Usefulness of platelet-rich fibrin as a scaffold for meniscal repair: A non-randomized controlled cohort/follow-up study.

Background: Although regenerative medicine treatment is still in its infancy in Japan, legislation within the past decade has provided opportunities to explore new treatment methods using regenerative medicine. We conducted a 2-year prospective follow-up study to statistically analyze treatment outcomes using platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) as effective scaffolds in meniscal repair.Questions/Purposes.1. Does the use of PRF and PRP for meniscal repair surgery regenerate the meniscus?2. Does augmentation of meniscal repair with PRF effectively improve knee function outcomes? Methods: Thirty-five patients underwent arthroscopic meniscal repair with PRP and PRF using new devices with all-inside techniques. Among these, 31 patients were evaluated for clinical outcomes postoperatively, and magnetic resonance imaging (MRI) findings were evaluated. The variables were coded appropriately by creating a new column based on the Kellgren-Lawrence classification over time. Log transformation of different time points (pre, post 6, 12, or 24 months) in relation to Lysholm, International Knee Documentation Committee (IKDC), Japanese Orthopedic Association (JOA), and Tegner scores were performed. Follow-up arthroscopy using a needle scope was performed in some cases 2 years later. The PRP and PRF used were characterized using the Minimum Information for Studies Evaluating Biologics in Orthopaedics classification. Results: Overall, 31 patients were evaluated (mean age = 39.1 ± 15.7 years; preoperative rehabilitation period = 9.5 ± 7.7 weeks). The PRP had mean platelet and white blood cell concentrations of approximately 5.5- and 3.6-fold, respectively. A significant association existed between sex and deformity deterioration but not in age between the two groups classified by deformity deterioration. Surgical intervention significantly and positively impacted knee function, although no significant changes were found in the activity of the participants over time. MRI findings showed no regeneration of the repaired meniscus; nevertheless, none of them worsened. Furthermore, a case where the traumatic cartilage defect was covered with fibrocartilage-like tissue as a secondary finding was observed. Conclusions: Meniscal repair surgery using PRP/PRF is an effective treatment option for improving knee function in patients with knee deformity. Level of evidence: Level III, Non-randomized controlled cohort/follow-up study.