Development of a Computational Model of the Mechanical Behavior of the L4-L5 Lumbar Spine: Application to Disc Degeneration.

Degenerative changes in the lumbar spine significantly reduce the quality of life of people. In order to fully understand the biomechanics of the affected spine, it is crucial to consider the biomechanical alterations caused by degeneration of the intervertebral disc (IVD). Therefore, this study is aimed at the development of a discrete element model of the mechanical behavior of the L4-L5 spinal motion segment, which covers all the degeneration grades from healthy IVD to its severe degeneration, and numerical study of the influence of the IVD degeneration on stress state and biomechanics of the spine.

[Combined treatment in malignant tumors of the head and neck with reconstructive-plastic surgery].

The article is devoted to conservative and reconstructive-plastic surgical interventions using biocompatible implants accompanied by various types of radiotherapy and modern anticancer drugs that have allowed improving basic survival with maintaining a high level of quality of life. Our method of combined treatment for larynx, hypopharynx, oral cavity and oropharynx cancer of stage II-III by chemoradotherapy shows high immediate effectiveness and allows achieving statistically significant increase of overall and disease-free survival in the remote period of observation. The use of NiTi implants provides reliable recovery of deleted structures, pressurization of the cranial cavity, reduces the duration of surgery, shortens the time of wound healing.