RESUMO
<p><b>OBJECTIVE</b>To evaluate the effectiveness of unilateral versus bilateral pedicle screw fixation in lumbar spinal fusion.</p><p><b>METHODS</b>Studies on comparison between unilateral and bilateral pedicle screw fixation in lumbar spinal fusion were identified from Medline, EMBASE, Cochrane CENTRAL (Third Quarter 2011), ScienceDirect, OVID, SpringerLink and The China Biological Medicine Database, and searched several related journals by hand. The included trials were screened out according to the criterion of inclusion and exclusion. The quality of included trials was evaluated. Data were extracted by two reviewers independently. RevMan 5.1.1 was used for data analysis.</p><p><b>RESULTS</b>Seven studies involving 480 patients were included, 246 in unilateral group, and 234 in bilateral group. The results of meta-analysis indicated that statistically significant difference were observed between the two fixation procedures in mean operation time (MD = -24.39, 95%CI: -33.16 to 15.61, P < 0.01), the amount of bleeding (MD = -118.73, 95%CI: -143.43 to -94.03, P < 0.01). There were no difference in inpatient stay, fusion rate, complication rate and excellent and good rate.</p><p><b>CONCLUSIONS</b>Both unilateral and bilateral pedicle screw fixation are effective in lumbar spinal fusion. To compare with bilateral fixation, unilateral fixation can shorten operation time, reduce amount of bleeding and medical expenses. And there is a similar effect of inpatient stay, fusion rate, complication rate and excellent and good rate.</p>