Knee osteoarthritis: pathophysiology and current treatment modalities

Acupotomy combined with intra-articular injection of sodium hyaluronate in the treatment of knee osteoarthritis

This retrospective study aimed to compare the effects of acupotomy combined with intra-articular injection of sodium hyaluronate (IA-SH) for the treatment of knee osteoarthritis (KOA). Eighty electronic medical records of patients with KOA were retrospectively analyzed. The patients were divided into an intervention group (n = 40, acupotomy plus IA-SH) and a control group (n = 40, IA-SH). Outcome measures included the visual analog scale, the Western Ontario and McMaster Universities Arthritis Index (WOMAC), and adverse events. Outcome data were collected and analyzed before and after treatment. The results of this study showed that there was a greater reduction in the visual analog scale (P < .01) and WOMAC scores (pain, P < .01; stiffness, P < .01; function, P < .01; total, P < .01) in the intervention group than in the control group. In addition, there were no significant differences in adverse events between the 2 groups. In this study, the effects of acupotomy plus IA-SH were superior to those of IA-SH alone for the treatment of patients with KOA. Further prospective studies are required to confirm these findings.

Natural Compounds Affecting Inflammatory Pathways of Osteoarthritis

Osteoarthritis (OA) is the most common type of arthritis and chronic joint disease, affecting more than 240 million people worldwide. Although there are numerous advances in using drugs in treating OA, the use of natural compounds has aroused much interest among researchers due to their safety margin. Recent discovery shows that natural compounds play an extensive role in the oxidative stress signaling pathway in treating OA. Thus, this review summarizes the commonly used natural compounds for treating OA focusing on the oxidative stress signaling pathway and its downstream mediators. Selected databases—such as Scopus, Web of Science, Nature, and PubMed—were used to search for potentially relevant articles. The search is limited to the last 15 years and the search was completed using the Boolean operator’s guideline using the keywords of natural product AND oxidative stress AND osteoarthritis OR natural extract AND ROS AND degenerative arthritis OR natural plant AND free radicals AND degenerative joint disease. In total, 37 articles were selected for further review. Different downstream mechanisms of oxidative stress involved in the usage of natural compounds for OA treatment and anabolic and catabolic effects of natural compounds that exhibit chondroprotective effects have been discussed with the evidence of in vitro and in vivo trials in this review.

Stromal Vascular Fraction for Knee Osteoarthritis - An Update

Orthobiologics never cease to cause popularity within the medical science field, distinctly in regenerative medicine. Recently, adipose tissue has been an object of interest for many researchers and medical experts due to the fact that it represents a novel and potential cell source for tissue engineering and regenerative medicine purposes. Stromal vascular fraction (SVF), for instance, which is an adipose tissue-derivative, has generated optimistic results in many scenarios. Its biological potential can be harnessed and administered into injured tissues, particularly areas in which standard healing is disrupted. This is a typical feature of osteoarthritis (OA), a common degenerative joint disease which is outlined by persistent inflammation and destruction of surrounding tissues. SVF is known to carry a large amount of stem and progenitor cells, which are able to perform self-renewal, differentiation, and proliferation. Furthermore, they also secrete several cytokines and several growth factors, effectively sustaining immune modulatory effects and halting the escalated pro-inflammatory status of OA. Although SVF has shown interesting results throughout the medical community, additional research is still highly desirable in order to further elucidate its potential regarding musculoskeletal disorders, especially OA.

Photobiomodulation therapy for osteoarthritis: Mechanisms of action

Photobiomodulation (PBM) is a non-invasive therapeutic modality with demonstrated effects in many fields related to regenerative medicine. In the field of orthopedics, in particular, PBM at various wavelengths has demonstrated the capacity to trigger multiple biological effects associated with protective mechanisms in musculoskeletal tissues. The articles cited in this review show that devices operating close to or within the near infrared range at low intensities can provoke responses which favor the shift in the predominant catabolic microenvironment typically seen in degenerative joint diseases, especially osteoarthritis (OA). These responses include proliferation, differentiation and expression of proteins associated with stable cell cycles. Additionally, PBM can also modulate oxidative stress, inflammation and pain by exerting regulatory effects on immune cells and blocking the transmission of pain through sensory neuron fibers, without adverse events. Collectively, these effects are essential in order to control the progression of OA, which is in part attributed to exacerbated inflammation and degradative enzymatic reactions which gradually contribute to the destruction of joint tissues. PBM may offer medical experts ease of application, financial viability, efficacy and lack of serious adverse events. Therefore, it may prove to be a suitable ally in the management of mild to moderate degrees of OA. This review explores and discusses the principal biological mechanisms of PBM and how the produced effects may contribute to the amelioration of osteoarthritic progression. Literature was reviewed using PubMed and Google Scholar in order to find studies describing the mechanisms of PBM. The investigation included a combination of nomenclature such as: “photobiomodulation”, “phototherapy”, “laser therapy”, “PBM”, “osteoarthritis”, low level light therapy”, “inflammation” and “cartilage”. We considered only articles written in English, with access to the full text.

Omega-3 Fatty Acids for the Management of Osteoarthritis: A Narrative Review

Osteoarthritis (OA) is a disease which results in degeneration of cartilage within joints and affects approximately 13.6% of adults over 20 years of age in Canada and the United States of America. OA is characterized by a state of low-grade inflammation which leads to a greater state of cellular catabolism disrupting the homeostasis of cartilage synthesis and degradation. Omega-3 polyunsaturated fatty acids (PUFAs) have been postulated as a potential therapeutic treatment option for individuals with OA. Omega-3 PUFAs are recognized for their anti-inflammatory properties, which could be beneficial in the context of OA to moderate pro-inflammatory markers and cartilage loss. The purpose of this narrative review is to outline recent pre-clinical and clinical evidence for the use of omega-3 in the management of OA.

Cooled and traditional thermal radiofrequency ablation of genicular nerves in patients with chronic knee pain: a comparative outcomes analysis

INTRODUCTION

Genicular nerve radiofrequency ablation (GNRFA) is a minimally invasive intervention for patients with chronic knee pain (CKP) not responding to conservative treatments. Few investigations have compared treatment outcomes of cooled-RFA (c-RFA) and thermal-RFA (t-RFA), two common approaches of GNRFA. This study aims to investigate and compare outcomes, including probability of treatment success, between c-RFA and t-RFA in patients with CKP.

METHODS

This retrospective cohort study analyzed a total of 208 propensity score matched patients, including 104 patients who received c-RFA and 104 patients who received t-RFA. The primary outcome was probability of pain relief after the procedure, defined as reduction in Numeric Rating Scale (NRS) pain score of 2 or greater. The secondary outcomes were degree of NRS pain score reductions, duration of relief, and the probability of patients receiving TKA within 1 year of treatment.

RESULTS

T-RFA was associated with a higher probability of pain relief within 1, 3, and 6 months after procedure when compared with c-RFA. Probabilities of pain relief from t-RFA and c-RFA were 62% (95% CI 51% to 71%) and 43% (95% CI 34% to 53%; p=0.01) within 1 month, 78% (95% CI 68% to 85%) and 55% (95% CI 45% to 64%; p<0.001) within 3 months, and 79% (95% CI 70% to 86%) and 59% (95% CI 49% to 68%; p<0.01) within 6 months, respectively. t-RFA was also associated with greater mean NRS pain score reduction at 1 month after procedure: -4.71 (95% CI -5.3 to -4.1) when compared with -3.59 (95% CI -4.3 to -2.9; p=0.02) from c-RFA. T-RFA and c-RFA were comparable in pain score reduction at 3, 6, 9 and 12 months after procedure. Both groups demonstrated comparable duration of relief and probability of patients receiving TKA within 1 year.

DISCUSSION

Both t-RFA and c-RFA effectively reduced NRS pain scores in most patients with CKP within the 1 year follow-up period. Genicular nerve t-RFA was associated with a higher probability of treatment success and a greater degree of pain relief at 1 month after the procedure when compared with c-RFA in propensity score matched patients with CKP.

A Review on Osteoarthritis Knee Management via Contrast Bath Therapy and Physical Therapy

One of the body's main weight-bearing joints is the knee joint. For this reason, osteoarthritis typically involves it. Osteoarthritis of the knee joint is the condition in which sub-chondral sclerosis of bone occurs, narrowing of joint space is present, and osteophyte formation is seen at the edges of the bone; because of this, there is pain, reduced knee range of motion, and this leads to functional activity limitations. This prevalence is increasing because of a reduced active lifestyle; this is becoming usual in younger populations. Non-pharmacological management of this condition using contrast bath therapy given by different methods like using hot and cold water, towel compression, and smart knee pad device, causes alternate vasodilatation and vasoconstriction helps to reduce pain symptoms. Physical therapy exercises like stretching, strengthening hip and knee muscles, and balance training showed beneficial effects on a range of motion and activities. Articles using keywords were searched on Google Scholar and PubMed, 70 articles were seen of which eight were reviewed that meet the inclusion criteria. Contrast therapy helps to remove metabolic waste by improving blood flow thus reducing pain. Strengthening the hip and knee muscles helps to stabilize the knee joint, and balance exercises help to improve proprioception. From this review, it is concluded that contrast bath therapy is effective in reducing pain when given with different methods of application as compared to individual hot or cold treatment, and given with the help of a device will be more effective than the traditional method. Along with this strengthening of the knee and hip musculature, stretching and balance exercise helps to improve range and functional activity. Exercise and electrotherapy aid in symptom relief and slow the progression rate of this condition.

