Effects of a Single Intra-Articular Injection of a Microsphere Formulation of Triamcinolone Acetonide on Knee Osteoarthritis Pain: A Double-Blinded, Randomized, Placebo-Controlled, Multinational Study

Advances in viscosupplementation and tribosupplementation for early-stage osteoarthritis therapy

Joint kinematic instability, arising from congenital or acquired musculoskeletal pathoanatomy or from imbalances in anabolism and catabolism induced by pathophysiological factors, leads to deterioration of the composition, structure and function of cartilage and, ultimately, progression to osteoarthritis (OA). Alongside articular cartilage degeneration, synovial fluid lubricity decreases in OA owing to a reduction in the concentration and molecular weight of hyaluronic acid and surface-active mucinous glycoproteins that form a lubricating film over the articulating joint surfaces. Minimizing friction between articulating joint surfaces by lubrication is fundamental for decreasing hyaline cartilage wear and for maintaining the function of synovial joints. Augmentation with highly viscous supplements (that is, viscosupplementation) offers one approach to re-establishing the rheological and tribological properties of synovial fluid in OA. However, this approach has varied clinical outcomes owing to limited intra-articular residence time and ineffective mechanisms of chondroprotection. This Review discusses normal hyaline cartilage function and lubrication and examines the advantages and disadvantages of various strategies for restoring normal joint lubrication. These strategies include contemporary viscosupplements that contain antioxidants, anti-inflammatory drugs or platelet-rich plasma and new synthetic synovial fluid additives and cartilage matrix enhancers. Advanced biomimetic tribosupplements offer promise for mitigating cartilage wear, restoring joint function and, ultimately, improving patient care.

Intra-articular corticosteroids for the treatment of osteoarthritis: A systematic review and meta-analysis on the comparison of different molecules and doses

Purpose

The purpose of this study was to quantify and compare the clinical relevance of the different intra-articular corticosteroids (CS) effects in vivo for osteoarthritis (OA) treatment.

Methods

The search was conducted on PubMed, Cochrane, and Web of Science in October 2023. The PRISMA guidelines were used. Inclusion criteria: animal or human randomized controlled trials (RCTs), English language and no time limitation, on the comparison of different intra-articular CS for OA treatment. The articles' quality was assessed using the Cochrane RoB2 and GRADE guidelines for human RCTs, and SYRCLE's tool for animal RCTs.

Results

Eighteen RCTs were selected (16 human and 2 animal studies), including 1577 patients (1837 joints) and 31 animals (51 joints). The CS used were triamcinolone (14 human and 2 animal studies), methylprednisolone (7 human and 1 animal study), betamethasone (3 human studies) and dexamethasone (1 human study). All studies addressed knee OA except for three human and one animal study. A meta-analysis was performed on the comparison of methylprednisolone and triamcinolone in humans with knee OA analysing VAS pain at very short- (≤2 weeks), short- (>2 and ≤4 weeks), mid- (>4 and ≤8 weeks), long- (>8 and ≤ 12 weeks), and very long-term (>12 and ≤24 weeks). Triamcinolone showed better post-injection values compared to methylprednisolone at very short-term (p = 0.028). No difference in terms of VAS improvement was observed at any follow-up.

Conclusions

The available preclinical and clinical literature provides limited evidence on the comparison of different CS, hindering the possibility of determining the best CS approach in terms of molecule and dose for the intra-articular injection of OA joints.

Level of Evidence

Level I.

The efficacy and safety of a fixed-dose combination of apocynin and paeonol, APPA, in symptomatic knee OA: A double-blind, randomized, placebo-controlled, clinical trial

OBJECTIVE

Apocynin (AP) and paeonol (PA) are low molecular weight phenolic compounds with a broad array of anti-inflammatory and immunoregulatory effects. This study assessed of a fixed-dose combination of APPA in people with symptomatic knee osteoarthritis (OA).

METHODS

A multi-center, randomized, placebo-controlled, double-blind phase 2a trial enrolled participants with radiographic knee OA (Kellgren-Lawrence, KL, grades 2-3) and pain ≥40/100 on WOMAC pain subscale, and evaluated the efficacy and safety of oral APPA over a 28-day period. APPA 800 mg or matching placebo was administered twice daily in a 1:1 ratio. Post-hoc analyses explored the response to APPA in sub-groups with more severe pain and structural severity.

RESULTS

The two groups were comparable at baseline; 152 subjects were enrolled and 148 completed the trial. There was no statistically significant difference between groups with respect to the primary outcome, WOMAC pain (mean difference between groups was -0.89, 95% CI: -5.62, 3.84, p = 0.71), nor WOMAC function or WOMAC total. However, predefined subgroup analyses of subjects with symptoms compatible with nociplastic/neuropathic pain features showed a statistically significant effect of APPA compared to placebo. Adverse events (mainly gastrointestinal) were mild to moderate.

CONCLUSION

Treatment with APPA 800 mg twice daily for 28 days in subjects with symptomatic knee OA was not associated with significant symptom improvement compared to placebo. The treatment was well-tolerated and safe. While the study was not powered for such analysis, pre-planned subgroup analyses showed a significant effect of APPA in subjects with nociplastic pain/severe OA, indicating that further research in the effects of APPA in appropriate patients is warranted.

A phase 2b double-blind placebo-controlled randomized clinical trial of SB-061, an aggrecan mimetic, in patients with symptomatic knee osteoarthritis

OBJECTIVES

To evaluate the efficacy and safety of intra-articular injections of a novel aggrecan mimetic, SB-061, in subjects with knee osteoarthritis (OA).

METHODS

This was a randomized, placebo-controlled, double-blind phase II study comparing intra-articular injections of SB-061 with placebo (isotonic saline) for 52 weeks, administered at baseline, Wk 16, and Wk 32. Eligible subjects had a KL grade of 2 or 3 on X-ray of the target knee and a Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) pain score ≥20 out of 50 at screening and baseline visits. Subjects having any other knee condition were excluded. Use of analgesics was prohibited, except for rescue medication. The primary endpoint was change from baseline (CFB) in WOMAC pain at Week 8. Secondary endpoints were CFB in WOMAC function and total, ICOAP, Patient Global Assessment, and 20-meter walk test. Exploratory endpoints included structural CFB in magnetic resonance imaging entities.

RESULTS

A total of 288 subjects were randomized to SB-061 (n = 145) or placebo (n = 143), and 252 (87.5%) completed injections. The groups were comparable at baseline. The primary endpoint was not met, as no significant difference in the CFB of the WOMAC pain score at Week 8 between groups was observed, nor at any other time point during the study. Similarly, neither of the secondary or exploratory endpoints indicated any significant difference between groups. The frequency and type of adverse events were similar between groups. SB-061 was well-tolerated.

CONCLUSION

Intra-articular injections of SB-061 administered at baseline, Week 16, and Week 32, over one year in subjects with knee OA, were safe but did not show any statistically significant effect on knee pain nor on other symptomatic or structural entities compared to placebo.

TRIAL REGISTRATION NUMBER EUDRACT NO

2019-004515-31.

Cryoneurolysis Associated with Improved Pain, Function, and Sleep in Patients Following Total Knee Arthroplasty: Use of a New Real-World Registry

INTRODUCTION

Total knee arthroplasty (TKA) is performed on approximately 790,000 patients annually in the United States and is projected to increase to 1.5 million by 2050. This study aimed at assessing the use of preoperative cryoneurolysis on patients undergoing TKA by analyzing: 1) pain severity; 2) opioid use; 3) functional status; and 4) sleep disturbance over 6 months following discharge.

METHODS

Patients enrolled in the Innovations in Genicular Outcomes Registry (iGOR) between September 2021 and February 2024 were followed for 6 months. Our analyses included patients undergoing unilateral primary TKA with no pre-operative opioid prescription who either received, or did not receive, cryoneurolysis. Baseline patient demographics were collected before TKA and tabulated. Pain management was assessed via the Brief Pain Inventory-Short Form (BPI-SF) instrument for pain severity. Sleep disturbance was measured using the Patient-Reported Outcomes Measurement Information System (PROMIS) questionnaire. Each outcome measure was assessed prior to TKA, weekly, and at monthly follow-up. Data was analyzed by a generalized linear mixed-effect regression model to compare cryoneurolysis versus control patients, with a P < 0.05 as significant.

RESULTS

There were 80 patients who were treated with preoperative cryoneurolysis, while 60 control patients did not have treatment. Patients receiving cryoneurolysis experienced significantly lower pain severity and sleep disturbance over the 6-month follow-up than control patients (P = 0.046). Cryoneurolysis was also associated with a trend toward greater functional improvement that did not reach statistical significance (P = 0.061). Further, patients who underwent cryoneurolysis were 72% less likely than controls to take opioids over six months following discharge (P <0.001).

CONCLUSIONS

Pre-operative cryoneurolysis therapy in opioid-naïve patients undergoing TKA is associated with improved pain, decreased opioid use, and improved sleep disturbance for 6 months postoperatively. Cryoneurolysis, a non-opioid pain relief modality administered pre-operatively, demonstrated substantial benefits in patients who underwent TKA.

