A dissolving-particle knee procedure gave 80% of assessed patients meaningful pain relief at one year in a 194-person study

A dissolving-particle knee procedure gave 80% of assessed patients clinically meaningful pain relief at one year in a 194-person study from Charité – Universitätsmedizin Berlin, published in Radiology. The patients all had knee osteoarthritis pain that had persisted after at least three months of conventional care, and none were compared with a control group.

Both halves of that sentence matter. The result is strong for an uncontrolled study, with a median pain score falling from 7 to 3 on a 10-point scale, but the design cannot separate the procedure from placebo effects or the natural course of the disease.

Genicular artery embolization with particles that dissolve

The procedure is genicular artery embolization, or GAE, a fluoroscopy-guided procedure in which particles are injected to block arteries supplying the knee. The twist in this study was the particle: rapidly resorbable gelatin-based microspheres that, according to the ScienceDaily account of the RSNA release, dissolve within hours. The authors suggest this combines the advantages of temporary agents with the controlled delivery of permanent microspheres.

The Radiology abstract describes a prospective, single-center observational study of consecutive adults. It enrolled 194 participants, 114 of them women, with a median age of 69, who underwent 239 procedures between July and November 2024. Forty-five participants were treated on both knees. Pain was scored on a 0-to-10 scale and function on the Knee Injury and Osteoarthritis Outcome Score, known as KOOS, at 6 weeks and at 3, 6 and 12 months.

All 239 procedures reached their intended vessels. No moderate or severe adverse events were recorded; mild, self-limited reactions occurred in 6.7% of procedures, mainly brief skin discoloration along with one superficial hematoma near the insertion site, and all resolved. The abstract itemizes transient skin discoloration after 6.3% of procedures and a superficial groin hematoma in one participant, 0.4% of the group, with no sequelae afterward.

Reading the 80% figure

The 80% is a share of patients who completed the pain assessment at 12 months, not of all 194 enrolled. Follow-up fell from 94% at six weeks to 79% at 12 months, which is 154 of 194 patients. Among those assessed, 80% improved by more than the minimum clinically important difference for pain, defined as a reduction of at least 2.0 points on the numeric scale. The abstract reports that across the KOOS subscores the share exceeding that threshold at 12 months ranged from 55% to 80%, depending on the subscore.

On pain alone, the median fell by 4 points between baseline and 12 months, with a 95% confidence interval of 3.5 to 4.0 and a p-value under .001 in the authors’ descriptive analysis. The median scores for function tell the same story at a smaller scale. KOOS daily-activities scores rose from 53 to 71.5, sports and recreation from 15 to 36, and quality of life from 19 to 40, all medians between baseline and 12 months. Dr. Florian Nima Fleckenstein, the lead author, said in the RSNA press release of June 16, 2026: “Most importantly, their quality of life significantly increased.” He described the procedure as a possible option between injections and joint replacement.

Because patients who left the study are missing from the 12-month tally, the 80% may overstate the benefit if people with poor results were less likely to return. The paper’s retention numbers allow that possibility, though the source does not show whether it happened. An orthopedic surgeon examined patients in person at six months, and the study is catalogued as Radiology 2026, volume 319, issue 3, so the figures are peer-reviewed, but they come from one hospital’s series of consecutive patients and not from a trial that randomized anyone.

Limits of an uncontrolled one-year study

The limits are listed plainly in the release coverage. There was no sham or untreated comparison group, so the study cannot separate the procedure’s effect from placebo or from the natural course of knee osteoarthritis. It was done at one center, 12-month follow-up reached 79% of patients, and it did not assess whether cartilage loss slows or whether patients avoid joint replacement later. The authors call for longer follow-up, larger controlled trials, ways to identify who responds, and comparisons with other embolic materials.

The ScienceDaily account also places the result among mixed controlled evidence. It cites a 50-patient randomized trial using polyvinyl alcohol particles, in which pain improved 72.7% with embolization plus standard care versus 24.2% with standard care alone, but no sham arm. It also cites a 58-patient sham-controlled randomized trial in European Radiology in which both groups improved with no statistically significant difference, and a September 2026 meta-analysis of 22 studies and 633 patients in which pooled data from three randomized trials showed no significant advantage over sham.

That literature, including a systematic review of sham-controlled randomized trials on the same procedure, is the context for reading a single-center series. The Society of Interventional Radiology’s 2026 position statement, as summarized by ScienceDaily, supports offering GAE to carefully selected patients with persistent symptoms who cannot or prefer not to have replacement surgery, alongside specialist training and further trials.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

More from Morning Overview