Structural predictors of response to intra-articular steroid injection in symptomatic knee osteoarthritis

Post-Traumatic Arthritis of the Knee and Ankle

Post-traumatic osteoarthritis (PTOA) occurs following injury to joints. It accounts for approximately 12% of osteoarthritis and has far-reaching effects on individual patients and social/health care systems. Present work focuses on evaluating the role of the post-traumatic inflammatory response in the development and progression of the disease. As there is minimal evidence to suggest the capacity of cartilage to undergo self-healing, most of this work focuses strictly on the avoidance or prevention of PTOA as opposed to treatment solutions following its onset. Ongoing and future investigations may reveal therapeutic targets for possible intervention and ultimately the prophylaxis of PTOA development.

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

BACKGROUND

Intra-articular corticosteroid injections may cause hyperglycemia (glucose level >180 mg/dL). In a phase 2 study of 33 patients who had osteoarthritis of the knee and type 2 diabetes mellitus, 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 osteoarthritis of the knee for ≥6 months, type 2 diabetes mellitus for ≥1 year, and hemoglobin A1c ≥6.5 and ≤9.0% were randomized to receive an intra-articular 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.

Immunomodulation and fibroblast dynamics driving nociceptive joint pain within inflammatory synovium: Unravelling mechanisms for therapeutic advancements in osteoarthritis

OBJECTIVE

Synovitis is a widely accepted sign of osteoarthritis (OA), characterised by tissue hyperplasia, where increased infiltration of immune cells and proliferation of resident fibroblasts adopt a pro-inflammatory phenotype, and increased the production of pro-inflammatory mediators that are capable of sensitising and activating sensory nociceptors, which innervate the joint tissues. As such, it is important to understand the cellular composition of synovium and their involvement in pain sensitisation to better inform the development of effective analgesics.

METHODS

Studies investigating pain sensitisation in OA with a focus on immune cells and fibroblasts were identified using PubMed, Web of Science and SCOPUS.

RESULTS

In this review, we comprehensively assess the evidence that cellular crosstalk between resident immune cells or synovial fibroblasts with joint nociceptors in inflamed OA synovium contributes to peripheral pain sensitisation. Moreover, we explore whether the elucidation of common mechanisms identified in similar joint conditions may inform the development of more effective analgesics specifically targeting OA joint pain.

CONCLUSION

The concept of local environment and cellular crosstalk within the inflammatory synovium as a driver of nociceptive joint pain presents a compelling opportunity for future research and therapeutic advancements.

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.

Longitudinal MRI-defined Cartilage Loss and Radiographic Joint Space Narrowing Following Intra-Articular Corticosteroid Injection for Knee Osteoarthritis: A Systematic Review and Meta-analysis

Background

Intra-articular corticosteroid injections (IACS) are interventions which provide pain relief in knee osteoarthritis (OA). It remains unclear whether IACS have a deleterious effect on knee cartilage structure.

Purpose

To estimate the effect of IACS on cartilage structure in patients with knee OA, using joint space width (JSW) (in radiographic studies), and cartilage thickness (in magnetic resonance imaging).

Materials and methods

A literature search was performed to identify randomized control trials and observational studies published from inception to June 15, 2022. Studies were included if patients received IACS for knee OA, with a control arm. Given the different metrics used in reporting continuous variable outcomes among studies, pooled estimates for cartilage thickness change were assessed using standardized mean differences (defined as the difference between the means of the groups divided by a within-group standard deviation) to odds ratio transformation. Sensitivity analyses were conducted based on outcome metric, imaging modality, and number of injections.

Results

Six studies (1437 participants) were identified. The estimated effect of IACS on cartilage structure revealed greater odds of cartilage structure worsening (Odds Ratio (OR): 2.01, 95% Confidence Interval (CI): 1.18,3.44). Sensitivity analyses revealed similar trends, with significant results for singular injections with preference to JSW (OR: 2.44, 95%CI: 1.23,4.82), radiographic outcomes with preference to KL grade (OR: 2.03, 95%CI: 1.01,4.10), binary outcomes with preference to KL grade (OR: 2.93, 95%CI: 1.18,7.25) and quantitative measures (Standardized Mean Differences (SMD): -0.34, 95%CI: -0.66, -0.02).

Conclusions

IACS use may contribute to imaging features of knee cartilage loss. Further studies are warranted to investigate the underlying pathogenesis.