Improved Pain and Function with Triamcinolone Acetonide Extended-Release and Cryoneurolysis for Knee Osteoarthritis: Use of a New Real-World Registry

INTRODUCTION

Knee osteoarthritis (OA) affects 19% of American adults over 45 years old and costs $27+ billion annually. A wide range of non-operative treatment options are available. This study compared six treatments: cryoneurolysis with deep genicular nerve block (Cryo-Deep/Both), cryoneurolysis with superficial nerve block (Cryo-Superficial), intra-articular hyaluronic acid (IA-HA) injections, non-steroidal anti-inflammatory drug injections (IA-NSAIDs), IA-corticosteroids (IA-CS) injections, or IA-triamcinolone extended release (IA-TA-ER) injections over 4 months for: 1) pain severity and analgesic use; and 2) physical function (from Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR)).

METHODS

Patients who had unilateral knee OA and received non-operative intervention were enrolled in the Innovations in Genicular Outcomes (iGOR) registry, a novel, multi-center real-world registry, between September 2021 and February 2024. A total of 480 patients were enrolled. Both pain and functional outcomes were assessed at baseline, weekly, and monthly, which were analyzed by: overall trend, magnitude changes pre- to post-treatment, and distribution-based minimal clinically important difference score (MCID). Multivariate linear regressions with adjustments for seven confounding factors were used to compare follow-up outcomes among six treatment groups.

RESULTS

Use of IA-TA-ER injections was associated with the lowest pain, greatest pain reduction, and highest prevalence of patients achieving MCID relative to other treatments (P < 0.001). Deep/Both-Cryo and IA-CS were associated with a higher prevalence of achieving MCID than IA-HA, IA-NSAIDs, and Cryo-Superficial (P ≤ 0.001). Use of IA-TA-ER was also associated with the greatest functional score, improvement from baseline, and highest prevalence of patients achieving MCID than other treatments (P ≤ 0.003).

CONCLUSIONS

The IA-TA-ER appears to outperform other treatments in terms of pain relief and functional improvement for up to 4 months following treatment. In addition, outcomes in the novel cryoneurolysis and conventional IA-CS were similar to one another and better than those in IA-HA and IA-NSAIDs.

Pharmacotherapy for osteoarthritis-related pain: current and emerging therapies

INTRODUCTION

Osteoarthritis (OA) related pain has affected millions of people worldwide. However, the current pharmacological options for managing OA-related pain have not achieved a satisfactory effect.

AREAS COVERED

This narrative review provides an overview of the current and emerging drugs for OA-related pain. It covers the drugs' mechanism of action, safety, efficacy, and limitations. The National Library of Medicine (PubMed) database was primarily searched from 2000 to 2024.

EXPERT OPINION

Current treatment options are limited and suboptimal for OA pain management. Topical nonsteroidal anti-inflammatory drugs (NSAIDs) are the recognized and first-line treatment in the management of OA-related pain, and other drugs are inconsistent recommendations by guidelines. Emerging treatment options are promising for OA-related pain, including nerve growth factor (NGF) inhibitors, ion channel inhibitors, and calcitonin gene-related peptide (CGRP) antagonists. Besides, drugs repurposing from antidepressants and antiepileptic analgesics are shedding light on the management of OA-related pain. The management of OA-related pain is challenging as pain is heterogeneous and subjective. A more comprehensive strategy combined with non-pharmacological therapy needs to be considered, and tailored management options to individualized patients.

Corticosteroid injections for the treatment of osteoarthritis present a wide spectrum of effects ranging from detrimental to disease-modifying: A systematic review of preclinical evidence by the ESSKA Orthobiologic Initiative

PURPOSE

Aim of this systematic review of preclinical evidence was to determine the effects of intra-articular corticosteroid (CS) injections in joints affected by osteoarthritis (OA).

METHODS

A systematic review was performed on animal studies evaluating intra-articular CS injections for OA joints. The search was performed on PubMed, Cochrane, and Web of Science databases. A synthesis of the results was performed investigating CS effects by evaluating studies comparing CS with control groups. Morphological, histological, immunohistochemistry evaluations, clinical outcomes, biomarkers and imaging results were evaluated. The risk of bias was assessed according to the Systematic Review Centre for Laboratory Animal Experimentation's tool.

RESULTS

Thirty-two articles analysing CS effects in OA animal models were included (1079 joints), 18 studies on small and 14 on large animals. CS injections showed overall positive effects in at least one of the outcomes in 68% of the studies, while 16% reported a deleterious effect. CS improved cartilage and synovial outcomes in 68% and 60% of the studies, but detrimental effects were documented in 11% and 20% of the studies, respectively. Clinical parameters evaluated in terms of pain, lameness or joint swelling improved in 63% of the studies but deteriorated in 13%. Evidence is limited on imaging and biomarkers results, as well as on the best CS type, dose, formulation and injection protocol. The risk of bias assessment revealed a 28% low and an 18% high risk of bias.

CONCLUSION

Intra-articular CS injections induced a wide range of results on OA joints in experimental animal models, from disease-modifying and positive effects on pain and joint function at short-term evaluation to the lack of benefit or even negative effects. This underlines the need to identify more specific indications and treatment modalities to avoid possible detrimental effects while maximising the anti-inflammatory properties and the benefits of intra-articular CS in OA joints.

LEVEL OF EVIDENCE

Level II.

Extended-Release Versus Immediate-Release Triamcinolone Acetonide in Patients Who Have Knee Osteoarthritis and Type 2 Diabetes Mellitus

BACKGROUND

Intra-articular (IA) corticosteroid injections may cause hyperglycemia (glucose level > 180 mg/dL). In a phase 2 study of 33 patients who had osteoarthritis of the knee (OAK) and type 2 diabetes mellitus (T2D), triamcinolone acetonide extended-release (TA-ER) was associated with minimal glycemic control disruption compared with triamcinolone acetonide immediate-release (TA-IR). This post hoc analysis characterizes the clinical relevance of these results.

METHODS

Patients who had symptomatic OAK for ≥ 6 months, T2D for ≥ 1 year, and hemoglobin A1c ≥ 6.5 and ≤ 9.0% were randomized to receive an IA injection of either TA-ER or TA-IR. Changes in continuous glucose monitor daily glucose level, percentage of time in or above the target glucose range (> 70 to 180 mg/dL), time to glucose level 250 mg/dL and maximum glucose level > 250 mg/dL, and glycemic variability were evaluated.

RESULTS

Across postinjection days 1 to 3, the TA-ER group (n = 18) had a lower median change from baseline in maximum glucose level (92.3 versus 169.1 mg/dL), a reduced percentage of time with a glucose level > 250 mg/dL (12 versus 26%), a smaller proportion of patients who had a maximum glucose level > 250 mg/dL (50 versus 93%), and a greater percentage of time in the target glucose range (62 versus 48%) versus the TA-IR group (n = 15). There was less glycemic variability and lower glucose spikes in the TA-ER versus TA-IR group. Median times to glucose level 250 mg/dL (44 versus 6 hours) and maximum glucose level (34 versus 13 hours) were significantly longer in the TA-ER versus TA-IR group.

CONCLUSIONS

Use of TA-ER was associated with a clinically meaningful reduction in hyperglycemia versus TA-IR.

Periprosthetic Joint Infection Risk After Primary Total Knee Arthroplasty: Are All Preoperative Corticosteroid Injections the Same?

BACKGROUND

Previous evidence has demonstrated an increased risk of periprosthetic joint infection (PJI) following primary total knee arthroplasty (TKA) in patients receiving corticosteroid injection (CSI) within 3 months of surgery. The study aimed to determine if PJI risk after TKA varied among different corticosteroid agents.

METHODS

A total of 85,073 patients undergoing primary TKA from 2009 to 2019 were identified from a large national database. Of these, 1,092 (1.3%) received an ipsilateral, intra-articular CSI within 90 days of TKA. These patients were compared to those not receiving CSI using multivariate logistic regressions following 1:4 propensity score matching, with PJI development as the primary outcome.

RESULTS

Patients given an injection of any corticosteroid within 90 days of TKA had significantly higher PJI rates compared to controls (1.6 versus 0.41%; P < .001). This finding was driven by patients receiving methylprednisolone acetate (n = 543) or betamethasone (n = 153), with prevalence rates of 1.7 and 2.6%, respectively (P = .003 and P = .01, respectively). No significant increase in the rate of PJI was observed for patients receiving triamcinolone (1.2%; P = .08; n = 342) or dexamethasone (0.0%; P = 1; n = 54) within 90 days preceding TKA. PJI risk for all agents, administered more than 90 days preoperatively normalized to control levels (0.51 versus 0.34%).

CONCLUSIONS

These results suggest that PJI risk varies with CSI type. In this large database study, only patients given methylprednisolone acetate or betamethasone injections within 90 days of surgery had significantly higher PJI rates compared to controls.

New therapeutic strategies in osteoarthritis

Osteoarthritis (OA) is the most prevalent arthritis-type and is a major contributor to chronic joint pain, impaired physical function, and limited mobility. By the end of 2020, a total of 595 million, equal to 7·6% of the global population, had OA; this figure is expected to rise exponentially by 2050. Even while the disorder's intricate pathophysiology is starting to appear intelligible, we are yet to have a cure for the disorder. OA is typically managed with traditional palliative measures, such as topical and systemic analgesics, including non-steroidal anti-inflammatory drugs, therapeutic exercise, and braces. Sometimes, intra-articular glucocorticoids, viscosupplementation, or regenerative interventions provide short-term pain relief and functional improvement; some may require arthroplasty. Researchers continue their efforts to unveil a new therapeutic target to be effective in OA that modifies symptoms and arrests disease progression as well. In the present literature review, insights into new therapeutic strategies in OA, for example, liposome-based dexamethasone, microspore-based triamcinolone, nerve growth factor antagonist, anti-ADAMTS-5 (A Disintegrin And Metalloproteinase Thrombospoidin Motifs - 5), pentosan polysulfate sodium, allogeneic stem cells, C-C chemokine receptor type-4 (CCR4) ligand 17 inhibitor, Wnt-signaling inhibitor, and anti-obesity medications are provided.

