A suture is a medical device that doctors use to hold skin, internal organs, blood vessels and all other tissues of the human body together, after they have been severed by injury or surgery. They must be strong enough to hold the tissue and flexible enough to be able to tie into knots easily.

 

Suture tensile strength determines where the suture can be used inside or outside of the body and for how long it is intended to remain. Sutures are absorbable or non-absorbable and in some cases, have needles attached.

Below we describe a typical suture tensile test and what type of equipment is needed to perform this test.

               

ADMET Universal Tensile Testing Machine-eXpert 7601, 1kN, with MTESTQuattro, servo control data acquisition, analysis, and reporting software controller, and pneumatic cord and yarn grips.

 

Types of Suture tests
1)Standard tensile pull test.
2)Knot pull tensile test- the knot is centered in between the grips.

3)Creep test- Pull to a desired load and hold.  

 

1)Insert non-absorbable suture sample into pneumatic cord and yarn grips.  The guage length is usually 10 inches from grip to grip with a 2.5 inch grip separation.It is very important that the sample

is lined up properly or it will impact the results of the test.

 

2) Set profile to pull suture at desire speed to a desired load or until the sample breaks. We used 12 in/min.

3)After sample breaks, the test stops.

 

From the data we can tell the tensile strength and peak load of nonabsorbable suture.

 

 

In other tests, we can tell the strength of a suture with and without a knot pull, and the strength of absorbable or non-absorbable sutures. In addition, you can perform creep tests and cyclic tests.

 

Reports can be customized using MTESTQuattro from ADMET.

 

Suture sizes are defined by the United States Pharmacopeia (U.S.P.) Atraumatic needles are manufactured in all shapes for most sizes. The actual diameter of thread for a given U.S.P. size differs depending on the suture material class. 

 

Many textile ASTM methods are used for thread testing.

ASTM D5034-95, ASTM D3787-89, ASTM D2256.