Table I.
Contact area, contact pressure, von Mises stress, and equivalent plastic strain of ultra high molecular weight polyethylene, highly cross-linked polyethylene, and vitamin E-stabilized polyethylene posts in fixed-bearing and mobile-bearing knee prostheses under neutral and malrotation contact.
| P. type | Contact area, mm2 | Contact pressure, MPa | von Mises stress, MPa | Plastic equivalent strain, % | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Fixed-bearing | Mobile-bearing | Fixed-bearing | Mobile-bearing | Fixed-bearing | Mobile-bearing | Fixed-bearing | Mobile-bearing | |||||||||
| Neutral | Malrotation | Neutral | Malrotation | Neutral | Malrotation | Neutral | Malrotation | Neutral | Malrotation | Neutral | Malrotation | Neutral | Malrotation | Neutral | Malrotation | |
| UHMWPE | 26.3 | 14.3 | 26.3 | 27.9 | 25.2 | 51.3 | 25.7 | 29.4 | 19.3 | 30.9 | 19.7 | 21.2 | 2.3 | 15.0 | 2.3 | 3.1 |
| HXLPE | 28.0 | 14.4 | 28.0 | 30.3 | 23.8 | 46.2 | 24.1 | 27.3 | 17.8 | 29.1 | 18.1 | 18.7 | 3.0 | 15.8 | 2.8 | 3.6 |
| VEPE | 26.3 | 14.3 | 26.3 | 27.1 | 26.4 | 54.7 | 26.9 | 31.0 | 21.1 | 32.0 | 21.3 | 23.2 | 1.7 | 14.9 | 1.8 | 2.8 |
HXLPE, highly cross-linked polyethylene; P., polyethylene; UHMWP, ultra high molecular weight polyethylene; VEPE, vitamin E-stabilized polyethylene.