Tan et al. published a meta-analysis about mesencymal stem cells in the tretment of osteoarhritis. They reported pooled estimates as follows:
The standardized mean differences (SMDs) for the visual analog scale (VAS) for pain at rest and upon exertion were –1.48 (95% CI, –1.85 to –1.11) and –2.25 (95% CI, –2.64 to –1.85), respectively.
This would mean that improvement in exercise related knee pain was more than two standard deviations. I´d say this quite an improvement considered that SMD of total knee replacement in the end-stage knee osteoarthritis is somewhere above 2 also. Seems highly implausible. Someone might also ask why this miracle treatment is not a standard treatment in our practise?