By: 26 April 2015
Biological barrage corrodes orthopaedic implants

Biological barrage corrodes orthopaedic implants

New research from Syracuse Biomaterials Institute is challenging conventional theories about why inflammation and infection can develop after hip replacement.
For over 40 years, the orthopaedic research community has thought that cobalt-chromium-molybdenum (CoCrMo) alloys used in hip implants have corroded as patients walk, leading to the release of damaging ions into the surrounding tissue over time.
Jeremy Gilbert’s latest research, published in the Journal of Biomedical Materials Research indicates that wear and tear is not the only way implants can corrode and that the body’s own biological reactions could be waging an attack on the foreign implant and directly causing corrosion, which is a “fundamentally different” way of thinking about the interaction, said Gilbert.
By closely examining hip and knee implants that had been removed from patients, Gilbert’s research team discovered tell-tale corrosive “footprints’ of phagocytic cells that had crept along the implant, corroding the surface along the way. The metal showed microscopic signs of deterioration from these cells in all areas of the implants.
“The idea that inflammatory cells in the body can directly corrode the surface of an implant opens up the possibility that it is not just wear and corrosion that causes adverse local tissue reactions, but that ‘adverse’ local tissue reactions can cause corrosion,” explained Gilbert. “A small fundamental advance like this can uncover countless new paths and questions that can lead to a many technical advances to help deal with an issue that is significant in orthopedics today.”

Gilbert, J.L., Sivan, S., Liu, Y., et al. Direct in vivo inflammatory cell-induced corrosion of CoCrMo alloy orthopedic implant surfaces. J. Biomed. Mater. Res. A. 2015 Jan;103(1):211-23. doi: 10.1002/jbm.a.35165.
Source: Syracuse University