The clinical performance, corrosion characteristics, and metallurgical properties of 82 retrieved stainless-steel bone plates have been examined. The plates had been in situ for periods ranging from one to 169 months. Only 29% of these devices (24 of 82 plates) were removed on a routine asymptomatic basis, while 62% (51 of 82 plates) were removed for cause-related reasons such as implant-related pain, infection, nonunion or malunion, and so forth; seven plates were removed for unknown reasons. Although most patients who had plates removed for pain reported some improvement in symptoms, others felt no improvement after removal. On examination, over 89% of the recovered implants displayed some degree of either surface (pitting) or screw-plate interface (crevice and fretting) corrosion or both. Statistical analyses revealed that the metallurgical properties of grain size and nonmetallic inclusion content correlated significantly with the degree of both types of corrosion. Furthermore, it appears possible to improve corrosion resistance by revising the current ASTM standards. Only 14 of the 82 implants studied (17%) did not satisfy current ASTM specifications for either grain size or inclusion content.
|Number of pages||12|
|Journal||Clinical orthopaedics and related research|
|State||Published - Jul 31 1985|