VOL. 10, NO. 10, OCTOBER 2021 650 Freely available online Follow us @BoneJointRes BJR A. Sanghani-Kerai, C. Black, S. O. Cheng, L. Collins, N. Schneider, G. Blunn, F. Watson, N. Fitzpatrick From Fitzpatrick Referrals, Godalming, UK Correspondence should be sent to Anita Sanghani-Kerai; email: anitas@ftzpatrickreferrals.co.uk doi: 10.1302/2046-3758.1010. BJR-2020-0540.R1 Bone Joint Res 2021;10(10):650– 658.  ARTHRITIS Clinical outcomes following intra- articular injection of autologous adipose-derived mesenchymal stem cells for the treatment of osteoarthritis in dogs characterized by weight- bearing asymmetry Aims This study investigates the efects of intra-articular injection of adipose-derived mesenchy- mal stem cells (AdMSCs) and platelet-rich plasma (PRP) on lameness, pain, and quality of life in osteoarthritic canine patients. Methods With informed owner consent, adipose tissue collected from adult dogs diagnosed with de- generative joint disease was enzymatically digested and cultured to passage 1. A small por- tion of cells (n = 4) surplus to clinical need were characterized using fow cytometry and tri- lineage diferentiation. The impact and degree of osteoarthritis (OA) was assessed using the Liverpool Osteoarthritis in Dogs (LOAD) score, Modifed Canine Osteoarthritis Staging Tool (mCOAST), kinetic gait analysis, and diagnostic imaging. Overall, 28 joints (25 dogs) were injected with autologous AdMSCs and PRP. The patients were followed up at two, four, eight, 12, and 24 weeks. Data were analyzed using two related-samples Wilcoxon signed-rank or Mann-Whitney U tests with statistical signifcance set at p < 0.05. Results AdMSCs demonstrated stem cell-like characteristics. LOAD scores were signifcantly lower at week 4 compared with preinjection (p = 0.021). The mCOAST improved signifcantly after three months (p = 0.001) and six months (p = 0.001). Asymmmetry indices decreased from four weeks post-injection and remained signifcantly lower at six months (p = 0.025). Conclusion These improvements in quality of life, reduction in pain on examination, and improved sym- metry in dogs injected with AdMSCs and PRP support the efectiveness of this combined treatment for symptom modifcation in canine OA for six months. Cite this article: Bone Joint Res 2021;10(10):650–658. Keywords: Osteoarthritis, Stem cells, Platelet-rich plasma Article focus  Intra-articular injection of adipose- derived stem cells (AdMCs) and platelet- rich plasma (PRP).  The efect of stem cells and PRP injection on lameness and pain scores in osteoar- thritic canine patients. Key messages  Intra-articular injection of autologous AdMSCs and PRP can be used in the management of canine osteoarthritis (OA).  Improvement in OA symptoms in clinical canine patients with large variability in ages, breeds, and weights.