Instrumented Posterior Lumbar intervertebral bone cement Interposition: indications and results

Background data: The presence of osteoporosis renders the PLIF not ideal for the treatment of lumbar instability and lumbar canal stenosis. Decortication of the bony end plates weakens the weight bearing functions of the vertebrae. Avoiding decortications of the bony end plates and using bone cement to fill the intervertebral space would theoretically overcome these mechanical disadvantages. Purpose of our study was to evaluate the results of instrumented intervertebral bone cement interposition in osteoporotic patients presented with lumbar instability and/or lumbar canal stenosis. Study Design: Prospective study. Material and Methods: 30 consecutive patients with a mean age of 70.3 years were operated upon using this technique. The study included 39 lumbar segments. Selective posterior decompression was done according to the extent and severity of the stenosis. The disc was removed together with the cartilaginous end plates without traumatizing the bony end plates. The disc space was filled with bone cement. The construct was augmented with transpedicular screw rod fixation of the affected segment(s). The mean follow up period was 32.07 months. The Visual Analogue Scale (VAS) for back and leg pain together with Oxford Claudication Score (OCS) were used to assess the patients pre- and post-operatively. Results: No neurological complications were encountered. The mean operative time was 84.67 minutes and the mean blood loss was 390 ml. The VAS for back and leg pain improved from 7.1 and 3 preoperatively to 1.6 and 0.4 at the end of follow up respectively. OCS also improved from (30.3) preoperatively to (15.8) at the end of follow up. Conclusion: Bone cement interposition after discectomy when combined with transpedicular fixation is a reasonable treatment option for elderly patients suffering from lumbar instability and/or stenosis. (2014ESJ072