Clinical Efficacy of Bone Cement Augmented Screw Fixation for the Severe Osteoporotic Spine

OBJECTIVE Transpedicular instrumentation of the osteoporotic spine is a challenge for the spine surgeon due to the probability of screw loosening and the potential possibility of nonunion. The purpose of this study was to evaluate the clinical efficacy of bone cement augmented screw fixation in patients with severe osteoporosis. METHODS Between February 2004 and August 2007, 250 patients with severe osteoporosis (T-score on BMD < -3.0) that had screw fixation were included in this study. The patients were divided into two groups (Group I: 157 patients that underwent bone cement augmented screw fixation that had a variety of spine spinal diseases including fractures, and Group II: 93 patients with severe osteoporosis that had screw fixation without bone cement augmentation). The imaging and clinical features were analyzed, including bone cement augmented levels, fusion rate and related complications. The visual analog scale (VAS), Oswestry disability questionnaire (ODI) and modified MacNab's criteria were used for the assessment of pain and functional capacity. RESULTS In both groups, a significant improvement in the VAS and ODI was achieved. 146 out of 157 patients (93%) in Group I and 83 out of 93 patients (90%) in Group II were graded as an excellent or good result according to the modified MacNab's criteria. None of the patients experienced serious complications. However, there were two cases with neurological deterioration as a result of bone cement extravasation in Group I. For Group II, there were five cases of screw loosening that required re-operation for bone cement augmentation. CONCLUSION Whether bone cement augmentation was performed or not, it was possible to achieve satisfactory results in patients with severe osteoporosis. However, if used carefully, bone cement augmented transpedicular screwing can reduce screw loosening and pullout in patients with severe osteoporosis.