Future directions for the management of pain in osteoarthritis

Outcomes of imaging-guided corticosteroid injections in hip and knee osteoarthritis patients: a systematic review

PURPOSE

The purpose of this systematic review is to evaluate the current literature on the use of image-guided corticosteroid injections in the treatment of patients with knee and hip OA.

EVIDENCE ACQUISITION

We conducted a comprehensive literature search through June 30, 2022. Publication type, study design, imaging guidance modality, osteoarthritis severity, number of injections, steroid type and dose, anesthetic type and dose, the total number of patients, follow-up intervals, and measured outcomes were extracted from the included studies.

EVIDENCE SYNTHESIS

There were 23 included studies (10 hips, 12 knees, 1 both hip and knee). Hip injections were found to be effective in treating short- and long-term pain and more effective than hyaluronic acid, Mepivacaine, NSAIDs, and normal saline in terms of improvement in pain and/or function. There was less impact on QoL. Knee injections were found either to have little or no impact or were similar or inferior to comparison injections (intra-articular hyaluronic acid, PRP, NSAIDs, normal saline, adductor canal blocks). Study data could not be aggregated because the corticosteroid types and doses, methods of outcome assessment, and follow-up time points varied widely.

CONCLUSION

Our systematic review found generally positive outcomes for the hip, but overall negative outcomes for the knee, although hip injections may carry a risk of serious adverse outcomes. A larger trial with uniform methodology is warranted. Specific studies on the adverse effects of corticosteroid injections are also warranted.

A glucuronated flavone TMMG spatially targets chondrocytes to alleviate cartilage degeneration through negative regulation of IL-1β

Chondrocytes are the only resident cell types that form the extracellular matrix of cartilage. Inflammation alters the anabolic and catabolic regulation of chondrocytes, resulting in the progression of osteoarthritis (OA). The potential of TMMG, a glucuronated flavone, was explored against the pathophysiology of OA in both in vitro and in vivo models. The effects of TMMG were evaluated on chondrocytes and the ATDC5 cell line treated with IL-1β in an established in vitro inflammatory OA model. An anterior cruciate ligament transection (ACLT) model was used to simulate post-traumatic injury in vivo. Micro-CT and histological examination were employed to examine the micro-architectural status and cartilage alteration. Further, serum biomarkers were measured using ELISA to assess OA progression. In-vitro, TMMG reduced excessive ROS generation and inhibited pro-inflammatory IL-1β secretion by mouse chondrocytes and macrophages, which contributes to OA progression. This expression pattern closely mirrored osteoclastogenesis prevention. In-vivo results show that TMMG prevented chondrocyte apoptosis and degradation of articular cartilage thickness, subchondral parameters, and elevated serum COMP, CTX-II, and IL-1β which were significantly restored in 5 and 10 mg.kg^-1day^-1 treated animals and comparable to the positive control Indomethacin. In addition, TMMG also improved cartilage integrity and decreased the OARSI score by maintaining chondrocyte numbers and delaying ECM degradation. These findings suggest that TMMG may be a prospective disease-modifying agent that can mitigate OA progression.

Tamarindus indica Seed Extract-Based Botanical Compositions Alleviate Knee Pain and Improve Joint Function in Mild-to-Moderate Osteoarthritis: A Randomized, Double-Blind, Placebo-Controlled Clinical Study

Objective

Knee pain and reduced joint function affect the quality of life of subjects suffering from knee osteoarthritis (KOA). The present randomized, double-blind, placebo-controlled study aimed to assess the clinical efficacy of two botanical compositions, NXT15906F6 and NXT19185, in pain relief and improvement in the musculoskeletal function of knee osteoarthritis (KOA) subjects. NXT15906F6 contains ethanol/aqueous extract of Tamarindus indica seeds and aqueous ethanol extract of Curcuma longa rhizome, and NXT19185 is a combination of NXT15906F6 and an aqueous ethanol extract of Garcinia mangostana fruit rind.

Methods

The present trial recruited ninety subjects with mild-to-moderate KOA, using a radiographic Kellgren–Lawrence (KL) grading system. The participants were randomized into one of three groups (n = 30) to receive either placebo, NXT15906F6 (250 mg/day), or NXT19185 (300 mg/day) for 56 days. The change in Western Ontario and McMaster Universities Arthritis Index (WOMAC) score was the primary efficacy measure of the study. Improvements in the functional scores, serum proinflammatory modulators, and cartilage degradation product in the urine samples were the secondary efficacy measures. Twenty-seven subjects in each group completed the trial.