Baseline Knee Pain Predicts Long-Term Response of Intra-Articular Steroid Injection in Symptomatic Knee Osteoarthritis: Data from OAI

OBJECTIVE

The current study aims to investigate the factors that could predict response to intra-articular corticosteroid injection (IACI) in patients with knee osteoarthritis (KOA).

METHODS

Data of participants were retrieved from the Osteoarthritis Initiative database. Participants with at least one IACI treatment on single or bilateral knees within the first 5 years of follow-up were retrospectively included. Demographic data, clinical and radiographic variables were collected at both baseline and the first follow-up after IACI treatment. Positive response to IACI treatment was defined as >20% reduction of Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score from V0 to V1. All the variables with P < 0.2 after the comparison between the response and non-response groups were included in a multivariable logistic regression model to identify independent response predictive patient-specific valuables. Receiver operating characteristic curves were performed to establish the cutoff values of independent predictors.

RESULTS

The current study included a total of 385 participants (473 knees), with 155 and 318 knees classified into the response group and non-response group, respectively. Those with satisfied responses to IACI treatment had significantly higher WOMAC pain score (P < 0.001), disability score (P = 0.002), and stiffness score (P = 0.015) at the baseline. Baseline WOMAC pain score showed significant association with positive response to IACI treatment in multivariate logistic analysis and the best cutoff value was 5 points. The rate of analgesics utilization was lower (P = 0.014) in the response group than the non-response group after the IACI treatment.

CONCLUSION

KOA patients with a baseline WOMAC pain score ≥5 are more likely to benefit from IACI treatment.

Pilot Study of Low-Dose Naltrexone for the Treatment of Chronic Pain Due to Arthritis: A Randomized, Double-blind, Placebo-Controlled, Crossover Clinical Trial

PURPOSE

Low-dose naltrexone (LDN) is commonly used to control pain and other symptoms, especially in patients with autoimmune diseases, but with limited evidence. This study tests the efficacy of LDN in reducing chronic pain in patients with osteoarthritis (OA) and inflammatory arthritis (IA), where existing approaches often fail to adequately control pain.

METHODS

In this randomized, double-blind, placebo-controlled, crossover clinical trial, each patient received 4.5 mg LDN for 8 weeks and placebo for 8 weeks. Outcome measures were patient reported, using validated questionnaires. The primary outcome was differences in pain interference during the LDN and placebo periods, using the Brief Pain Inventory (scale, 0-70). Secondary outcomes included changes in mean pain severity, fatigue, depression, and multiple domains of health-related quality of life. The painDETECT questionnaire classified pain as nociceptive, neuropathic, or mixed. Data were analyzed using mixed-effects models.

FINDINGS

Seventeen patients with OA and 6 with IA completed the pilot study. Most patients described their pain as nociceptive (n = 9) or mixed (n = 8) rather than neuropathic (n = 3). There was no difference in change in pain interference after treatment with LDN (mean [SD], -23 [19.4]) versus placebo (mean [SD], -22 [19.2]; P = 0.90). No significant differences were seen in pain severity, fatigue, depression, or health-related quality of life.

IMPLICATIONS

In this small pilot study, findings do not support LDN being efficacious in reducing nociceptive pain due to arthritis. Too few patients were enrolled to rule out modest benefit or to assess inflammatory or neuropathic pain.

CLINICALTRIALS

gov identifier: NCT03008590.

Oligonucleotide Therapeutics for Age-Related Musculoskeletal Disorders: Successes and Challenges

Age-related disorders of the musculoskeletal system including sarcopenia, osteoporosis and arthritis represent some of the most common chronic conditions worldwide, for which there remains a great clinical need to develop safer and more efficacious pharmacological treatments. Collectively, these conditions involve multiple tissues, including skeletal muscle, bone, articular cartilage and the synovium within the joint lining. In this review, we discuss the potential for oligonucleotide therapies to combat the unmet clinical need in musculoskeletal disorders by evaluating the successes of oligonucleotides to modify candidate pathological gene targets and cellular processes in relevant tissues and cells of the musculoskeletal system. Further, we discuss the challenges that remain for the clinical development of oligonucleotides therapies for musculoskeletal disorders and evaluate some of the current approaches to overcome these.

Two-year outcomes comparing Embosphere® microspheres versus Imipenem Cilastatin for genicular artery embolization in patients with moderate to severe knee osteoarthritis

BACKGROUND

Genicular artery embolization (GAE) is a novel technique and has the potential to provide midterm relief of pain for patients with mild-to-moderate knee osteoarthritis resistant to conservative management. This study compares the efficacy and safety of trisacryl gelatin microspheres to Imipenem/Cilastatin particles for GAE with 2 years of clinical follow-up.

