A Phase 4 interventional study of Zilretta Injectable Product or Placebo in Osteoarthritis, Knee, Meniscus Tear and Meniscus; Degeneration, sponsored by The Cleveland Clinic. Active, not recruiting at 2 sites in United States. Open to participants aged 40 Years and older. Per ClinicalTrials.gov, last updated 2026-08-31.
Sponsored by The Cleveland Clinic · Phase 4, Interventional, and Treatment
Synovitis has an important role in the symptoms and progression of Osteoarthritis (OA). Inflamed synovium has been associated with both increased symptoms and increased progression in OA patients. Furthermore, synovitis observed during knee arthroscopy in our patients undergoing arthroscopic partial meniscectomy (APM) was associated with worse symptoms while adjusting for confounding factors.Therefore, a better understanding of synovitis as a predictor of outcome after APM and as a target for treatment is needed to improve outcomes in this patient population.
Triamcinolone has been shown to decrease synovitis-associated outcomes in both animal and human studies after anterior cruciate ligament (ACL) injury. In a porcine model of ACL injury, treatment with triamcinolone resulted in decreased formation of synovitis-related collagen breakdown products as well as decreased cellularity of the synovium.And in a trial of triamcinolone injected after ACL injury, similar findings of decreased C-telopeptide of type II collagen (CTX-II), associated with collagen type II breakdown, was found in knees administered triamcinolone compared to placebo controls.
Symptomatic meniscal tear with pain and mechanical symptoms of catching and locking ,a phenotype of early OA, and often prompts patients who have failed physical therapy to elect APM to improve their symptoms. This arthroscopic surgery presents a unique opportunity to evaluate the intraarticular status of the joint including joint fluid biomarkers and synovial tissue for signs of inflammation in patients with mild to moderate OA. Since no post-op tissue repair is desired after APM, in contrast to other post-traumatic OA (PTOA) models such as anterior cruciate ligament reconstruction, the APM cohort can be used to test novel interventions to slow down PTOA development by suppressing synovitis and inflammation. Results from this trial in this patient population could be applied to the broader population of many millions of patients with mild to moderate OA who never undergo arthroscopy.
There are currently approximately 1,000,000 APMs performed in the United States each year, and about 70 percent of patients have a clinically significant improvement in symptoms after surgery. Much of this variation in outcome is unexplained but is hypothesized to be related to synovitis and joint inflammation that is currently unmeasured and untreated in usual clinical care.
This is a randomized controlled trial of extended release triamcinolone for efficacy to improve patient reported outcome measures after APM. The investigators will evaluate joint fluid and synovial tissue biomarkers to assess joint inflammation as a predictor of treatment response, use quantitative 3T MRI to evaluate cartilage and meniscus composition and 3D bone shape, which are sensitive imaging markers for early joint degeneration, and use a prospective surgical episode data collection system to capture patient reported outcomes and surgeon reported operative data.
3,292 studies on the registry are indexed under Osteoarthritis, Knee; 623 are open to participants now.
This study's planned enrollment of 150 is above the median of 68 across 2,714 interventional studies indexed under Osteoarthritis, Knee.
Browse Osteoarthritis, Knee studies →The Cleveland Clinic is the lead sponsor of 831 studies on the registry; 119 are open to participants now.
Of its 90 completed or terminated interventional studies of FDA-regulated products, 73 (81%) have results posted.
