Polyether-ether-ketone (PEEK), cobalt-chromium-molybdenum (CoCrMo), and highly cross-linked polyethylene (HXLPE) are biomaterials used in orthopedic implants; their wear particles are considered to induce peri-implant osteolysis. We examined whether different particle types induce the same degree of peri-implant osteolysis.
Forty female rabbits were randomly divided into four groups—the control group (n = 10), which received implantation operation and sham operation at 1 month postoperation; three experimental groups (n = 10 in each group), which received implantation operation along with administration of 0.1 mL of particle suspension (approximately 1.0 × 108 PEEK, CoCrMo, or HXLPE wear particles) into the knee joint at 1 month postoperation. All rabbits were sacrificed at 2 months postoperation. The synovium was removed and histologically assessed. The distal femurs with the implants were analyzed via micro-computed tomography (CT) and hard tissue biopsy.
The average size of almost 90% of the particles was < 5 μm, indicating no significant difference in the three particle types. IL-1β, IL-8, TNFα, RANKL, and MCP-1 expression in PEEK and CoCrMo groups was high, while that in the HXLPE group was low. The bone density (BD) and bone volume/total volume (BV/TV) of the porous structures (part of the implants in all groups) in experimental groups did not decrease markedly (p > 0.05), while BD in the peripheral regions in experimental groups decreased markedly compared to control groups (p < 0.05). BV/TV in the peripheral regions was significantly decreased in PEEK and CoCrMo groups when compared to control group (p < 0.05), while no significant difference was noted between HXLPE and control groups (p > 0.05). The changes in BV observed in the hard tissue sections were consistent with those noted in the micro-CT findings.
PEEK, CoCrMo, and HXLPE wear particles (approximately having the same size and doses) induce peri-implant osteolysis to a different degree: HXLPE particles induce peri-implant osteolysis to a mild degree, while PEEK and CoCrMo particles caused significant peri-implant osteolysis. In case of a porous implant, osteolysis occurred primarily in the peripheral region, rather than in the porous structures. Our findings would be helpful for implant designers to choose friction pairs in orthopedic components.
McKellop H, Shen FW, DiMaio W, Lancaster JG. Wear of gamma-crosslinked polyethylene acetabular cups against roughened femoral balls. Clin Orthop Relat Res. 1999;369:73–82. CrossRef
Willert HG, Semlitsch M. Tissue reactions to plastic and metallic wear products of joint endoprostheses. Clin Orthop Relat Res. 1996;333:4–14.
Jacobs JJ, Roebuck KA, Archibeck M, Hallab NJ, Glant TT. Osteolysis: basic science. Clin Orthop Relat Res. 2001;393:71–7. CrossRef
Hallab NJ, Jacobs JJ. Biologic effects of implant debris. Bull NYU Hosp Jt Dis. 2009;67(2):182–8. PubMed
Shanbhag AS, Kaufman AM, Hayata K, Rubash HE. Assessing osteolysis with use of high-throughput protein chips. J Bone Joint Surg Am. 2007;89(5):1081–9. PubMed
Paulus AC, Hasselt S, Jansson V, Giurea A, Neuhaus H, Grupp TM, et al. Histopathological analysis of PEEK wear particle effects on the synovial tissue of patients. Biomed Res Int. 2016;2016:2198914. doi: https://doi.org/10.1155/2016/2198914.
- The degree of peri-implant osteolysis induced by PEEK, CoCrMo, and HXLPE wear particles: a study based on a porous Ti6Al4V implant in a rabbit model
- BioMed Central
Neu im Fachgebiet Orthopädie und Unfallchirurgie
Mail Icon II