METHODS

In this retrospective study, eight patients with knee osteoarthritis (11 knees) who underwent GAE with 100-300 μm trisacryl gelatin microspheres particles were compared with six patients (nine knees) who underwent GAE with Imipenem/Cilastatin particles. Clinical outcomes were evaluated at 3-month and 24-month follow-ups and compared to baseline using the WOMAC questionnaire.

RESULTS

The median follow-up was 796 days (range: 736-808). There were no significant differences in clinical outcome measures at the 3-month or 24-month follow-up. Both embolic materials resulted in a decrease in Pain WOMAC and Total WOMAC scores at 3 months (p < 0.05), and the effect of treatment on Pain WOMAC and Total WOMAC score reduction was sustained until the 24-month follow-up (p < 0.05). Minor events (Clavien-Dindo classification grade I) included transient cutaneous color change (n = 3) and transient leg numbness (n = 1) after embolization with trisacryl gelatin microspheres particles (p = 0.08). All minor adverse events resolved spontaneously. There were no major adverse events.

CONCLUSION

One hundred to three hundred μm trisacryl gelatin microspheres particles can be considered for genicular artery embolization and is comparable to Imipenem/Cilastatin particles in pain reduction of moderate to severe knee osteoarthritis. A sustained effect is observed for up to 2 years of follow-up.

Gender, age, disease severity, body mass index and diabetes may not affect response to subcutaneous tanezumab in patients with osteoarthritis after 16 weeks of treatment. A subgroup analysis of placebo-controlled trials

AIM

To assess the impact of pre-specified patient characteristics on efficacy and safety of subcutaneous tanezumab in patients with osteoarthritis (OA).

METHODS

Data were pooled from two (efficacy; N = 1545) or three (safety; N = 1754) phase 3 placebo-controlled trials. Change from baseline to week 16 in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain, WOMAC Physical Function and patient global assessment of OA (PGA-OA) scores was compared between tanezumab (2.5 and 5 mg) and placebo groups via analysis of covariance. Treatment-emergent adverse events (TEAEs) were summarised descriptively. Analyses were done in patient subgroups (men or women; age <65, ≥65, or ≥75 years; body mass index [BMI] <25, 25 to <30, 30 to <35 or ≥35 kg/m² ; diabetes or no diabetes; baseline WOMAC Pain score <7 or ≥7; and Kellgren-Lawrence [KL] grades 2, 3 or 4 in the index joint) and the overall population.

RESULTS

In all subgroups, improvements in WOMAC Pain were numerically greater and often statistically significant (P < .05) for both tanezumab groups compared with placebo. Results were similar for WOMAC Physical Function and PGA-OA. TEAE profiles were generally consistent across subgroups and similar to the overall population (ie slightly higher rates of TEAEs, serious TEAEs and severe TEAEs with tanezumab relative to placebo) with a few exceptions. Exceptions included women reporting slightly more TEAEs with tanezumab than men, and patients with diabetes reporting slightly more severe TEAEs with tanezumab than patients without diabetes. Additionally, TEAEs were more frequent with tanezumab than placebo in the age ≥65 and ≥75 years, but not the age <65 years, subgroups.

CONCLUSIONS

Efficacy and safety/tolerability of tanezumab may not be meaningfully impacted by gender, age, BMI, diabetes status, baseline pain severity or KL grade in the index joint. Conclusions are limited by low patient number in some subgroups. Clinicaltrials.gov: NCT02697773, NCT02709486, NCT01089725.

Oligonucleotide Therapies in the Treatment of Arthritis: A Narrative Review

Osteoarthritis (OA) and rheumatoid arthritis (RA) are two of the most common chronic inflammatory joint diseases, for which there remains a great clinical need to develop safer and more efficacious pharmacological treatments. The pathology of both OA and RA involves multiple tissues within the joint, including the synovial joint lining and the bone, as well as the articular cartilage in OA. In this review, we discuss the potential for the development of oligonucleotide therapies for these disorders by examining the evidence that oligonucleotides can modulate the key cellular pathways that drive the pathology of the inflammatory diseased joint pathology, as well as evidence in preclinical in vivo models that oligonucleotides can modify disease progression.

