Introduction: The results of the FDA trial for Dynesys stabilisation implied that the procedure was effective as a method of treatment for this condition. However, all the American cases had adjunct decompressive treatment. In this study we report the outcome of the first two years following DYNESYS for Spondylolisthesis in two groups of patients; Dynesys alone and Dynesys with fusion.

Method: Fifty five patients had Dynesys for symptomatic Spondylolisthesis which was indicated for surgical treatment. Average age for group 1 was 51 years with range of 36–85 years whereas in group 2, average age was 59 years with range of 31–79 years. Patients were evaluated preoperatively using ODI, SF36, VAS, plain x-ray, MRI scanning & discography. 33 of the patients underwent Dynesys alone (group 1) while 22 underwent dynesys with fusion (group 2). Previous decompression surgery was noted in 10 in group 1 and 8 in group 2.

Results: In the first year following Dynesys, both groups did show significant improvement in all the four parameters; VAS (back and leg), ODI and SF36. In group 2 slight deterioration was noted in year 2 and while group 1 continued to improve, Subsequently 3 group 1 patients underwent fusion and 12 required removal/revision of Dynesys (40%).

Discussion & Conclusions: Dynesys alone in the treatment of spondylolysthesis resulted in a 45% re-operation rate, and we believe it should not be recommended as an indication.

Introduction: We report the outcome two years following Dynesys for the treatment of Spinal Canal Stenosis. In both the FDA trial and the European multicentre study, stenosis was invariably combined with decompression, invalidating conclusions on the results of Dynesys alone.

Method: Eighteen patients had symptomatic Spinal Canal Stenosis with root claudication sufficient to justify surgical intervention. Average age of patients was 68 with a range between 44–86 years. Dynesys was applied for the treatment of a single level in 4, two levels in 8, and more than two levels in 6.

Patients were evaluated preoperatively using ODI, SF36, VAS, plain x-ray, MRI scanning & discography. Questionnaires were evaluated at the first and second years.

Results: 2 patients had undergone previous spinal decompression, and decompression at the time of Dynesys surgery in 7. In the remaining 9 cases, no decompression was used, relying on distraction alone as in the X stop system. In this latter group, stenotic symptoms failed to resolve. Removal of Dynesys was indicated in 3 (16.6%).

Discussion & Conclusions: Dynesys alone is not recommended as a treatment for symptomatic spinal stenosis. A separate study is required to address the question of whether Dynesys adjunct improves the back pain outcome compared with decompression alone.