Results

After the trial, NXT15906F6 and NXT19185 significantly improved (P < 0.05) the WOMAC scores from baseline compared with placebo. In the subgroup analyses, the knee pain and functional scores were significantly improved in the KL-II and KL-III grade KOA subjects. At the end of the study, the NXT15906F6- and NXT19185-supplemented participants showed significant (P < 0.05) improvement in the functional scores, inflammatory status, and collagen breakdown product in the urine samples. Summary. The present study demonstrates that NXT15906F6 and NXT19185 supplementations reduce knee pain and improve the musculoskeletal function of KOA subjects. Moreover, these herbal compositions helped reduce inflammation and inflammation-induced cartilage degeneration in the participants. NXT15906F6 and NXT19185 supplementations are further documented to be tolerable and safe to the participants.

Fatty Acids and Oxylipins in Osteoarthritis and Rheumatoid Arthritis-a Complex Field with Significant Potential for Future Treatments

Purpose of Review

Osteoarthritis (OA) and rheumatoid arthritis (RA) are characterized by abnormal lipid metabolism manifested as altered fatty acid (FA) profiles of synovial fluid and tissues and in the way dietary FA supplements can influence the symptoms of especially RA. In addition to classic eicosanoids, the potential roles of polyunsaturated FA (PUFA)-derived specialized pro-resolving lipid mediators (SPM) have become the focus of intensive research. Here, we summarize the current state of knowledge of the roles of FA and oxylipins in the degradation or protection of synovial joints.

Recent Findings

There exists discordance between the large body of literature from cell culture and animal experiments on the adverse and beneficial effects of individual FA and the lack of effective treatments for joint destruction in OA and RA patients. Saturated 16:0 and 18:0 induce mostly deleterious effects, while long-chain n-3 PUFA, especially 20:5n-3, have positive influence on joint health. The situation can be more complex for n-6 PUFA, such as 18:2n-6, 20:4n-6, and its derivative prostaglandin E₂, with a combination of potentially adverse and beneficial effects. SPM analogs have future potential as analgesics for arthritic pain.

Summary

Alterations in FA profiles and their potential implications in SPM production may affect joint lubrication, synovial inflammation, pannus formation, as well as cartilage and bone degradation and contribute to the pathogeneses of inflammatory joint diseases. Further research directions include high-quality randomized controlled trials on dietary FA supplements and investigations on the significance of lipid composition of microvesicle membrane and cargo in joint diseases.

The effectiveness of Kinesio Taping® for mobility and functioning improvement in knee osteoarthritis: a randomized, double-blind, controlled trial

OBJECTIVE

To evaluate the effectiveness of the Kinesio Taping^® method for mobility and functioning improvement for patients with knee osteoarthritis (KO).

DESIGN

Randomized, double-blinded, controlled trial.

SETTING

Outpatient rehabilitation department.

SUBJECTS

A total of 187 subjects with symptomatic I-III grade KO participated; of these, 157 subjects were included in the analyses (intervention group, n = 81 (123 knees); control group, n = 76 (114 knees).

INTERVENTION

The intervention group received a specific Kinesio Taping application, and the control group received non-specific knee taping for a month.

MAIN MEASURES

Changes in Knee injury and Osteoarthritis Outcome Scores (KOOS), knee active range of motion, 10-Meter Walk, and the five times sit to stand tests (5xSST) were assessed at baseline, after four weeks of taping, and a month post taping intervention. Subjective participants' experiences and opinions on the effect of knee taping were evaluated. The chosen level of significance was p < 0.05.

RESULTS

The mean age of participants was 68.7 ± 9.9 in intervention group and 70.6 ± 8.3 in control group (p > 0.05). The change from baseline in gait speed in the intervention group after taping month was +0.04 ± 0.1 m/s, at follow-up +0.06 ± 0.1 m/s; in control group +0.07 ± 0.1 m/s, and +0.09 ± 0.1 m/s; the change in time needed to accomplish 5xSST was -2.2 ± 3.2 seconds, at follow-up -2.4 ± 3.1 seconds; in control group -2.8 ± 3.6 seconds, and -2.4 ± 4 seconds. Improved knee flexion and enhancement in functioning assessed by KOOS were noticed in both groups, with lasting improvement to follow up. No difference in the change in the above-mentioned outcomes was found between groups (p > 0.05). Fewer subjects (6.2% (5) vs. 21.1% (16), χ² = 7.5, df = 2, p = 0.024) from Kinesio Taping group were unsure if taping alleviated their mobility and more intervention group patients indicated higher subjective satisfaction with the effect of knee taping to symptom and mobility alleviation than control group (p < 0.005).

