ABSTRACT
The ideal surgical treatment of spondylolisthesis is PLIF. Tricortical autologous bone graft is associated with several complications so interbody cage has been developed to replace the tricortical interbody graft in PLIF procedure. The aim of this study is to evaluate the outcomes of instrumented posterior lumbar interbody fusion [PLIF] in surgical treatment of lytic spondylolisthesis using autologous tricortical iliac bone graft in comparison with cage. A prospective study. This study included 48 patients with low grade lytic lumbar spondylolisthesis [grade I and II] treated by pedicular fixation and posterior lumbar interbody fusion [PLIF]. They were divided into 2 groups: Iliac graft group [26 patients] was treated by PLIF using tricortical iliac bone graft and the cage group [22 patients] treated by PLIF using cages. Through the lateral radiograph, the percentage of slippage, disc height and foramen height were assessed preoperatively, immediate postoperatively, and at latest follow up. The fusion was assessed according to Brantigan criteria. Visual Analogue Scale [VAS] was used to assess back and radicular pain preoperatively and at latest follow up. Finally, function ability of all patients was assessed according to Oswestery Disability index [ODI] score. The average slip percentage of spondylolisthesis of both iliac graft and cage groups improved from 25% and 20.5% preoperatively to 5% and 4.3% immediate postoperatively, and 6.2% and 5.5% at latest follow up in this order. The average disc height of both groups improved from 7.4mm and 7.5 mm preoperatively to 11.4 mm and 11.4 mm immediate postoperatively, and 10.7 and 11.1 mm at latest follow up in this order. The average foramen height improved from 14.1 mm and 14.2 mm preoperatively to 18.2 mm and 18.1 mm immediate postoperatively, and 17.5 mm and 17.8 mm at latest follow up in this order. Certain fusion was achieved in 24 patients [92.3%] in iliac graft group and 21 [95.4%] in cage group. The Visual Analogue Scale [VAS] of back and radicular pain and ODi improved significantly from before surgery to latest follow up in both groups. Both groups showed significant good radiological and clinical final outcomes with no significant difference between the two groups