curb the pain of spondylolisthesis; comparing posterolateral fusion with posterior lumbar interbody fusion

background & aim: the purpose of this study was to evaluate and compare the pain of patients with spondylolisthesis who had undergone either of the surgery techniques: posterolateral fusion (plf) or posterior lumbar interbody fusion (plif). methods & materials/patients: in a prospective observational study, 102 surgical candidates with low grade degenerative and isthmic spondylolisthesis were enrolled from 2012 to 2014. the observed patients were into two groups: plf and plif. assessing of pain has been done by a questionnaire using visual analogue scale (vas) scores. the questionnaire was completed by all patients before surgery, the day after surgery, after six months and after one year. results: there were no statistically significant differences in terms of age and sex distribution, type of spondylolisthesis and pre-operation pain between groups (p>0.05). comparison of the mean vas scores of two groups over the whole study period showed a significant statistical difference (p-value<0.05), although comparison of vas at three points in time showed a mixed result. vas scores showed no significant differences between two groups before surgery, the day after surgery and one year after surgery (p>0.05), but the difference of mean vas scores between groups 6 months after surgery was statistically significant (p<0.05). analyzing the course of vas scores over the study period showed a descending pattern for either of the groups (p<0.0001). conclusion: both surgical fusion techniques (plf & plif) showed to be effective in treating low grade degenerative and isthmic spondylolisthesis, but plif was related to better outcome with respect to pain control.