Cationic peptide carriers enable long-term delivery of insulin-like growth factor-1 to suppress osteoarthritis-induced matrix degradation

Background

Insulin-like growth factor-1 (IGF-1) has the potential to be used for osteoarthritis (OA) treatment but has not been evaluated in clinics yet owing to toxicity concerns. It suffers from short intra-joint residence time and a lack of cartilage targeting following its intra-articular administration. Here, we synthesize an electrically charged cationic formulation of IGF-1 by using a short-length arginine-rich, hydrophilic cationic peptide carrier (CPC) with a net charge of +14, designed for rapid and high uptake and retention in both healthy and arthritic cartilage.

Methods

IGF-1 was conjugated to CPC by using a site-specific sulfhydryl reaction via a bifunctional linker. Intra-cartilage depth of penetration and retention of CPC-IGF-1 was compared with the unmodified IGF-1. The therapeutic effectiveness of a single dose of CPC-IGF-1 was compared with free IGF-1 in an IL-1α-challenged cartilage explant culture post-traumatic OA model.

Results

CPC-IGF-1 rapidly penetrated through the full thickness of cartilage creating a drug depot owing to electrostatic interactions with negatively charged aggrecan-glycosaminoglycans (GAGs). CPC-IGF-1 remained bound within the tissue while unmodified IGF-1 cleared out. Treatment with a single dose of CPC-IGF-1 effectively suppressed IL-1α-induced GAG loss and nitrite release and rescued cell metabolism and viability throughout the 16-day culture period, while free IGF at the equivalent dose was not effective.

Conclusions

CPC-mediated depot delivery of IGF-1 protected cartilage by suppressing cytokine-induced catabolism with only a single dose. CPC is a versatile cationic motif that can be used for intra-cartilage delivery of other similar-sized drugs.

The efficacy and safety of Jinwu Gutong capsule in the treatment of knee osteoarthritis: A meta-analysis of randomized controlled trials

ETHNOPHARMACOLOGICAL RELEVANCE

The Jinwu Gutong (JWGT) capsule is a Chinese patent medicine that is widely used in the treatment of knee osteoarthritis (KOA) and osteoporosis in China and is considered to have the potential for good clinical efficacy.

AIM OF THE STUDY

The purpose of this study was to systematically evaluate the clinical efficacy and safety of JWGT in the treatment of KOA.

MATERIALS AND METHODS

We searched the China National Knowledge Infrastructure (CNKI), Wanfang, SinoMed, PubMed, Embase and Cochrane Library databases to identify clinical trials that explore the use of JWGT only or JWGT combined with Western drugs (JWGT group) compared with the use of conventional Western drugs (Western drugs group) for the treatment of KOA. The clinical trials, that were retrieved from each database from the inception of the database to December 2021, were screened. We used the risk of bias assessment tool recommended by Cochrane to evaluate the quality of the included literature and RevMan 5.3 software for data analysis.

RESULTS

A total of 17 clinical randomized controlled trials (RCTs) were included in this study, with a total of 1930 participants, including 1015 people in the experimental group and 915 people in the control group. The results of the meta-analysis showed that the JWGT group exhibited better efficacy than the Western drug group with respect to WOMAC score (WMD = -6.25, 95% CI = -8.09 to -4.41, P < 0.001), VAS score (WMD = -1.36, 95% CI = -2.17 to -0.55, P = 0.001), KSS score (WMD = 23.01, 95% CI = 21.42 to 24.59, P < 0.001), IL-6 (SMD = -3.30, 95% CI = -4.84 to -1.76, P < 0.001), TNF-α (SMD = -1.70, 95% CI = -2.02 to -1.38, P < 0.001). The effective rate (OR = 2.56, 95% CI = 1.83 to 3.57, P < 0.001) and incidence of adverse reactions was significantly lower in the JWGT group than in the control group (OR = 0.13, 95% CI = 0.07 to 0.21, P < 0.001). Subgroup analysis showed that JWGT + NSAIDs had more advantages in regard to efficacy (OR = 2.05, 95% CI = 1.35 to 3.12, P < 0.001), and reducing adverse reactions (OR = 0.10, 95% CI = 0.06 to 0.18, P < 0.001), VAS score (WMD = -1.00, 95% CI = -1.93 to -0.07, P = 0.04), KSS score (WMD = 17.39, 95% CI = 15.39 to 19.39, P < 0.001), WOMAC score (WMD = -2.84, 95% CI = -10.75 to 5.08, P < 0.001), IL-6 (SMD = -1.42, 95% CI = -2.08 to -0.75, P < 0.001) and TNF-α (SMD = -1.68, 95% CI = -1.93 to -1.43, P < 0.001) than NSAIDs alone. Compared with hyaluronic acid (HA) alone, JWGT + HA had better clinical efficacy (OR = 3.08, 95% CI = 1.48 to 6.40, P < 0.001). Compared with glucosamine (GS) alone, JWGT + GS significantly reduced the Lequesne index score (WMD = -0.53, 95% CI = -0.85 to -0.21, P = 0.001) and the serum TNF-α level (SMD = -1.68, 95% CI = -1.93 to -1.43, P < 0.001), but it had no significant advantage in reducing the serum IL-6 level (SMD = -4.53, 95% CI = -10.13 to 1.07, P = 0.11).

CONCLUSION

JWGT is considered effective and safe in the treatment of KOA and is worthy of clinical application. In addition, the application of JWGT combined with NSAIDs, HA or GS can significantly improve the clinical efficacy of the latter agents in KOA treatment.

A narrative review of mesenchymal stem cells effect on osteoarthritis

Objective

To describe and discuss the purposed mechanism of mesenchymal stem cells (MSCs) and their effect as a potential therapeutic in osteoarthritis (OA).

Background

OA is a chronic, degenerative joint disease affecting millions worldwide. Traditional management, including physical therapy, anti-inflammatories, intra-articular injections, and surgical procedures are directed towards symptom control rather than disease modification. In light of a better understanding that low-grade inflammation disrupts articular cartilage homeostasis in OA, application of MSCs as a form of regenerative medicine has emerged with the goal to provide symptomatic relief as well as reverse the articular cartilage damage seen in OA.

Methods

PubMed was searched using terms 'osteoarthritis', 'mesenchymal stem cell', 'regenerative medicine', 'chondrocyte', and 'articular cartilage' available from 2006 through May 2021.

Conclusions

The use of MSC therapy for articular cartilage regeneration through direct tissue growth, differentiation, and inflammation modulations for the treatment of OA is promising. MSCs migrate to injured sites, inhibit pro-inflammatory pathways, and promote tissue repair by releasing paracrine signals and differentiating into specialized chondrocytes. Multiple clinical trials have displayed a significant improvement in both pain and joint function, inflammatory cell reduction within a joint, and articular cartilage growth as well as patient safety. However, high quality evidence supporting the beneficial role of MSCs is lacking due to the limited number of studies, small populations tested, and the use of various derivatives. Although limited, current evidence suggests MSCs are a potential therapeutic in OA and provides a great foundation for further research.

Muscle activation, strength, and volume in people with patellofemoral osteoarthritis: a systematic review and meta-analysis

OBJECTIVE

This systematic review investigated whether people with patellofemoral osteoarthritis (PFOA) have muscle strength, volume, and activation around the hip and knee that is different from asymptomatic controls.

METHODS

Searches were carried out in five electronic databases, with terms related to PFOA, including muscle strength, volume and activation. Only studies with at least one group with symptomatic PFOA and one asymptomatic group were included. The methodological quality of the studies was assessed using the Downs and Black checklist. Certainty of evidence was assessed using the GRADE methodology. Using the random effects model, a meta-analysis was performed when there were at least two studies reporting the same domain.

RESULTS

Eight studies (250 participants) met the inclusion criteria. Subjects with PFOA had weaker hip abduction (SMD -0.96; 95%CI = -1.34 to -0.57), hip external rotation (-0.55;-1.07 to -0.03), hip extension (-0.72;-1.16 to -0.28), and knee extension (-0.97;-1.41 to -0.53) when compared to asymptomatic controls. People with PFOA also presented with smaller volumes of the gluteus medius, gluteus minimus, tensor fascia lata, vastus medialis (VM), vastus lateralis (VL) and rectus femoris when compared to asymptomatic controls. Also, people with PFOA presented with changes in muscle activation for the VL, VM and gluteus maximus (GMax) when compared to asymptomatic controls.

