Search PubMed⌕ Search

Biomedical subjects

P Rathert

Publications and source records attributed to P Rathert.

76 records · Page 5Linked to original sources

[Thermal knot fixation].

Knots represent the weakest point in suture material. As a result of bending and tension, forces develop within the knot that exceed the strength of the suture material and lead to rupture. Furthermore, because of their relatively large surface area, the most pronounced reactions occur in the vicinity of knots. The results of in vitro experiments conducted with the aim of improving the strength of knots are reported. The knot holding capacity of polypropylene filaments (EP 5/USP 2) was determined at room temperature (22 degrees C) after exposure to temperatures of 63, 98 and 150 degrees C. Knots that were exposed to a temperature of 98 degrees C for 10 seconds had a 50% higher holding capacity than untreated knots. With a higher knot holding capacity, secure fixation can be achieved with fewer knots. Since fewer knots have a smaller surface area, a reduction in tissue reaction may be expected.

Heating↗

[Suture surface and suture strength of polypropylene monofilaments].

Knots form the weakest sections in suture materials. The addition of forces in the knot caused by bend and tension exceed the strength of the suture material and lead to rupture in the knot. Furthermore the most pronounced tissue reactions occur in the surrounding of knots because of their relatively large surface as compared to the linear filament. With a higher knot holding capacity a secure fixation can be achieved with less knots. As a reduced number of knots leads to a smaller surface a reduced tissue reaction can be expected. Because of high rigidity and a low coefficient of friction synthetic monofilaments achieve only a low knot holding capacity. To improve the knot holding capacity a usually large number of knots is being used. With increasing surface of exogenous materials the extent of foreign-body reactions increases, e.g. formation of granuloma. Results of in-vitro experiments are reported that were conducted to identify the smallest secure knot in polypropylene filaments of various diameters.

Humans↗