Applying additional autologous platelet-rich fibrin matrix or serial platelet-rich plasma to microfracture technique increases the quality of the repaired cartilage

Purpose The aim of the present study is to investigate and compare the effects of biological adjuvants (platelet-rich plasma, platelet-rich fibrin matrix) and microfracture technique individually and in combination on full thickness chondral defects in a rabbit model.Methods A total of 60 New Zealand White rabbits were randomly divided into six groups according to treatment modality as follows: control (C), microfracture (MF), platelet-rich plasma (PRP), platelet-rich fibrin matrix (PRFM), platelet-rich fibrin matrix after microfracture (MF + PRFM) and platelet-rich plasma after microfracture (MF + PRP) groups. The cartilage repair tissue was assessed histologically via International Cartilage Repair Score (ICRS) and macroscopically via ICRS macroscopic assessment scale.Results It was shown that overall macroscopic scores of the groups with MF were higher than those of the groups without MF. The cell morphology observed in the defect areas was mostly characterized with non-chondrocyte cells in the groups without MF, whereas chondrocyte cells mostly prevailed in the groups with MF. There was a greater integration through the cartilage-like tissue in the MF + PRP and MF + PRFM groups. The control group showed either fissures or fissures partially filled with fibrous tissue. When the groups were individually examined, there were statistically significant differences between the control and MF groups (p = 0.002), between the control and MF + PRFM groups (p = 0.001), between the control and MF + PRP groups (p < 0.001), between the PRFM and MF + PRFM groups (p = 0.014) and between the PRFM and MF + PRP (p = 0.023) groups in terms of histological evaluation scores.Conclusion The application of PRP and PRFM in combination with MF treatment exhibited a positive impact on the repair and restoration of cartilage, and produced better outcomes than the individual use of PRP and PRFM. Nevertheless, in the treatment of full thickness chondral defects, the use of PRFM injection is recommended, which is performed intraoperatively at a single time and with no difficulty of repeating after surgery, instead of serial PRP injections based on the macroscopic and histological results obtained in the present study indicating that there was no significant difference between the use of these two adjuvants.