Research Progress on Injectable Microspheres as New Strategies for the Treatment of Osteoarthritis Through Promotion of Cartilage Repair

Osteoarthritis (OA) is a degenerative disease caused by a variety of factors with joint pain as the main symptom, including fibrosis, chapping, ulcers, and loss of cartilage. Traditional treatment can only delay the progression of OA, and classical delivery system have many side effects. In recent years, microspheres have shown great application prospects in the field of OA treatment. Microspheres can support cells, reproduce the natural tissue microenvironment in vitro and in vivo, and are an efficient delivery system for the release of drugs or biological agents, which can promote cell proliferation, migration, and differentiation. Thus, they have been widely used in cartilage repair and regeneration. In this review, preparation processes, basic materials, and functional characteristics of various microspheres commonly used in OA treatment are systematically reviewed. Then it is introduced surface modification strategies that can improve the biological properties of microspheres and discussed a series of applications of microsphere functionalized scaffolds in OA treatment. Finally, based on bibliometrics research, the research development, future potential, and possible research hotspots of microspheres in the field of OA therapy is systematically and dynamically evaluated. The comprehensive and systematic review will bring new understanding to the field of microsphere treatment of OA.

Intra-articular corticosteroid injections provide a clinically relevant benefit compared to placebo only at short-term follow-up in patients with knee osteoarthritis: A systematic review and meta-analysis

PURPOSE

To quantify the clinical relevance of intra-articular corticosteroid effects compared to placebo for the injective treatment of knee osteoarthritis (OA).

METHODS

The PubMed, Cochrane Library and Web of Science databases were searched on May 3, 2023. This study was conducted in accordance with the PRISMA guidelines. The inclusion criteria were randomized controlled trials (RCTs), published in English, with no time limitation regarding publication date, comparing intra-articular corticosteroids and placebo injections for knee OA. The effects were quantified at short- (≤6 weeks), mid- (>6 weeks and ≤3 months), and long-term (≥6 months) follow-ups. The minimal clinically important difference (MCID) for the outcomes (visual analogue scale for pain - VAS: 1.4, Western Ontario and McMaster University Osteoarthritis Index - WOMAC: 9) was used to interpret the clinical improvement provided by intra-articular corticosteroid injections compared to placebo. The quality of each article was assessed using the Cochrane RoB 2 tool and the GRADE guidelines.

RESULTS

Among the 1030 articles retrieved, 11 RCTs (842 patients) were included. A comparison of the two groups revealed statistically significant differences in the improvement of VAS and WOMAC scores in terms of the mean difference (MD); this difference was in favour of corticosteroids at short-term (p < 0.001, MD = -1.6 and p < 0.001, MD = -9.9, respectively) and mid-term follow-ups (p = 0.001, mean MD = -1.3 and p = 0.005, MD = -4.9, respectively). No difference was observed at the long-term follow-up. The MDs between the improvements in the two groups reached the MCID values for the VAS and WOMAC only at the short-term follow-up. The RoB 2 tool and the GRADE evaluations showed the presence of risk of bias and limited quality of evidence.

CONCLUSION

This systematic review and meta-analysis demonstrated that intra-articular corticosteroid injections offer clinically perceivable pain relief and functional improvement higher than the placebo effect only at short-term follow-up in patients affected by knee OA, with benefits losing clinical relevance already after 6 weeks. These results, together with the low number and the limited quality of the RCTs comparing this treatment with placebo, question the indication for the use of corticosteroid injections in clinical practice for the treatment of knee OA.

LEVEL OF EVIDENCE

Level I.

Poly-beta-amino-ester licofelone conjugates development for osteoarthritis treatment

Disease-modifying osteoarthritis drugs (DMOADs) are a new therapeutic class for osteoarthritis (OA) prevention or inhibition of the disease development. Unfortunately, none of the DMOADs have been clinically approved due to their poor therapeutic performances in clinical trials. The joint environment has played a role in this process by limiting the amount of drug effectively delivered as well as the time that the drug stays within the joint space. The current study aimed to improve the delivery of the DMOADs into cartilage tissue by increasing uptake and retention time of the DMOADs within the tissue. Licofelone was used a model DMOAD due to its significant therapeutic effect against OA progression as shown in the recent phase III clinical trial. For this purpose licofelone was covalently conjugated to the two different A16 and A87 poly-beta-amino-ester (PBAEs) polymers taking advantage of their hydrolysable, cytocompatible, and cationic nature. We have shown cartilage uptake of the licofelone-PBAE conjugates increased 18 times and retention in tissues was prolonged by 37 times compared to the equivalent dose of the free licofelone. Additionally, these licofelone conjugates showed no detrimental effect on the chondrocyte viability. In conclusion, the cationic A87 and A16 PBAE polymers increased the amount of licofelone within the cartilage, which could potentially enhance the therapeutic effect and pharmacokinetic performance of this drug and other DMOADs clinically.

Recent advances in polymeric microparticle-based drug delivery systems for knee osteoarthritis treatment

Due to the poor bioavailability and high joint clearance of drugs, sustained delivery of therapeutic agents has proven difficult in the treatment of osteoarthritis (OA). Intra-articular (IA) drug delivery strategy is an attractive option for enhancing OA patients' prognosis, for which various polymer materials have been used as drug carriers due to their attractive delivery properties, to slow or even reverse the progress of OA by prolonging the duration of therapeutic agent residence in the joint. This article focuses on the recent developments in natural and synthetic polymer-based microsphere drug delivery systems for treating knee osteoarthritis. It evaluates the translational potential of some novel formulations for clinical application.

Asymmetric Flexion Contracture is Associated With Leg Length Inequality in Patients With Knee Osteoarthritis: Data From the Osteoarthritis Initiative

OBJECTIVE

To evaluate whether knee flexion contracture (FC) was associated with leg length inequality (LLI) and/or morbidity in knee osteoarthritis (OA).

DESIGN

We accessed 2 databases: (1) the Osteoarthritis Initiative (OAI) cohort, including participants with, or at-risk of OA, and (2) the Ottawa Knee Osteoarthritis cross-sectional database (OKOA), including participants with primary advanced knee OA. Both included demographics, radiographic data, knee range of motion, leg length, pain, and function scales.

SETTING

Tertiary care academic rheumatology and orthopedic clinics.

PARTICIPANTS

Patients with or at-risk of primary OA. We included 881 OAI and 72 OKOA participants (N=953).

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURES

The primary outcome tested the association between the difference in knee extensions of the OA and contralateral knees (the knee extension difference, or KExD) and LLI. This was evaluated using bivariate regression, followed by a multivariable linear regression model.

RESULTS

OAI participants had less severe knee OA [Kellgren and Lawrence (KL) score 1.9±1.3] vs OKOA (KL score 3.4±0.6). The KExD correlated with LLI for both databases (OAI: R=0.167; P≤.001; OKOA: R=0.339; P=.004). Multivariable regression showed an effect of KExD on LLI in both databases (OAI: β=0.37[0.18,0.57]; P<.001, OKOA: β=0.73[0.20,1.26]; P=.007). When broken down by subgroup, the OAI moderate-severe OA group showed a significant effect of KExD on LLI (β=0.60 [0.34,0.85]; P<.001).

CONCLUSIONS

OA-related loss of knee extension was associated with LLI for those with moderate-severe OA. Because LLI correlates with worse knee OA symptoms, discovering an FC should cue clinicians to evaluate for LLI, an easily-treatable finding that may help reduce OA-associated morbidity for those approaching the need for arthroplasty.

Corticosteroid Injections for Symptomatic Treatment of Osteoarthritis of the Knee: A Pilot Blinded Randomized Trial

OBJECTIVE

To quantify the effect of corticosteroids compared to lidocaine-only injections over 12 weeks among patients with knee osteoarthritis (KOA).

METHODS

Participants with KOA were randomized to receive a knee injection of methylprednisolone acetate 1 mL (40 mg) plus 2 mL lidocaine (1%) or 1 mL saline and 2 mL lidocaine. Participants and providers were blinded to treatment allocation using an opacified syringe. The outcome was the average change from baseline of the total Knee Injury and Osteoarthritis Outcome Score (KOOS) (range 0-100) assessed at 2-week intervals over 12 weeks. Participants received KOOS questionnaires on their smartphones through a web-based platform. We used linear mixed-effects regressions with robust variance estimators to evaluate the association between the intervention and change in KOOS total and subscales (ClinicalTrials.gov identifier NCT03835910; registered 2019-02-11).