CONCLUSION

People with PFOA present with lower strength and volume of the hip and quadriceps muscles and altered muscle activation of the VM, VL and GMax during ascending and descending stairs when compared to asymptomatic controls. However, the certainty of these findings are very low.

TRIAL REGISTRATION NUMBER

PROSPERO systematic review protocol (ID = CRD42020197776).

Effect of Human Synovial Fluid From Osteoarthritis Patients and Healthy Individuals on Lymphatic Contractile Activity

The lymphatic system has been proposed to play a crucial role in preventing the development and progression of osteoarthritis (OA). As OA develops and progresses, inflammatory cytokines and degradation by-products of joint tissues build up in the synovial fluid (SF) providing a feedback system to exacerbate disease. The lymphatic system plays a critical role in resolving inflammation and maintaining overall joint homeostasis; however, there is some evidence that the lymphatics can become dysfunctional during OA. We hypothesized that the functional mechanics of lymphatic vessels (LVs) draining the joint could be directly compromised due to factors within SF derived from osteoarthritis patients (OASF). Here, we utilized OASF and SF derived from healthy (non-OA) individuals (healthy SF (HSF)) to investigate potential effects of SF entering the draining lymph on migration of lymphatic endothelial cells (LECs) in vitro, and lymphatic contractile activity of rat femoral LVs (RFLVs) ex vivo. Dilutions of both OASF and HSF containing serum resulted in a similar LEC migratory response to the physiologically endothelial basal medium-treated LECs (endothelial basal medium containing serum) in vitro. Ex vivo, OASF and HSF treatments were administered within the lumen of isolated LVs under controlled pressures. OASF treatment transiently enhanced the RFLVs tonic contractions while phasic contractions were significantly reduced after 1 h of treatment and complete ceased after overnight treatment. HSF treatment on the other hand displayed a gradual decrease in lymphatic contractile activity (both tonic and phasic contractions). The observed variations after SF treatments suggest that the pump function of lymphatic vessel draining the joint could be directly compromised in OA and thus might present a new therapeutic target.

Epigallocatechin-3-O-gallate ameliorates oxidative stress-induced chondrocyte dysfunction and exerts chondroprotective effects via the Keap1/Nrf2/ARE signaling pathway

Oxidative stress-induced degeneration and dysfunction of chondrocytes play a key role in the pathological progression of osteoarthritis (OA), a common degenerative joint disease in the elderly. Epigallocatechin-3-O-gallate (EGCG) increases Nrf2-mediated antioxidase expression levels. We aimed to determine the effects of EGCG on C28/I2 human chondrocytes subjected to interleukin-1β (IL-1β)-induced oxidative stress. EGCG suppressed IL-1β-induced oxidative stress, as indicated by decreased malondialdehyde (MDA) and reactive oxygen species (ROS) generation. Additionally, EGCG attenuated the IL-1β-induced reduction in cartilage matrix generated by chondrocytes by upregulating collagen II, aggrecan, sulfated proteoglycans, and SRY-box transcription factor 9 (SOX9). EGCG reversed the IL-1β-induced increased cyclooxygenase 2 (COX2), inducible nitric oxide synthase (iNOS), collagen X, and matrix metalloproteinases (MMPs). Furthermore, EGCG inhibited apoptosis and senescence of IL-1β-treated chondrocytes, as indicated by the decrease in mitochondrial membrane potential and senescence-associated β-galactosidase-positive cells, respectively. Mechanically, EGCG upregulated nuclear factor erythroid 2-related factor 2 (Nrf2), oxygenase-1 (HO-1), and NADPH quinone oxidoreductase1 (NQO1). The antioxidant and chondroprotective effects of EGCG were blocked by ML385, a Keap1/Nrf2/ARE signaling pathway inhibitor. Thus, EGCG ameliorated oxidative stress-induced chondrocyte dysfunction and exerted chondroprotective effects via Keap1/Nrf2/ARE signaling. This provides a novel perspective on the molecular mechanisms underlying the therapeutic effects of EGCG on OA.

A Comprehensive Update of Prolotherapy in the Management of Osteoarthritis of the Knee

This is a comprehensive review of the literature focusing on the use of prolotherapy in the treatment of osteoarthritis of the knee. It covers the background, efficacy, and advantages of prolotherapy in the management of osteoarthritis symptoms and then covers the existing evidence of the use of prolotherapy for this purpose. Current treatments for osteoarthritis of the knee are numerous, yet patients continue to endorse chronic pain and poor quality of life. Prolotherapy is a treatment that has been inadequately studied with poor sample sizes and lack of standardization between trials. However, in recent years the literature on prolotherapy in the treatment of knee osteoarthritis has grown. Although there is still a lack of homogeneity, trials have shown that dextrose prolotherapy, autologous conditioned serum, hyaluronic injections, and normal saline administered either intra- or peri-articularly are comparable in reducing pain scores to other primary treatment options. The mechanism of action for prolotherapy is still unclear, but researchers have found that prolotherapy plays some role in cartilage growth or chondrogenesis and has been shown to have improved radiographic outcomes. Prolotherapy appears to be a safe treatment alternative that has been shown to improve stiffness, pain, function, and quality of life in osteoarthritis of the knee. Knee osteoarthritis is remarkably prevalent in the United States and is one of the most common causes of disability in the elderly population. Although there are many treatment options, patients continue to live with chronic pain which can incur high costs for patients. A safe, long-term, and effective solution has not yet been identified. Prolotherapy has been shown to be a safe option for improving pain, function, and quality of life as effectively as other treatment options.

Role and Effectiveness of Intra-articular Injection of Hyaluronic Acid in the Treatment of Knee Osteoarthritis: A Systematic Review

Osteoarthritis (OA) is a degenerative joint disease that causes persistent joint pain and stiffness of mainly the large peripheral weight-bearing joints. It is a leading cause of functional disability and poor quality of life. Various modalities of therapy are recommended by different research organizations at different stages of OA including non-pharmacological, pharmacological, and surgical interventions. Intra-articular injections of hyaluronic acid (HA) is widely used for over three decades in the treatment of OA. However controversies exist regarding its safety and efficacy, the number of injections and courses, type of preparation, duration of its effects, and combining it with other drugs or molecules. This study aimed to review the most recent data available in the published literature to address these.

Electronic databases like Medline, Embase, ProQuest, and Google Scholar were searched for articles using keywords, intraarticular injections, hyaluronic acid, and osteoarthritis knee. The review was carried out as per PRISMA guidelines.

Thirty-eight randomized control trials (RCTs) investigating the efficacy and safety of intra-articular injection of HA were included in the systematic review. Out of the 38 studies, 22 (57.9%) were double-blind, eight (21%) single-blind, three (7.9%) non-blind, four (10%) with simple randomization, and one (2.7%) was open-labeled. Total 5,025 patients were included in these studies. The mean age of the patients was 60.28 years and the osteoarthritis grade of the knee joint was 1 to 3. HA was studied as a test preparation in 19 (50%) while in another 19 (50%) it was studied as a control. In 24 (63.2%) studies, HA was used as high molecular weight preparation in eight (21%) as low molecular weight preparation while in six studies the information was not available. HA was used as a standalone preparation in 31 studies, in two studies it was injected with platelet-rich plasma (PRP) and with either low-level laser therapy (LLLT), triamcinolone (TA), betamethasone (CS), poly deoxyribonucleotide (PDRN) or dexamethasone (DX) in one study each. In the majority of the studies, HA was given as a single injection (52.6% studies) or weekly three injections (28.9% studies). In 13.2 %, it was given as weekly 5 injections and in 5.3% as weekly two injections.

IA-HA injections have a limited role in the treatment of knee osteoarthritis in those patients who do not have sufficient pain relief with topical or oral medication and physical therapy. It is safe and effective except for minor side effects such as local pain and swelling lasting for a few days. Severe allergic reactions are extremely rare. They provide adequate pain relief and functional improvement for up to six months irrespective of a number of injections and type of preparations used. The combination formulations with corticosteroids or PRP or MSCs show better results than HA alone. Combining HA with newer molecules such as peptides or diclofenac for sustained and disease-modifying effects requires more studies in the future.

Genicular Nerve Ablation Review Using Cooled-Radiofrequency Nerve Ablation

Osteoarthritis (OA) is globally the most prevalent joint disease and causes patients great pain, limited joint mobility, and psychological distress. Short- and long-term therapies like steroid injections and arthroplasty exist, respectively. Joint arthroplasty can effectively treat symptomatic end-stage OA, but most patients do not go through with surgery because they are not qualified, have comorbidities, or do not wish to undergo surgery. As a result, patients can turn to opioid agonists for pain relief, which contributes to the growing opioid epidemic that mars our communities. Cooled radiofrequency ablation (C-RFA) is an effective treatment modality that can alleviate the pain associated with moderate to severe OA, especially in patients who have tried and failed conservative therapy. This review article elucidates the benefits of C-RFA, while also walking through the technical steps to performing the procedure. For patients suffering from debilitating joint OA, especially of the knee, C-RFA is a minimally invasive procedure that ensures pain relief.

