Needle insertion test by porcine ligamentum flavum

Abstract

Needles for the epidural anesthesia are designed, as a curved tip allows direction of the catheter in the epidural space. Purpose of the current study was to check the effect of the curved tip and slower insertion speed on puncturing dynamics for the ligamentum flavum. Porcine spines from a slaughterhouse were employed. Two Tuhoy needles fabricated by different manufacture and an injection needle were compared. Peak value of force was measured as insertion resistance. Deformation of the ligamentum flavum before the needle puncture was measured. Difference of the peak force among three types of needles, two groups of spine (thoracic and lumber) was statically significant. Peak forces observed in the speed 0.4 mm/s were smaller than those in the speed 2 mm/s. Difference of the deformation between the Tuhoy needle and the injection needle was statically significant. Effect of the insertion speed and location of the spine on the deformation was not obtained.