THE MORPHOLOGICAL AND MORPHOMETRIC STUDY OF THE SCIATIC NERVE AFTER AMPUTATION AND PROSTHETICS OF THE LEG EXPERIMENTALLY USING AN ORIGINAL IMPLANT

Abstract

Purpose of the Study was to identify the morphological and morphometric changes in the sciatic nerve after amputation and prosthetics of the leg with an original implant experimentally. Six dogs had underwent the tibia osteotomy at the border of the upper and middle thirds, and an implant of PressFit type was driven in. The stump was modeled. The fixation of the bone and compression load on the bone (Fl=20N) was performed with a special device. The sciatic nerves were studied 180 days after prosthetics. Sciatic nerves of 5 intact dogs were control. About 6.39 % of myelin fibers demonstrated signs of myelin and axon damage. The number of myelin fibers increased 1.81-fold with 2.05-fold decrease in axon diameter, 3.52-fold decrease – in myelin thickness (p=0.000) and with loss of large myelin fibers with a diameter of more than 10 microns. The number of non-myelinated fibers increased 4.23-fold (p=0.000). The retrograde changes revealed in the sciatic nerve in the form of neuropraxia and axonotmesis, loss of large myelin fibers and regenerative processes may be one of the causes of post-amputation pain syndrome. © 2023 Stavropol State Medical University. All rights reserved.