The Association between Modifiable Risk Factor with Inflammatory Marker in Knee Osteoarthritis Women

Background: IL-1β and TNF-α are vital inflammatory cytokines in the pathophysiological process of Osteoarthritis (OA). Several risk factors can increase the expression of these cytokines, such as BMI, physical activity, and menopausal status.   Aims: This study aims to determine the relationship of modifiable factors with synovial fluid IL-1β and TNF-α levels in knee OA women.   Methods: The cross-sectional study was conducted at the orthopedic poly hospital Arifin Achmad Riau Province and Ibnu Sina Hospital in Pekanbaru City. A total of 93 women with knee OA were taken as samples by consecutive sampling. Data were obtained directly from respondents by conducting interviews using a questionnaire, measuring weight and height, examining levels of IL-1β and TNF-α from the synovial fluid using the enzyme-linked immunosorbent assay (ELISA) method. The data were processed computerized using the Person correlation test, One Way Anova, and t-Test. The statistical analysis results were considered significant if the p-value was 0<05.   Results: the average age of subjects was 60.67 + 9.99 years, 87.8% aged > 40 years, 84.9% had menopause, and at most had moderate physical activity degrees (51.6%). The mean BMI was 27.18+4.17, the average of IL-1β 424.73+188.01 pg/mL, and TNF-α 105,17+48.98 ng/L. There was a significant positive correlation with moderate strength between BMI and levels of IL-1β and TNF-α synovial fluid (p=0.037, r=0.217, and p=0.047, r=0.207).   Conclusion: BMI is a risk factor for IL-1β and TNF-α levels in synovial fluid of knee joints in women with OA, but physical activity and menopausal status are not risk factors.

Injectable hydrogels for articular cartilage and nucleus pulposus repair: Status quo and prospects

Osteoarthritis (OA) and chronic low back pain due to degenerative (intervertebral) disc disease (DDD) are two of the major causes of disabilities worldwide, affecting hundreds of millions of people and leading to a high socioeconomic burden. Although OA occurs in synovial joints and DDD occurs in cartilaginous joints, the similarities are striking, with both joints showing commonalities in the nature of the tissues and in the degenerative processes during disease. Consequently, repair strategies for articular cartilage (AC) and nucleus pulposus (NP), the core of the intervertebral disc, in the context of OA and DDD share common aspects. One of such tissue engineering approaches is the use of injectable hydrogels for AC and NP repair. In this review, the state-of-the-art and recent developments in injectable hydrogels for repairing, restoring, and regenerating AC tissue suffering from OA and NP tissue in DDD are summarized focusing on cell-free approaches. The various biomaterial strategies exploited for repair of both tissues are compared, and the synergies that could be gained by translating experiences from one tissue to the other are identified.

Leukocyte-Rich versus Leukocyte-Poor Platelet-Rich Plasma for the Treatment of Knee Osteoarthritis: A Double-Blind Randomized Trial

BACKGROUND

Platelet-rich plasma (PRP) is gaining large interest in clinical practice as a minimally invasive injective treatment for knee osteoarthritis (OA). Different preparation methods are available, and the presence of leukocytes, deemed detrimental in some preclinical studies, is one of the most debated aspects regarding PRP efficacy.

PURPOSE

To compare the safety and effectiveness of leukocyte-rich PRP (LR-PRP) and leukocyte-poor PRP (LP-PRP) for the treatment of knee OA.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 192 patients with symptomatic knee OA (Kellgren-Lawrence grade 1-3) were randomly allocated to 3 weekly injections of LR-PRP or LP-PRP. LP-PRP was obtained with a filter for leukodepletion. LR-PRP and LP-PRP were divided into aliquots of 5 mL, with a mean platelet concentration of 1146.8 × 10⁹/L and 1074.9 × 10⁹/L and a mean leukocyte concentration of 7991.4 × 10⁶/L and 0.1 × 10⁶/L, respectively. Patients were evaluated at baseline and thereafter at 2, 6, and 12 months for the primary outcome, the International Knee Documentation Committee (IKDC) subjective score; and for secondary outcomes, the Knee injury and Osteoarthritis Outcome Score (KOOS) subscales, EuroQol-visual analog scale (EQ-VAS), and Tegner score.

RESULTS

No differences between groups were observed in terms of absolute values or improvement of the clinical scores across all follow-up intervals. The mean IKDC subjective score at baseline and 12 months improved from 45.6 to 60.7 in the LR-PRP group as compared with 46.8 to 62.9 in the LP-PRP group (P = .626). No severe adverse events were described in either group, although 15 mild adverse events (knee pain or swelling) were reported: 12.2% for LR-PRP and 4.7% for LP-PRP (P = .101). No statistically significant difference was also found between LR-PRP and LP-PRP in terms of failures (7.8% vs 3.5%, P = .331).

CONCLUSION

This double-blind randomized trial showed that 3 intra-articular LR-PRP or LP-PRP injections produced similar clinical improvement in the 12 months of follow-up in patients with symptomatic knee OA. Both treatment groups reported a low number of adverse events, without intergroup differences. The presence of leukocytes did not significantly affect the clinical results of PRP injections.

REGISTRATION

NCT02923700 (ClinicalTrials.gov identifier).

The Role of Synovial Membrane in the Development of a Potential In Vitro Model of Osteoarthritis

There is a lack of in vitro models able to plausibly represent the inflammation microenvironment of knee osteoarthritis (OA). We analyzed the molecules released from OA tissues (synovial membrane, cartilage, infrapatellar fat pad) and investigated whether the stimulation of human synovial fibroblasts (SFs), with synthetic cytokines (IL-1β and TNF-α or IFN-γ) or conditioned media (CM) from OA tissues, influence the SFs’ response, in the sense of pro-inflammatory cytokines, chemokines, growth factors, and degradative enzymes modulation. Human SFs were obtained from OA synovial membranes. SFs and their CM were analyzed for biomarkers, proliferation rate, protein profile and gene expression, before and after stimulation. Real-time PCR and multiplex assays quantified OA-related gene expression and biomolecule production. Unlike other activators, CM from OA synovial membrane (CM-SM), significantly up-regulated all genes of interest (IL-6, IL-8, MMP-1, MMP-3, RANTES, MCP-1, TSG-6, YKL-40) in SFs. Multiplex immunoassay analysis showed that levels of OA-related cytokines (IL-6, IL-8, MCP 1, IL-1Ra), chemokine (RANTES) and growth factor (VEGF), produced by CM-SM stimulated SFs, increased significantly compared to non-stimulated SFs. Molecules released from the SM from OA patients induces OA-like changes in vitro, in specific OA synovial populations (SFs). These findings promote the use and establish a compelling in vitro model that simulates the versatility and complexity of the OA disease. This model, in the future, will allow us to study new cell therapies or test drugs by reducing or avoiding animal models.

Structural origins of cartilage shear mechanics

Articular cartilage is a remarkable material able to sustain millions of loading cycles over decades of use outperforming any synthetic substitute. Crucially, how extracellular matrix constituents alter mechanical performance, particularly in shear, remains poorly understood. Here, we present experiments and theory in support of a rigidity percolation framework that quantitatively describes the structural origins of cartilage's shear properties and how they arise from the mechanical interdependence of the collagen and aggrecan networks making up its extracellular matrix. This framework explains that near the cartilage surface, where the collagen network is sparse and close to the rigidity threshold, slight changes in either collagen or aggrecan concentrations, common in early stages of cartilage disease, create a marked weakening in modulus that can lead to tissue collapse. More broadly, this framework provides a map for understanding how changes in composition throughout the tissue alter its shear properties and ultimate in vivo function.

Quantifying Region-Specific Elastic Properties of Distal Femoral Articular Cartilage: A Shear-Wave Elastography Study

Knee osteoarthritis is a disease with the degeneration of articular cartilage as its main feature. Cartilage thickness cannot become a single index to evaluate cartilage degeneration, so it is essential to also evaluate the stiffness. The purposes were as follows: (1) to examine test-retest reliabilities of the elastic modulus measurement in distal femoral articular cartilage (FAC) and compare the changes in specific-regional of distal FAC, (2) to explore the difference in distal FAC stiffness and thickness between the dominant and nondominant sides, and (3) to examine the correlation between the elastic properties of cartilage and the thickness of cartilage. Twenty healthy participants were recruited. The stiffness of distal FAC at the lateral femoral condyle (LFC), medial femoral condyle (MFC), and intercondylar notch (IN) was quantified using shear-wave elastography (SWE). Intra- and interrater reliabilities were excellent for measuring the stiffness of distal FAC (ICC: 0.83-0.98). About a 50% increase in the stiffness of LFC (40.78 kPa) was found when compared with IN (21.82 kPa) and MFC (18.34 kPa). No significant difference was found between the dominant and nondominant sides in distal FAC stiffness and thickness. There was no correlation between the stiffness and thickness of the distal FAC. In conclusion, SWE can quantify the stiffness of the distal FAC.

