Arthrosamid® heeft zich bewezen als een langdurige en effectieve behandeling voor patiënten met knieartrose. Klinische studies tonen aan dat 80% van de behandelde patiënten een significante verbetering ervaren in pijnreductie, mobiliteit en functie. Deze verbeteringen blijven jaren na de eerste injectie behouden (tot wel 5 jaar).
Arthrosamid® is een injecteerbare hydrogel, bestaande uit 97,5% water en 2,5% gecrosslinked polyacrylamide. De behandeling verloopt via zes afzonderlijke injecties van 1 ml, waarbij de hydrogel in de synoviale ruimte wordt ingebracht. Dit leidt tot de volgende fysiologische veranderingen:
✔ Weefselingroei en verdikking – Na injectie groeit het synoviale weefsel in de open structuur van Arthrosamid®, waardoor het gewrichtskapsel verdikt en versterkt.
✔ Duurzame aanwezigheid – Arthrosamid® wordt niet geresorbeerd of afgebroken, maar blijft permanent in het weefsel aanwezig.
✔ Veiligheid en lange termijn gebruik – Meer dan 1.700.000 behandelingen zijn wereldwijd uitgevoerd zonder blijvende nadelige bijwerkingen.
✔ Knieprothese mogelijk na behandeling – In een 10-jarige retrospectieve studie onder 120 patiënten had 56% na 10 jaar nog geen knieprothese nodig. Voor de overige patiënten die een prothese kregen, waren er geen bijwerkingen gerelateerd aan de hydrogel.
✔ Verbeterde weefselelasticiteit – Klinisch onderzoek toont een 15% toename in elasticiteit van het synoviale weefsel, waardoor de gewrichtsfunctie normaliseert.
✔ Minder pijnsignalen – Door de verbeterde elasticiteit wordt de nocisensorische pijnperceptie verminderd, wat leidt tot verminderde pijnklachten.
✔ Ontstekingsremmend effect – Arthrosamid® verdikt het synoviale weefsel en creëert een natuurlijke barrière voor ontstekingscellen, waardoor ontstekingsactiviteit afneemt en mobiliteit verbetert en de pijnklachten verminderen.
✔ Gezondere gewrichtsvloeistof – Recent onderzoek (2025) toont aan dat patiënten met een positieve respons meer hyaluronzuur en minder interleukine-6 (IL-6) in hun synoviale vloeistof hebben, wat wijst op een verminderde pro-inflammatoire activiteit.
De biochemische en mechanische veranderingen na behandeling met Arthrosamid® dragen bij aan een gezonder gewricht en mogelijk een vertraagde progressie van artrose. Dit maakt Arthrosamid® een veelbelovende langetermijnoptie in de behandeling van knieartrose.
Statistically significant reduction in pain maintained at 5 years.1
Polyacrylamide Hydrogel for Knee Osteoarthritis: 5-Year Results from a Prospective Study
Presented at WCO-IOF-ESCEO 2025.
Link: https://www.wco-iof-esceo.org/download/2025/abstract-book pagina 562
Authors: H. Bliddal et al.
This research evaluated the long-term efficacy and safety of a single 6 mL intra-articular injection of polyacrylamide hydrogel (iPAAG) for treating knee osteoarthritis (OA). The study followed 49 participants (average age 70 years) over five years across multiple sites in Denmark. Outcomes were assessed using the WOMAC and Patient Global Assessment (PGA) measures.
Results showed a statistically significant reduction in pain scores over five years, with similar improvements observed in sensitivity analyses. The treatment maintained clinical effectiveness and was well tolerated, with no treatment-related serious adverse events reported.
The findings support iPAAG as a long-lasting, 5 years, non-surgical intervention for knee OA.
Acknowledgments This study was sponsored by Contura International A/S.
iPAAG: injectable polyacrylamide hydrogel
Title 10-Year Safety Follow-Up of Intra-Articular 2.5% Polyacrylamide Hydrogel (iPAAG) in Knee Osteoarthritis (OA)
Presented at: WCO-IOF-ESCEO 2025, Rome
Authors: H. Bliddal, et all.