RESULTS

Of the 33 randomized participants, 31 were included in the final analysis. The predicted mean (SE) change in total KOOS over the 12-week follow-up was 9.4 (3.2) in the corticosteroids arm versus -1.3 (1.4) in the control arm (P = 0.003). Of participants, 47% achieved change as large as the minimal clinically important difference (16 units) in the intervention arm compared to 6% of participants in the lidocaine arm. Further, there were greater improvements in the intervention arm for KOOS subscales and for Patient Reported Outcomes Measurement Information System (PROMIS) assessments of pain intensity, behavior, and interference.

CONCLUSION

Corticosteroid injections demonstrated clinically meaningful improvements in KOA symptoms over 12 weeks of follow-up. These data support larger studies to better quantify short-term benefits.

Debate: Intra-articular steroid injections for osteoarthritis - harmful or helpful?☆,☆☆

Intra-articular corticosteroids injections are a widely used treatment for pain from symptomatic osteoarthritis. Systematic reviews show that the treatment effect is modest compared with intra-articular saline (often considered as placebo) and lasts for 2-4 weeks on average. Potentially as a consequence of limited therapeutic duration, repeated injections are often given up to 4 injections annually. In this context of repeat injections, recent evidence has emerged that intra-articular corticosteroids might be associated with more MRI-assessed quantitative cartilage thickness loss than saline injections. Guidelines vary in the recommendation for use of intra-articular corticosteroids. Given the frequency with which intra-articular corticosteroids injections are used, the size and scale of the population with osteoarthritis, it is critical to fully understand the benefits and drawbacks of intra-articular corticosteroids injections. That is the focus of this debate article.

Customizable 3D Printed Implants Containing Triamcinolone Acetonide: Development, Analysis, Modification, and Modeling of Drug Release

Three-dimensional-printed customizable drug-loaded implants provide promising opportunities to improve the current therapy options. In this study, we present a modular implant in which shape, dosage, and drug release can be individualized independently of each other to patient characteristics to improve parenteral therapy with triamcinolone acetonide (TA) over three months. This study focused on the examination of release modification via fused deposition modeling and subsequent prediction. The filaments for printing consisted of TA, ethyl cellulose, hypromellose, and triethyl citrate. Two-compartment implants were successfully developed, consisting of a shape-adaptable shell and an embedded drug-loaded network. For the network, different strand widths and pore size combinations were printed and analyzed in long-term dissolution studies to evaluate their impact on the release performance. TA release varied between 8.58 ± 1.38 mg and 21.93 mg ± 1.31 mg over three months depending on the network structure and the resulting specific surface area. Two different approaches were employed to predict the TA release over time. Because of the varying release characteristics, applicability was limited, but successful in several cases. Using a simple Higuchi-based approach, good release predictions could be made for a release time of 90 days from the release data of the initial 15 days (RMSEP ≤ 3.15%), reducing the analytical effort and simplifying quality control. These findings are important to establish customizable implants and to optimize the therapy with TA for specific intra-articular diseases.

Reduction of systemic exposure and side effects by intra-articular injection of anti-inflammatory agents for osteoarthritis: what is the safer strategy?

Osteoarthritis (OA) is a chronic degenerative joint disease associated with pain, inflammation, and cartilage degradation. However, no current treatment can effectively halt the progression of the disease. Therefore, the use of NSAIDs and intra-articular corticosteroids is usually recommended as the primary treatment for OA-associated pain and inflammation. However, there is accumulating evidence that the long-term use of oral NSAIDs and intra-articular corticosteroids can lead to a myriad of negative side effects. Although numerous efforts have been made to develop intra-articular formulations for NSAIDs, the systemic exposure of intra-articular injection of NSAIDs and its potential side effects have not been explicitly investigated. To ascertain the evident and potential side effects of intra-articular injection of anti-inflammatory agents, we have summarised in this review the systemic exposure, local side effects, and systemic side effects of intra-articular injections of anti-inflammatory agents, including NSAIDs and corticosteroids. For developing a safer treatment to fulfil the unmet long-term use needs of patients, a new therapy, which combines the locally active drug and a sustained-release formulation, has been proposed in this review.

Failure of cartilage regeneration: emerging hypotheses and related therapeutic strategies

Osteoarthritis (OA) is a disabling condition that affects billions of people worldwide and places a considerable burden on patients and on society owing to its prevalence and economic cost. As cartilage injuries are generally associated with the progressive onset of OA, robustly effective approaches for cartilage regeneration are necessary. Despite extensive research, technical development and clinical experimentation, no current surgery-based, material-based, cell-based or drug-based treatment can reliably restore the structure and function of hyaline cartilage. This paucity of effective treatment is partly caused by a lack of fundamental understanding of why articular cartilage fails to spontaneously regenerate. Thus, research studies that investigate the mechanisms behind the cartilage regeneration processes and the failure of these processes are critical to instruct decisions about patient treatment or to support the development of next-generation therapies for cartilage repair and OA prevention. This Review provides a synoptic and structured analysis of the current hypotheses about failure in cartilage regeneration, and the accompanying therapeutic strategies to overcome these hurdles, including some current or potential approaches to OA therapy.

The OA Trial Bank: Update of individual patient data meta-analysis of intra-articular glucocorticoids in persons with knee and hip osteoarthritis

Objective

To evaluate the efficacy of intra--articular (IA) glucocorticoid for knee or hip osteoarthritis (OA) in specific subgroups of patients according to the baseline severity of pain and inflammatory signs using individual patient data (IPD) from existing trials. Furthermore, this study aims to assess if a baseline pain cut-off was associated with clinically important effectiveness of IA glucocorticoid. This is an update of an IA glucocorticoid IPD meta-analysis by the OA Trial Bank.

Method

Randomized trials evaluating one or more IA glucocorticoid preparations in hip and knee OA, published to May 2018 were selected. IPD of patient and disease characteristics and outcome measures were acquired. The primary outcome was pain severity at short-term follow-up (up to 4 weeks). Potential interaction effect of severe pain (≥70 points, 0-100 scale) and signs of inflammation at baseline were studied using a two-stage approach with general liner model followed by random effects model. Analysis of trend was conducted, assessing if a baseline pain cut-off was associated with the threshold for clinically important treatment effect of IA glucocorticoid compared to placebo.

Results

Four out of 16 eligible randomized clinical trials (n ​= ​641) were combined with the existing OA Trial Bank studies (n ​= ​620), yielding 1261 participants from eleven studies. Participants with severe baseline pain compared to those with less severe pain had greater pain reduction at mid-term (around 12 weeks) (mean reduction: -6.90 (95%CI -10.91; -2.90)), but not at short- and long-term. No interaction effects were found between inflammatory signs and IA glucocorticoid injections compared to placebo at all follow-up time-points. Analysis of trend demonstrated treatment response to IA glucocorticoid from baseline pain levels >50 (0-100 scale) and above.

Conclusion

This updated IPD meta-analysis demonstrated that participants with severe pain compared to those with less severe pain at baseline experienced significantly more pain relief with IA glucocorticoid compared with placebo at mid-term.

Innovation in Targeted Intra-articular Therapies for Osteoarthritis

Osteoarthritis is the most common chronic joint disease characterized by progressive damage to the joints, leading to pain and loss of function. There is currently no cure or disease-modifying therapy for osteoarthritis. Hence, the increasing disease prevalence linked with ageing and obesity represents a substantial socio-economic burden. Intra-articular therapy by injection of drugs into affected joints can optimize local drug bioavailability, while reducing risks of systemic toxicity, a concern in an ageing patient population. In this review, we investigate the current landscape of intra-articular drug therapies for osteoarthritis, including established approaches and those in clinical development. We performed a literature review using PubMed, complemented with a search for clinical trials using the ClinicalTrials.gov repository. Additionally, conference abstracts and presentations were identified and systematic snowballing was applied. Identified drugs were divided into several groups by main mechanism of action, and include drugs that reduce inflammation (anti-inflammatory), drugs aiming to prevent or reverse structural damage (structure modifying), drugs that aim to reduce the pain, and other drugs with a specific target. Most studies have been performed for osteoarthritis of the knee, a joint that is easily accessible for intra-articular treatments. Optimal therapy would provide symptomatic relief, while preventing further damage to the joint. The field of intra-articular drug therapies for osteoarthritis is rapidly evolving with clear challenges identified: definition of relevant outcome measures, optimization of clinical trial set-ups, and dealing with placebo responses. While many uncertainties persist, it appears that the innovation in drug development and improved clinical trial set-up may finally deliver successful therapies for this important disease.

The Corticosteroid Meniscectomy Trial of Extended-Release Triamcinolone Injection After Arthroscopic Partial Meniscectomy: Protocol for a Double-Blind Randomized Controlled Trial

Background

Meniscal tear in older adults often accompanies knee osteoarthritis and is commonly treated with arthroscopic partial meniscectomy (APM) when patients have persistent pain after a trial of physical therapy. Cross-sectional evidence suggests that synovitis is associated with baseline pain in this patient population, but little is known about the relationship between synovitis and postoperative recovery or progression of knee osteoarthritis.

Purpose/Hypothesis

Intra-articular extended-release triamcinolone may reduce inflammation and thereby improve outcomes and slow disease progression. This article presents the rationale behind the Corticosteroid Meniscectomy Trial (CoMeT) and describes its study design and implementation strategies.

Study Design

Randomized controlled trial.