Autologous conditioned serum applications in the treatment of musculoskeletal diseases: a narrative review

Aim:

Autologous conditioned serum has been studied as a treatment option in musculoskeletal disorders and resulted in varying outcomes. This study aims to pool the current data on this matter.

Materials & methods:

Major databases were searched for the topics, and after screening the results, the final 21 papers (level of evidence I or II) were included.

Results & conclusion:

This study showed a major focus of the literature on the effectiveness of autologous conditioned serum in osteoarthritis, in which there is much high-quality evidence suggesting its safety and efficacy. Also, some of the available experiments are assessing its application in tendinopathies and radiculopathies which, despite positive results, recommend further evaluations on this topic.

Autologous conditioned serum (ACS) is a cell-free blood product rich in anti-inflammatory components; this study aims to provide a review of the available data on its clinical applications in musculoskeletal disorders. The most studied subject was joint diseases and mainly osteoarthritis, for which some high-quality papers suggested ACS to be an effective and safe option. A few papers assessed the effectiveness of ACS in soft tissue injuries like tendinopathies and plantar fasciitis, and also cervical and lumbar radiculopathies in human subjects; despite some positive results, a further high-quality investigation is required on this matter.

The Association between Gut Microbiota and Osteoarthritis: Does the Disease Begin in the Gut?

Some say that all diseases begin in the gut. Interestingly, this concept is actually quite old, since it is attributed to the Ancient Greek physician Hippocrates, who proposed the hypothesis nearly 2500 years ago. The continuous breakthroughs in modern medicine have transformed our classic understanding of the gastrointestinal tract (GIT) and human health. Although the gut microbiota (GMB) has proven to be a core component of human health under standard metabolic conditions, there is now also a strong link connecting the composition and function of the GMB to the development of numerous diseases, especially the ones of musculoskeletal nature. The symbiotic microbes that reside in the gastrointestinal tract are very sensitive to biochemical stimuli and may respond in many different ways depending on the nature of these biological signals. Certain variables such as nutrition and physical modulation can either enhance or disrupt the equilibrium between the various species of gut microbes. In fact, fat-rich diets can cause dysbiosis, which decreases the number of protective bacteria and compromises the integrity of the epithelial barrier in the GIT. Overgrowth of pathogenic microbes then release higher quantities of toxic metabolites into the circulatory system, especially the pro-inflammatory cytokines detected in osteoarthritis (OA), thereby promoting inflammation and the initiation of many disease processes throughout the body. Although many studies link OA with GMB perturbations, further research is still needed.

Ononin ameliorates inflammation and cartilage degradation in rat chondrocytes with IL-1β-induced osteoarthritis by downregulating the MAPK and NF-κB pathways

BACKGROUND

Osteoarthritis (OA) treatment aims to improve inflammation and delay cartilage degeneration. However, there is no effective strategy presently available. Ononin, a representative isoflavone glycoside component extracted from natural Chinese herbs, exerts anti-inflammatory and proliferative effects. However, the therapeutic effect of ononin on chondrocyte inflammation remains unclear.

METHODS

In this study, we explored the therapeutic effect and potential mechanism of ononin in OA by establishing an interleukin-1 beta (IL-1β)-induced chondrocyte inflammation model.

RESULTS

Our results verified that ononin alleviated the IL-1β-induced decrease in chondrocyte viability, attenuated the overexpression of the inflammatory factors tumour necrosis factor α (TNF-α) and interleukin 6 (IL-6), and simultaneously inhibited the expression of cartilage extracellular matrix (ECM)-degrading enzymes such as matrix metalloproteinase-13 (MMP-13). Furthermore, the decomposition of Collagen II protein could be alleviated in the OA model by ononin. Finally, ononin improved chondrocyte inflammation by downregulating the mitogen-activated protein kinase (MAPK) and nuclear factor kappa-B (NF-κB) signalling pathways.

CONCLUSION

Our findings suggested that ononin could inhibit the IL-1β-induced proinflammatory response and ECM degradation in chondrocytes by interfering with the abnormal activation of the MAPK and NF-κB pathways, indicating its protective effect against OA.

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.

Wearable transcutaneous electrical nerve stimulation (actiTENS®) is effective and safe for the treatment of knee osteoarthritis pain: a randomized controlled trial versus weak opioids

INTRODUCTION

Despite their poor tolerance, especially in the elderly, weak opioids (WO) remain commonly prescribed for patients with knee osteoarthritis (KOA). We compared the efficacy and safety of a new wearable transcutaneous electrical nerve stimulation (W-TENS) device with WO for the treatment of moderate-to-severe, nociceptive KOA chronic pain.

METHODS

The study was a non-inferiority, multicentric, prospective, randomized, single-blind, controlled, 2-parallel groups Trial. A total of 110 patients with KOA were included (Kellgren-Lawrence radiographic grade ⩾2; American College of Rheumatology criteria), with chronic moderate-to-severe nociceptive pain (mean 8-day pain intensity (PI) ⩾ 4 on an 11-point numerical rating scale), in failure to non-opioid analgesics, including nonsteroidal anti-inflammatory drugs (NSAIDs). Patients with neuropathic pain were excluded. The co-primary endpoints were mean PI at 3 months (M3) and number of potentially treatment-related adverse events (TRAEs). Secondary outcomes included Western Ontario MAC Master University function subscale (range, 0-68), additional pain and quality of life measures, and responder rates.

RESULTS

The non-inferiority of W-TENS was demonstrated in both the per protocol (PP) and intent-to-treat (ITT) populations. At M3, PI in PP population was 3.87 (2.12) compared with 4.66 (2.37) [delta: -0.79 (0.44); 95% CI (-1.65, 0.08)] in W-TENS and WO groups, respectively. A planned superiority analysis showed a significant superiority of W-TENS over WO on PI at M3 (p = 0.0124). The number of TRAEs was significantly lower in the W-TENS group (n = 7) than in the WO group (n = 36) (p < 0.001). Other secondary outcomes also favored W-TENS.

CONCLUSION

W-TENS was more effective and better tolerated than WO in the treatment of chronic nociceptive KOA pain and offers an interesting non-pharmacological analgesic alternative in the management of KOA.Trial Registration: ClinicalTrials.gov: NCT03902340.

Biomaterials-assisted exosomes therapy in osteoarthritis

Due to the avascular characteristic of articular cartilage, its self-repair capacity is limited. When cartilage is damaged or forms osteoarthritis, clinical treatment is necessary. However, conventional treatments, including joint replacement, microfracture, cell and drug therapies, have certain limits. Lately, the exosomes derived from mesenchymal stem cells (MSCs-EXO), which consist of complex transcription factors, proteins and targeting ligand components, have shown great therapeutic potentials. With recent advancements in various biomaterials to extend MSCs-EXO's retention time and control the release properties in vivo, biomaterials-assisted exosomes therapy has been soon becoming a practically powerful tool in treating OA. This review analyzes the effects of MSCs-EXO on osteoarthritis inflammation, metabolism, ageing and apoptosis, and introduces the combinational systems of MSCs-EXO with biomaterials to enhance the repair, anti-inflammatory, and homeostasis regulation functions. Moreover, different types of natural or synthetic biomaterials and their applications with MSCs-EXO were also described and discussed. And finally, we presage the future perspective in the development of biomaterial-assisted exosome therapies, as well as the potential to incorporate with other treatments to enhance their therapeutic effects in osteoarthritis.

Biomechanical Characteristics of the Knee Joint during Gait in Obese versus Normal Subjects

Knee osteoarthritis (OA) is a growing source of pain and disability. Obesity is the most important avoidable risk factor underlying knee OA. The processes by which obesity impacts osteoarthritis are of tremendous interest to osteoarthritis researchers and physicians, where the joint mechanical load is one of the pathways generally thought to cause or intensify the disease process. In the current work, we developed a hybrid framework that simultaneously incorporates a detailed finite element model of the knee joint within a musculoskeletal model to compute lower extremity muscle forces and knee joint stresses in normal-weight (N) and obese (OB) subjects during the stance phase gait. This model accounts for the synergy between the active musculature and passive structures. In comparing OB subjects and normal ones, forces significantly increased in all muscle groups at most instances of stance. Mainly, much higher activation was computed with lateral hamstrings and medial gastrocnemius. Cartilage contact average pressure was mostly supported by the medial plateau and increased by 22%, with a larger portion of the load transmitted via menisci. This medial compartment experienced larger relative movement and cartilage stresses in the normal subjects and continued to do so with a higher level in the obese subjects. Finally, the developed bioengineering frame and the examined parameters during this investigation might be useful clinically in evaluating the initiation and propagation of knee OA.

