A within-person, between-knee comparison of intra-articular platelet-rich plasma versus placebo injection in knees osteoarthritis: a randomized, double-blind comparison
Bibliographic record
Abstract
Abstract Background Evidence is growing for the efficacy of platelet-rich plasma (PRP) in knee osteoarthritis (OA). Here, we investigated the effects of PRP and placebo by performing a randomized, double-blind, within-person between knees comparison of measurements.Methods Thirty patients with equal radiographic grades of OA in both knees received a single injection of PRP in one knee and normal saline as a placebo in the contralateral knee. Knee symptoms were assessed at baseline and at 6-week follow-up using the WOMAC (Western Ontario and McMaster Universities) Osteoarthritis Indices for pain, stiffness, and physical function and the pain visual analog scale (VAS) assessments.Results The VAS-pain and the mean WOMAC subscales- pain, stiffness, and function- decreased significantly (P = 0.001, 0.005, 0.024, and 0.005, respectively) from baseline to week 6 in the PRP-injected knees, while in the placebo-injected knees there were only a significant reduction of VAS and no difference in WOMAC outcomes. Intergroup comparison of pain-VAS and WOMAC sub-scales revealed no statistically significant differences between PRP- and placebo-treated knees of patients post-injection.Conclusion This study found little difference between the effects of intra-articular PRP injection and placebo when applied to the same patient. Non-significant improvement in osteoarthritis indices between the treatment and placebo-received knees indicate the need for additional clinical trials of crossover design.Trial registration: IRCT2016030626922N1
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.007 | 0.005 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.006 | 0.003 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.003 | 0.002 |
| Insufficient payload (model declined to judge) | 0.006 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".