Table 1.

Summary of main findings of included clinical studies

References	Main findings
Al-Ajlouni et al. [23]	Intra-articular administration of three doses of PL injected every 3 weeks is safe and led to statistically significant improvement in the overall KOOS and all KOOS subscales at 32 and 52 weeks follow-up compared to the baseline
Jeyaraman et al. [24]	Intra-articular administration of three doses of PL injected every 4 weeks is safe and led to statistically significant improvements in the VAS and WOMAC scores at 12 months follow-up compared to the baseline and PRP group
Hosseini et al. [25]	Intra-articular administration of three doses of PL injected every 21 days is safe and led to statistically significant improvements in the VAS and WOMAC scores and ROM at 6 months follow-up compared to the baseline and PRP group

PL platelet lysate, KOOS Knee Injury and Osteoarthritis Outcome Score, VAS visual analogue scale, WOMAC Western Ontario and McMaster Universities Arthritis Index, PRP platelet-rich plasma, ROM range of motion