THE EFFECT OF HYPODERMIC NEEDLE PERFORATIONS ON THE TENSILE PROPERTIES OF CHICKEN TENDONS

Corticosteroid injection using hypodermic needles is one of the commonly accepted treatments for patients with hand conditions. However, in some cases the needle perforations may cause tendon ruptures. This paper aims to investigate the relationships between a tendon's ultimate tensile strength (UTS) and the number of hypodermic needle perforations as well as needle sizes. The UTS was determined for all specimens at the loading rate of 0.4 mm/s. Tendon specimens with perforations punctured by large-sized (19 G) hypodermic needles were found to have significantly lower UTS than those with perforations punctured by medium-sized (23 G) and small-sized (27 G) needles. For specimens punctured by medium- and small-sized needles, no significant difference in UTS was observed between tendons with three perforations and those with one perforation.