STUDY DESIGN: A retrospective study OBJECTIVES: To demonstrate the early experience of operative treatment about adjacent segments degeneration after lumbar fusion. SUMMARY OF LITERATURE REVIEW: The treatment of degenerative changes at adjacent segment after lumbar spinal fusion have not been well described in literature. MATERIALS AND METHODS: A retrospective reviews of radiographs, medical records and follow up study were undertaken in eight patients who had been treated surgically due to degenerative changes at adjacent segment after lumbar fusion. Average follow up duration was 25 months. Causes of secondary operation were 3 cases of segmental instability, 2 cases of degenerative spondylolisthesis, 2 cases of degenerative spinal stenosis, 2 cases of cauda equina syndrome, 1 case of disc degeneration. Clinical results were evaluated by using of author's criteria. For the radiographic evaluation, plain roentgenogram(AP, Lat. flextion/extension Lat.), CT, MRI were checked. RESULTS: The mean time interval to secondary operation from first operation was seven years nine months. At the preoperative CT or MRI film review, there were initial adjacent segment degenerative changes in half of the cases preoperatively. The level developing degenerative changes were upper segment in 5 cases, lower segment in 2 cases and both segment in 1 case. Most common segment was L3,4 in 5 cases. The second operations were mainly PLIF in 7 cases and PL fusion in 1 case. All cases showed solid fusion. Clinical results were excellent in 3 cases, good in 4 cases, fair in 1 case and poor in no case. CONCLUSION: The early clinical and radiographic results of surgical treatment was satisfactory. If the degenerative changes of adjacent segments are detected preoperatively, there are some needs to consider the extension of surgery according to the severity of the lesions. We think that the results of secondary operation was better in case of PLIF than posterolateral fusion because PLIF provided more rigid stability which enabled early walking stability and better corrective power. But long term results of that should be followed up.