Osteogenic effect of platelet-rich fibrin on a bone defect model of long bone in rabbits

This study aims to evaluate the osteogenic effect of platelet-rich fibrin (PRF) graft with periosteal repair on a bone defect of long bone in rabbits, compared to control group that underwent periosteal repair alone.

A total of 12 female New Zealand white rabbits were used in this study. Two rabbits were designated for PRP preparation, mixed with a human thrombin agent to produce PRF. A bone defect (5 mm in diameter and 7 mm in depth) was created in both proximal tibiae of 10 rabbits. The defect site of the right proximal tibia was filled with PRF, followed by periosteal repair (PRF group). In contrast, only periosteal repair was performed on the left proximal tibia (control group). For histological evaluation, hematoxylin and eosin (HE) and Masson's trichrome (MT) staining were performed at Weeks 4 and 8 after surgery. The bone healing ratio, defined as the proportion of newly formed bone area to surgically created defect area, was calculated to assess bone regeneration. For radiological examination, micro-computed tomography (micro-CT) was conducted at Week 8 after surgery.

A total of nine rabbits survived until the planned euthanasia time points (four rabbits at Week 4 and five at Week 8). At Week 4 postoperatively, HE staining revealed a higher bone healing ratio in the PRF group compared to the control group; however, the difference was not statistically significant (PRF group: 71.0 ± 15.6, control group: 59.5 ± 18.1, p = 0.34). At Week 8 postoperatively, histological analysis showed no difference in the bone healing ratio between the two groups (PRF group: 79.3 ± 8.7, control group: 75.9 ± 13.2, p = 0.55). Micro-CT analysis demonstrated a superior LaneSandhu score in the PRF group compared to the control group, although this difference was not statistically significant (p = 0.15).

The PRF graft with periosteal repair appears to promote improved early-stage new bone formation in bone defects of long bone in an animal model compared to periosteal repair alone, although it does not reach statistical significance.