Clinical and radiologic study evaluating the outcome after nucleotomy with dynamic stabilization compared with nucleotomy alone. To investigate the effect of dynamic stabilization on the progression of segmental degeneration after nucleotomy. Nucleotomy as treatment for lumbar disc prolapse in combination with initial segment degeneration may lead to segmental instability. Dynamic stabilization systems restrict segmental motion and thus prevent further degeneration of the lumbar spine. They are designed to avoid the disadvantages of rigid fixation, such as pseudarthrosis and adjacent segment degeneration. Eighty-four patients underwent nucleotomy of the lumbar spine for the treatment of symptomatic disc prolapse. Additional dynamic stabilization (DYNESYS) was performed in 35 of those cases. All patients showed signs of initial disc degeneration (MODIC I). They underwent evaluation before surgery, 3 months after surgery, and at follow-up. The mean duration of follow-up was 34 months. Examinations included radiographs, magnetic resonance imaging (MRI), physical examination, and subjective patient evaluation using Oswestry score and visual analog scale (VAS). Clinical symptoms, Oswestry score, and VAS improved significantly in both groups after 3 months. At follow-up, a significant increase in the Oswestry score and in the VAS was seen only in the nonstabilized group. In the dynamically stabilized group, no progression of disc degeneration was noted at follow-up, whereas radiologic signs of accelerated segmental degeneration existed in the solely nucleotomized group. There were no implant-associated complications. The applied dynamic stabilization system is useful to prevent progression of initial degenerative disc disease of lumbar spinal segments after nucleotomy.
The current gold standard in lumbar fusion consists of transpedicular fixation in combination with an interbody interponate of autologous bone from iliac crest. Because of the limited availability of autologous bone as well as the still relevant donor site morbidity after iliac crest grafting the need exists for alternative grafts with a comparable outcome. Forty patients with degenerative spinal disease were treated with a monosegmental spondylodesis (ventrally, 1 PEEK-cage; dorsally, a screw and rod system), and randomly placed in two groups. In group 1, autogenous iliac crest cancellous bone was used as a cage filling. In group 2 the cages were filled with an allogenic cancellous bone graft. Following 3, 6, 9 and 12 months, the clinical outcome was determined on the basis of: the Oswestry Low Back Pain Disability Questionnaire; patient satisfaction; patient willingness to undergo the operation again; and a visual analog scale for pain. The radiological outcome was based on both fusion rate (radiographs, computed tomography), and on the bone mineral density of the grafts. After 6 months, the X-rays of the patients in group 2 had a significantly lower rate of fusion. Aside from this, there were no further significant differences. After 12 months, radiological results showed a similar fusion rate in both groups. Donor site complications consisted of five patients with hematoma, and three patients with persistent pain in group 1. No implant complications were observed. If a bone bank is available for support and accepting the low risk of possible transmission of infectious diseases, freeze–dried allogenic cancellous bone can be used for monosegmental spondylodeses. The results demonstrated an equivalent clinical outcome, as well as similar fusion rates following a 12-month period. This is in despite of a delayed consolidation process.