All-polyethylene patellar components are not the answer.

J P Collier; J L McNamara; V A Surprenant; R E Jensen; H P Surprenant

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PubMed · 1959272

All-polyethylene patellar components are not the answer.

J P Collier·J L McNamara·V A Surprenant·R E Jensen·H P Surprenant

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Abstract

Recent reports of the high incidence of polyethylene failure of metal-backed patellar components have rekindled the interest in cemented, all-polyethylene designs. One hundred four retrieved patellar components of metal-backed and all-polyethylene designs were analyzed for wear. Additionally, patellofemoral contact stress as a function of flexion angle was measured for unused components using pressure-sensitive Fuji film. Significant wear (2+ on a 0-3 scale) was seen in 65% of metal-backed designs and in 78% of all-polyethylene components. Severe wear (3) was seen in 44% of all-polyethylene components and in 39% of metal-backed devices. The incidence of severe wear (3) of congruent designs was statistically significantly lower than that of the noncongruent designs. Contact stress analysis confirmed that dome-type geometries typically resulted in stresses that exceed the yield strength of the polyethylene, whereas the more congruent geometries generated significantly reduced stress levels.

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Biomechanical Phenomena Humans Knee Prosthesis Movement Polyethylenes Prosthesis Design Prosthesis Failure Stress, Mechanical Journal Article

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J P Collier, J L McNamara, V A Surprenant, R E Jensen, H P Surprenant. 1991. All-polyethylene patellar components are not the answer.. https://pubmed.ncbi.nlm.nih.gov/1959272/

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