SynthesisCartilage2021
The Long-Lasting Effects of "Placebo Injections" in Knee Osteoarthritis: A Meta-Analysis.
Synthesis in Cartilage, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 64 papers, 15 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
64 citing papers in PubMed, 15 syntheses or guidelines pooled it, 109 citations in OpenAlex.
- Platelet-Rich Plasma Accelerates the Return to Sport in Athletes with Acute Muscle Injuries: A Systematic Review and Statistical Fragility Index-Based Meta-Analysis of Randomized Controlled Trials.Sports medicine - open · 2026Pooled it
- Pooled it
- Placebo Effect Sizes in Clinical Trials of Knee Osteoarthritis Using Intra-Articular Injections of Biologic Agents.Arthritis care & research · 2025Pooled it
- PRP Injections for the Treatment of Knee Osteoarthritis: The Improvement Is Clinically Significant and Influenced by Platelet Concentration: A Meta-analysis of Randomized Controlled Trials.The American journal of sports medicine · 2025Pooled it
- The Efficacy of Polydioxanone Sutures in Treating Mild-to-Moderate Knee Osteoarthritis: A Systematic Review and Meta-Analysis.Medicina (Kaunas, Lithuania) · 2025Pooled it
- Pooled it
- Predictors of Placebo Response to Local (Intra-Articular) Therapy In Osteoarthritis: An Individual Participant Data Meta-Analysis.Arthritis care & research · 2024Pooled it
- Placebo Response to Oral Administration in Osteoarthritis Clinical Trials and Its Associated Factors: A Model-Based Meta-analysis.JAMA network open · 2022Pooled it
- Pooled it
- PRP Injections for the Treatment of Knee Osteoarthritis: A Meta-Analysis of Randomized Controlled Trials.Cartilage · 2021Pooled it
- Platelet-rich plasma injections induce disease-modifying effects in the treatment of osteoarthritis in animal models.Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA · 2021Pooled it
- Safety and early results of Subchondroplasty® for the treatment of bone marrow lesions in osteoarthritis: a systematic review.Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA · 2021Pooled it
- Intra-articular therapy with methotrexate or tumor necrosis factor inhibitors in rheumatoid arthritis: a systematic review.BMC musculoskeletal disorders · 2021Pooled it
- Bone marrow concentrate injections for the treatment of osteoarthritis: evidence from preclinical findings to the clinical application.International orthopaedics · 2021Pooled it
- Evidence on ankle injections for osteochondral lesions and osteoarthritis: a systematic review and meta-analysis.International orthopaedics · 2021Pooled it
- Platelet-Rich Plasma Injections Do Not Improve the Recovery After Arthroscopic Partial Meniscectomy: A Double-Blind Randomized Controlled Trial.The American journal of sports medicine · 2024Trial
- Genicular artery embolisation versus sham embolisation for symptomatic osteoarthritis of the knee: a randomised controlled trial.BMJ open · 2024Trial
- Cell-based versus corticosteroid injections for knee pain in osteoarthritis: a randomized phase 3 trial.Nature medicine · 2023Trial
- Efficacy of Mesotherapy for Pain, Function and Quality of Life in Patients with Mild and Moderate Knee Osteoarthritis: A Randomized Controlled Trial.Journal of musculoskeletal & neuronal interactions · 2023Trial
- Comparing efficacy of a single intraarticular injection of platelet-rich plasma (PRP) combined with different hyaluronans for knee osteoarthritis: a randomized-controlled clinical trial.BMC musculoskeletal disorders · 2022Trial
4 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
6 authors at 2 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectivesTo quantify the placebo effect of intraarticular injections for knee osteoarthritis in terms of pain, function, and objective outcomes. Factors influencing placebo effect were investigated.
designMeta-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:
resultsOut 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;
conclusionsThe 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.
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What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.