Surgical treatment in spinal stenosis is aimed at decompressing completely the nervous structures in the areas in which they are compressed. However complete decompression sometimes carries a risk of spinal instability and to prevent these problems posterolateral fusion is usually recommended. But fusion without internal fixation devices often results in pseudarthrosis that in recent years many authors recommend various internal fixation devices including pedicle screws. From March 1989 to December 1989 16 cases of degenerative spinal stenosis were managed by C-D or MOSS instrumentation and followed for at least 12 months at Department of Orthopedic Surgery, Chun Cheon Sacred Heart Hospital. The followings are the results we obtained. 1. By the criteria of "Success rate" Grading Scale (Steffee, 1986). 7 cases were excellent and the other 7 cases were good. Remaining 2 cases were fair. 2. Internal fixation by means of C-D or MOSS instrumentation allowed early ambulation. 3. Restoration of lumbar lordotic curve in sagittal curvature could be obtained by bending the rod.