Haematological and inflammatory responses of intramedullary tibial iron based implant in sheep

Abstract

Iron-based implants have been widely researched as biodegradable orthopaedic implants although non-degradable metallic materials are still the golden standard as orthopaedic implant to avoid removing implant surgery when bone healing achieved. The aim of this study was to observe haematological and inflammatory responses of iron-based intramedulary biodegradable implants. Eight sheep were divided into two groups according to the material implanted, which were the control group using stainless steel Steinman pin and treatment group using degradable iron-based pin. The pin was inserted into a transverse fracture of sheep tibial bone medullary cavity. Blood sampling was performed on jugular vein on day 0, 1, 3, 7, and 14 after implantation. The examination includes the number of erythrocytes, haematocrite values, hemoglobin levels, platelet values, the number of leukocytes, and leukocyte differential cell. Iron-based bone pin implantation did not cause significant changes on erythrocyte profile, leukocyte count and leukocyte differential cell when compared to stainless steel bone pin. The interaction between iron-based implant and bone tissue, acute and chronic inflammatory responses shows a dynamic variation. It can be concluded the iron-based implant is still tolerated sub-chronically in sheep.