Wear of medical grade silicone rubber against titanium and ultrahigh molecular weight polyethylene

Abstract

The replacement of arthritic small joints, such as the fingers and wrist, has typically involved the use of one-piece silicone rubber implants. Newer designs have involved the silicone moving against either a titanium or ultrahigh molecular weight polyethylene (UHMWPE) component. The aim of this study was to investigate the wear of medical grade silicone rubber against titanium and UHMWPE. A pin-on-disc apparatus was used to slide a titanium and UHMWPE pin against a silicone disc, in the presence of either a Ringer's solution or bovine serum lubricant. Testing was undertaken at a sliding speed of 0.079 m/s and was continued for 10 km. Wear factors for titanium against silicone were 40.0 x 10(-6) mm(3)/N m and 66.5 x 10(-6) mm(3)/N m for bovine serum and Ringer's solution, respectively. The wear factors for UHMWPE against silicone were higher with values of 84.4 x 10(-6) mm(3)/N m and 88.3 x 10(-6) mm(3)/N m for bovine serum and Ringer's solution, respectively. The results of this study will be useful in future designs of finger and wrist implants that combine silicone rubber with either titanium or UHMWPE.

Frequency dependence of viscoelastic properties of medical grade silicones

“…The silicone elastomers used in this study are classified as short-term implants as they have only passed screening tests applicable to products intended to be implanted for 29 days. These medical grade silicone elastomers are the commercially available and unrestricted versions, commonly used for research, [26][27][28][29] of the Silastic 1 implant material, which has been used to manufacture the Swanson Silastic 1 finger joint. [28][29][30][31][32] According to the suppliers' data sheets, the composition and tabulated properties of the short-term implant material and those intended for longer-term implantation, such as Silastic 1 , are closely similar as shown in Tables II and III.…”

Aesthetic finger prosthesis with silicone biomaterial

“…There are various methods to increase the retention of the prosthesis such as the use of retentive finger rings,14 15 medical grade adhesives,16 implants,17 etc along with the basic positive contact of the prosthesis with the tissues. Leow et al 18 studied optimal circumference reduction of finger models for a good prosthetic fit of a thimble-type prosthesis for distal finger amputations and found out that 5–7% circumference reduction in the finger was shown to be best among 1–3% and 8–9% of reduction 18…”

Silicone Finger Prosthesis. A Clinical Report

“…The most challenging cases are those where suction is not feasible or is compromised, as is seen in cases of a short or fleshy residual finger. 13 This problem can be overcome with the use of medical grade adhesives to hold the prosthesis in position. In case of multiple missing fingers, extensive skin coverage can be considered.…”