The aggregated data from normal saline placebo arms of hyaluronic acid and other knee injection studies for OA can be used as a control group for single-armed knee injection studies
Bibliographic record
Abstract
Purposes: Platelet-rich plasma (PRP) and stem cell treatments are commonly used for the treatment of osteoarthritis (OA). Studies of these treatments are often criticized due to lack of a control group. However, controlled studies are both prohibitively expensive and resisted by patients. There are numerous controlled studies of hyaluronic acid and other injectates that report detailed characteristics of their placebo arms in which saline was injected. The accumulated data from these placebo arms can serve as a historical control. Our objective was to characterize the magnitude and duration of this placebo/saline effect for the purpose of providing a control group against which the effects of knee injection can be measured in single armed OA knee injection studies without control groups. Methods: We performed a comprehensive search of the MEDLINE database for randomized clinical trials in adult humans of an injective therapy for osteoarthritis of the knee which included injection of ‘normal’ or physiological saline (0.9% NaCl) as a placebo cohort. Included studies reported results to at least 3 months post-injection using either a visual analog scale for pain (VAS) and/or a WOMAC total score (the Western Ontario and McMaster Universities Osteoarthritis Index). Studies were excluded if the injective therapy was paired with additional intervention including physical therapy and surgical procedures. Mean scores were calculated for pre-treatment and at 3 months and 6 months post treatment. Reported scores at other intervals were noted for secondary review. Results: 33 study arms met the criteria of which 24 reported WOMAC total scores and 19 reported VAS scores. The mean change in WOMAC scores peaked at 1-3 weeks, then declined below or near the minimal clinically important difference (MCID) by 12 weeks. The mean VAS scores similarly peaked at 1-3 weeks but never exceeded MCID at any time point. Conclusions: The normal saline therapeutic effect for knee injection for OA is small, peaks early, is short-lived and relatively consistent among studies. It can provide a useful valid control group against which to measure the therapeutic effects of single armed knee injection studies of PRP, stem cell or other injection treatments for osteoarthritis.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.052 | 0.134 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.009 | 0.010 |
| Bibliometrics | 0.026 | 0.021 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.003 | 0.003 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.003 | 0.002 |
| Insufficient payload (model declined to judge) | 0.013 | 0.002 |
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".