CONCLUSION

Investigated Kinesio Taping technique did not produce better results in mobility and functioning improvement over non-specific knee taping; however, it had higher patient-reported subjective value for symptom attenuation and experienced mobility enhancement.

Molecular taxonomy of osteoarthritis for patient stratification, disease management and drug development: biochemical markers associated with emerging clinical phenotypes and molecular endotypes

PURPOSE OF REVIEW

This review focuses on the molecular taxonomy of osteoarthritis from the perspective of molecular biomarkers. We discuss how wet biochemical markers may be used to understand disease pathogenesis and progression and define molecular endotypes of osteoarthritis and how these correspond to clinical phenotypes.

RECENT FINDINGS

Emerging evidence suggests that osteoarthritis is a heterogeneous and multifaceted disease with multiple causes, molecular endotypes and corresponding clinical phenotypes. Biomarkers may be employed as tools for patient stratification in clinical trials, enhanced disease management in the primary care centres of the future and for directing more rational and targeted osteoarthritis drug development. Proximal molecular biomarkers (e.g synovial fluid) are more likely to distinguish between molecular endotypes because there is less interference from systemic sources of biomarker noise, including comorbidities.

SUMMARY

In this review, we have focused on the molecular biomarkers of four distinct osteoarthritis subtypes including inflammatory, subchondral bone remodelling, metabolic syndrome and senescent age-related endotypes, which have corresponding phenotypes. Progress in the field of osteoarthritis endotype and phenotype research requires a better understanding of molecular biomarkers that may be used in conjunction with imaging, pain and functional assessments for the design of more effective, stratified and individualized osteoarthritis treatments.

Activated platelet-rich plasma improves cartilage regeneration using adipose stem cells encapsulated in a 3D alginate scaffold

In the current study, the effect of superimposing platelet-rich plasma (PRP) on different culture mediums in a three-dimensional alginate scaffold encapsulated with adipose-derived mesenchymal stem cells for cartilage tissue repair is reported. The three-dimensional alginate scaffolds with co-administration of PRP and/or chondrogenic supplements had a significant effect on the differentiation of adipose mesenchymal stem cells into mature cartilage, as assessed by an evaluation of the expression of cartilage-related markers of Sox9, collagen II, aggrecan and collagen, and glycosaminoglycan assays. For in vivo studies, following induction of osteochondral lesion in a rabbit model, a high degree of tissue regeneration in the alginate plus cell group (treated with PRP plus chondrogenic medium) compared with other groups of cell-free alginate and untreated groups (control) were observed. After 8 weeks, in the alginate plus cell group, functional chondrocytes were observed, which produced immature matrix, and by 16 weeks, the matrix and hyaline-like cartilage became completely homogeneous and integrated with the natural surrounding cartilage in the defect site. Similar effect was also observed in the subchondral bone. The cell-free scaffolds formed fibrocartilage tissue, and the untreated group did not form a continuous cartilage over the defect by 16 weeks.

The effectiveness of Kinesio Taping® for pain management in knee osteoarthritis: a randomized, double-blind, controlled clinical trial

Background:

Kinesio Taping® method is a nonpharmacological alternative for pain management in musculoskeletal disorders. However, the existing evidence is insufficient to assess its full effectiveness for pain management in knee osteoarthritis (KO). Our aim was to evaluate the effectiveness of the Kinesio Taping method in reducing knee pain for KO patients.

Methods:

In this randomized, double blind, controlled trial, we recruited 187 patients with grade I-III KO who were allocated to either the Kinesio Taping or control group. The study was carried out in outpatient facility. Either Kinesio Taping or nonspecific taping was applied on the affected knee area for 4 weeks. Pain evaluation was performed at baseline, after 1 month of taping and after 1 further month without taping. The data on usage of painkillers were collected; Numeric Pain Rating Scale; an algometer, and Knee injury and Osteoarthritis Outcome Scores (KOOS) pain subscale were used to assess pain. Tolerance and subjective opinions toward the effectiveness of taping were evaluated. The chosen level of significance was p < 0.05, ß ⩽ 0.2.

