IntroductionAutologous conditioned plasma (ACP) is a single-spin, leukocyte-poor platelet-rich plasma (PRP) that provides a plasma with a platelet concentration 2 to 3 times the blood platelet concentration. The objective of this study was to investigate the clinical effectiveness of ACP intra-articular injection in patients with knee osteoarthritis (OA) and to identify any demographic, disease-associated, or biological predictors of outcome.MethodsA prospective cohort study was conducted between 2022 and 2023 in a single high-volume tertiary center, including 42 patients (54 knees) who consented to be enrolled. Patients underwent a series of 3 injections of ACP at weekly intervals, prepared using the Arthrex ACP Double-Syringe System. Lysholm scores were collected at baseline, 3-months, and 6-months post-injection.ResultsForty patients (49 knees) completed the follow-up and were included in the final analysis. The mean age was 53.8 ± 10.16 years (range 35-76 years), and the median body mass index (BMI) was 29 (interquartile range [IQR]: 27-34). There were 22 females and 18 males. Treatment failure occurred in 12 out of 49 cases (24.49%). The mean platelet concentration in the ACP was 588.5 ± 183.2 × 10