The synthetic artificial stem cell (SASC): Shifting the paradigm of cell therapy in regenerative engineering

This paper presents the synthetic artificial stem cell (SASC) system: a versatile therapy which provides the ability to tailor paracrine responses of different cells and provide a more potent regenerative effect for targeted tissues. Upon challenging the SASC system against an osteoarthritis model, we demonstrate that the factors combined tailored for chondrogenesis have a potent antiinflammatory and chondroprotective effect. This paper also demonstrates the in vivo capacity of SASC to attenuate proteoglycan depletion in the cartilage extracellular matrix while also improving biomechanical properties of the resulting cartilage. We report the first of many applications of the SASC system, which provides a promising step toward clinical translation of a minimally immunogenic stem cell with many commercial advantages over its biological counterpart.

Stem cells are of great interest in tissue regeneration due to their ability to modulate the local microenvironment by secreting bioactive factors (collectively, secretome). However, secretome delivery through conditioned media still requires time-consuming cell isolation and maintenance and also may contain factors antagonistic to targeted tissue regeneration. We have therefore engineered a synthetic artificial stem cell (SASC) system which mimics the paracrine effect of the stem cell secretome and provides tailorability of the composition for targeted tissue regeneration. We report the first of many applications of the SASC system we have formulated to treat osteoarthritis (OA). Choosing growth factors important to chondrogenesis and encapsulating respective recombinant proteins in poly (lactic-coglycolic acid) 85:15 (PLGA) we fabricated the SASC system. We compared the antiinflammatory and chondroprotective effects of SASC to that of adipose-derived stem cells (ADSCs) using in vitro interleukin 1B-induced and in vivo collagenase-induced osteoarthritis rodent models. We have designed SASC as an injectable therapy with controlled release of the formulated secretome. In vitro, SASC showed significant antiinflammatory and chondroprotective effects as seen by the up-regulation of SOX9 and reduction of nitric oxide, ADAMTS5, and PRG4 genes compared to ADSCs. In vivo, treatment with SASC and ADSCs significantly attenuated cartilage degeneration and improved the biomechanical properties of the articular cartilage in comparison to OA control. This SASC system demonstrates the feasibility of developing a completely synthetic, tailorable stem cell secretome which reinforces the possibility of developing a new therapeutic strategy that provides better control over targeted tissue engineering applications.

An Investigation into the Effects of a Curcumin Extract (Curcugen®) on Osteoarthritis Pain of the Knee: A Randomised, Double-Blind, Placebo-Controlled Study

Curcumin, a phytochemical from the spice turmeric, has anti-inflammatory properties and has been shown to have pain-relieving effects. In this 8-week, randomised, double-blind, placebo-controlled study, 101 adults with knee osteoarthritis received either 500 mg twice daily of a standardised curcumin extract (Curcugen^®) or placebo. Outcome measures included the Knee Injury and Osteoarthritis Outcome Score (KOOS), knee pain ratings, Japanese Orthopaedic Association Score for Osteoarthritic Knees (JOA), PROMIS-29, and performance-based testing comprising the 40-m fast-paced walk test, 6-min walk test, timed up-and-go test, and 30-s chair stand test. Compared to the placebo, curcumin significantly reduced the KOOS knee pain score (p = 0.009) and numeric knee pain ratings (p = 0.001). Curcumin was also associated with greater improvements (p ≤ 0.05) than the placebo on the timed up-and-go test, 6-min walk test, and the JOA total score; but not the 30-s chair stand test or 40-m fast-paced walk test. Pain-relieving medication was reduced in 37% of participants on curcumin compared to 13% on placebo. The findings support the potential efficacy of curcumin for the treatment of osteoarthritis of the knee but studies of longer duration, varying treatment doses, differing curcumin extracts, and the use of other objective outcome measures will be helpful to expand on these findings.

Advances on biological functions of exosomal non-coding RNAs in osteoarthritis

Exosomes can be secreted by various cells and function as intercellular communication vehicles by delivering specific cargoes from the donor cells to the recipient cells through their paracrine activity. Recently, an increasing number of studies have shown that non-coding RNAs (ncRNAs) could be entrapped in and transferred between cartilage-related cells as exosomal cargoes to modulate the expression of various target genes by regulation at post-transcriptional and post-translational levels. They are mainly comprised of microRNAs, long non-coding RNAs, and circular RNAs. Articular cartilage degeneration is one of the main pathological features of osteoarthritis. Exosomal ncRNAs are involved in pathological processes of osteoarthritis, such as proliferation, migration, chondrogenesis, chondrocyte differentiation induction, extracellular matrix formation, apoptosis, and inflammation. In this review, we summarize the biological functions of exosomal ncRNAs in cartilage homeostasis and osteoarthritis progression and discuss the perspectives and challenges of exosomal ncRNAs application for osteoarthritis patients in the future. Exosomal ncRNA has an important regulatory role in the pathogenesis of osteoarthritis, but more evidence is needed for clinical application.

Method Categorization of Stem Cell Therapy for Degenerative Osteoarthritis of the Knee: A Review

Current clinical applications of mesenchymal stem cell therapy for osteoarthritis lack consistency because there are no established criteria for clinical processes. We aimed to systematically organize stem cell treatment methods by reviewing the literature. The treatment methods used in 27 clinical trials were examined and reviewed. The clinical processes were separated into seven categories: cell donor, cell source, cell preparation, delivery methods, lesion preparation, concomitant procedures, and evaluation. Stem cell donors were sub-classified as autologous and allogeneic, and stem cell sources included bone marrow, adipose tissue, peripheral blood, synovium, placenta, and umbilical cord. Mesenchymal stem cells can be prepared by the expansion or isolation process and attached directly to cartilage defects using matrices or injected into joints under arthroscopic observation. The lesion preparation category can be divided into three subcategories: chondroplasty, microfracture, and subchondral drilling. The concomitant procedure category describes adjuvant surgery, such as high tibial osteotomy. Classification codes were assigned for each subcategory to provide a useful and convenient method for organizing documents associated with stem cell treatment. This classification system will help researchers choose more unified treatment methods, which will facilitate the efficient comparison and verification of future clinical outcomes of stem cell therapy for osteoarthritis.

Platelet-rich plasma injections induce disease-modifying effects in the treatment of osteoarthritis in animal models

PURPOSE

The mechanisms of action and disease-modifying potential of platelet-rich plasma (PRP) injection for osteoarthritis (OA) treatment are still not fully established. The aim of this systematic review of preclinical evidence was to determine if PRP injections can induce disease-modifying effects in OA joints.

METHODS

A systematic review was performed on animal studies evaluating intra-articular PRP injections as treatment for OA joints. A synthesis of the results was performed investigating the disease-modifying effects of PRP by evaluating studies that compared PRP with OA controls or other injectable products, different PRP formulations or injection intervals, and the combination of PRP with other products. The risk of bias was assessed according to the SYRCLE's tool.

RESULTS

Forty-four articles were included, for a total of 1251 animals. The publication trend remarkably increased over time. PRP injections showed clinical effects in 80% and disease-modifying effects in 68% of the studies, attenuating cartilage damage progression and reducing synovial inflammation, coupled with changes in biomarker levels. Evidence is limited on the best PRP formulation, injection intervals, and synergistic effect with other injectables. The risk of bias was low in 40%, unclear in 56%, and high in 4% of items.

CONCLUSION

Intra-articular PRP injections showed disease-modifying effects in most studies, both at the cartilage and synovial level. These findings in animal OA models can play a crucial role in understanding mechanism of action and structural effects of this biological approach. Nevertheless, the overall low quality of the published studies warrants further preclinical studies to confirm the positive findings, as well as high-level human trials to demonstrate if these results translate into disease-modifying effects when PRP is used in the clinical practice to treat OA.

LEVEL OF EVIDENCE

Level II.

In Vitro and In Vivo Effects of Light Therapy on Cartilage Regeneration for Knee Osteoarthritis: A Systematic Review

OBJECTIVE

To analyze the effects of light therapy (LT) on cartilage repair for knee osteoarthritis (OA) treatment.

DESIGN

The PubMed, Embase, Scopus, and Web of Science databases were searched up to August 31, 2020 to identify in vitro and in vivo studies that analyzed the effects of LT on knee cartilage for OA treatment. The study and sample characteristics, LT intervention parameters and posttreatment outcomes were analyzed. Risk of bias was assessed using the Risk of Bias Assessment for Non-randomized Studies (RoBANS) tool.

RESULTS

Three in vitro and 30 in vivo studies were included. Most studies were judged as high risk of performance and detection bias. Biochemical outcomes were analyzed for both in vitro and in vivo studies, and histological and behavioral outcomes were analyzed for in vivo studies. LT reduced extracellular matrix (ECM) degradation, inflammation, and OA progression, promoting ECM synthesis. LT improved pain-like behavior in animal models, having no apparent effect on gait performance. There were conflicting findings of some of the biochemical, histological, and behavioral outcomes.

CONCLUSION

The included studies presented different strategies and LT parameters. LT resulted in positive effects on cartilage repair and may be an adequate therapy for OA treatment.

