https://youtu.be/OWjVWnG5hzU
In this episode of the Nupsala Podcast, we’re joined by Dr Jason Lowe, equine veterinarian and Chief Veterinary Officer at Contura, to take a deep dive into his 2024 paper examining the histologic and cytologic response of normal equine joints following injection with 2.5% injectable polyacrylamide hydrogel (iPAAG).
With over 30 years of global clinical experience, Dr Lowe walks us through the rationale, design and key findings of this in vivo safety study, explaining what a low-level macrophage-driven foreign body response actually means in practice, and why it should not be confused with fibrosis, granuloma formation, or adverse inflammatory reactions.
The discussion explores:
- How iPAAG integrates into the synovium and restores joint biomechanics
- Why a transient macrophage response is part of normal tissue integration
- What scanning electron microscopy revealed about gel behaviour and stability
- Practical clinical takeaways around case selection, dosing, timelines for response, and managing post-injection flares
- How this work fits into a broader shift towards viewing the synovium as the key organ of the joint
Dr Lowe also looks ahead to emerging research into macrophage phenotypes, transcriptomics, and how restoring joint biomechanics may influence downstream inflammatory pathways in osteoarthritis.
This episode is essential listening for equine vets using (or considering) iPAAG as part of long-term osteoarthritis management, and for anyone interested in the evolving science behind synovial-focused therapies.
References mentioned:
- Lowe, J., Clifford, L. de, Julian, A., & Koene, M. (2024). Histologic and cytologic changes in normal equine joints after injection with 2.5% injectable polyacrylamide hydrogel reveal low-level macrophage-driven foreign body response. Journal of the American Veterinary Medical Association, 262(5), 649–647.
- Tnibar, A. et al. (2015) International multi-centre prospective study on the efficacy of an intraarticular polyacrylamide hydrogel in horses with osteoarthritis: a 24 months follow-up. Acta veterinaria scandinavica. [Online] 57 (1).
- Menarim, B. C., MacLeod, J. N., & Dahlgren, L. A. (2021). Bone marrow mononuclear cells for joint therapy: The role of macrophages in inflammation resolution and tissue repair. World journal of stem cells, 13(7), 825–840.
| Time | Chapter Title |
|---|---|
| 00:37 | Introduction to Ross Allan, his background, and role at Roundhouse Referrals |
| 02:30 | Importance of OA knowledge for first-opinion vets |
| 04:03 | Collaborative approach to managing OA in practice |
| 05:44 | Introduction to intra-articular therapies in small animals |
| 07:54 | Overcoming fear and practical tips for joint injections |
| 10:30 | Benefits of intra-articular vs systemic treatments |
| 13:30 | Case example: Labrador with elbow OA |
| 15:48 | The Joint Organ Concept: definition and application |
| 19:53 | Using visuals, emojis, and models to explain OA to clients |
| 22:41 | VOACON 2026: upcoming lectures and seminar topics |
| 24:03 | RCVS Cruciate Registry: enrolling vets and pet owners, data collection, and benefits |
| 28:26 | How real-world data can improve patient management and OA care |