A Malaysian Delphi consensus on managing knee osteoarthritis

BACKGROUND

The 2013 Malaysian Clinical Practice Guidelines on the Management of Osteoarthritis (OA) recommend a linear step-up approach to manage knee OA. However, patients with knee OA often require a multimodal approach to address OA-related pain symptoms and functional limitations. This consensus aimed to provide doctors with an updated set of evidence-based, clinical experience-guided recommendations to manage knee OA.

METHODS

A multi-speciality expert panel consisting of nine Malaysian physicians from different healthcare settings who manage a diverse OA patient population was convened. Using a combination of the ADAPTE process and modified Delphi method, the panel reviewed current evidence on the management of knee OA and synthesised a set of nine recommendations on the management of knee OA, supported by an algorithm that summarises the consensus' core messages.

RESULTS

A multimodal intervention strategy is the mainstay of OA management and the choice of any single or multimodal intervention may vary over the course of the disease. Overall, a non-pharmacological core treatment set of patient education, weight loss and exercise is recommended for all patients. When pharmacotherapy is indicated, symptomatic slow-acting drugs for osteoarthritis are recommended at the early stage of disease, and they can be paired with physical therapy as background treatment. Concurrent advanced pharmacotherapy that includes non-steroidal anti-inflammatory drugs, intraarticular injections and short-term weak opioids can be considered if patients do not respond sufficiently to background treatment. Patients with severe symptomatic knee OA should be considered for knee replacement surgery. Management should begin with specific treatments with the least systemic exposure or toxicity, and the choice of treatment should be determined as a shared decision between patients and their team of healthcare providers.

CONCLUSIONS

This consensus presents nine recommendations that advocate an algorithmic approach in the management of patients living with knee OA. They are applicable to patients receiving treatment from primary to tertiary care providers in Malaysia as well as other countries.

Common Practices in Intra-Articular Corticosteroid Injection for the Treatment of Knee Osteoarthritis: A Survey of the American Association of Hip and Knee Surgeons Membership

BACKGROUND

Knee osteoarthritis nonoperative management options remain limited. Our aim is to define the current American Association of Hip and Knee Surgeons (AAHKS) members' practices and perceptions in terms of the frequency, formulation, use of concomitant aspiration, maximum lifetime number of injections, efficacy, interval between injection and surgery and complication rates.

METHODS

A 22-question survey based on Likert scale response anchors was approved and distributed by the AAHKS Research Committee to its membership by email during the Spring 2019 meeting. Data were managed with REDCap software.

RESULTS

Membership response totaled 537 of 2365 (22.7%) members. Highlights include every respondent using intra-articular corticosteroid injections (ICIs) in their practice, and most use a three-month minimum interval, although the preferred interval is longer. Near consensus was found waiting three months before surgery. There was a great variability in the number of injections allowed, and injections before surgery were very common. Nearly all responders use a local anesthetic mixture with the cortisone injection, but there was great variation in corticosteroid type: methylprednisolone (42%), triamcinolone (41%), betamethasone (13.3%), and dexamethasone (3.7%).

CONCLUSION

The results of our survey indicate the majority of the AAHKS members who completed the survey use ICIs routinely for treatment of knee osteoarthritis. There was near consensus in ICIs, which is effective with decreasing efficacy over serial injections, and an absolute minimum interval between injections was believed by most to be three months with no clearly defined lifetime limit and strong consensus for a three-month preoperative interval. The formulation of steroid, local anesthetic, and skin preparation technique varied greatly.

Efficacy and predictive factors of response to intra-articular corticosteroids in knee osteoarthritis

In knee osteoarthritis (KOA), synovial inflammation is linked with pain, swelling and structural abnormalities. Intra-articular corticosteroids (IACS) have been considered for pain relief in subjects who are non-responders to standard therapy. However, the results vary across different studies. This review aims to determine efficacy of IACS in KOA by review of the existing data.

In several randomized controlled trials (RCTs), meta-analyses and uncontrolled studies a single IACS resulted in pain relief from 1 to a few weeks. In a few studies repeated IACS every three months provided a longer duration of pain relief and functional improvement in a proportion of patients. Baseline synovitis was predictor of treatment response in some but not all studies.

Based upon the existing data, IACS provides a short-term pain relief in a proportion of patients. Given, anti-inflammatory properties of IACS, it is likely to be more effective in subgroups of KOA who display inflammatory phenotype.

Intra-Articular Injection of Amniotic Membrane and Umbilical Cord Particulate for the Management of Moderate to Severe Knee Osteoarthritis

Objective

To evaluate the long-term benefit of a single injection of amniotic membrane/umbilical cord (AM/UC) particulate in patients with moderate to severe knee osteoarthritis (OA).

