and improved function in patients affected by osteoarthritis. CS is a sulfated glycosaminoglycan that is currently produced mainly by extraction from animal tissues, and it is commercialized as a pharmaceutical-grade ingredient and/or food supplement. However, public concern on animal product derivatives has prompted the search for alternative non-extractive production routes. Thus, different approaches were established to obtain animal-free natural identical CS. On the other hand, the unsulfated chondroitin, which can be obtained biotechnological processes, demonstrated promising anti-inflammatory properties , in chondrocytes isolated from osteoarthritic patients. Therefore, the aim of this study was to explore the potential of chondroitin, with respect to the better-known CS, in an mouse model of knee osteoarthritis. Results indicate that the treatment with biotechnological chondroitin (BC), similarly to CS, significantly reduced the severity of mechanical allodynia in an MIA-induced osteoarthritic mouse model. Decreased cartilage damage and a reduction of inflammation- and pain-related biochemical markers were also observed. Overall, our data support a beneficial activity of biotechnological unsulfated chondroitin in the osteoarthritis model tested, thus suggesting BC as a potential functional ingredient in pharmaceuticals and nutraceuticals with the advantage of avoiding animal tissue extraction.

Spinal cord stimulation (SCS) is an important option for patients with chronic neuropathic pain. In the United States, a successful SCS trial determines eligibility for SCS implant. Metrics to determine success are often self-reported and subjective, which may limit achievement of patient goals. This study aimed to assess whether patients undergoing SCS implant after successful trial felt that use of external accelerometry prior to implant was a useful educational tool to objectively appraise function and achievement of treatment goals.

Recent neuroimaging studies have indicated a wide range of structural and regional functional alterations in patients with classic trigeminal neuralgia (CTN). However, few studies have focused on the intrinsic functional characteristics of network organization in the whole brain. Therefore, the present study aimed to characterize the potential intrinsic dysconnectivity pattern of the whole brain functional networks at the voxel level using the degree centrality (DC) analysis in CTN patients.