OBJECTIVETo study the causes of failure in the treatment of lumbar spondylolisthesis, and revision techniques and therapeutic effects.

METHODSEight cases with failed spondylolisthesis surgery were treated. There were 3 male and 5 female with an average age of 54 years old,ranging from 42 to 71 years. Among them, there were 6 cases of pedicle screws breakage, 1 case of fusion cage sinking and pedicle screws breakage, 1 case of osteoporosis and pedicle screws loosening. Their clinical symptoms included deformity, local pain, leg pain and numbness. The revision surgery was performed by the posterior decompression, instrumentation,intervertebral and posterolateral bone grafting, in which large diameter or long screws were applied for pedicle screws fixation.

RESULTSAll cases were followed-up from 6 to 24 months after revision(mean, 16 months). The clinical result was satisfied and the excellent or good results were 87.5%. There was no infection and other major complications. All patients had achieved solid fusion.

CONCLUSIONPoor technique and skill are considered as the primary causes leading to surgical failure of lumbar spondylolisthesis. The satisfactory outcome could be obtained by appropriately using the revision techniques.