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Ultrahigh molecular weight polyethylene as used in articular prostheses (a molecular weight distribution study)
Author(s) -
Crugnola Aldo M.,
Radin Eric L.,
Rose Robert M.,
Paul Igor L.,
Simon Sheldon R.,
Berry Mark B.
Publication year - 1976
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1976.070200321
Subject(s) - ultra high molecular weight polyethylene , polyethylene , materials science , brittleness , composite material , polymer , brittle fracture , lubricant , fracture (geology) , molar mass distribution
Abstract Currently there is widespread use of ultrahigh molecular weight polyethylene (UHMWPE) acetabular components in total joint replacement prostheses. What has been most surprising about the wear of UHMWPE under such circumstances is the occurrence of brittle fracture. Such fracture had not been observed in the usual engineering tests done in the laboratory on UHMWPE. It was only when prosthese which had been removed from patients were examined or run in hip joint simulators with serum or synovial fluid as the lubricant, that brittle fracture was encountered. The problem of environment‐enhanced brittle fracture in plastics dates back to 1946. Interestingly, the phenomenon was first described in polyethylene. The prime variables involved are polymer molecular weight, sensitizing environment, stress filed, and temperature. Other things being equal, brittle behavior in polyethylene is extremely sensitive to the amount of low molecular weight polymer present. In the light of the foregoing we have studied the molecular weight distribution in six commercially available UHMWPE components. These were obtained from six different manufacturers. The specimens were characterized both on their bearing (wear) surfaces and in their interior bulk. The results obtained indicate that: 1 The UHMWPE components contain substantial amounts of low molecular weight polymer. 2 The UHMWPE components differ significantly in molecular weight distribution. 3 The UHMWPE components contain substantial amounts of crosslinked polymer.