APPLICATION OF MANUAL TRACTION FORCES ON THE CERVICAL DISCS WITH DEGENERATIVE ANNULAR FIBERS: A FINITE ELEMENT MODEL ANALYSIS

摘要

Degeneration in intervertebral discs is a complex multifactorial process. Studies have speculated the biomechanical and biochemical reasons factoring the degenerative disc pathology. Disc degeneration begins in inner nucleus pulposus (NP) that has high fluid content. As degeneration advances over time, the load is shifted from inner NP to outer annulus fibrosus (AF) that is more fibrous in nature. In addition to morphological changes in the discs that occur with degeneration in the form of tears and delamination, tissue compositional variations are also noted. These degenerative changes have not only been seen in the disc tissue matrix, but they are also quite apparent in the fibers of AF in the form of incompleteness and laxity [1], These tensile fibers in AF have a critical functionality in maintaining the mechanical strength of the disc segments, and any form of degenerative impairment in these fibers may lead to abnormal physiology, both in the AF and NP.