Effectiveness and safety of polyacrylamide hydrogel injection for knee osteoarthritis: results from a 12-month follow up of an open-label study

J Orthop Surg Res. 2024 May 2;19(1):274. doi: 10.1186/s13018-024-04756-2.

Abstract

Objective: There are few effective osteoarthritis (OA) therapies. A novel injectable polyacrylamide hydrogel (iPAAG) previously demonstrated efficacy and safety up to week 26 in an open-label study of knee OA. Here we report longer-term effectiveness and safety data.

Methods: This multi-centre, open-label study included patients with symptomatic and radiographic knee OA. Primary outcome was WOMAC pain (0-100 scale) at 13 weeks, and patients continued to 26 weeks before entering a further 26-week extension phase. Secondary efficacy outcomes included WOMAC stiffness and function subscales, Patient Global Assessment (PGA) and proportion of OMERACT-OARSI responders. Safety outcomes were adverse events (AEs).

Results: 49 participants (31 women, mean age 70) received an ultrasound-guided, intra-articular injection of 6 ml iPAAG; 46 completed the extension phase to 52 weeks. There was a significant reduction in the WOMAC pain score from baseline to 52 weeks (- 17.7 points (95% CI - 23.1; - 12.4); p < 0.0001). Similar sustained improvements were observed for WOMAC stiffness (11.0 points; 95% CI - 17.0; - 4.9), physical function (18.0 points; 95% CI - 19.1; - 10.6), and PGA (16.3 points; 95% CI - 23.1; - 9.4). At 52 weeks 62.2% of patients were OMERACT-OARSI responders. From 26 to 52 weeks, 8 adverse effects (AE), including 1 serious AE (cerebrovascular accident) were reported in 5 subjects. None of the new adverse events were thought to be device related.

Conclusion: This open-label study suggests persistent benefits and safety of iPAAG through 52 weeks after a single injection.

Trial registration: Clinicaltrials.gov NCT04179552.

Keywords: Intra-articular; Knee; Osteoarthritis; Pain; Polyacrylamide; WOMAC.

Publication types

  • Multicenter Study

MeSH terms

  • Acrylic Resins* / administration & dosage
  • Aged
  • Aged, 80 and over
  • Female
  • Follow-Up Studies
  • Humans
  • Hydrogels / administration & dosage
  • Injections, Intra-Articular
  • Male
  • Middle Aged
  • Osteoarthritis, Knee* / drug therapy
  • Time Factors
  • Treatment Outcome

Substances

  • Acrylic Resins
  • polyacrylamide gels
  • Hydrogels

Associated data

  • ClinicalTrials.gov/NCT04179552