Results:

The majority (>70%) of both groups’ patients indicated that tapes reduced the knee pain. The reported use of painkillers decreased, in addition to self-reported increase in the KOOS subscale, thereby indicating pain alleviation. All self-reported improvement remained at the 1-month follow up (p < 0.05). Significantly higher and clinically meaningful reduction of pain intensity was found in the Kinesio Taping group after the treatment month, in comparison with the control group (p < 0.05). More pain reduction was reported in the daytime for participants in the Kinesio Taping group at the follow up (p = 0.022). No changes in algometry results were observed.

Conclusions:

Elastic taping can safely relieve knee pain and reduce the need for pharmacological management in KO. A specific Kinesio Taping technique is clinically more beneficial for knee-pain alleviation in comparison with nonspecific taping.

[ClinicalTrials.gov identifier: NCT03076177.]

The Association Between Knee Osteoarthritis and HLA-DRB1*0101 in the East of Iran

BACKGROUND

Osteoarthritis (OA) is a painful social problem, which breaks down the articular cartilage, causes the failure of synovial joints and subchondral bone sclerosis. OA etiology is not completely understood, but joint trauma, infection, obesity, and diseases are the most important risk factors for OA developing. Recent studies suggested inflammatory factors and genetic components can be involved in the pathogenesis of OA. Experimental evidences suggest a linkage between Human Leukocyte Antigen (HLA) genetic diversity and OA. But a few studies have been conducted in this subject.

OBJECTIVE

To investigate the association between HLA-DRB1*0101 and OA in Iranian patients.

METHODS

Thirty patients with knee osteoarthritis and 30 healthy people as the control group were included in the study. Sex, weight, age, Body mass index (BMI) and height of all participants were recorded. HLA-DRB1*0101 was typed by PCR using the sequence-specific primer.

RESULTS

Our results showed 80% of knee osteoarthritis patients were positively HLA-DRB1*0101 (n=24), while only 26.7% of controls were positive (n=8) (P= 0.015).

CONCLUSION

These findings proposed that there is a significant association between HLADRB1* 0101 and susceptibility to knee osteoarthritis.

Efficacy of Methotrexate on Pain Severity Reduction and Improvement of Quality of Life in Patients with Moderate to Severe Knee Osteoarthritis

Background

Knee osteoarthritis (OA) leads to low quality of life due to pain and limitation in daily activities. Recent studies indicated that Methotrexate (MTX) could reduce pain due to its anti-inflammatory effects.

Objectives

In this study, the researchers aimed at evaluating the efficacy of MTX in pain control and improvement of quality of life in patients with moderate to severe knee OA.

Methods

In this randomized clinical trial, 100 patients with moderate to severe knee OA were allocated to receive MTX (n = 50) 7.5 mg weekly to be increased to 15 mg weekly after first months or placebo (n = 50) for six months. Pain severity was measured using the numerical rating scale (NRS), so was functional status by Western Ontario and McMaster Universities Arthritis Index (WOMAC) and quality of life by SF-12 questionnaire before the treatment, and three months and six months after the intervention. The results were compared between the groups subsequently. Nine patients from the MTX group were excluded due to the use of corticosteroids during the treatment period.

Results

The MTX group compared to the placebo group had significant improvement in pain severity and quality of life during six months and WOMAC parameters at three and six months after the intervention. The need for NSAIDS was slightly higher in the placebo group with no significant difference (22% versus 36%, P = 0.14). The MTX adverse effects were not observed.

Conclusions

Treatment of moderate to severe knee OA with MTX could reduce pain severity and improve functional status and quality of life in OA patients.