An Insight into the Role of Apoptosis and Autophagy in Nitric Oxide-Induced Articular Chondrocyte Cell Death

OBJECTIVE

To investigate the role and characterize the molecular mechanisms regulating apoptosis and autophagy in nitric oxide (NO)-induced chondrocyte cell death.

DESIGN

Cell apoptosis and autophagy were evaluated in chondrocytes treated with sodium nitroprusside (SNP) combined with the presence or absence of interleukin-1 beta (IL-1β) and nutrient-deprived conditions. The concentration of nitrite was determined by Griess reaction. Activation of apoptosis and autophagy were determined by immunocytochemistry, Western blot, and quantitative real-time polymerase chain reaction (qPCR) analysis. Flow cytometry and MTT assay were used to assess cell viability.

RESULTS

Cotreatment of chondrocytes with SNP and IL-1β under nutrient-deprived condition potentially enhanced the effect of NO-induced cell death. Immunocytochemistry, Western blot, and qPCR analysis indicated that treatment of chondrocytes with SNP significantly reduced autophagic activity, autophagic flux, and multiple autophagy-related (Atg) genes expression. These findings were associated with an increase in ERK, Akt, and mTOR phosphorylation, whereas autophagy induction through mTOR/p70S6K inhibition by rapamycin significantly suppressed NO-induced cell apoptosis. Furthermore, the cleavage of poly(ADP-ribose) polymerase (PARP) and caspase-3 activation in response to apoptosis was weakly detected. These results corresponded with a significant increase in apoptosis-inducing factor (AIF) expression, suggesting the involvement of the caspase-independent pathway.

CONCLUSIONS

These results demonstrate that in chondrocyte cultures with cells induced into an osteoarthritis state, NO inhibits autophagy and induces chondrocyte apoptosis mainly, but not completely through the caspase-independent pathway. Our data suggest that autophagy is a protective mechanism in the pathogenesis of osteoarthritis and could be proposed as a therapeutic target for degenerative joint diseases.

State of art in intra-articular hip injections of different medications for osteoarthritis: a systematic review

BACKGROUND

Intra-articular hip injections for osteoarthritis represent a useful instrument to reduce pain and disability in the common clinical practice. Several medications can be injected locally with different level of evidence-based efficacy.

OBJECTIVE

The objective of this systematic review is to investigate the effectiveness of intra-articular injections of different medications or substances for the pain treatment and the management of disability in subjects affected by hip osteoarthritis.

METHODS

Two reviewers selected independently randomised controlled trials published in the last 10 years, using PubMed and Scopus databases. The risk of bias was evaluated with Cochrane library assessment tool.

RESULTS

12 randomised controlled trials have been selected. We found 8 papers comparing hyaluronic acid with platelet rich plasma, with corticosteroids and with saline solution; 1 paper compares two types of hyaluronic acid with different molecular weights; 3 papers study the effects of corticosteroids alone or compared to ketorolac or saline solution.

CONCLUSIONS

The studies reviewed were heterogeneous regarding sample size, level of osteoarthritis, evaluated with Kellegren-Lawrence score, medications used and follow up timings. However, we have observed that intra-articular injections of platelet-rich plasma seem to decrease pain at short term and disability at long term, in patients affected by hip osteoarthritis better than hyaluronic acid. The association of hyaluronic acid and corticosteroids could give better results compared to hyaluronic acid alone, while the use of intra-articular ketorolac and saline solution requires more studies.

Patients' Use of Mobile Health for Self-management of Knee Osteoarthritis: Results of a 6-Week Pilot Study

Background

In a previous study, a prototype mobile health (mHealth) app was co-designed with patients, family physicians, and researchers to enhance self-management and optimize conservative management for patients with mild to moderate knee osteoarthritis (OA).

Objective

This study aims to evaluate the overall usability, quality, and effectiveness of the mHealth app prototype for aiding knee OA self-management from the perspectives of patients with OA and health care providers (HCPs).

Methods

Using methods triangulation of qualitative and quantitative data, we conducted a pilot evaluation of an mHealth app prototype that was codeveloped with patients and HCPs. We recruited adult patients aged ≥20 years with early knee OA (n=18) who experienced knee pain on most days of the month at any time in the past and HCPs (n=7) to participate. In the qualitative assessment, patient and HCP perspectives were elicited on the likeability and usefulness of app features and functionalities and the perceived impact of the app on patient-HCP communication. The quantitative assessment involved evaluating the app using usability, quality, and effectiveness metrics. Patient baseline assessments included a semistructured interview and survey to gather demographics and assess the quality of life (European Quality-of-Life 5-Dimension 5-Level Questionnaire [EQ-5D-5L]) and patient activation (patient activation measure [PAM]). Following the 6-week usability trial period, a follow-up survey assessed patients’ perceptions of app usability and quality and longitudinal changes in quality of life and patient activation. Semistructured interviews and surveys were also conducted with HCPs (n=7) at baseline to evaluate the usability and quality of the app prototype.

Results

Interviews with patients and HCPs revealed overall positive impressions of the app prototype features and functionalities related to likeability and usefulness. Between the baseline and follow-up patient assessments, the mean EQ-5D-5L scores improved from 0.77 to 0.67 (P=.04), and PAM scores increased from 80.4 to 87.9 (P=.01). Following the 6-week evaluation, patients reported a mean System Usability Scale (SUS) score of 57.8, indicating marginal acceptability according to SUS cutoffs. The mean number of goals set during the usability period was 2.47 (SD 3.08), and the mean number of activities completed for knee OA self-management during the study period was 22.2 (SD 17.8). Spearman rank correlation (r_s) calculations revealed that the follow-up PAM scores were weakly correlated (r_s=−0.32) with the number of goals achieved and the number (r_s=0.19) of activities performed during the 6-week usability period. HCPs reported a mean SUS score of 39.1, indicating unacceptable usability.

Conclusions

This evidence-based and patient-centered app prototype represents a potential use of mHealth for improving outcomes and enhancing conservative care by promoting patient activation and patient-HCP communication regarding OA management. However, future iterations of the app prototype are required to address the limitations related to usability and quality.

Monocytes, Macrophages, and Their Potential Niches in Synovial Joints - Therapeutic Targets in Post-Traumatic Osteoarthritis?

Synovial joints are complex structures that enable normal locomotion. Following injury, they undergo a series of changes, including a prevalent inflammatory response. This increases the risk for development of osteoarthritis (OA), the most common joint disorder. In healthy joints, macrophages are the predominant immune cells. They regulate bone turnover, constantly scavenge debris from the joint cavity and, together with synovial fibroblasts, form a protective barrier. Macrophages thus work in concert with the non-hematopoietic stroma. In turn, the stroma provides a scaffold as well as molecular signals for macrophage survival and functional imprinting: “a macrophage niche”. These intricate cellular interactions are susceptible to perturbations like those induced by joint injury. With this review, we explore how the concepts of local tissue niches apply to synovial joints. We introduce the joint micro-anatomy and cellular players, and discuss their potential interactions in healthy joints, with an emphasis on molecular cues underlying their crosstalk and relevance to joint functionality. We then consider how these interactions are perturbed by joint injury and how they may contribute to OA pathogenesis. We conclude by discussing how understanding these changes might help identify novel therapeutic avenues with the potential of restoring joint function and reducing post-traumatic OA risk.

Immunomodulatory Actions of Mesenchymal Stromal Cells (MSCs) in Osteoarthritis of the Knee

Cellular therapy offers regeneration which curbs osteoarthritis of the knee. Among cellular therapies, mesenchymal stromal cells (MSCs) are readily isolated from various sources as culture expanded and unexpanded cellular population which are used as therapeutic products. Though MSCs possess a unique immunological and regulatory profile through cross-talk between MSCs and immunoregulatory cells (T cells, NK cells, dendritic cells, B cells, neutrophils, monocytes, and macrophages), they provide an immunotolerant environment when transplanted to the site of action. Immunophenotypic profile allows MSCs to escape immune surveillance and promotes their hypoimmunogenic or immune-privileged status. MSCs do not elicit a proliferative response when co-cultured with allogeneic T cells in vitro. MSCs secrete a wide range of anti-inflammatory mediators such as PGE-2, IDO, IL-1Ra, and IL-10. They also stimulate the resilient chondrogenic progenitors and enhance the chondrocyte differentiation by secretion of BMPs and TGFβ1. We highlight the various mechanisms of MSCs during tissue healing signals, their interaction with the immune system, and the impact of their lifespan in the management of osteoarthritis of the knee. A better understanding of the immunobiology of MSC renders them as an efficient therapeutic product for the management of osteoarthritis of the knee.