Methods

CoMeT is a 2-arm, 3-center, randomized placebo-controlled trial designed to establish the clinical efficacy of extended-release triamcinolone administered via intra-articular injection immediately after APM. The primary outcome is change in Knee injury and Osteoarthritis Outcome Score Pain subscore at 3-month follow-up. Synovial biopsy, joint fluid aspirate, and urine and blood sample analyses will examine the associations between various objective measures of baseline inflammation and pre- and postoperative outcome measures and clinical responses to triamcinolone intervention. Quantitative 3-T magnetic resonance imaging will evaluate cartilage and meniscal composition and 3-dimensional bone shape to detect early joint degeneration.

Results

We discuss methodologic innovations and challenges.

Conclusion

To our knowledge, this is the first randomized double-blind clinical trial that will analyze the effect of extended-release triamcinolone acetonide on pain, magnetic resonance imaging measures of structural change and effusion/synovitis, soluble biomarkers, and synovial tissue transcriptomics after APM.

A Review of Recent Innovations in Cartilage Regeneration Strategies for the Treatment of Primary Osteoarthritis of the Knee: Intra-articular Injections

Background

The pathology of primary osteoarthritis (OA) begins with structural cartilage damage, which initiates a self-propagating inflammatory pathway that further exacerbates cartilage deterioration. Current standard of care for knee primary OA involves treating the inflammatory symptoms to manage pain, which includes intra-articular (IA) injections of cortisone, an anti-inflammatory steroid, followed by a series of joint-cushioning hyaluronic acid gel injections. However, these injections do not delay the progression of primary OA. More focus on the underlying cellular pathology of OA has prompted researchers to develop treatments targeting the biochemical mechanisms of cartilage degradation.

Purpose

Researchers have yet to develop a United States Food and Drug Administration (FDA)-approved injection that has been demonstrated to significantly regenerate damaged articular cartilage. This paper reviews the current research on experimental injections aimed at achieving cellular restoration of the hyaline cartilage tissue of the knee joint.

Study Design

Narrative review.

Methods

The authors conducted a narrative literature review examining studies on primary OA pathogenesis and a systematic review of non-FDA-approved IA injections for the treatment of primary OA of the knee, described as "disease-modifying osteoarthritis drugs" in phase 1, 2, and 3 clinical trials.

Conclusion

New treatment approaches for primary OA investigate the potential of genetic therapies to restore native cartilage. It is clear that the most promising IA injections that could improve treatment of primary OA are bioengineered advanced-delivery steroid-hydrogel preparations, ex vivo expanded allogeneic stem cell injections, genetically engineered chondrocyte injections, recombinant fibroblast growth factor therapy, injections of selective proteinase inhibitors, senolytic therapy via injections, injectable antioxidant therapies, injections of Wnt pathway inhibitors, injections of nuclear factor-kappa β inhibitors, injections of modified human angiopoietin-like-3, various potential viral vector-based genetic therapy approaches, and RNA genetic technology administered via injections.

Injectable Drug Delivery Systems for Osteoarthritis and Rheumatoid Arthritis

Joint diseases are one of the most common causes of morbidity and disability worldwide. The main diseases that affect joint cartilage are osteoarthritis and rheumatoid arthritis, which require chronic treatment focused on symptomatic relief. Conventional drugs administered through systemic or intra-articular routes have low accumulation and/or retention in articular cartilage, causing dose-limiting toxicities and reduced efficacy. Therefore, there is an urgent need to develop improved strategies for drug delivery, in particular, the use of micro- and nanotechnology-based methods. Encapsulation of therapeutic agents in delivery systems reduces drug efflux from the joint and protects against rapid cellular and enzymatic clearance following intra-articular injection. Consequently, the use of drug delivery systems decreases side effects and increases therapeutic efficacy due to enhanced drug retention in the intra-articular space. Additionally, the frequency of intra-articular administration is reduced, as delivery systems enable sustained drug release. This review summarizes various advanced drug delivery systems, such as nano- and microcarriers, developed for articular cartilage diseases.

Recent advances in the pharmacotherapy of osteoarthritis

Introduction: Osteoarthritis (OA) is a common debilitating disease affecting the geriatric population. Management of osteoarthritis is a challenge for orthopedicians because till date there has been no such drug that can completely cure the disease or at least retard/arrest the disease progression. In addition to the currently available treatment options for OA like NSAIDs, opioids, nutraceuticals (glucosamine sulphate and chondroitin sulphate), many new drugs are being discovered or repurposed for use in osteoarthritis. Most of these recent drugs aim at retarding the disease progression rather than providing just a symptomatic relief.

Materials and methods: All relevant articles regarding approved new drugs and pipeline drugs for osteoarthritis published between 2012–2021 were analysed. Those included animal studies as well as clinical trials. Some older articles were also referred to, provided they highlighted any significant data. The obtained data were analysed and compiled.

Results and discussion: Broadly the recent drugs for OA can be classified based upon their site of action as (i) drugs targeting articular cartilage, (ii) drugs targeting inflammation, (iii) drugs targeting the subchondral bone, and (iv) drugs for relieving pain. Ranging from in vitro studies to clinical trials, these drugs are in various phases of drug discovery. Early diagnosis of OA and its management with a drug that retards disease progression rather than prescribing just a symptom reliever is very much necessary in the current situation.

Conclusion: Need for new drugs for OA is increasing day by day. More number of clinical trials with larger sample sizes alone can satisfy the need of disease modifying drugs for OA. This review provides a deep insight into all the recent advances in the pharmacotherapy of osteoarthritis.

Graphical abstract:

Changes and Associations Between Gait Biomechanics and Knee Inflammation After Aspiration and Glucocorticoid Injection for Knee Osteoarthritis

OBJECTIVE

Although knee inflammation is thought to adversely affect joint function in patients with knee osteoarthritis (OA), the effects of reducing knee inflammation on gait biomechanics and strength are unknown. Our objectives were to compare ultrasound (US) measures of knee inflammation, gait biomechanics, knee extension and flexion strength, and pain before and after knee aspiration and glucocorticoid injection, and to explore associations among changes.

METHODS

Forty-nine patients (69 knees) with symptomatic knee OA and synovitis were tested before and 3-4 weeks after US-guided knee aspiration and glucocorticoid injection. At each visit, participants completed US assessments for inflammatory features of knee OA, 3D gait analysis, isokinetic knee extension and flexion strength tests, and Knee Osteoarthritis Outcome Score (KOOS) pain subscales. Linear and polynomial mixed-effects regression models were used to investigate changes and their associations.

RESULTS

Changes were observed for the synovitis score (unstandardized β [post-injection minus pre-injection] -0.55/9 [95% confidence interval (95% CI) -0.97, -0.12]), effusion depth (-1.05 mm [95% CI -1.07, -0.39]), KOOS pain (unstandardized β 5.91/100 [95% CI 1.86, 9.97]), peak external knee flexion and extension moments (KFM; 3.33 Nm [95% CI 0.45, 6.22]), KEM (-2.99 Nm [95% CI -5.93, -0.05]), and knee extension strength (4.70 Nm [95% CI 0.39, 9.00]) and flexion strength (3.91 Nm [95% CI 1.50, 6.81]). The external KFM increased during 13-38% and 76-89% of stance post-injection. When controlled for time, greater synovitis was associated with lower knee extension strength, while lower pain was associated with increased knee extension and flexion strength.

CONCLUSION

In patients with knee OA and synovitis, reduced inflammation and pain after aspiration and glucocorticoid injection are associated with changes in knee gait biomechanics and strength.

Normal saline injection produces a therapeutic effect in patients with plantar fasciitis: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Injectable therapies have been increasingly investigated to treat plantar fasciitis in randomized controlled trials (RCT) where normal saline injections are frequently used as placebo. The purpose was to quantify the effect of saline injections and compared against available minimal clinically important difference (MCID) criteria specific for plantar fasciitis to assess if changes were clinically meaningful.

METHODS

RCT including a placebo group (normal saline) and reporting changes in pain and functional outcomes in plantar fasciitis were identified through a search in MEDLINE, Embase, Web of Science, and Scopus to February 2022. PRISMA guidelines and a registered protocol (PROSPERO: CRD42020214035) were followed to conduct the study.

RESULTS

Pooled analysis of 13 RCT (379 subjects) included for analysis revealed a significant improvement on pain (P < .00001) and functional scores (P < .00001) after normal saline injections. These changes exceeded the established MCID criteria.

CONCLUSIONS

Normal saline injections in plantar fasciitis showed a therapeutic effect with statistically and clinically meaningful improvement when administered in the setting of an RCT for up to 12 months. The control of potential confounders influencing the effect of saline injections is required for future research.

Polymeric Nanoparticles for Drug Delivery in Osteoarthritis

Osteoarthritis (OA) is a degenerative musculoskeletal disorder affecting the whole synovial joint and globally impacts more than one in five individuals aged 40 and over, representing a huge socioeconomic burden. Drug penetration into and retention within the joints are major challenges in the development of regenerative therapies for OA. During the recent years, polymeric nanoparticles (PNPs) have emerged as promising drug carrier candidates due to their biodegradable properties, nanoscale structure, functional versatility, and reproducible manufacturing, which makes them particularly attractive for cartilage penetration and joint retention. In this review, we discuss the current development state of natural and synthetic PNPs for drug delivery and OA treatment. Evidence from in vitro and pre-clinical in vivo studies is used to show how disease pathology and key cellular pathways of joint inflammation are modulated by these nanoparticle-based therapies. Furthermore, we compare the biodegradability and surface modification of these nanocarriers in relation to the drug release profile and tissue targeting. Finally, the main challenges for nanoparticle delivery to the cartilage are discussed, as a function of disease state and physicochemical properties of PNPs such as size and surface charge.