Inhibition of PI3K/Akt/NF-κB signaling with leonurine for ameliorating the progression of osteoarthritis: In vitro and in vivo studies

Osteoarthritis (OA) is characterized as the degeneration and destruction of articular cartilage. In recent decades, leonurine (LN), the main active component in medical and edible dual purpose plant Herba Leonuri, has been shown associated with potent anti-inflammatory effects in several diseases. In the current study, we examined the protective effects of LN in the inhibition of OA development as well as its underlying mechanism both in vitro and in vivo experiments. In vitro, interleukin-1 beta (IL-1β) induced over-production of prostaglandin E2, nitric oxide, inducible nitric oxide synthase, cyclooxygenase-2, interleukin-6 and tumor necrosis factor alpha were all inhibited significantly by the pretreatment of LN at a dose-dependent manner (5, 10, and 20 µM). Moreover, the expression of thrombospondin motifs 5 (ADAMTS5) and metalloproteinase 13 (MMP13) was downregulated by LN. All these changes led to the IL-1β induced degradation of extracellular matrix. Mechanistically, the LN suppressed IL-1β induced activation of the PI3K/Akt/NF-κB signaling pathway cascades. Meanwhile, it was also demonstrated in our molecular docking studies that LN had strong binding abilities to PI3K. In addition, LN was observed exerting protective effects in a surgical induced model of OA. To sum up, this study indicated LN could be applied as a promising therapeutic agent in the treatment of OA.

Joint problems arising from lack of repair mechanisms: can cannabinoids help?

Osteoarthritis (OA) is the most common disease of joints, which are complex organs where cartilage, bone and synovium cooperate to allow a range of movements. During progression of the disease, the function of all three main components is jeopardized. Nevertheless, the involvement of each tissue in OA development is still not established and is the topic of the present review. The OA therapies available are symptomatic, largely targeting pain management rather than disease progression. The strong need to develop a treatment for cartilage degeneration, bone deformation and synovial inflammation has led to research on the involvement of the endocannabinoid system in the development of OA. The current review discusses the research on this topic to date and notes the advantages of exploiting endocannabinoid system modulation for cartilage, bone and synovium homeostasis, which could prevent the further progression of OA. LINKED ARTICLES: This article is part of a themed section on 8^th European Workshop on Cannabinoid Research. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.10/issuetoc.

Effects of oral glucosamine hydrochloride and mucopolysaccharide protein in a rabbit model of osteoarthritis

AIM

The aim was to study whether oral glucosamine hydrochloride (GlcN.HCl) or mucopolysaccharide protein (MucoP) has a structure-modifying effect on an anterior cruciate ligament transection (ACLT) rabbit model of osteoarthritis (OA).

METHODS

OA was surgically induced in the right knees of rabbits by transection of the ACLT. The left knees served as a sham-operated control. The animals were divided into four groups (n = 6 each): negative control (phosphate buffered saline, orally), positive control (oral celecoxib 10 mg/kg body weight/day), GlcN.HCl (oral 100 mg/kg/day) and MucoP (oral 100 mg/kg/day). Experimental animals were sacrificed after 8 weeks of treatment and the distal femur was removed for macroscopic examination, histological assessment, and terminal deoxynucleotidyl transferase-mediated nick-end labeling (TUNEL) assay of the OA rabbits.

RESULTS

On gross morphology, severe lesions were observed in articular cartilage in the negative control group. In the GlcN.HCl and MucoP treatment groups, fibrillations and cartilaginous lesions were significantly (P < 0.05) decreased compared to the negative control group. In particular, degenerative changes in cartilage and chondrocyte cellularity were significantly reduced (P < 0.05) in the positive control (celecoxib) group, GlcN.HCl treatment group and MucoP treatment group compared with the negative control group. TUNEL assay showed that apoptotic chondrocytes were significantly suppressed in the celecoxib group. Similar significant (P < 0.05) results were seen in the GlcN.HCl group and MucoP group but apoptosis of chondrocytes were high in the negative control group.

CONCLUSION

These data suggest that the protective effects of GlcN.HCl and MucoP may play a useful role in the clinical treatment of OA.

Patterns of intra-articular injection use after initiation of treatment in patients with knee osteoarthritis: data from the osteoarthritis initiative

OBJECTIVE

We sought to describe and evaluate longitudinal use of intra-articular injections after treatment initiation among adults with radiographically confirmed knee osteoarthritis (OA).

METHOD

Using data from the Osteoarthritis Initiative (OAI), we included participants with radiographically confirmed OA (Kellgren-Lawrence grade (K-L) ≥ 2) in ≥1 knee at baseline. With 9 years of data, 412 participants newly initiating hyaluronic acid or corticosteroid injections with their index visit were identified. For each type of injection initiated, socio-demographic and clinical characteristics were described by patterns of treatments (one-time use, switched, or continued injections). Multinomial logistic models estimated the extent to which patient-reported symptoms (post-initial injection and changes over time) were associated with patterns of injection use.

