European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society
-
Laminectomy is a standard surgical procedure for elderly patients with symptomatic degenerative lumbar stenosis. The procedure aims at decompression of the affected nerves, but it also causes a reduction of spinal shear strength and shear stiffness. The magnitude of this reduction and the influence of bone mineral density (BMD) and disc degeneration are unknown. We studied the influence of laminectomy, BMD, and disc degeneration on shear force to failure (SFF) and shear stiffness (SS). ⋯ In conclusion, low BMD significantly decreased SFF before and after lumbar laminectomy. Therefore, DXA assessment may be an important asset to preoperative screening. Lumbar disc degeneration did not affect shear properties of lumbar segments before or after laminectomy.
-
Comparative Study
Cervical disc prosthesis versus arthrodesis using one-level, hybrid and two-level constructs: an in vitro investigation.
The purpose of this experimental study was to analyse cervical spine kinematics after 1-level and 2-level total disc replacement (TDR) and compare them with those after anterior cervical arthrodesis (ACA) and hybrid construct. Kinematics and intradiscal pressures were also investigated at adjacent levels. ⋯ Although 1- and 2-level TDR restored only partially native kinematics of the cervical spine, these constructs generated better biomechanical conditions than arthrodesis at adjacent levels limiting contribution of these segments to global ROM and reducing the amount of their internal stresses.
-
In 1959, Harmon was the first to implant a vitallium sphere into the intervertebral disc space in order to preserve mobility and maintain disc height in patients with back pain secondary to degenerative disc disease. Fernstrom reported good results after implantation of stainless steel spheres. However, a reduction in disc height frequently occurred secondary to sphere subsidence into the endplates. This often led to revision surgery, and the concept was abandoned. ⋯ To the best of our knowledge, this is the first report describing the complications resulting from cobalt chrome sphere implantation and revision strategies for managing the recently resurrected cobalt chrome sphere.
-
A finite element model of the L4-L5 human segment was employed to carry out a parametric biomechanical investigation of lumbar interbody fusion with a novel "sandwich" cage having an inner stiff core and two softer layers in the areas close to the endplates, with and without posterior fixation. ⋯ The soft layers of the "sandwich" cage had the potential to limit the risk of cage subsidence and to preserve a significant loading of the structure even in combination with flexible posterior instrumentation, which may have a beneficial effect in promoting bony fusion.
-
Nowadays, endoscopic techniques are widely used in surgical procedures. Retroperitoneoscopy has been an extremely valuable tool for a wide variety of urologic disorders, whereas, it has limited use in orthopedic procedures. ⋯ Retroperitoneoscopic drainage of psoas abscesses gains advantages in terms of rapid recovery, minimal invasiveness, absence of radiation, and shorter hospital stay. This procedure can be used not only for cold abscesses but also for other pathologies of lumbar vertebral area.