RESUMO
Posterior lumbar interbody fusion [PLIF] is now considered to be the golden standard for lumbar instability caused by spondylolysis or spondylolisthesis. PLIF has many limitations because of the technical difficulties, complications and the gained postoperative increase of the disc height tends to return to preoperative level. The use of poly-ether-ether ketone cage for posterior lumbar interbody fusion is technically less difficult with minimal complications. Twelve patients; ten were female and two male; with spondylolysis and spondylolisthesis of different causes were treated by PEEK interbody cage and interpedicular fixation with or without posterolateral fusion. Age of the patients ranged from 38 to 62 years [mean 50 years]. The patients were followed for a mean 1 year duration and were evaluated both clinically and radiologically. All twelve patients were improved clinically except two patients had partial improvement with occasional and temporary back pain due to causes other than cage complications