RESULTS

Of those initiating injections, ∼19% switched, ∼21% continued injection type, and ∼60% did not report any additional injections. For participants initiating corticosteroid injections, greater symptoms post-initial injection were associated with lower odds of continued use compared to one-time users (adjusted odds ratio (aOR) for Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain: 0.91; 95%, confidence interval (CI): 0.83 to 0.99; aORstiffness: 0.77; CI: 0.63 to 0.94; aORphysical function: 0.97; CI: 0.94 to 1.00). Symptom changes over time (e.g., worsened or improved) were not associated with patterns of injections use.

CONCLUSION

After treatment initiation, the proportion of patients switching injection use and one-time users was substantial. Symptoms post-initial injection appear to be associated with patterns of injection use. The extent to which these patterns are an indication of lack of impact on patient-reported symptoms should be explored.

TGFβ1 induces hypertrophic change and expression of angiogenic factors in human chondrocytes

The transforming growth factor β1 (TGFβ1) plays an important role in cartilage development. However, whether TGFβ1 stimulates chondrocyte proliferation and cartilage regeneration in osteoarthritis (OA) remains elusive, especially in the context of different treatment and tissue environments. In the present study, we investigated the role of TGFβ1 in human chondrocyte culture in vitro, focusing on the morphological change of chondrocytes and the expression of angiogenic factors upon TGFβ1 stimulation. We found increased expression of biomarkers indicating chondrocyte hypertrophy and the chondrocytes aggregated to form networks when they were treated with TGFβ1. DNA microarray analysis revealed significantly increased expression of genes related to blood vessel formation in TGFβ1 treatment group compared to control group. Matrigel assay further demonstrated that chondrocytes had the potential to form network-like structure. These results suggested that TGFβ1 induces the hypertrophic change of chondrocytes culture in vitro and induce expression of angiogenic biomarkers. Therefore, application of TGFβ1 for chondrocyte culture in practice should be considered prudentially and targeting TGFβ1 or relevant receptors to block the signaling pathway might be a strategy to prevent or alleviate progression of osteoarthritis.

Efficacy of CR4056, a first-in-class imidazoline-2 analgesic drug, in comparison with naproxen in two rat models of osteoarthritis

Purpose

CR4056, (2-phenyl-6-(1H-imidazol-1yl) quinazoline), an imidazoline-2 (I2) receptor ligand, is a promising analgesic drug that has been reported to be effective in several animal models of pain. The aim of this study was to evaluate the effects of CR4056 in two well-established rat models of osteoarthritis (OA), mimicking the painful and structural components of human OA.

Methods

Knee OA was induced either by single intra-articular injection of monoiodoacetate (MIA) or by medial meniscal tear (MMT) in the right knee of male rats. In the MIA model, allodynia and hyperalgesia were measured as paw withdrawal threshold to mechanical stimulation. In the MMT model, pain behavior was analyzed as weight-bearing asymmetry (i.e. difference in hind paw weight distribution, HPWD) between the injured and the contralateral limbs.

Results

Acute oral administration of CR4056, 14 days after MIA injection, significantly and dose-dependently reduced allodynia and hyperalgesia 90 minutes after treatment, whereas acute naproxen administration significantly reduced allodynia but not hyperalgesia. After 7 days of repeated treatment, both CR4056 and naproxen showed significant anti-allodynic and anti-hyperalgesic effects in the MIA model. Rats undergoing MMT surgery developed a significant and progressive asymmetry in HPWD compared with sham-operated animals. Repeated treatment with CR4056 significantly reduced the progression of the pain behavior, whereas naproxen had no effects.

Conclusion

The data presented here show that the I2 ligand CR4056 could be a new effective treatment for OA pain. The compound is currently under Phase II clinical evaluation for this indication.