The Role of Vitamin D in Early Knee Osteoarthritis and Its Relationship with Their Physical and Psychological Status

Osteoarthritis (OA) is a common joint condition and one of the greatest causes of disability worldwide. The role of vitamin D in the origin and development of the disease is not clear, although it could have important implications for diagnosis and treatment. For this proposal, a cross-sectional study with a non-probabilistic sample was performed. In total, 48 with early osteoarthritis (EOA) and 48 matched controls were selected, and serum 25(OH)D and parathyroid hormone (PTH) levels were analyzed. In addition, physical and psychological variables were measured to establish their relationship with vitamin D levels. Patients with EOA showed lower levels (22.3 ± 7.3 ng/mL) in comparison to matched controls (29.31 ± 9.2 ng/mL). A statistically significant higher number (Chi-squared = 8.525; p = 0.004) of patients with EOA had deficiency levels (<20 ng/mL) compared to the control group. Patients with lower vitamin D levels showed higher levels of pain intensity, disability, and anxiety, as well as poorer values for sit-to-stand, walking speed, and social participation. Correlation analysis showed a relationship between serum 25(OH)D, PTH and pain intensity, and social participation. These results highlight the relevance of vitamin D in the early diagnosis and prevention of EOA.

A Comprehensive Review of Viscosupplementation in Osteoarthritis of the Knee

Purpose of Review

The purpose of this systematic review is to discuss emerging evidence in the field of viscosupplementation for chronic knee pain secondary to Osteoarthritis (OA). This review focuses on types of viscosupplementation that are clinically available currently, evidence to support their use, contraindications, and adverse events.

Recent Findings

OA, also known as degenerative joint disease, is the most common form of arthritis in the United States, affecting 54.4 million, or 22.7% of the adult population. The knee is the most common joint affected in OA, with up to 41% involvement, 30% in the hands, and 19% in the hips. The pathophysiology of OA is complex, with contributing factors including mechanical stress to the joint, as well as many person-specific factors such as genetic susceptibility, ethnicity, nutrition, and sex. Treatment modalities include weight control, exercise, non-steroidal and steroidal anti-inflammatory drugs, opioids, intra-articular platelet-rich plasma, placebo, corticosteroid injection, intra-articular viscosupplementation, and surgery. Viscosupplementation consists of injection of hyaluronic acid (HA) into affected joints, intending to restore the physiologic viscoelasticity in the synovial fluid (SF) in the absence of inflammation. HA has also been shown to downregulate pro-inflammatory factors, such as PGE2 and NFkB, and proteases and proteinases known to break down the joint matrix.The contraindications for HA injection are similar to any other injection therapy, and adverse events are usually mild, local, and transient. Viscosupplementation (VS) is effective over placebo and more effective than NSAIDs and corticosteroids in pain reduction and improved functionality; however, guidelines recommend neither for nor against its use, demonstrating variability in the existing evidence base.Current VS options divide primarily into native vs. cross-linked and low-molecular-weight vs. high-molecular-weight. Current treatment options include Hylan g-f-20, Sodium Hyaluronate preparations (Suparts Fx, Euflexxa, Gelsyn-3, Durolane, Hyalgen), single-use agents (Gel-One, Synvisc-One, Monovisc), and Hyaluronan (Orthovisc, Monovisc, Hymovic). They share a common safety profile, and all have evidence supporting their efficacy. Their specific details are reviewed here.

Summary

OA is the most common form of arthritis. It is a chronic, debilitating illness with a high impact on the functionality and quality of life of a significant part of the population in the western world. Treatments include medical management, physical therapy, activity modification, injection, and surgery. VS effectively reduces pain, increases functionality, and delays surgery in the knee to treat osteoarthritis. While previous studies have demonstrated variable results, more evidence is becoming available generally supportive of the benefit of VS in the treatment of knee OA.

Effectiveness of intra-articular autologous-conditioned serum injection in knee osteoarthritis: a meta-analysis study

Aim

Knee osteoarthritis is a common disabling disorder, with no curative treatment. This study aims to assess autologous conditioned serum effectiveness in its treatment.

Materials & methods

Following a systematic search (2000-2020) on major databases and screening and filtering processes, eight articles were included in the final analyses. The pooled effect of visual analog scale (VAS) and the Western Ontario and McMaster Universities (WOMAC) variables was evaluated before and after the intervention.

Results

The combined standardized mean difference for the global WOMAC score was -2.44 and the combined weighted mean difference was -22.92. The combined standardized mean difference for the VAS score was -3.77 and the combined weighted mean difference was -32.37 (p < 0.000).

Conclusion

This meta-analysis reported that the autologous conditioned serum can reduce pain and improve function (VAS and WOMAC outcome measures) in patients with knee osteoarthritis.

The Efficacy of Harpagophytum procumbens (Teltonal) in Patients with Knee Osteoarthritis: A Randomized Active-Controlled Clinical Trial

Purpose

The high prevalence of knee osteoarthritis (KOA) is a major cause of disability among elders. NSAIDs are recommended to reduce KOA patients' symptoms, but their adverse side effects limit their consumption. In this study, we evaluated the effectiveness of Harpagophytum procumbens compared to a routine NSAID (meloxicam) on pain reduction and functional improvement of KOA patients. Patients and Methods. Sixty patients aged 40–60 years, with painful knee osteoarthritis (grades 1-2 of Kellgren–Lawrence scale) for at least one month, were randomized into two groups with different routine medication periods. Group A consisted of daily administration of two Harpagophytum procumbens (Teltonal) tablets (2∗480 mg) for one month, and group B consisted of daily administration of meloxicam (15 mg) for ten days. The visual analogue scale (VAS), Western Ontario McMaster University Osteoarthritis Index (WOMAC), Oxford Knee Scale (OKS), and patient satisfaction were evaluated at the baseline and after 2, 4, and 8 weeks.

Results

There were no statistically significant differences between demographic characteristics, pain intensity, and function scores before the treatment. VAS, OKS, and WOMAC scores improved in both groups (p < 0.001) over time, but no significant superiority was shown; after 8 weeks: VAS (Teltonal (4.80 ± 1.80) vs. meloxicam (5.06 ± 1.43)), OKS (34.06 ± 4.38, 34.00 ± 7.87, Teltonal vs. meloxicam, respectively), and WOMAC scores (25.73 ± 10.11 Teltonal vs. 26.20 ± 13.94, meloxicam).

Conclusion

Teltonal is an effective and safe treatment in patients with mild KOA in the short term. However, no significant superiority was shown in using Teltonal or meloxicam, in people who cannot take NSAIDs, it can be a good alternative, although difference in medication periods should be considered.

Mesenchymal Stem Cell-Derived Exosomes and MicroRNAs in Cartilage Regeneration: Biogenesis, Efficacy, miRNA Enrichment and Delivery

Exosomes are the small extracellular vesicles secreted by cells for intercellular communication. Exosomes are rich in therapeutic cargos such as microRNA (miRNA), long non-coding RNA (lncRNA), small interfering RNA (siRNA), DNA, protein, and lipids. Recently, many studies have focused on miRNAs as a promising therapeutic factor to support cartilage regeneration. Exosomes are known to contain a substantial amount of a variety of miRNAs. miRNAs regulate the post-transcriptional gene expression by base-pairing with the target messenger RNA (mRNA), leading to gene silencing. Several exosomal miRNAs have been found to play a role in cartilage regeneration by promoting chondrocyte proliferation and matrix secretion, reducing scar tissue formation, and subsiding inflammation. The exosomal miRNA cargo can be modulated using techniques such as cell transfection and priming as well as post-secretion modifications to upregulate specific miRNAs to enhance the therapeutic effect. Exosomes are delivered to the joints through direct injection or via encapsulation within a scaffold for sustained release. To date, exosome therapy for cartilage injuries has yet to be optimized as the ideal cell source for exosomes, and the dose and method of delivery have yet to be identified. More importantly, a deeper understanding of the role of exosomal miRNAs in cartilage repair is paramount for the development of more effective exosome therapy.

Intra-articular steroid injections in large joint arthritis: A survey of current practice

INTRODUCTION

Intra-articular corticosteroid injections are widely used as a management modality for mild large joint osteoarthritis (OA). In contrast, there is little guidance or consensus on the use of steroids in moderate to severe disease. The aim of this study is to explore the current practice of surgeons in relation to the use of therapeutic intra-articular steroid injections in patients awaiting large joint arthroplasty for OA.

METHODS

An anonymous questionnaire was distributed to consultants performing large joint arthroplasty in four National Health Service Trusts. Participants were questioned on their use of intra-articular therapeutic steroid injections in patients listed for elbow, shoulder, hip or knee arthroplasty. Data was collected over 6 months and analysed using Microsoft Excel.

RESULTS

A total of 42 surgeons were included in the study with the majority performing lower limb arthroplasty (73%). About 21 (50%) surgeons indicated they would perform injections in the patient group of interest. Two would perform an unlimited number of injections, whilst the remainder would perform between one and three injections. Respondents most commonly indicated they would tell patients that an injection would provide between 6 and 12 weeks of benefit (14 of 39 surgeons, 36%). Most injecting surgeons (88%) leave 4 months between an injection and subsequent arthroplasty due to increased risk of infection if surgery is performed sooner.

CONCLUSION

This study demonstrates variation in practice in the use of intra-articular steroids in the analysed patient group, and the way surgeons council their patients. National or specialist society guidelines may help to reduce this variation in practice.