Methods

A single-center, investigator-initiated, retrospective study of patients who received intra-articular injection of 100 mg lyophilized and micronized AM/UC for radiographically confirmed, Kellgren–Lawrence (KL) grade 3 or 4 symptomatic knee OA. Data regarding demographics, OA severity, comorbidities, treatment regimens, complications, and patient-reported outcomes were collected and assessed. Patient Global Impression of Change (PGIC) was assessed on a 7-point scale, and Global Perceived Improvement (GPI), expressed as percent improvement relative to baseline, was used to further quantify the degree of symptomatic change. Clinically important response to treatment was assessed at 12 months using simplified OMERACT–OARSI responder criteria.

Results

A total of 42 patients with KL grade 3 (36%) and 4 (64%) knee OA were included for analysis. Prior to injection, patient-rated pain was 6.6 ± 1.5 out of 10 (median: 7, range: 3–10) despite prior treatment with oral/topical NSAIDs (62%) and intra-articular injection(s) of corticosteroids (57%) and/or hyaluronic acid (48%). Twelve months following AM/UC injection, 31 patients (74%) reported significant clinical improvement via PGIC, and the OMERACT–OARSI treatment response rate was 81% (34/42). GPI of pain and function was 62 ± 24%, 69 ± 27%, 69 ± 27%, and 64 ± 31% at 1, 3, 6, and 12 months, respectively. Symptomatic improvement was maintained for an average duration of 12.1 ± 4.5 months (median: 12, range: 3–22). One patient developed swelling in the knee within 36 hours of injection. No other adverse events or complications were reported.

Conclusion

Intra-articular injection of AM/UC particulate may be effective in alleviating pain and improving function in patients with moderate to severe knee OA, with the potential to delay total knee replacement for up to 12 months.

Intra-articular Corticosteroid Injections for the Treatment of Hip and Knee Osteoarthritis-related Pain: Considerations and Controversies with a Focus on Imaging-Radiology Scientific Expert Panel

Current management of osteoarthritis (OA) is primarily focused on symptom control. Intra-articular corticosteroid (IACS) injections are often used for pain management of hip and knee OA in patients who have not responded to oral or topical analgesics. Recent case series suggested that negative structural outcomes including accelerated OA progression, subchondral insufficiency fracture, complications of pre-existing osteonecrosis, and rapid joint destruction (including bone loss) may be observed in patients who received IACS injections. This expert panel report reviews the current understanding of pain in OA, summarizes current international guidelines regarding indications for IACS injection, and considers preinterventional safety measures, including imaging. Potential profiles of those who would likely benefit from IACS injection and a suggestion for an updated patient consent form are presented. As of today, there is no established recommendation or consensus regarding imaging, clinical, or laboratory markers before an IACS injection to screen for OA-related imaging abnormalities. Repeating radiographs before each subsequent IACS injection remains controversial. The true cause and natural history of these complications are unclear and require further study. To determine the cause and natural history, large prospective studies evaluating the risk of accelerated OA or joint destruction after IACS injections are needed. However, given the relatively rare incidence of these adverse outcomes, any clinical trial would be challenging in design and a large number of patients would need to be included.

The perspectives of intra-articular therapy in the management of osteoarthritis

Management of Osteoarthritis (OA) still is a challenge for clinicians. Taking into account a multidisciplinary approach including pharmacological and non-pharmacological treatments, intra-articular (IA) injection could be considered as an effective local therapy. Areas covered This review provides a new perspective of IA treatment going beyond current available IA agents. We describe novel biological targets for developing new IA agents and innovative modalities of delivery systems. Additional topics include predictors of response for a better choice of IA agents for each patient, diagnostic and prognostic role of biomarkers, accuracy of IA injection, and cost-effectiveness of IA injection. Expert opinion IA treatments seem to be very promising for the management of OA. Identifying clinical and biochemical predictive factors could drive clinician to the appropriate therapeutic approach. To date, there is a gap regarding the benefit of IA treatments in the 'real practice' once they have been adopted. However, considering these promising effects of IA approach, several open questions remain not clarified.

