Autologous PRP injection,
does it really help with Recovery of pain and function in chronic midportion Achilles tendinopathy?
research showsOne PRP injection is rated F because it did not restore pain and function in chronic midportion Achilles tendinopathy. Kearney randomized 240 and analyzed 221; the adjusted six-month VISA-A difference was -2.7 (95% CI -8.8 to 3.3). Twelve points was a prespecified clinically important difference threshold used for sample-size design, not a universally validated MCID, and there is no single consensus MCID for VISA-A. The Biomet Biologics LLC-funded de Vos 2010 sham trial also failed in 54 participants, with an adjusted 24-week difference of -0.9 (-12.4 to 10.6), and a meta-analysis of four trials and 170 participants was null.
ads claimMarketing can misattribute within-group improvement from natural history and rehabilitation to tendon regeneration caused by PRP.
Useful facts when choosing a product
- The pivotal trial evaluated one intratendinous injection of PRP prepared from autologous blood.
- The sham group received a sham procedure and the same postprocedure advice.
What the research actually shows
Kearney randomized 240 participants and analyzed 221. The adjusted six-month VISA-A difference was -2.7 (95% CI -8.8 to 3.3), P=.36, excluding the prespecified 12-point clinically important difference threshold used for sample-size design. The paper noted that no single consensus MCID exists for VISA-A. The Biomet Biologics LLC-funded de Vos 2010 JAMA 303(2):144-149 sham trial analyzed all 54 participants; its prespecified 24-week VISA-A primary endpoint failed with an adjusted difference of -0.9 (-12.4 to 10.6). A meta-analysis of four trials and 170 participants was also null.
Why this is classified as F (10)
Kearney randomized 240 and analyzed 221; the adjusted six-month difference of -2.7 (95% CI -8.8 to 3.3) excluded the prespecified 12-point clinically important difference threshold, while no single consensus MCID exists for VISA-A. The Biomet-funded de Vos sham trial and a four-trial, 170-participant meta-analysis were also null in the same indication, yielding F with 10 points.
Counterpoint. Benefits of loading rehabilitation must be separated from effects of the PRP injection itself.
Rejudgment record. Cross-check applied — Applied repeated same-indication refutation from Kearney, the Biomet-funded de Vos sham trial, and a four-trial, 170-participant meta-analysis; treated 12 VISA-A points as a prespecified clinically important difference threshold used for sample-size design rather than a consensus MCID
Sub-claim grades by effect
This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.
| Effect (sub-claim) | Grade | Basis |
|---|---|---|
| Six-month pain and functional recovery in Achilles tendinopathy | F | The large sham trial failed and excluded the prespecified 12-point clinically important difference threshold. |
| Improved VISA-A score at 24 weeks | F | A Biomet-funded double-blind sham trial also failed. |
| Reduced pain from Achilles tendinopathy | F | Pain endpoints at two weeks, three months, and six months were also null in the large trial. |
Cross-check — Codex and Claude
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| Kearney RS et al. 2021 | Participant-blinded 24-center sham-controlled randomized trial | 111 | Research grant from nonprofit charity Versus Arthritis; the funder and University of Warwick had no role in design or analysis | Primary six-month VISA-A pain-function-activity composite; prespecified clinically important difference threshold of 12 points (no single consensus MCID exists for VISA-A) | Primary endpoint failed: adjusted difference -2.7 (95% CI -8.8 to 3.3), P=.36; clinically important benefit excluded. | Large direct refutation trial |
| de Vos RJ et al. 2010 | Single-center double-blind saline-controlled randomized trial | 54 | Funded by PRP-device manufacturer Biomet Biologics LLC; company had no role in design or analysis | Primary endpoint of VISA-A improvement through 24 weeks | Primary endpoint failed: adjusted 24-week between-group difference -0.9 (95% CI -12.4 to 10.6). | Repeated failure in a manufacturer-funded sham trial in the same indication |
Receipt — 2 References
All 2 cited sources were verified for existence at the original page (as of 2026-07-24).
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-24 · Corrections: none
Cite this verdict
[Chamgap] Autologous PRP injection x pain and functional recovery in chronic midportion Achilles tendinopathy — Evidence Grade F·10. 2 cited sources checked. Source: https://chamgap.com/en/verdicts/joint-bone/prp-chronic-midportion-achilles-tendinopathy/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
What this document does and does not do
Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.