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
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Lesions of the intervertebral disc accompanying vertebral fractures are the subject of controversy and discussion regarding the extent and manner of surgical intervention. The question of when to perform disc resection and intervertebral fusion, in particular, has not been answered satisfactorily. In order to evaluate short- and medium-term lesions of the discoligamentous complex associated with thoracolumbar burst fractures, magnetic resonance images made after stabilisation and again after implant removal were compared. ⋯ No disruption of the fibrous ring or of the posterior longitudinal ligament was observed, nor was there any prolapse of intervertebral discs. When the intervertebral disk is intact and has normal morphology and a normal T2-weighted MRI signal, resection or fusion of the fracture adjacent discs appears unjustified. In our opinion, the results do not support the possibility of predicting degradation in those discs that showed an altered T2-weighted signal after the first operation.
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Transient or persistent alterations in the L5 lumbar nerve root have been described as a complication after the reduction of spondylolistheses. In a retrospective analysis of our own patients, we observed a higher incidence of transient motor and sensomotor deficits after single-sitting anatomic correction of May-erding grade IV anterolistheses and spondyloptoses. These findings are consistent with those of other authors. ⋯ Its course was constantly ventral to the L5 nerve root, which was also adherent to the periosteum of the sacrum distal to this constriction in one-fifth of the specimens. The average pressure exerted on the nerve root during the distraction and translation process was over 30 mmHg in the area of this lumbosacral ligamentous connection, at a distance of greater than 20 mm. When the translation distance was further increased, perineural fatty tissue was discharged, due to increasing perineural pressure.
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Comparative Study
Augmentation of mechanical properties in osteoporotic vertebral bones--a biomechanical investigation of vertebroplasty efficacy with different bone cements.
Recent clinical trials have reported favorable early results for transpedicular vertebral cement reinforcement of osteoporotic vertebral insufficiencies. There is, however, a lack of basic data on the application, safety and biomechanical efficacy of materials such as polymethyl-methacrylate (PMMA) and calciumphospate (CaP) cements. The present study analyzed 33 vertebral pairs from five human cadaver spines. ⋯ The lower the initial BMD, the more pronounced was the augmentation effect. Both PMMA and EBC augmentation reliably and significantly raised the stiffness and maximal tolerable force until failure in osteoporotic vertebral bodies. In non-porotic specimens, no significant increase was achieved.
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Instability of the cervical spine following whiplash trauma has been demonstrated in a number of studies. We hypothesized that, in patients with whiplash-associated disorder, rotation of the head would be accompanied by an earlier onset of neck muscle activity to compensate for intrinsic instability. The aim of the study was to examine the range of motion (RoM) of the cervical spine and the onset and activity of the sternocleidomastoid (SCM) muscles during axial rotation, in healthy control subjects and in patients with chronic whiplash-associated disorder. ⋯ The whiplash patient group showed no evidence of the predicted earlier activation of SCM muscles. Many patients never reached the point in the RoM where SCM muscle activity rises steeply, as it does in the healthy controls (the 'elastic zone'), and their movements remained mostly within the region of low muscle activity (the 'neutral zone'). The whiplash patients appeared either unable or unwilling to drive the cervical spine into this region of high muscle activity, possibly because they were restricted by existing pain or fear of pain.