Abstract
PURPOSE: The reported clinical trial aimed to determine the clinical efficacy of ex vivo mesenchymal stromal cells (MSCs) derived from bone marrow (BM), aspirated from the posterior iliac crest and proximal tibia, in comparison to autologous platelet-rich plasma (PRP) for the knee osteoarthritis (KOA) treatment and to assess the differences in cellular yield between the two harvest sites. METHODS: A single-centre, parallel, randomised controlled trial was designed to investigate the clinical effects of bone marrow aspirate (BMA) from the posterior iliac crest compared to BMA from the proximal tibia in treating KOA, with a control group receiving PRP. Ninety patients with KOA were divided equally among the three groups. Visual Analogue Score (VAS) and Western Ontario and McMaster Universities Arthritis Index (WOMAC) score were used for clinical outcome evaluation at 6 months after the treatment, and cellular analysis of BMA was performed. RESULTS: Cell count confirmed that the posterior iliac crest was significantly more densely populated with mononuclear cells than the proximal tibia. Flow cytometric analysis of ex vivo BMA also confirmed a significantly greater number of MSCs in the BM-derived from the posterior iliac crest when compared with the proximal tibia, together with a significantly higher number of platelets. The analysis confirmed that the improvement in early pain and function scores after each treatment was statistically significant within each of the three groups (median VAS decrease: PRP Group -2 (p < 0.001), Crest Group -2 (p < 0.001), Tibia Group -2 (p < 0.001)), (median WOMAC decrease: PRP Group -13.5 (p < 0.001), Crest Group -12.5 (p < 0.001), Tibia Group -12 (p < 0.001)). However, no statistically significant differences were observed in the improvements among the three study groups. A significantly greater improvement in VAS was observed in patients with Kellgren Lawrence (KL) I-II. In the Tibia Group, the effect of BMA on the change in VAS was associated with BMI and %MSCs, whereas in the Crest Group, the change in WOMAC score was associated with %BM and platelet count. CONCLUSION: The iliac crest yields a higher concentration of MSCs compared to the proximal tibia. However, both sources demonstrated a beneficial clinical outcome in the treatment of KOA, with no evidence of superiority over PRP treatment. LEVEL OF EVIDENCE: Level I.