Microcarriers in application for cartilage tissue engineering: Recent progress and challenges

Successful regeneration of cartilage tissue at a clinical scale has been a tremendous challenge in the past decades. Microcarriers (MCs), usually used for cell and drug delivery, have been studied broadly across a wide range of medical fields, especially the cartilage tissue engineering (TE). Notably, microcarrier systems provide an attractive method for regulating cell phenotype and microtissue maturations, they also serve as powerful injectable carriers and are combined with new technologies for cartilage regeneration. In this review, we introduced the typical methods to fabricate various types of microcarriers and discussed the appropriate materials for microcarriers. Furthermore, we highlighted recent progress of applications and general design principle for microcarriers. Finally, we summarized the current challenges and promising prospects of microcarrier-based systems for medical applications. Overall, this review provides comprehensive and systematic guidelines for the rational design and applications of microcarriers in cartilage TE.

•

This review summarized fabrication techniques and cartilage repaired application of microcarriers.

•

The appropriate materials and design principle for microcarriers in cartilage tissue engineering are discussed.

•

Promising future perspectives and challenges in microcarriers fields are outlined.

Corticosteroid injections 2 months before arthroscopic meniscectomy increases the rate of postoperative infections requiring surgical irrigation and debridement

PURPOSE

Consensus guidelines recommend administering a corticosteroid injection (CSI) for patients with a symptomatic degenerative meniscus lesion prior to arthroscopic partial meniscectomy (APM). A recent study found that CSI administered within 1 month prior to meniscectomy is associated with an increased risk of postoperative infection. However, infections may range in severity from superficial infections to serious infections requiring surgical interventions. The aim of this analysis was to define the rate of infections requiring surgery after APM and determine its relationship to preoperative CSI.

METHODS

The PearlDiver Mariner administrative claims database was queried for patients > 35 years old who had a CSI in the year prior to isolated APM. Rates of deep infection and infection requiring surgery within 6 months were reported between matched patients with a CSI and no injection.

RESULTS

After matching, there were 16,009 patients per group with a mean age of 59.4 years (SD = 9.6), 53.5% obesity, and 40% male. Forty-four of 113 patients who developed a postoperative deep infection went on to have a reoperation for irrigation and/or debridement (0.1% of all APM). Of these 44 patients, 30 had a preoperative CSI and 14 were controls unadjusted odds ratio (unadj-OR) if given CSI = 1.95, 95% CI 1.03-3.68, P = 0.04). Having a CSI within the month before surgery conferred a 4.56-fold increase in odds of an infection warranting surgery (95% CI 1.96-10.21, P < 0.01), whilst having a CSI 4-8 weeks before surgery conferred a 2.42-fold increase in odds (95% CI 1.04-5.42, P = 0.03). Receiving multiple CSI in the year prior to APM was associated with 5.27-fold increased odds of an infection requiring surgery (95% CI 1.19-23.27, P = 0.03), compared to having a single CSI.

CONCLUSIONS

Serious infections requiring a surgical intervention are rare after a meniscectomy, occurring in 0.1% of APMs in a matched cohort of patients over 35. Patients were five times more likely to return to the operating room for infection after APM if they had a CSI in the month before or had multiple CSIs in the year before surgery. The risk of infection was no longer significant if there was at least a 2-month interval between preoperative CSI and APM.

LEVEL OF EVIDENCE

Level III.

Associations between single-question Visual Analogue Scale pain score and weight-bearing and non–weight-bearing domains of Western Ontario and McMaster Universities Arthritis Index pain: data from 2 phase 3 clinical trials

A cross-sectional study demonstrating a moderate Visual Analogue Scale/WOMAC pain scale agreement with scale discordance driven by non–weight-bearing properties of Western Ontario and McMaster Universities Arthritis Index pain and increasing with the Kellgren–Lawrence grade.

Introduction:

Visual Analogue Scale (VAS) and the pain subscale of the Western Ontario and McMaster Universities Arthritis Index (WOMAC) are commonly used measuring tools of osteoarthritis (OA) pain.

Objectives:

The objective of this cross-sectional study was to explore the associations between single-question VAS pain and the weight-bearing and non–weight-bearing domains of WOMAC pain.

Methods:

Data from 2093 patients with OA participating in 2 phase 3 clinical trials were included for post hoc analyses. Univariate Pearson correlations and comparison of r values were made using z statistics obtained using the Fisher r to z test for all items of the VAS pain scale, the WOMAC pain subscale, the weight-bearing and non–weight-bearing constructs of WOMAC pain subscale, and by subgroups of WOMAC pain quintiles and Kellgren–Lawrence grades.

Results:

The correlations between VAS pain and WOMAC pain were significant (r = 0.67, P < 0.001) with a slope of 0.57 (95% confidence interval [CI]: 0.54–0.61). A similar correlation was found for weight-bearing pain (r = 0.68, P < 0.001, slope: 0.62 (95% CI: 0.59–0.65) but significantly lower for non–weight-bearing pain (r = 0.55, P < 0.001, slope: 0.49 (95% CI: 0.46–0.52). The degree of disagreement between the 2 instruments seemed to be lesser in the extreme ends of the scales, and the observed association between Kellgren–Lawrence grade and disagreement between VAS and WOMAC was driven by non–weight-bearing pain.

Conclusion:

In conclusion, VAS pain and WOMAC pain subscale correlation was found to be moderate and the VAS pain scale correlated more accurately with the WOMAC pain weight-bearing questions. This constitutes novel insight into patient with OA pain reporting.

Targeting the tamoxifen receptor within sodium channels to block osteoarthritic pain

Voltage-gated sodium channels (NaV) in nociceptive neurons initiate action potentials required for transmission of aberrant painful stimuli observed in osteoarthritis (OA). Targeting NaV subtypes with drugs to produce analgesic effects for OA pain management is a developing therapeutic area. Previously, we determined the receptor site for the tamoxifen analog N-desmethyltamoxifen (ND-Tam) within a prokaryotic NaV. Here, we report the pharmacology of ND-Tam against eukaryotic NaVs natively expressed in nociceptive neurons. ND-Tam and analogs occupy two conserved intracellular receptor sites in domains II and IV of NaV1.7 to block ion entry using a "bind and plug" mechanism. We find that ND-Tam inhibition of the sodium current is state dependent, conferring a potent frequency- and voltage-dependent block of hyperexcitable nociceptive neuron action potentials implicated in OA pain. When evaluated using a mouse OA pain model, ND-Tam has long-lasting efficacy, which supports the potential of repurposing ND-Tam analogs as NaV antagonists for OA pain management.

Physical and natural cross-linking approaches on 3D gelatin microspheres for cartilage regeneration

The use of gelatin microspheres (GM) as a cell carrier has been extensively researched. One of its limitation is that it dissolves rapidly in aqueous settings, precluding its use for long-term cell propagation. This circumstance necessitates the use of cross-linking agents to circumvent the constraint. Thus, the current study examines two different methods of cross-linking and their effect on the microsphere's '"physicochemical and cartilage tissue regeneration capacity. Crosslinking was accomplished by physical [Dehydrothermal (DHT)] and natural (Genipin) cross-linking of the 3D gelatin microspheres (GM). We begin by comparing the microstructures of the scaffolds and their long-term resistance to degradation under physiological conditions (in isotonic solution, at 37 °C, pH = 7.4). Infrared spectroscopy indicated that the gelatin structure was preserved after the cross-linking treatments. The cross-linked GM" 'demonstrated good cell adhesion, viability, proliferation, and widespread 3D scaffold colonization when seeded with human bone marrow mesenchymal stem cells (BMSCs). Additionally, the cross-linked microspheres enhanced chondrogenesis, as demonstrated by the data. It was discovered that cross-linked GM increased the expression of cartilage-related genes and the biosynthesis of a glycosaminoglycan-positive matrix as compared to non-crosslinked GM. In comparison, DHT-crosslinked results were significantly enhanced. To summarize, DHT treatment was found to be a superior approach for cross-linking the GM in order to promote better cartilage tissue regeneration.

Management of Knee Osteoarthritis: What Internists Need to Know

Knee osteoarthritis (OA) is a common and morbid condition. No disease-modifying therapies exist; hence the goals of current treatment are to palliate pain and to retain function. OA pain is significantly influenced by the placebo effect. Nonpharmacologic interventions are essential and have been shown to improve outcomes. Canes, unloading braces, and therapeutic heating/cooling may be valuable. Pharmacotherapy options include topical and oral nonsteroidal anti-inflammatory drugs, duloxetine, and periodic intra-articular glucocorticoids and hyaluronans. Opioids, intra-articular stem cells, and platelet-rich plasma are not recommended. Novel targets such as nerve growth factor are under investigation and may be approved soon for OA pain.

Effect of Intramuscular vs Intra-articular Glucocorticoid Injection on Pain Among Adults With Knee Osteoarthritis: The KIS Randomized Clinical Trial

IMPORTANCE

Intra-articular (IA) glucocorticoid injection is widely used in patients with knee osteoarthritis (OA), but the safety of this technique is in question among physicians. Intramuscular (IM) glucocorticoid injection could be an alternative approach.

