Arthrosamid®: Klinische effectiviteit en toepassingen

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).

Klinische resultaten en werkingsmechanisme

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 gewrichtsvloeistofRecent 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.

Vertraagde progressie van artrose

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.

IDA 5 YEAR

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

10 years safety follow-up Arthrosamid

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:https://www.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.

A RANDOMISED CONTROLLED STUDY (ROSA)

3 YEARRESULTS FROM A PROSPECTIVE STUDY OF POLYACRYLAMIDE HYDROGEL FOR KNEE OSTEOARTHRITIS
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

A Mechanistic and Clinical study of intra-articular Arthrosamid for knee osteoarthritis
Presented at the ISAKOS congres 2025
Author(s):Sharon Owen, et all.
Link: https://isakos.com/GlobalLink/Abstract/8064

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.

RESPONSE RATE WITH ARTHROSAMID®

A randomised study of one-year performance of polyacrylamide hydrogel (iPAAG) vs. hyaluronic acid.

ARTHROSAMID LITERATUUR OVERZICHT

  1. Intra-articular 2.5% polyacrylamide hydrogel, a new concept in the medication of equine osteoarthritis: A review; Tnibar A. Equine Vet Sci. 2022; 119: 104143
    Link: https://www.sciencedirect.com/science/article/abs/pii/S0737080622002799
  2. Synovial incorporation of polyacrylamide hydrogel after injection into normal and osteoarthritic animal joints; Christensen, L, et al. Osteoarthritis Cartilage. 2016; 24 (11): 1999-2002
    Link: https://www.oarsijournal.com/action/showPdf?pii=S1063-4584%2816%2930189-3
  3. An international multi-centre prospective study on the efficacy of an intraarticular polyacrylamide hydrogel in horses with osteoarthritis: a 24 months follow-up;Tnibar A, et al. Acta Vet Scand. 2015; 57 (1)
    Link: https://pmc.ncbi.nlm.nih.gov/articles/PMC4403890/pdf/13028_2015_Article_110.pdf
  4. 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

  5. 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

    Link: https://pubmed.ncbi.nlm.nih.gov/30148430/

  6. 6 Months – Polyacrylamide Hydrogel Injection for Knee Osteoarthritis: A 6 Months Prospective Study. Bliddal H, Overgaard A, Hartkopp A, et al. J; Orthop Res Ther 6. 2021; 1188.
    Link: doi: 10.29011/2575-8241.001188
  7. 12 MonthsPolyacrylamide Hydrogel Injection for Knee Osteoarthritis: Results of a 52 Week Prospective Study. Bliddal H, Overgaard A, Hartkopp A, et al. Abstract, Osteoarthritis and Cartilage. 2021; 29: S278.
    Link: doi: 10.1016/j.joca.2021.02.366
  8. 12 months –Effectiveness and safety of polyacrylamide hydrogel injection for knee osteoarthritis: results from a 12-month follow up of an open-label stu. Bliddal H, et al. Journal of Orthopaedic Surgery and Research Surg Res 2024;19, 274.
    Link: doi: 10.1186/s13018-024-04756-2
  9. 24 Months –A Prospective Study of Polyacrylamide Hydrogel for Knee Osteoarthritis: Results from 2 years After Treatment. Bliddal H, Beier J, Hartkopp A, et al. Abstract, Osteoarthritis and Cartilage. 2022; 30: S372.
    Link: doi: 10.1016/j.joca.2022.02.499
  10. 36 Months –3 Year Results from a Prospective Study of Polyacrylamide Hydrogel for Knee Osteoarthritis. Abstract, Osteoarthritis and Cartilage. Henriksen M, Beier J, Hartkopp A, et al. 2023; 31: 682-683.
    LINK:doi: 10.1016/j.joca.2023.02.023
  11. 4-years- POLYACRYLAMIDE HYDROGEL FOR KNEE OSTEOARTHRITIS: 4-YEAR RESULTS FROM A PROSPECTIVE STUDY; Henning Bliddal, EORS 2024, Oral presentation abstract. www.EORS2024.org
    Link: chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://eors2024.org/wp-content/uploads/2024/09/all_oral_abstracts.pdf
  12. Polyacrylamide Hydrogel for Knee Osteoarthritis: 5-Year Results from a Prospective Study; Bliddal et al. ;Presented at WCO-IOF-ESCEO 2025.
    Link: https://www.oarsijournal.com/article/S1063-4584(22)00533-7/fulltext
  13. One year Performance of Polyacrylamide Hydrogel vs. Hyaluronic Acid: A Randomised Controlled Study. Bliddal H, Beier J, Hartkopp A, et al. Abstract, Osteoarthritis and Cartilage. 2022; 30: 371.
    Link: doi: 10.1016/j.joca.2022.02.497
  14. Polyacrylamide gel versus hyaluronic acid for the treatment of knee osteoarthritis: A randomised controlled study. Bliddal H, Beier J, Hartkopp A, et al. Clinical and Experimental Rheumatology. 2024 Mar 19.
    Link: org/10.55563/clinexprheumatol/i3fqee Epub ahead of print. PMID: 38525999
  15. Histological Appearance of the Synovial Membrane after Treatment of Knee Osteoarthritis with Polyacrylamide Gel Injections: A Case Report. Christensen LH, Daugaard S. J Arthritis. 2016; 5: 5.
    Link: doi: 10.4172/2167-7921.100021
  16. Reduction in Patellofemoral Bone Marrow Lesions Following Single Arthrosamid Intra-Articular Injection of Polyacrylamide Hydrogel (iPAAG) in the Treatment of Advanced Osteoarthritis. Maulana R, Cole A, Lee PYF. Journal of Arthritis. 2022; 11 (3): 024-026
    Link: https://www.theregenerativeclinic.co.uk/wp-content/uploads/2022/07/Treatment-of-Advanced-Osteoarthritis_P.Lee_.pdf#:~:text=We%20present%20the%20first%20case%20of%20a%20reduction,presented%20to%20the%20clinic%20with%20anterior%20knee%20pain.
  17. Review, A Systematic Review of the Novel Compound Arthrosamid Polyacrylamide (PAAG) Hydrogel for Treatment of Knee Osteoarthritis. Cole A, Maulana R, Whitehead J.P, Lee. Medical Research Archives. 2022; 10 (8)
    Link: https://esmed.org/MRA/mra/article/view/2950/193546227
  18. 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:https://wco-iof-esceo.org/download/2025/abstract-book page 58 OC11
  19. A Mechanistic and Clinical study of intra-articular Arthrosamid for knee osteoarthritis Presented at the ISAKOS congres 2025
    Author(s):Sharon Owen, et all.
    Link: https://isakos.com/GlobalLink/Abstract/8064
  20. Polyacrylamide Hydrogel for Knee Osteoarthritis: 5-Year Results from a Prospective Study
    Presented at WCO-IOF-ESCEO 2025.
    Authors: H. Bliddal, et all.
    Link: https://www.arthrosamid.nl/meer-te-weten-komen-over-de-gegevens/ (copy uit abstract book)