Beyond Revision Surgery: Work-Up and Interventional Treatments for the Painful Total Knee Arthroplasty

Total knee arthroplasty is a common and successful treatment modality for knee arthritis that is refractory to conservative management strategies. Over 600,000 arthroplasties are performed per year in the United States, and this number is expected to increase in the coming years. Unfortunately, 8% to 34% of patients experience chronic pain after having a total knee arthroplasty. These patients should undergo an appropriate work-up by the orthopedic surgeon, but many times a surgical problem is not uncovered. In these situations, a thorough and specific plan for pain management should be sought. In this article, we outline the work-up of a painful total knee arthroplasty. Then we provide a thorough review of interventional pain management strategies and highlight the pertinent literature. Lastly, we hypothesize future developments in the field that may provide better outcomes for patients suffering from painful total knee arthroplasty.

Do Clinical Correlates of Knee Osteoarthritis Predict Outcome of Intraarticular Steroid Injections?

OBJECTIVE

To determine whether clinical correlates of knee osteoarthritis (OA) affect the outcome of intraarticular steroid injections (IASI) in symptomatic knee OA.

METHODS

Men and women aged ≥ 40 years with painful knee OA who participated in an open-label trial of IASI completed questionnaires and clinical examination. The Outcome Measures in Rheumatology (OMERACT)-Osteoarthritis Research Society International (OARSI) criteria were used to assess response to therapy in the short term (within 2 weeks). Among those who initially responded, those whose pain had not returned to within 20% of the baseline Knee Injury and Osteoarthritis Outcome Score pain score at 6 months were characterized as longer-term responders. Log-binomial regression was used to examine factors associated with outcome.

RESULTS

One hundred ninety-nine participants were included, of whom 146 (73.4%) were short-term and 40 (20.1%) longer-term responders. Compared to short-term nonresponders, participants with these characteristics were more likely to be short-term responders: medial joint line tenderness [relative risk (RR) 1.42, 95% CI 1.10-1.82], medial and lateral joint line tenderness (RR 1.38, 95% CI 1.03-1.84), patellofemoral tenderness (RR 1.27, 95% CI 1.04-1.55), anserine tenderness (RR 1.27, 95% CI 1.06-1.52), and a belief that treatment would be effective [RR/unit increase (range 0-10) = 1.05 (1.01-1.09)]. Aspiration of joint fluid (RR 0.79, 95% CI 0.66-0.95) and previous ligament/meniscus injury (RR 0.63, 95% CI 0.44-0.91) were associated with a reduced risk of being a short-term responder. Compared to initial nonresponders and those whose pain recurred within 6 months, participants with a higher number of pain sites [RR/unit increase (range 0-10) = 0.83, 95% CI 0.72-0.97], chronic widespread pain (RR 0.32, 95% CI 0.10-0.98), perceived chronicity of disease [RR/unit increase (range 0-10) = 0.86, 95% CI 0.78-0.94], and a higher depression score [RR/unit increase (range 0-21) = 0.89, 95% CI 0.81-0.99] were less likely to be longer-term responders.

CONCLUSION

Among patients with symptomatic knee OA, tenderness around the knee was associated with better short-term outcome of IASI. However, clinical-related factors did not predict longer-term response, while those with chronic widespread pain and depressive symptoms were less likely to obtain longer-term benefits.

The association between synovial fluid serine proteinase activity and response to intra-articular corticosteroid injection in psoriatic arthritis

INTRODUCTION/OBJECTIVES

Intra-articular corticosteroid (IAS) injections are often used for the immediate relief of pain and inflammation in the joint of psoriatic arthritis (PsA) patients. However, studies identifying factors that predict response to the IAS injections are lacking. We aimed to assess the usefulness of serine proteinase activity measurements in PsA synovial fluid (SF) samples obtained at the time of injection in predicting clinical response.

METHODS

The PsA patients with available SF samples from the knee joint were identified from the University of Toronto PsA cohort. Clinical response was defined as an absence of tenderness or swelling in the injected joint at the first post-injection visit, at either 3 or 6 months. SF proteinase activity was determined by measuring cleavage of fluorogenic tri-peptide substrates for trypsin-like (VPR-AMC and VLK-AMC) and chymotrypsin-like (AAPF-AMC) serine proteinases. Generalized estimating equation (GEE) models were used to investigate factors associated with response.

RESULTS

A total of 32 patients with 60 injected joints and data available for follow-up at 3 or 6 months were included in the analysis, with 25 (41.7%) injected joints resulting in clinical response. Age, sex, active joint count, systemic medications and SF serine proteinase activity at the time of injection were included as covariates. Only treatment with biologics was significantly associated with response at 3 or 6 months in the multivariate reduced model (OR 3.02, p = 0.027).

CONCLUSIONS

We could not demonstrate an association between SF serine proteinase activity and response to IAS injection. Biologic agents significantly improve the likelihood of achieving clinical response.

