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Hip simulator testing of the taper‐trunnion junction and bearing surfaces of contemporary metal‐on‐cross‐linked‐polyethylene hip prostheses
Author(s) -
Bhalekar Rohan M.,
Smith Simon L.,
Joyce Thomas J.
Publication year - 2020
Publication title -
journal of biomedical materials research part b: applied biomaterials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.665
H-Index - 108
eISSN - 1552-4981
pISSN - 1552-4973
DOI - 10.1002/jbm.b.34374
Subject(s) - polyethylene , materials science , cross linked polyethylene , bearing surface , bearing (navigation) , titanium , composite material , total hip replacement , biomedical engineering , surgery , medicine , metallurgy , cartography , geography , lubrication
Adverse reaction to metal debris released from the taper‐trunnion junction of modular metal‐on‐polyethylene (MoP) total hip replacements (THRs) is an issue of contemporary concern. Therefore, a hip simulator was used to investigate material loss, if any, at both the articulating and taper‐trunnion surfaces of five 32‐mm metal‐on‐cross‐linked‐polyethylene THRs for 5 million cycles (Mc) with a sixth joint serving as a dynamically loaded soak control. Commercially available cobalt–chromium–molybdenum femoral heads articulating against cross‐linked polyethylene (XLPE) acetabular liners were mounted on 12/14 titanium (Ti6Al4V) trunnions. Weight loss (mg) was measured gravimetrically and converted into volume loss (mm 3 ) for heads, liners, and trunnions at regular intervals. Additionally, posttest volumetric wear measurements of the femoral tapers were obtained using a coordinate measuring machine (CMM). The surface roughness (Sa) of femoral tapers was measured posttest. After 5 Mc, the mean volumetric wear rate for XLPE liners was 2.74 ± 0.74 mm 3 /Mc. The CMM measurements confirmed material loss from the femoral taper with the mean volumetric wear rate of 0.045 ± 0.024 mm 3 /Mc. The Sa on the worn area of the femoral taper showed a significant increase ( p < 0.001) compared with the unworn area. No other long‐term hip simulator tests have investigated wear from the taper‐trunnion junction of contemporary MoP THRs. © Crown Copyright. Journal of Biomedical Materials Research Part B: Applied Biomaterials 108B:156–166, 2020.