OBJECTIVE

To investigate whether an IM glucocorticoid injection is noninferior to an IA glucocorticoid injection in reducing knee pain for patients with knee OA in primary care.

DESIGN, SETTING, AND PARTICIPANTS

The KIS trial, a multicenter, open-label, randomized clinical noninferiority trial including patients with symptomatic knee OA, was conducted in 80 primary care general practices in the southwest of the Netherlands. The study was conducted from March 1, 2018, to July 28, 2020.

INTERVENTIONS

Patients were randomly allocated to receive an injection of triamcinolone acetonide, 40 mg, either IM in the ipsilateral ventrogluteal region or IA in the knee joint. All patients were followed up for 24 weeks.

MAIN OUTCOMES AND MEASURES

The pain score at 4 weeks measured with Knee Injury and Osteoarthritis Outcome Score (range, 0-100; 0 indicates extreme pain), with a noninferiority margin of -7 (IM minus IA). A per-protocol analysis was prespecified as the primary analysis.

RESULTS

A total of 145 patients (94 women [65%]; mean [SD] age, 67 [10] years) were included; of these, 138 patients (IM, 72; IA, 66) were included in the per-protocol analysis. Clinically relevant improvements in knee pain were reached up to 12 weeks after the injection in both groups. At 4 weeks, the estimated mean difference in the Knee Injury and Osteoarthritis Outcome Score between the 2 groups was -3.4 (95% CI, -10.1 to 3.3). Noninferiority could not be declared because the lower limit exceeded the noninferiority margin. Intramuscular injection was noninferior to IA injection at 8 (mean difference, 0.7; 95% CI, -6.5 to 7.8) and 24 (mean difference, 1.6; 95% CI, -5.7 to 9.0) weeks. No significant difference was found among all the secondary outcomes. These results were similar for the sensitivity analysis in an intention-to-treat population. The most frequently reported adverse events were hot flush (IM, 7 [10%] vs IA, 14 [21%]) and headache (IM, 10 [14%] vs IA, 12 [18%]), and all events were classified as nonserious.

CONCLUSIONS AND RELEVANCE

Based on the findings of this trial, among patients with knee OA in primary care, IM glucocorticoid injection could present an inferior effect in reducing pain at 4 weeks compared with IA injection. Noninferiority of an IM injection was observed at 8 and 24 weeks after injection. This trial provides data for shared decision-making, taking into account the advantages and disadvantages of both types of injections.

TRIAL REGISTRATION

Dutch Trial Registry: NTR6968.

Do Glucocorticoid Injections Increase the Risk of Knee Osteoarthritis Progression Over 5 Years?

OBJECTIVE

Recent findings have demonstrated that intraarticular (IA) glucocorticoid injections can be deleterious for knees with osteoarthritis (OA). This study was undertaken to assess, in a real-life setting, the risk of knee OA progression in patients who received IA glucocorticoid injections over a 5-year follow-up period.

METHODS

We used marginal structural modeling with inverse probability of treatment weighting to determine the causal association between IA glucocorticoid injections and the 5-year risk of disease progression in patients with symptomatic knee OA from the Knee and Hip Osteoarthritis Long-term Assessment cohort. OA progression was defined as an incident total knee replacement (TKR) and/or radiographic worsening (Kellgren/Lawrence [K/L] grade or joint space narrowing [JSN]). We also examined these outcomes in knees that received IA hyaluronan (IAHA) injections.

RESULTS

Among the 564 patients with knee OA included in the study sample, 51 (9.0%) and 99 (17.5%) received IA glucocorticoid or IAHA injections, respectively, and 414 (63.1%) did not receive any injection during follow-up. Compared to untreated knees, those treated with IA glucocorticoid injections had a similar risk of incident TKR (hazard ratio [HR] 0.92 [95% confidence interval (95% CI) 0.20, 4.14]; P = 0.91) or K/L grade worsening (HR 1.33 [95% CI 0.64, 2.79]; P = 0.44). IAHA injections had no effect on the risk of TKR (HR 0.81 [95% CI 0.14, 4.63]; P = 0.81) or K/L grade worsening (HR 1.36 [95% CI 0.85, 2.17]; P = 0.20). Similar results were obtained for JSN, and when TKR and radiographic outcomes were combined.

CONCLUSION

In this study, IA glucocorticoid injections for symptomatic knee OA did not significantly increase the 5-year risk of incident TKR or radiographic worsening. These findings should be interpreted cautiously and replicated in other cohorts.

A Randomized, Open-Label, Single-Dose Study to Assess Safety and Systemic Exposure of Triamcinolone Acetonide Extended-Release in Patients With Hip Osteoarthritis

Introduction

Intra-articular (IA) corticosteroids, including triamcinolone acetonide (TA), are a recommended treatment for hip osteoarthritis. We compared the safety and systemic exposure of TA extended-release (TA-ER) versus TA crystalline suspension (TAcs) in patients with hip osteoarthritis.

Methods

In this phase 2, randomized, multicenter, open-label, single-dose study (NCT03382262), patients with hip osteoarthritis were randomly assigned 1:1 to receive single IA injections of TA-ER 32 mg or TAcs 40 mg. Safety assessments included treatment-emergent adverse events (TEAEs). Blood samples were collected for pharmacokinetic (PK) analysis up to day 85. PK parameters included area under the concentration–time curve, total body drug clearance, maximum concentration (C_max), mean residence time, half-life, and time to maximum concentration.

Results

Of 30 patients (TA-ER: n = 15; TAcs: n = 15) randomized and included in the Safety Population, 25 patients were evaluated in the PK Population. TEAEs were reported in four of 15 (26.7%) patients who received TA-ER and in seven of 15 (46.7%) patients who received TAcs. The most common TEAEs included arthralgia and headache. All TEAEs were of grade 1 or 2 in severity. TA-ER produced substantially lower peak plasma TA concentrations compared with TAcs (C_max geometric mean: 890.4 vs. 5549.4 pg/ml), and these were less variable with TA-ER versus TAcs. Similarly, overall TA systemic exposure was substantially lower for TA-ER versus TAcs, with gradual elimination from systemic circulation through day 85.

Conclusions

Following a single IA injection in the hip, TA-ER was generally well tolerated, with a safety profile comparable to that of TAcs. Systemic TA exposure was markedly lower in TA-ER-treated patients, consistent with the PK profile observed in knee osteoarthritis.

Clinicaltrials.gov identifier: NCT03382262.

TLC599 in patients with osteoarthritis of the knee: a phase IIa, randomized, placebo-controlled, dose-finding study

Background

Corticosteroid injection for knee osteoarthritis is limited by its modest duration of treatment effect. The liposome formulation of dexamethasone sodium phosphate (TLC599) was developed for the sustained relief of osteoarthritis pain. This clinical study was conducted to evaluate the efficacy and safety of TLC599 at two dose levels in patients with knee osteoarthritis.

Methods

A randomized, double-blinded, placebo-controlled study was conducted in 75 patients with osteoarthritis of the knee from 13 study centers. Patients were randomized and administered a single intra-articular injection of TLC599 or placebo and assessed for efficacy and safety for 24 weeks. Patient-reported outcomes included the Western Ontario and McMaster Universities Arthritis (WOMAC) Index for pain and function and visual analog scale for pain.

Results

TLC599 at 12 mg demonstrated significantly greater reduction in WOMAC pain through 12 weeks (least squares (LS) mean difference = − 0.37, p = 0.0027) and through 24 weeks (LS mean difference = − 0.35, p = 0.0037) when compared to placebo. TLC599 12 mg also exhibited significantly greater improvement in function when compared to placebo at 24 weeks (LS mean difference = − 0.26, p = 0.0457). TLC599 18 mg did not significantly improve pain or function in comparison with placebo. The use of acetaminophen during the study was less in both TLC599 groups in comparison with placebo. No major or unexpected safety issues were reported.

Conclusions

In participants with symptomatic knee osteoarthritis, TLC599 is a well-tolerated treatment that reduces pain and improves function for up to 24 weeks, a longer duration than that reported for existing IA treatments.

Trial registration

ClinicalTrials.gov, NCT03005873. Registered on 29 December 2016

Osteoarthritis year in review 2021: biology

This year in review on osteoarthritis biology summarizes a series of research articles published between the 2020 and 2021 Osteoarthritis Research Society International (OARSI) World Congress. Research hightlights were selected and discussed based on the new discoveries of OA's cellular molecular mechanism, anatomical signatures, potential therapeutic targets, and regenerative therapy. The recently developed potential therapeutic targets are summarized, and the research focuses on TGFβ and WNT signaling in joint tissue homeostasis, joint aging and the dynamic of synolytics in OA joint, and the roles of TRP2, LDHA, OSCAR in cartilage homeostasis and OA joints are highlighted. Subsquencially, new anatomical structures and OA features are introduced, such as synovitis-induced venous portal circulation, horiozontal fissures between cartilage and subchondral bone, the cellular derivation of osteophytes formation, OA subtypes, and subchondral remodeling and pain biology. Then, research on the possibility of tissue regeneration in OA joints are discussed; skeletal stem cells in OA cartilage regeneration, and preclinical results of regenerative therapy for meniscus tear and osteochondral tissue morphoghesis are included. At last, the clinical evidence of the importance of delivery site of bone marrow stem cells for OA treatment is discussed. These findings represent advances in our understanding of OA pathophysiology.

