Non-absorbable sutures

Surgical cotton From these cottons were obtained from the natural cellulose which is soft and silky. We can find cotton remains in body tissues, where the suture loses 50% of its strength within 6 to 9 months. The permeability of this multifilament suture to bacteria is similar to that of silk and is the major factor affecting tissue reaction. 

Poly-butester A special type of polyester is poly-butester (novafil). It has the capacity of non-absorbable suture materials. 

It is the newest among polyesters. Poly-glycolterephthate and poly-butyleneterephthate are copolymers. The Novafil is a monofilament sutures which possesses the merits of polypropylene and polyester polymers. For example, it is very slippery and is elastic in nature like polypropylene, but it is easy to tie with polyester. 

Bone fixation devices The metal fixation in fractured bone is the most popular and successful painless treatment. Mechanical properties are very different for critical bone and steel. The elasticity constant of the steel and the bone differ completely. The elasticity of bone is 110 whereas for the steel it was 10 times lesser. Thus, removal of metal implants can lead to weakened bones with the danger of re-fracture. 

Applications of biodegradable polymers are numerous. With the help of endoprosthetic joint replacement methods, we can fill the bone marrow instead of mechanical filling when there is defects in bone. 

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Sutures remain the most common method of tpproximating the divided edges of tissue (1). Sutures are categorised by size, material, design and behaviour. Absorbable and nonabsorbable materials are further divided into synthetic versus natural products, some of vdiich can be fabricated in braided and/or monofilament form. Non-absorbable sutures have played an important role in the development of surgical procedures, generally made of silk, polyamide, polyester, polypropylene, polyethylene and poly(tetrafluoroethylene) (2). 

In this study, two most commonly used, non-absorbable sutures namely silk and polyamide 6 (PA6) have been used in order to see the effect of in vivo conditions on the mechanical performance in terms of fracture mechanism. All sutures were assured in sterile form. Fig.l shows the sutures used in this study. 

Although polyamide is considered a non>absorbable suture, it still undergoes partial degradation through hydrolysis at a very slow rate due to -T HCO- groups on the polymer backbone as they are very polar mid can hydrogen bond with water easily. 

This study has analysed ftacture mechanisms of two non-absorbable sutures before and after 3 and 8 weeks implantation in rats. Scaiming Electron Microscope (SEM) and optical light microscope were used for analysis of fiacture mechanisms and sur ce changes of the sutures. A clear in vivo effect on the ftacture mechanism was seen for braided silk suture. Typical ductile fiacture for polyamide suture was observed. In terms of ftacture mechanism it was not affected by the implantation and the implantation time. In the knotted ftmn, the break was always l eath Ae knot and the knot was securely in place for silk suture. In polyamide suture, imdone knots were observed. While silk Woodhead Publishing Limited, 2010 435... 

An absorbable suture was one that lost a significant portion of its mechanical strength over a period of 2 months > hile a non-absorbable suture was one that maintained a significant portion of its strength longer than 2 months [4]. A suture may lose its toisile strength over a relatively short period of time, but require months or evoi years to absorb completely and be eliminated from the body. The prinuiry mode of degradation for natural materials is enzymolysis, vdiereas for synthetic absorbable materials it is hydrolysis [3]. 

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