Treatment of High-Impact Injuries of Thoracic and Lumbar Spine

Introduction. Surgical treatment of patients with spinal injuries with traumatic spinal canal stenosis is an important and widely discussed problem of contemporary vertebrology. Injuries to the spine in the incidence structure of isolated or combined injuries occupy a special place due to their high social and clinical significance. Long-term outcomes of traumatic disease in patients with combined trauma to the thoracic and lumbar spine are studied, as before, by ever larger groups of researchers in connection to the new generations of spinal fixation devices being introduced.Materials and methods. 111 patients with various thoracolumbar spine injuries treated surgically were included in the study. In 40 patients, the post-traumatic stenosis was treated with the use of ligamentotaxis and transpedicular osteosynthesis. Thll–Thl2, Th12–L1 and L1–L2 were the most frequent localisations of the level of injury in the study group.Results and discussion. The immediate treatment outcomes observed were as follows — good in 33 (82.5%) cases, satisfactory in 6 (15.0%), unsatisfactory — in 1 (2.5%). Long-term outcomes with follow-up longer than a year were recorded in 27 (67.5%) patients with good outcomes in 20 (74.1%) and satisfactory in 7 (25.9%).Conclusion. A correct stabilisation with metal systems makes it possible to verticalize the patient quickly and shorten the rehabilitation period in all patients including those of active working age, as well as minimize the risks in the long term.

Effect of Subsurface Deformation on Sliding Wear Behavior of Ti-29Nb-13Ta-4.6Zr Alloys for Biomedical Applications

The wear mechanisms of conventional Ti–6Al–4V extra-low interstitial (Ti64) and the new Ti–29Nb–13Ta–4.6Zr (TNTZ) were studied to investigate the wear properties of Ti64/TNTZ for application in spinal fixation devices. Ti64 and TNTZ balls and discs were first prepared as wear-test specimens. A ball-on-disc frictional wear-testing machine was used in air to perform the frictional wear tests of the Ti64 and TNTZ discs mated against Ti64 and TNTZ balls. The wear mechanisms were investigated using a scanning electron microscopy to analyze the worn surfaces and wear debris. The volume losses for the TNTZ discs were larger than those for the Ti64 ones, regardless of the mating ball material. Furthermore, the morphologies of the wear tracks and the debris of the Ti64 and TNTZ discs were different, suggesting that the wear mechanisms for the Ti64 and TNTZ discs were abrasive and delamination wear caused by mild and severe subsurface deformations of the Ti64 and TNTZ, respectively, regardless of the mating ball material.

Wear Properties of Ti-6Al-4V/Ti-29Nb-13Ta-4.6Zr Combination for Spinal Implants

The wear mechanisms of a conventional titanium alloy, Ti–6Al–4V extra-low interstitial (Ti64), and a new titanium alloy, Ti–29Nb–13Ta–4.6Zr alloy (TNTZ) were studied to investigate the wear properties of a Ti64/TNTZ combination for spinal fixation devices. Balls and discs made of Ti64 and TNTZ were prepared to be used as wear-test specimens. Frictional wear tests of Ti64 and TNTZ discs were carried out against Ti64 and TNTZ balls in air using a ball-on-disc frictional wear testing system. The wear mechanisms were investigated by analysis of worn surfaces and wear debris using scanning electron microscopy. Volume losses of the TNTZ discs were found to be larger than those of the Ti64 discs, regardless of mating ball. Furthermore, the morphologies of wear tracks and debris were found to be different between TNTZ and Ti64 discs. It is considered that the wear mechanism for a Ti64 disc is oxidative wear, whereas that for a TNTZ disc is delamination wear, regardless of mating ball material.