Injectable hyaluronic acid hydrogels encapsulating drug nanocrystals for long-term treatment of inflammatory arthritis

Antiproliferative chemotherapeutic agents offer a potential effective treatment for inflammatory arthritis. However, their clinical application is limited by high systemic toxicity, low joint bioavailability as well as formulation challenges. Here, we report an intra-articular drug delivery system combining hyaluronic acid hydrogels and drug nanocrystals to achieve localized and sustained delivery of an antiproliferative chemotherapeutic agent camptothecin for long-term treatment of inflammatory arthritis. We synthesized a biocompatible, in situ-forming injectable hyaluronic acid hydrogel using a naturally occurring click chemistry: cyanobenzothiazole/cysteine reaction, which is the last step reaction in synthesizing D-luciferin in fireflies. This hydrogel was used to encapsulate camptothecin nanocrystals (size of 160-560 nm) which released free camptothecin in a sustained manner for 4 weeks. In vivo studies confirmed that the hydrogel remained in the joint over 4 weeks. By using the collagen-induced arthritis rat model, we demonstrate that the hydrogel-camptothecin formulation could alleviate arthritis severity as indicated by the joint size and interleukin-1β level in the harvested joints, as well as from histological and microcomputed tomography evaluation of joints. The hydrogel-nanocrystal formulation strategy described here offers a potential solution for intra-articular therapy for inflammatory arthritis.

New developments in osteoarthritis pharmacological therapies

OA is an increasingly common, painful condition with complex aetiology and limited therapies. Approaches to expanding our therapeutic armamentarium have included repurposing existing therapies used for other rheumatological conditions, modifying existing OA preparations to enhance their benefits, and identifying new therapeutics. HCQ and low-dose MTX have been unsuccessful in improving hand OA pain or reducing structural progression. Anti-IL-6 and anti-GM-CSF also did not improve symptoms in hand OA trials, but IL-1 remains an intriguing target for large-joint OA, based on reduced joint replacements in a post hoc analysis from a large cardiovascular disease trial. The peripheral nociceptive pathway appears an attractive target, with mAbs to nerve growth factor and IA capsaicin demonstrating efficacy; tropomyosin receptor kinase A inhibitors are at an earlier stage of development. Limited evidence suggests pharmacological therapies can modify cartilage and bone structural progression, though evidence of synchronous symptom benefits are lacking.

The Long-Lasting Effects of "Placebo Injections" in Knee Osteoarthritis: A Meta-Analysis

OBJECTIVES

To quantify the placebo effect of intraarticular injections for knee osteoarthritis in terms of pain, function, and objective outcomes. Factors influencing placebo effect were investigated.

DESIGN

Meta-analysis of randomized controlled trials; Level of evidence, 2. PubMed, Web of Science, Cochrane Library, and grey literature databases were searched on January 8, 2020, using the string: (knee) AND (osteoarthritis OR OA) AND (injections OR intra-articular) AND (saline OR placebo). The following inclusion criteria were used: double-blind, randomized controlled trials on knee osteoarthritis, including a placebo arm on saline injections. The primary outcome was pain variation. Risk of bias was assessed using the RoB 2.0 tool, and quality of evidence was graded following the GRADE (Grading of Recommendations Assessment, Development and Evaluation) guidelines.

RESULTS

Out of 2,363 records, 50 articles on 4,076 patients were included. The meta-analysis showed significant improvements up to the 6-month follow-up: Visual Analogue Scale (VAS)-pain -13.4 mean difference (MD) (95% confidence interval [CI]: -21.7/-5.1; P < 0.001), Western Ontario and McMaster Osteoarthritis Index (WOMAC)-pain -3.3 MD (95% CI: -3.9/-2.7; P < 0.001). Other significant improvements were WOMAC-stiffness -1.1 MD (95% CI: -1.6/-0.6; P < 0.001), WOMAC-function -10.1 MD (95% CI: -12.2/-8.0; P < 0.001), and Evaluator Global Assessment -21.4 MD (95% CI: -29.2/-13.6; P < 0.001). The responder rate was 52% (95% CI: 40% to 63%). Improvements were greater than the "minimal clinically important difference" for all outcomes (except 6-month VAS-pain). The level of evidence was moderate for almost all outcomes.

CONCLUSIONS

The placebo effect of knee injections is significant, with functional improvements lasting even longer than those reported for pain perception. The high, long-lasting, and heterogeneous effects on the scales commonly used in clinical trials further highlight that the impact of placebo should not be overlooked in the research on and management of knee osteoarthritis.

Intraarticular Corticosteroids for Hip Osteoarthritis: A Review

INTRODUCTION

Hip osteoarthritis is a prevalent condition responsible for important pain and disability. Most available guidelines for nonsurgical management of hip osteoarthritis recommend a combination of nonpharmacological and pharmacological treatment modalities. Intraarticular corticosteroid injections have been used for decades, although evidence is quite scarce, and many controversies remain.

METHODS

This article reviews the available literature from Medline and Embase and discusses the evidence for intraarticular corticosteroid injections in hip osteoarthritis, where only 5 randomized controlled trials were found in the literature. These are analyzed in this article, which also aims to explain the main characteristics and features of glucocorticoids, along with their contraindications and potential adverse effects.

RESULTS

Available randomized controlled trials show that intraarticular corticosteroid injections provide pain relief and functional improvement in hip osteoarthritis. This efficacy has not been shown with intraarticular hyaluronic acid injections.

CONCLUSION

This review shows that intraarticular corticosteroid injections are efficacious in hip osteoarthritis and that this benefit can last up to 12 weeks.

Improved Treatment Effect of Triamcinolone Acetonide Extended-Release in Patients with Concordant Baseline Pain Scores on the Average Daily Pain and Western Ontario and McMaster Universities Osteoarthritis Index Pain Scales

Introduction

A phase 3 randomized controlled study comparing triamcinolone acetonide extended-release (TA-ER) to conventional TA crystalline suspension (TAcs) reported variable efficacy results. Enrollment criteria may have contributed to this discrepancy, as moderate-to-severe average daily pain (ADP) was required at baseline, whereas no limitations were placed on Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC-A) pain severity. We conducted a post hoc sensitivity analysis to compare treatment effects in patients reporting moderate-to-severe osteoarthritis (OA) pain on both scales.

Methods

Participants > 40 years old with symptomatic knee OA were randomly assigned to a single intra-articular injection of TA-ER 32 mg, TAcs 40 mg, or saline-placebo and followed for 24 weeks. Patient-reported ADP, WOMAC-A, rescue medication usage, and adverse events (AEs) were assessed. Participants who reported moderate-to-severe OA pain at baseline using both instruments (ADP ≥ 5 to ≤ 9, maximum 10 and WOMAC-A ≥ 2, maximum 4) were categorized as “concordant” pain reporters; patients with baseline moderate-to-severe OA on ADP only were termed “discordant” pain reporters.

Results

Two-hundred-ninety-two concordant pain reporters of 484 total subjects received TA-ER 32 mg (n = 95), TAcs 40 mg (n = 100), or saline-placebo (n = 97). Baseline characteristics and AE profiles of the concordant and discordant pain responders were consistent with the full analysis population. Among concordant pain reporters, TA-ER significantly (p < 0.05) improved ADP scores vs. TAcs (weeks 5–19; area-under-the-effect [AUE]_weeks1–12; AUE_weeks1–24) and saline-placebo (weeks 1–20; AUE_weeks1–12; AUE_weeks1–24). At week 12, a higher proportion reported no knee pain (ADP = 0) with TA-ER (~ 28%) vs. TAcs (~ 8%). TA-ER significantly improved WOMAC-A vs. TAcs at weeks 4, 8, and 12, with significant reduction in rescue medication usage observed with TA-ER from weeks 2 to 20 vs. TAcs.

Conclusions

In patients reporting moderate-to-severe knee OA pain at baseline based on concordant ADP and WOMAC-A scores, TA-ER provided statistically significant pain relief for ≥ 12 weeks compared with conventional TAcs.

Trial Registration

ClinicalTrials.gov Identifier: NCT02357459.

Osteoarthritis is a chronic condition that greatly impacts patients. Pain is the most common symptom of osteoarthritis. Clinical trials evaluating the effects of new drugs to treat osteoarthritis pain frequently use scales to rate overall pain following treatment. Patients may rate their pain using a number that best describes their pain, with the lowest number typically meaning “no pain,” and the highest number typically meaning “pain as bad as you can imagine.” Other rating scales may be used to rate pain in situations commonly associated with osteoarthritis.

Results from a large clinical trial demonstrated that injection of an extended-release steroid significantly reduced pain compared with a conventional steroid injection on only one of the two pain-reporting scales used in the trial. A closer look found that some patients reported their pain differently on the two rating scales at the start of the trial, with some reporting moderate-to-severe pain using one questionnaire and mild pain using the other. Here, we focused on those patients who reported having moderate-to-severe osteoarthritis knee pain on both pain scales at the start and found that the pain relief benefit associated with the extended-release steroid injection was greatly improved compared with the conventional steroid injection with both measures. Patients receiving the extended-release steroid injection also decreased their use of rescue medication for pain relief.