Leukocyte-poor platelet-rich plasma is more effective than the conventional therapy with acetaminophen for the treatment of early knee osteoarthritis

Arch Orthop Trauma Surg. 2016 Dec;136(12):1723-1732. doi: 10.1007/s00402-016-2545-2. Epub 2016 Aug 9.


Introduction: Knee osteoarthritis (OA) is a degenerative and progressive articular cartilage disease. Infiltration of autologous platelet-rich plasma (PRP) has been proposed as a therapeutic alternative due to the content of biologically active cytokines in PRP. We aimed to compare the clinical response of acetaminophen and intra-articular leukocyte-poor PRP (LP-PRP) in early knee OA.

Materials and methods: A total of 65 patients with clinically and radiographically documented knee OA (grade 1-2) were analyzed. Patients were randomized into two groups: 32 were treated with acetaminophen (500 mg/8 h) over 6 weeks, and 33 received three intra-articular injections of autologous LP-PRP (once every 2 weeks). All patients were evaluated by the Visual Analogue Scale (VAS), the Western Ontario and McMaster Universities (WOMAC) score, and the SF-12 health survey at baseline and 6, 12, and 24 weeks of follow-up. All LP-PRP preparations were analyzed for the platelet, leukocyte, IL-1ra, and TGF-β concentrations.

Results: The decrease in the VAS pain level in the LP-PRP group was greater than that in the acetaminophen group (p < 0.05). Patients treated with LP-PRP showed a sustained improvement in knee function at week 24 (p < 0.01). The SF-12 results only indicated an improvement in quality-of-life in the LP-PRP group at 6, 12, and 24 weeks of follow-up (p < 0.01). Both IL-1ra and TGF-β were detected in the LP-PRP samples (313.8 ± 231.6 and 21,183.8 ± 8556.3 pg/mL, respectively).

Conclusions: Treatment with LP-PRP injections resulted in a significantly better clinical outcome than did treatment with acetaminophen, with sustained lower EVA and WOMAC scores and improvement in quality-of-life (higher SF-12 score). Therapy with LP-PRP may positively modify the inflammatory joint environment by counteracting IL-1β action.

Keywords: Acetaminophen; Intra-articular infiltration; Leukocyte-poor platelet-rich plasma; Osteoarthritis.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Acetaminophen / therapeutic use*
  • Analgesics, Non-Narcotic / therapeutic use
  • Arthralgia / diagnosis
  • Arthralgia / etiology
  • Arthralgia / therapy*
  • Female
  • Humans
  • Injections, Intra-Articular
  • Knee Joint
  • Male
  • Middle Aged
  • Osteoarthritis, Knee / complications
  • Osteoarthritis, Knee / physiopathology
  • Osteoarthritis, Knee / therapy*
  • Pain Measurement
  • Platelet-Rich Plasma*
  • Treatment Outcome


  • Analgesics, Non-Narcotic
  • Acetaminophen