Verdict No. 1907 · Search date 2026-08-01 · Methodology v0.6
Intra-articular polynucleotide,
does it really help with Improved pain and function in knee osteoarthritis?
30-Second Summary
C
Evidence Grade C · 45 · Safety caution
Short-term pain differed, but large independent evidence for function and durability is absent
Injection-site pain and swelling can occur, and rare joint infection requires sterile technique and clinical monitoring.
What the
research showsThe grade is C. A 90-participant trial analyzed 82 completers and favored polynucleotide for 16-week weight-bearing pain, but a 60-participant trial funded by the same manufacturer found no significant between-group difference among 47 completers. The small active-control evidence lacks nonmanufacturer confirmation, giving C with 45 points.
research showsThe grade is C. A 90-participant trial analyzed 82 completers and favored polynucleotide for 16-week weight-bearing pain, but a 60-participant trial funded by the same manufacturer found no significant between-group difference among 47 completers. The small active-control evidence lacks nonmanufacturer confirmation, giving C with 45 points.
What the
ads claimThe evidence does not establish cartilage regeneration or reliably longer benefit than hyaluronic acid. It supports only a short-term pain difference in small trials, with uncertain function and durability.
ads claimThe evidence does not establish cartilage regeneration or reliably longer benefit than hyaluronic acid. It supports only a short-term pain difference in small trials, with uncertain function and durability.
Useful facts when choosing a product
- The pivotal trial compared three weekly intra-articular PN injections with conventional or crosslinked hyaluronic acid.
- The primary efficacy analysis used 82 completers rather than all 90 randomized participants; a supportive imputed analysis included 83.
- Verdict 1818 is D with 28 points for periocular cosmetic skin injections, not intra-articular treatment of knee pain.
Gap Measurement · Verdict 1907 · C 45
What the research actually shows
Both the positive and null trials were small product studies supported by Pharma Research Products. They used active hyaluronic-acid comparators without placebo, and no nonmanufacturer confirmatory trial was identified. The pivotal defects are active control without placebo and the small 90-randomized, 82-completer analysis.
Why this is classified as C (45)
Small positive and null trials shared manufacturer funding, with no placebo or nonmanufacturer confirmation, giving C with 45 points.
Counterpoint. C does not mean no effect; it means a large independent placebo-controlled trial has not established the size and durability of benefit.
Rejudgment record. Cross-check applied — One small manufacturer-funded active-control trial was positive, but a second same-manufacturer trial was null and nonmanufacturer confirmation is absent
Scoring profile behind this grade
| Endpoint | P | Patient-reported treatment goal - the symptom is the goal |
| Replication | R1 | Single confirmatory trial |
| Independence | I0 | Evidence comes only from manufacturer studies |
| Effect size | E~ | Statistically positive but below the threshold |
The scoring table and the verdict agree (C).
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 |
|---|---|---|
| Improved weight-bearing pain at 16 weeks | C | Positive in an 82-completer active-control analysis with very wide intervals. |
| Improved function | D | The 2019 synthesis found no functional advantage over hyaluronic acid. |
| Durable long-term pain superiority | D | Consistent superiority beyond four months has not been established. |
Cross-check — Codex and Claude
This verdict was drafted by Codex through literature review and source-existence checks, cross-checked through blind grading and adversarial audit, and settled by reapplying the methodology boundary rules. Cases with split grades were resolved through rejudgment.
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| Study 1 | Randomized double-blind three-arm active-control trial | 82 | Funded by PN manufacturer Pharma Research | Between-group difference in 16-week weight-bearing VAS change, the primary endpoint | PN versus conventional HA -17.6 mm, 95% CI -35.1 to -0.1, adjusted P=0.048; versus crosslinked HA -22.4 mm, 95% CI -41.5 to -3.3, adjusted P=0.016. | Pivotal positive but small completer-based active-control trial |
| Study 2 | Multicenter double-blind randomized hyaluronic-acid active-control trial | 26 | Supported by Pharma Research Products | Percentage change in weight-bearing pain at week 16 | -54.0±38.1% versus -42.8±35.8%, P=0.296; other pain and function measures also showed no significant between-group differences. | Null replication trial funded by the same manufacturer |
Receipt — 5 References
All 5 cited sources were verified for existence at the original page (as of 2026-08-01).
Moon JY, Kim J, Lee JY, et al. Comparison of Polynucleotide, Sodium Hyaluronate, and Crosslinked Sodium Hyaluronate for the Management of Painful Knee Osteoarthritis: A Multi-Center, Randomized, Double-Blind, Parallel-Group Study. Pain Med. 2023;24(5):496-506. DOI: 10.1093/pm/pnac155.
checkedKim MS, Cho RK, In Y. The efficacy and safety of polydeoxyribonucleotide for the treatment of knee osteoarthritis: systematic review and meta-analysis of randomized controlled trials. Medicine (Baltimore). 2019;98(39):e17386. PMID: 31574892. DOI: 10.1097/MD.0000000000017386.
checkedThe promising potential of polynucleotide injections for knee osteoarthritis: a systematic review of literature and meta-analysis of randomized control trials. 2025. PMCID: PMC12442440.
checkedNewberry SJ, FitzGerald J, SooHoo NF, et al. Treatment of Osteoarthritis of the Knee: An Update Review. AHRQ Comparative Effectiveness Review No. 190. 2017. Appendix I: MCID Cutoffs.
checkedKim TW, Chang MJ, Shin CY, Chang CB, Kang SB. A randomized controlled trial for comparing efficacy and safety between intraarticular polynucleotide and hyaluronic acid for knee osteoarthritis treatment. Sci Rep. 2023;13:9419. DOI: 10.1038/s41598-023-35982-z.
checkedDraft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-08-01 · Corrections: none
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-08-01 · Corrections: none
Cite this verdict
[Chamgap] Intra-articular polynucleotide x knee osteoarthritis pain and function — Evidence Grade C·45. 5 cited sources checked. Source: https://chamgap.com/en/verdicts/joint-bone/intraarticular-polynucleotide-knee-osteoarthritis-pain-function/ · 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.