title: Profiling the third-body wear damage produced in CoCr surfaces by bone cement, CoCr, and Ti6Al4V debris: a 10-cycle metal-on-metal simulator test.
abstract: Particles of bone cement (polymethyl methacrylate), CoCr and Ti6Al4V were compared for their abrasion potential against CoCr substrates. This appears to be the first study utilizing CoCr and Ti6Al4V particulates to abrade CoCr bearings and the first study profiling the morphology of third-body abrasive wear scratches in a hip simulator. The 5 mg debris allotments (median size range 140-300 µm) were added to cups mounted both inverted and anatomically with metal-on-metal (MOM) bearings in a 10-cycle, hip simulator test. Surface abrasion was characterized by roughness indices and scratch profiles. Compared to third-body abrasion with metal debris, polymethyl methacrylate debris had minimal effect on the CoCr surfaces. In all, 10 cycles of abrasion with metal debris demonstrated that roughness indices (Ra, PV) increased approximately 20-fold from the unworn condition. The scratch profiles ranged 20-108 µm wide and 0.5-2.8 µm deep. The scratch aspect ratio (W/PV) averaged 0.03, and this very low ratio indicated that the 140 µm CoCr beads had plastically deformed to create wide but shallow scratches. There was no evidence of transfer of CoCr beads to CoCr bearings. The Ti64 particles produced similar scratch morphology with the same aspect ratio as the CoCr particulates. However, the titanium particulates also showed a unique ability to flatten and adhere to the CoCr, forming smears and islands of contaminating metal on the CoCr bearings. The morphology of scratches and metal transfer produced by these large metal particulates in the simulator appeared identical to those reported on retrieved metal-on-metal bearings.
authors: Donaldson Arthritis Research Foundation, Colton, CA, USA.
authors: Thomas
authors: T
authors: Halim
authors: Donaldson Arthritis Research Foundation, Colton, CA, USA.
authors: Michelle
authors: M
authors: Burgett
authors: Donaldson Arthritis Research Foundation, Colton, CA, USA.
authors: Thomas K
authors: TK
authors: Donaldson
authors: Orthopedic Joints Devices Branch/DSORD/ODE/CDRH/FDA, Food and Drug Administration, Silver Spring, MD, USA.
authors: Christina
authors: C
authors: Savisaar
authors: Anterior Spine Devices Branch/DOD/ODE/CDRH, Food and Drug Administration, Silver Spring, MD, USA.
authors: John
authors: J
authors: Bowsher
authors: Donaldson Arthritis Research Foundation, Colton, CA, USA Orthopedic Research, Department of Orthopedics, LLUMC, Loma Linda University, Loma Linda, CA, USA hipgeek5@yahoo.com.
authors: Ian C
authors: IC
authors: Clarke
mesh_terms: D000497:Alloys; D001843:Bone Cements / Q000737:chemistry*; D002858:Chromium Alloys / Q000737:chemistry*; D019544:Equipment Failure Analysis; D017276:Friction; D006622:Hip Prosthesis; D008422:Materials Testing; D061825:Metal-on-Metal Joint Prostheses; D010316:Particle Size; D011474:Prosthesis Design; D011475:Prosthesis Failure; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D000497:Alloys; D001843:Bone Cements; D002858:Chromium Alloys; C031462:titanium alloy (TiAl6V4); D014025:Titanium
keywords: CoCr; Hip simulator; metal-on-metal; third-body wear