Three injections of freeze-dried platelet factor concentrate provide greater clinical response than single injection in the treatment of knee osteoarthritis
In brief
Three platelet-factor injections linked to 10-point higher 12-month pain response
In this nonrandomized cohort, 70.9% of patients receiving three injections met the pain-response threshold at 12 months, versus 60.9% after one injection; benefits were most apparent in early osteoarthritis. More patients in the three-injection group reported adverse events overall, although rates per injection were similar, and patient-preference allocation means the comparison cannot establish cause and effect.
- Journal
- Journal of experimental orthopaedics (Q1)
- Published
- 29 September 2026
- Study design
- Prospective / inception cohort
- Evidence level
- Level 2, Moderate (CEBM 2b)
- Authors
- Tadahiko Ohtsuru, Hiroto Hanai, Taro Akimori, Wataru Ando, Norimasa Nakamura, Stephen Lyman
- PMID
- 42813099
- DOI
- 10.1002/jeo2.70906
Why clinicians should know about it
- Picked for Rheumatology (top studies of the week, 4 October 2026): Three vs single PFC‑FD injections, knee OA
Abstract
PURPOSE: Single-injection freeze-dried platelet factor concentrate (PFC-FD) has been shown to be safe and effective in the treatment of early knee osteoarthritis (OA) with clear advantages over other PRP processing methods. No previous clinical investigations have examined multiple PFC-FD doses. The aim of this study was to assess the safety and effectiveness of one versus three PFC-FD injections in patients with knee OA. METHODS: Patients with Kellgren-Lawrence (KL) Grade I-IV knee OA were prospectively recruited via shared decision-making based on patient preference to receive either one (n = 1054) or three (n = 317) PFC-FD injections. Patients completed a pre-injection knee injury and OA outcomes survey (KOOS). Post-injection, patients completed the KOOS at 1, 3, 6 and 12 months. Adverse events were documented. Response to treatment was assessed using the Outcome Measures in Rheumatology (OMERACT)-Osteoarthritis Research Society International responder criteria. Multivariable modelling assessed treatment effectiveness, adjusting for patient differences. RESULTS: The three-injection cohort demonstrated a small advantage in all KOOS subscales except quality of life (QOL) at 1 month (2.4-4.0 points, p < 0.0001-0.004), but this advantage disappeared by 3 months. When only early OA (KLI-II) was considered, the three-injection cohort demonstrated higher improvement at 1, 3 and/or 6 months for most KOOS subscales. No such differences were observed for advanced OA patients. Multivariable analysis demonstrates that three-injection patients were more likely to achieve responder status for KOOS-Pain and KOOS-activities of daily living (ADL) at 12 months (70.9% vs. 60.9%, p = 0.02 and 55.7% vs. 47.3%, p = 0.009, respectively). Overall patient-level adverse events were higher in the three-injection group (21.3% vs. 6.9%; p < 0.001), though adverse events per injection did not differ between groups (one-injection 6.9%, three-injection 8.6%; p = 0.19). CONCLUSION: Based on non-randomized allocation, a three-injection PFC-FD treatment protocol demonstrates a higher likelihood of clinical response compared to a one-injection protocol, particularly for relief of early knee OA symptoms, without evidence of an adverse immune response. LEVEL OF EVIDENCE: Level II, prognostic prospective cohort study (patients enroled at different stages of disease progression).
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.