The effect of equine-derived bone protein extract (Colloss-E) in the treatment of cavitary bone defects: an experimental study.

Objective: Bone protein extract (BPE) usually requires a carrier or a scaffold for implantation. We aimed to compare the effect of equine-derived BPE, an osteoinductive agent composed of a high amount of type-I collagen and other bone proteins (Colloss-E), with that of human demineralized bone matrix (DBM) for treating cavitary bone defects not requiring scaffold use.

Methods: Rabbit distal femoral condyle was used as a stable cavitary bone defect model. Bone defects of 6-mm diameter and 10-12-mm depth were created in the femoral condyles. Rabbits were assigned into the equine-derived BPE (BPE), human-derived DBM (DBM), and control (C) groups. Approximately 20 mg of BPE was implanted into the defect in the equine-derived BPE group (n=6), whereas 0.3 cc of DBM was implanted in the DBM group (n=6). Defects were left empty in the C group (n=6). The defect area was histologically examined after 6 weeks.

Results: There were no instances of macroscopic defect collapse or failure. Histopathological examination revealed that the BPE group had better scores (statistically significant) than both the other groups in terms of quality of union. The BPE group also had higher scores than the DBM group in terms of graft incorporation and new-bone formation.

Conclusion: The current study revealed results consistent with those of the previous studies concerning BPEs. Equine-derived BPE was found to be successful for treating cavitary bone defects not requiring scaffold use.