Science2010sUnited Stateshigh confidence

In a Mayo Clinic study, all 25 participants had two arthritic knees, and both knees improved dramatically even though only one knee received stem cells while the other received only a saline control injection.

Notes on verification

Confirmed by Mayo Clinic's own reporting, an independent watchdog (HealthNewsReview), and the peer-reviewed source study (Shapiro et al., 2017, AJSM) registered on ClinicalTrials.gov. All details align: 25 participants, both knees arthritic, one saline-only knee, both improved. [tier=gold indep_score=0.95 clusters=3 claim_tier=notable]

Sources