Therapeutic options for targeting inflammatory osteoarthritis pain

Pain is the major symptom of osteoarthritis (OA) and is an important factor in strategies to manage this disease. However, the current standard of care does not provide satisfactory pain relief for many patients. The pathophysiology of OA is complex, and its presentation as a clinical syndrome is associated with pathologies of multiple joint tissues. Inflammation is associated with both OA pain and disease outcome and is therefore a major treatment target for OA and OA pain. Unlike TNF inhibitors and IL-1 inhibitors, established drugs such as glucocorticoids and methotrexate can reduce OA pain. Although central nociceptive pathways contribute to OA pain, crosstalk between the immune system and nociceptive neurons is central to inflammatory pain; therefore, new therapies might target this crosstalk. Newly identified drug targets, including neurotrophins and the granulocyte-macrophage colony-stimulating factor (GM-CSF)-CC-chemokine ligand 17 (CCL17) chemokine axis, offer the hope of better results but require clinical validation.

Baseline self-report 'central mechanisms' trait predicts persistent knee pain in the Knee Pain in the Community (KPIC) cohort

OBJECTIVES

We investigated whether baseline scores for a self-report trait linked to central mechanisms predict 1 year pain outcomes in the Knee Pain in the Community cohort.

METHOD

1471 participants reported knee pain at baseline and responded to a 1-year follow-up questionnaire, of whom 204 underwent pressure pain detection thresholds (PPTs) and radiographic assessment at baseline. Logistic and linear regression models estimated the relative risks (RRs) and associations (β) between self-report traits, PPTs and pain outcomes. Discriminative performance for each predictor was compared using receiver-operator characteristics (ROC) curves.

RESULTS

Baseline Central Mechanisms trait scores predicted pain persistence (Relative Risk, RR = 2.10, P = 0.001) and persistent pain severity (β = 0.47, P < 0.001), even after adjustment for age, sex, BMI, radiographic scores and symptom duration. Baseline joint-line PPTs also associated with pain persistence (RR range = 0.65 to 0.68, P < 0.02), but only in univariate models. Lower baseline medial joint-line PPT was associated with persistent pain severity (β = -0.29, P = 0.013) in a fully adjusted model. The Central Mechanisms trait model showed good discrimination of pain persistence cases from resolved pain cases (Area Under the Curve, AUC = 0.70). The discrimination power of other predictors (PPTs (AUC range = 0.51 to 0.59), radiographic OA (AUC = 0.62), age, sex and BMI (AUC range = 0.51 to 0.64), improved significantly (P < 0.05) when the central mechanisms trait was included in each logistic regression model (AUC range = 0.69 to 0.74).

CONCLUSION

A simple summary self-report Central Mechanisms trait score may indicate a contribution of central mechanisms to poor knee pain prognosis.

Intra-articular Corticosteroid Injections in the Hip and Knee: Perhaps Not as Safe as We Thought?

Osteoarthritis (OA) of the hip and knee is among the most common joint disorders. Intra-articular corticosteroid (IACS) injections are frequently performed to treat OA and other joint-related pain syndromes; however, there is conflicting evidence on their potential benefit. There is a lack of prospective and large retrospective studies evaluating potential joint findings, including increased risk for accelerated OA progression or adverse joint events, after treatment with IACS injection. Four main adverse joint findings have been structurally observed in patients after IACS injections: accelerated OA progression, subchondral insufficiency fracture, complications of osteonecrosis, and rapid joint destruction, including bone loss. Physicians, including radiologists, should be familiar with imaging findings and patient characteristics that may help them identify potential joints at risk for such events. The purpose of this report is to review the existing literature, describe observed adverse joint events after IACS injections, and provide an outlook on how this may affect clinical practice. Additional research endeavors are urgently needed to better understand and identify risk factors prior to intervention and to detect adverse joint events after injection as early as possible to prevent or minimize complications.

Intra-articular Corticosteroid Injections for Symptomatic Knee Osteoarthritis: What the Orthopaedic Provider Needs to Know

Intra-articular corticosteroid injections have been used for decades in the management of symptomatic osteoarthritis of the knee and remain a common practice. The pain relief from a steroid injection is thought to work by reducing inflammation within the arthritic knee. Substantial variability remains among providers with regard to the technique used to perform the procedure, including the site of the injection, the medications injected, and the level of sterility. The success of steroid injections in relieving arthritic knee pain most often occurs in the short term. However, the efficacy of intra-articular corticosteroid injections varies within the published literature. The latest American Academy of Orthopaedic Surgeons clinical practice guideline does not support conclusive recommendations about the use of intra-articular corticosteroid injections for symptomatic knee osteoarthritis. Providers should be aware of the adverse effects and potential complications of these injections when using them in clinical practice.

