Andrew P. Bathe; Rachel Mercedes Read; Carly Briggs Rossdales Equine Hospital, Newmarket, United Kingdom
Introduction: Polyacrylamide hydrogel (PAAG) is a novel treatment for osteoarthritis (OA), but many previous case series have poorly defined clinical inclusion criteria. The aim of this study was to determine the efficacy of PAAG in equine arthritic interphalangeal joints, which had not responded to previous intra-articular treatment with corticosteroids.
Materials and Methods: Lameness was localized to the proximal/distal interphalangeal joint by diagnostic analgesia; radiography/standing MRI was consistent with OA. After treatment with 1ml of PAAG (Arthramid Vet, Contura International) intra-articularly horses had 4 weeks of exercise restriction before a progressive return to ridden exercise. Follow-up was by re-examination and telephone survey.
Results: 20 horses met the inclusion criteria. All were adult sport horses with persistent lameness after previous treatment with corticosteroids. The average lameness duration was 15mo and average lameness score was 3/10. 10 had arthritic changes evident radiologically. 18 underwent MRI examination and all had osteoarthritic changes. One horse was treated twice, and had a transient adverse reaction. Long term follow-up was available on 18 cases; with median follow-up of 12mo. 12/18 returned to full function; 3/18 to lower level and 3/18 failed to improve.
Discussion/Conclusion: The success rate and long-term duration is encouraging given the case severity. A control group would have been preferable, but each case could act as its own control, as conventional treatments had already failed. The only significant difference in the management of each case was the PAAG treatment. The method of action of PAAG is uncertain, and further work is required to study this.
Acknowledgement: Contura International for supplying the PAAG.