Link: httpwww.wco-iof-esceo.org/download/2025/abstract-book page 58 OC11
This long-term observational study assessed the safety of intra-articular 2.5% polyacrylamide hydrogel (iPAAG) in knee osteoarthritis (OA) patients over a follow-up period of 7 to 14 years (mean: 9.92 years). The study included 61 patients (89 treated knees), with an average injection age of 64 years. Safety outcomes showed no significant adverse events (AEs) related to iPAAG, including no allergic reactions, infections, or systemic effects.
Among treated knees, 43.8% underwent knee replacement surgery, with an average time to replacement of 3.4 years. 56,2% Surgical complications were minimal and unrelated to iPAAG. Findings support iPAAG as a long-term, well-tolerated non-surgical option for OA, reassuring healthcare providers about its safety profile and potential to delay knee arthroplasty; 56,2% didn’t receive any knee replacement in 10 years after the one single treatment.
Long-term results after iPAAG indicated a favourable safety profile of the product. Surgical records from subsequent knee replacements gave no indications of unusual adverse reactions.
3 YEARRESULTS FROM A PROSPECTIVE STUDY OF POLYACRYLAMIDE HYDROGEL FOR KNEE OSTEOARTHRITIS
Authors: M. Henriksen1, et all.
Link: https://www.oarsijournal.com/article/S1063-4584(23)00647-7/fulltext
This prospective, multicenter study in Denmark evaluated the long-term effects of a single 6 mL intra-articular injection of Arthrosamid® for knee osteoarthritis (OA). Initially planned for one year, the study was extended to five years, with participants re-consenting for continued follow-up. A total of 49 participants (average age ~70 years) were treated, with follow-up visits scheduled over three years.
Outcomes were assessed using WOMAC pain, stiffness, and function subscales, as well as Patient Global Assessment (PGA). Statistical analyses showed significant improvements in OA symptoms over three years, with clinically relevant reductions in pain scores. Sensitivity analyses confirmed the consistency of results.
Adverse events (AEs) were reported throughout the study, including 19 new events between the second and third years. None were linked to the treatment, and the most frequent AE was Covid-19 infection. Overall, Arthrosamid® demonstrated continued effectiveness and a strong safety profile over three years.
A Mechanistic and Clinical study of intra-articular Arthrosamid for knee osteoarthritis
Presented at the ISAKOS congres 2025
Author(s):Sharon Owen, et all.
This study investigated the clinical effectiveness and potential mechanism of action of Arthrosamid®, a biocompatible injectable hydrogel, for knee osteoarthritis (OA). A total of 62 patients (68 knees) received a single 6 mL injection and were followed for up to 12 months. Primary outcomes were measured using the WOMAC index, with secondary outcomes including KOOS scores and adverse events.
Results showed a significant improvement in WOMAC and KOOS scores over time, indicating strong clinical effectiveness. The overall response rate at six months was 76%. Synovial fluid analysis suggested an anti-inflammatory mechanism of action and increase of HA among responders, though further bioinformatic analysis is ongoing. Adverse events were primarily mild, including arthralgia and swelling.
Findings support Arthrosamid® as a promising non-surgical option for managing knee OA symptoms.
A randomised study of one-year performance of polyacrylamide hydrogel (iPAAG) vs. hyaluronic acid.
Use of a 2.5% Cross-Linked Polyacrylamide Hydrogel in the Management of Joint Lameness in a Population of Flat Racing Thoroughbreds: A Pilot Study; de Clifford LT, et al. J Equine Vet Sci. 2019; 77: 57-62
Link: https://www.sciencedirect.com/science/article/abs/pii/S0737080618307615
Intra-articular 2.5% polyacrylamide hydrogel for the treatment of knee osteoarthritis: an observational proof-of-concept cohort study;1Henriksen M, et al. Clin Exp Rheumatol. 2018; 36 (6): 1082-1085
