Surgical management of low grade isthmic spondylolisthesis; a randomized controlled study of the surgical fixation with and without reduction

Background: spondylolisthesis is a condition in which a vertebra slips out of the proper position onto the bone below it as a result of pars interarticularis defect. The slipped segment produces abnormal positioning of the vertebrae in relation to each other along the spinal column and causes mechanical back pain and neural breach. Materials and methods: A randomized and double blinded study consisted of 41 patients aged 36-69 years (18 females and 28 males) treated for symptomatic spondylolisthesis between December, 2006 and December, 2009. All patients were randomly distributed into two groups I and II. Twenty patients were in Group I; they underwent reduction of the slipped vertebrae by using Reduction-Screw Technique and posterior lumbar interbody fixation (PLIF). Group II consisted of twenty one patients who underwent only surgical fixation (PLIF) without reduction. All patients in this study had same pre and post operative management. Results: only one case had broken rod in group I that required revision. Superficial wound infection was experienced in two patients and one patient, from group II, developed wound hematoma. The outcome in both groups was variable on the short term but was almost the same on the long term follow up. Conclusion: surgical management of symptomatic low grade spondylolisthesis should include neural decompression and surgical fixation. Reduction of slipped vertebral bodies is unnecessary as the ultimate outcome will be likely similar.