Chondroprotective Factors in Osteoarthritis: a Joint Affair

PURPOSE OF THE REVIEW

Osteoarthritis is widely regarded as a spectrum of conditions that affect all joint tissues, typified by a common entity: cartilage loss. Here, we review recent progress and challenges in chondroprotection and discuss new strategies to prevent cartilage loss in osteoarthritis.

RECENT FINDINGS

Advances in clinical, molecular, and cellular characterization are enabling improved stratification of osteoarthritis subtypes. Integration of next-generation sequencing and "omics" approaches with clinically relevant readouts shows promise in delineating both subtypes of disease and meaningful trial end points. Novel delivery strategies are enabling joint-specific delivery. Chondroprotection requires a whole joint approach, stratification of patient groups, and use of patient-relevant end points. Drug development should continue to explore new targets, while using modern technologies and recent knowledge to re-visit unsuccessful therapeutics from the past. The overarching goal for chondroprotection is to provide the right treatment(s) for the right patient at the right time.

The effects of ultrasound-guided corticosteroid injection compared to oxygen-ozone (O2-O3) injection in patients with knee osteoarthritis: a randomized controlled trial

Osteoarthritis (OA) is a chronic multifactorial disease characterized by progressive joint degeneration. The purpose of this study was to compare the effects of ultrasound-guided corticosteroid injection with oxygen-ozone injection in patients with knee OA. This double-blind randomized clinical trial was performed on 62 patients with knee OA. The patients were randomly divided into two groups. In the first group 40 mg triamcinolone (1 cc) and in the second group 10 cc (15 μg/ml) oxygen-ozone (O₂-O₃) were injected into the knee joint under ultrasound guidance. Outcome measures included the Western Ontario and McMaster Universities Osteoarthritis (WOMAC), knee flexion range of motion (ROM), effusion in ultrasound images of the suprapatellar recess, and visual analog scale (VAS), which were evaluated before injection, 1 week, 1 month, and 3 months after the treatment. Sixty-two patients (10 men and 52 women) were enrolled with mean age of 57.9 years. VAS improved in both groups (steroid P value = 0.001, oxygen-ozone P value > 0.001). The improvements seen in VAS and WOMAC scores 3 months after treatment were in favor of the oxygen-ozone group when compared to the steroid group (P = 0.041 vs P = 0.19). There was no significant difference between the two groups in ROM and joint effusion seen under ultrasound (ROM p = 0.880, effusion p = 0.362). However, in the oxygen-ozone-receiving group, joint effusion was decreased significantly (p < 0.001). Both steroid and oxygen-ozone injections are effective in patients with knee osteoarthritis. Our study showed that the effects of oxygen-ozone injection last longer than those of steroid injection to the knee joint.

[Pharmacological treatment of osteoarthritis-related pain]

Joint pain due to osteoarthritis (OA) is often severe and disabling and affects a large proportion of the aging population impairing daily living and quality of life. Numerous pharmacological treatment approaches are available. Including major OA guidelines this review presents the current evidence of pharmacological therapies in OA-related pain and covers topical, oral and intraarticular treatment approaches. In patients with mild OA topical nonsteroidal antiinflammatory drugs (NSAIDs) can be recommended. Topical capsaicin can be used when other treatments are ineffective or contraindicated. In patients with moderate to severe OA oral NSAIDs are suggested at the lowest effective dose for the shortest possible duration to control symptoms. Importantly, drug-related side effects and gastrointestinal, cardiovascular and renal comorbidities need to be taken into account. In patients with multiple-joint OA and high risk of NSAID-induced adverse events duloxetine can be considered. The evidence of metamizole, symptomatic slow-acting drugs in osteoarthritis and other nutritional supplements in the treatment of OA pain is uncertain and the use of opioids is not routinely recommended. In patients suffering from severe OA-related pain intraarticular injections with glucocorticoids can be suggested to achieve short-term pain relief. Evidence for interventional approaches using hyaluronic acid or platelet-rich plasma is uncertain. Yet, the efficacy of pharmacological therapies in OA-related pain is often inconsistent and severe adverse events might occur. Thus, critical use of the different treatment options considering patient-related comorbidities and nonpharmacological therapies is of major importance.