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Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
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Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Triamcinolone extended release (32 mg) administered as an intraarticular injection at the conclusion of arthroscopic partial meniscectomy. * Knee injury and Osteoarthritis Outcome Score (KOOS) pain at 6 and 12 months * T1ρ and T2 imaging of cartilage and meniscus at 3 and 12 months * Morphologic grading of cartilage using the MOAKS score at 3 and 12 months * 3D bone shape from MRI Osteoarthritis Knee Score (MOAKS) using statistical shape modeling at 3 and 12 months * Improvement in blood, serum and urine inflammatory biomarker profiles at 3 and 12 months
Drug: Zilretta Injectable Product or Placebo
Normal saline of 5 mL administered as an intraarticular injection at the conclusion of arthroscopic partial meniscectomy. * KOOS pain at 6 and 12 months * T1ρ and T2 imaging of cartilage and meniscus at 3 and 12 months * Morphologic grading of cartilage using the MOAKS score at 3 and 12 months * 3D bone shape from MRI using statistical shape modeling at 3 and 12 months * Improvement in blood, serum and urine inflammatory biomarker profiles at 3 and 12 months
Drug: Zilretta Injectable Product or Placebo
The purpose of this intervention is to determine the use of extended release steroid knee injection (Zilretta) at the end of the surgery and its effects on your knee pain.In this study Zilretta will be injected intra-operatively for your arthroscopic partial meniscectomy (APM) surgery.Participants will have MRIs x-rays, and provide a sample of the synovial fluid from both knees at the beginning of surgery. This fluid is drained at the beginning of surgery and then usually discarded. Three samples each of blood and urine will be collected over the study period from each participant and sample of joint (synovial tissue) taken. Participants will be asked to answer questions about knee pain.
Also known as: triamcinolone acetonide
Change in Knee injury and Osteoarthritis Outcome Score (KOOS) from baseline and 3 months.
Knee pain of participants; a higher score represents a desired outcome; zero representing extreme knee problems and 100 representing no knee problems
Time frame: 0 and 3 months
Change in Knee injury and Osteoarthritis Outcome Score (KOOS) from baseline, 6 and 12 months.
Knee pain of participants; a higher score represents a desired outcome; zero representing extreme knee problems and 100 representing no knee problems
Time frame: 0, 6, and 12 months
Change in Inflammatory biomarkers in circulation from baseline, 3 and 12 months.
Urine; CTX-II
Time frame: 0, 3, and 12 months
Change in Inflammatory biomarkers of the knee joint from baseline, 3, and 12 months.
The increase or decrease from the combination of following markers in the Synovial fluid will help characterize the profile of knee joint; TGF-ß1, neutrophil elastase, IL-1, IL-6, IL-8, TNF, MCP-1, MIP1, MMP-3, MMP-10, MMP activity, sGAG, aggrecanase, TIMP-1, and PGE2
Time frame: 0, 3, and 12 months
Change in Inflammatory biomarkers in circulation from baseline, 3 and 12 months.
The increase or decrease from the combination of the following markers in the serum will help characterize the inflammatory profile of the individual systemically; hyaluronic acid, IL-1, IL-6, IL-8, TNF, TIMP-1, MMP-10, MCP-1, MIP1, and PGE2
Time frame: 0, 3 and 12 months
Change in Magnetic Resonance Imaging relaxation time (milliseconds of T1 and T2) from baseline, 3, and 12 months.
Quantitative measurement of cartilage, longer relaxation time represents a poor outcome
Time frame: 0, 3 and 12 months
Change in Whole-Organ Magnetic Resonance Imaging Score (WORMS) from baseline, 3, and 12 months.
Bone shape, a higher score represents a poor outcome; zero representing no knee problems and 332 representing knee problems
Time frame: 0, 3 and 12 months
Change in Magnetic Resonance Imaging morphological grading from baseline, 3, and 12 months.
Modified MRI Osteoarthritis Knee Score (MOAKS); a higher score represents a poor outcome; zero representing no knee problems and 332 representing knee problems
Time frame: 0, 3 and 12 months
Plan to share: No
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Ran from May 2021 to primary completion in Aug 2026, 62 months.
Of 88 non-industry phase 4 interventional studies under Osteoarthritis, Knee, half reached primary completion within 19 months of starting (the median), counting those still running; a quarter within 10 and three quarters within 32. This study's 62 months is above that.
Counting every sponsor, half of 97 studies reached it within 19 months; a quarter within 10 and three quarters within 36.
How these figures are worked out, and which studies are left out of them.
This study is active, not recruiting, as verified in Mar 2026. You cannot join it, but the record below documents what was studied.
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