Osteoarthritis: from pathogenic mechanisms and recent clinical developments to novel prospective therapeutic options

Osteoarthritis (OA) is a degenerative joint disease that, despite recent progress, has no curative treatment. Considerable research has recently been initiated to identify new potential therapeutic targets. In this review, we will set forth some of the major discoveries in the past 5 years, notably those dealing with the identification of pathogenic factors [hypoxia-inducible factors (HIFs), complement, transforming growth factor (TGF)-β and zinc-ZIP8]. New drugs and concepts currently in clinical development [anti-nerve growth factor (NGF), mesenchymal stromal cells and fibroblast growth factor (FGF)-18] will then be addressed. Finally, we will consider prospective avenues that could lead to mid-to-long-term developments of novel therapeutic concepts, notably those dealing with autophagy regulation and induced pluripotent stem cells.

Possible role of the Ec peptide of IGF‑1Ec in cartilage repair

The Ec peptide (PEc) of insulin-like growth factor 1 Ec (IGF-1Ec) induces human mesenchymal stem cell (hMSC) mobilization and activates extracellular signal‑regulated kinase 1/2 (ERK 1/2) in various cells. The aim of the present study was to examine the effects of PEc on the mobilization and differentiation of hMSCs, as well as the possibility of its implementation in combination with transforming growth factor β1 (TGF‑β1) for cartilage repair. The effects of the exogenous administration of PEc and TGF‑β1, alone and in combination, on hMSCs were assessed using a trypan blue assay, reverse transcription-quantitative polymerase chain reaction, western blot analysis, Alcian blue staining, wound healing assays and migration/invasion assays. It was determined that PEc is involved in the differentiation process of hMSCs towards hyaline cartilage. Treatment of hMSCs with either PEc, TGF‑β1 or both, demonstrated comparable cartilage matrix deposition. Furthermore, treatment with PEc in combination with TGF‑β1 was associated with a significant increase in hMSC mobilization when compared with treatment with TGF‑β1 or PEc alone (P<0.05). Thus, PEc appears to facilitate in vitro hMSC mobilization and differentiation towards chondrocytes, enhancing the role of TGF‑β1.

Indication of nerve growth factor binding components from herbal extracts by HerboChip: a platform for drug screening on a chip

Background

HerboChip is an array of different fractions deriving from herbal extracts. This study aimed to identify effective components from Chinese medicine (CM) that interact with nerve growth factor (NGF) as a target using HerboChip.

Methods

Fifty types of CM that are traditionally used as remedies for emotion imbalance were selected and extracted with 50 % ethanol. Biotinylated-NGF was hybridized with over 300 chips coated with different HPLC-separated fractions from CM extracts and straptavidin-Cy5 was used to identify the NGF-bound fractions.

Results

Over 300 chips were screened within a week, and 17 positive hits were identified. The interaction of the identified herbal extracts with NGF was confirmed in cultured PC12 cells. Co-application of NGF and herbal extract interfered with NGF-induced expression of neurofilaments, including NF68 and NF200 in cell cultures. Western blot analysis comparing the intensity of phosphorylated cAMP response element-binding protein (CREB) over total CREB showed NGF-induced CREB phosphorylation was modulated by the identified herbal extracts. Five CM herbs showed activating activities on the NGF response and nine CM herbs showed inhibiting activities.

Conclusion

The current result supported the applicability of HerboChip for screening NGF binding components from herbal extracts.

Electronic supplementary material

The online version of this article (doi:10.1186/s13020-016-0107-8) contains supplementary material, which is available to authorized users.

Successful management of an equine carpal chip fracture by intra-articularly injected adipose-derived stromal vascular fraction after arthroscopic removal

Carpal chip fractures are common causes of lameness in racehorses. Due to disadvantages in surgical management, adjuvant treatment modalities are usually necessary. Adipose-derived stem cells (ADSCs) have the potential to differentiate into other cell types including bone and cartilage cells. Adipose-derived stromal vascular fraction (SVF) is produced during ADSCs isolation from adipose tissue. The purpose of this report was to present the successful management of a grade III chip fracture in the right carpus of a 5-year-old Thoroughbred gelding by intra-articularly injected autologous SVF one month after the arthroscopic removal of the fracture. This treatment resulted in lameness improvement and short rehabilitation period to previous racing activities. High performance levels and no recurrent injuries were recorded during a twenty month follow-up period.

Predictive factors and clinical biomarkers for treatment in patients with chronic pain caused by osteoarthritis with a central sensitisation component

AIMS

The aim of this non-systematic review was to provide a practical guide for clinicians on the evidence for central sensitisation in chronic osteoarthritis (OA) pain and how this pain mechanism can be addressed in terms of clinical diagnosis, investigation and treatment.

