Deconvoluting the cellular black box of cell therapies for osteoarthritis: A mandate for protocol standardization

Autologous cell therapies for knee osteoarthritis, including bone marrow aspirate concentrate (BMAC) and stromal vascular fraction (SVF), have advanced clinically despite an incomplete understanding of their mechanisms. Chatterjee et al. apply single-cell transcriptomics to multicenter trial of stem cell therapy for osteoarthritis (MILES) trial samples, revealing that site-to-site technical variability in BMAC composition overwhelms biological signals associated with treatment response. This finding mandates urgent standardization of harvest protocols before personalized genomic profiling can be meaningfully implemented. While responder/non-responder differences were subtle, pathway enrichment analyses and cell-cell communication inferences suggest that therapeutic outcomes may depend more on dynamic post-injection interactions than on baseline cellular states. The study establishes a foundational framework for evidence-based quality control in cellular orthopedics.