METHODS

The authors undertook a non-systematic review of the literature including a MEDLINE search (search terms included central sensitisation, osteoarthritis, osteoarthrosis) for relevant and current clinical studies, systematic reviews and narrative reviews. Case reports, letters to the editor and similar literature sources were excluded. Information was organised to allow a pragmatic approach to the discussion of the evidence and generation of practical recommendations.

RESULTS

There is good evidence for a role of central sensitisation in chronic OA pain in a subgroup of patients. Clinically, a central sensitisation component in chronic OA pain can be suspected based on characteristic pain features and non-pain features seen in other conditions involving central sensitisation. However, there are currently no diagnostic inventories for central sensitisation specific to OA. Biomarkers may be helpful for confirming the presence of central sensitisation, especially when there is diagnostic uncertainty. Several non-pharmacological and pharmacological treatments may be effective in OA patients with central sensitisation features. Multimodal therapy may be required to achieve control of symptoms.

DISCUSSION

Clinicians should be aware of central sensitisation in patients with chronic OA pain, especially in patients presenting with severe pain with unusual features.

Safety issues of current analgesics: an update

Pain represents a complex experience which can be approached by various medicines. Non-opioid and opioid analgesics are the most common drugs used to manage different types of pain. The increased attention nowadays to pain management entailed concomitantly more frequent adverse drug reactions (ADRs) related to analgesic use. Drug-drug interactions can be sometimes responsible for the adverse effects. However, a significant proportion of analgesic ADRs are preventable, which would avoid patient suffering. In order to draw the attention to analgesics risks and to minimize the negative consequences related to their use, the present review comprises a synthesis of the most important safety issues described in the scientific literature. It highlights the potential risks of the most frequently used analgesic medicines: non-opioid (paracetamol, metamizole, non-steroidal anti-inflammatory drugs) and opioid analgesics. Even if there is a wide experience in their use, they continue to capture attention with safety concerns and with potential risks recently revealed. Acknowledging potential safety problems represents the first step for health professionals in assuring a safe and efficient analgesic treatment with minimum risks to patients. Taking into consideration all medical and environmental factors and carefully monitoring the patients are also essential in preventing and early detecting analgesic ADRs.

Pain sensitization and degenerative changes are associated with aberrant plantar loading in patients with painful knee osteoarthritis

OBJECTIVES

This study focused on the biomechanical implications of knee osteoarthritis (OA) and the association with pain. The plantar loading force distribution of the foot was determined and correlated to degenerative knee changes, function, pain intensity, and pain sensitization.

METHOD

Knee OA patients (n = 34) with moderate and mild knee pain were characterized and compared to matched controls (n = 16). The Plantar Foot Posture Index (FPI) and mean maximum plantar forces were determined by pressure-sensitive insoles. Pain intensity and function were assessed by the Western Ontario and McMaster Universities Arthritis Index (WOMAC) and the Brief Pain Inventory (BPI). Local knee pain sensitization was assessed by pressure pain thresholds (PPTs) from eight knee locations. Spreading sensitization was assessed by PPTs from two extra-segmental test sites. Temporal summation to repeated pressure stimulation (knee and extra-segmental stimulation) and conditioning pain modulation (CPM) were assessed, representing central pain mechanisms.

RESULTS

The maximum force (MF) applied by the medial forefoot correlated to knee PPTs (r = 0.524, p < 0.001), CPM potency (r = 0.532, p < 0.001), and BPI (r = -0.325, p < 0.05) and WOMAC scores (pain r = -0.425, p < 0.01; stiffness r = -0.386, p < 0.01; function r = -0.378, p < 0.05). The MF applied by the medial hindfoot correlated negatively to scores on the FPI (r = -0.394, p < 0.01) and the Kellgren-Lawrence (K-L) grading scale (r = -0.330, p < 0.05). The MF applied by the medial forefoot correlated to extra-segmental PPTs (r = 0.554, p < 0.001) and the potency of CPM (r = 0.561, p < 0.0001). The MF applied by the lateral hindfoot correlated negatively to the PPT assessed extra-segmentally (r = -0.367, p < 0.05) and positively to CPM potency (r = 0.322, p < 0.05).

CONCLUSIONS

This study shows that mean maximum plantar foot force distribution in patients with painful knee OA is associated with specific pain mechanisms, function, radiological findings, and pain intensity.