Introduction: Forward slip of the above vertebra may compromise the exit foramen and produce nerve root signs. Conservative management should be attempted first. However in 10–15% surgical procedures are required to control symptoms of backpain and radiculopathy.

In this cohort study, we compare the functional outcome of Dynesys in patients with degenerative spondylolisthesis categorised in three subgroups.

Material & Methods: Seventy eight patients with degenerative spondylolisthesis were treated with Dynesys. Patients were sub-grouped into Dynesys alone (group 1 n=31), Adjunct fusion (group 2 n=34) and Adjunct decompression (group 3 n=13). Three main outcome parameters were reviewed; ODI, VAS and the need for further surgeries. Patients follow up was arranged at 2 weeks, 3 months, 6 months, 12 months then annually.

Results: Average follow up was 53 months, 47 months & 55 months in groups 1, 2 & 3 respectively.

Patients with Dynesys alone had initial good improvement in ODI & VAS but this was not maintained. Secondary surgery was needed in 32% at 28.2 months.

Dynesys with adjunct PLIF showed clinically & statistically maintained ODI & VAS outcome. Secondary surgery rate was 11.7% at 26 months.

Dynesys with adjunct decompression group was favoured by clinically & statistically improved functional outcome. Second surgery was necessary in 7.6%.

Discussion: Dynesys stands as an innovative device for the treatment of backpain. However, its clinical indications were not refined. Patients with degenerative spondylolisthesis require decompression with instrumented stabilisation.

Conclusion: Dynesys alone is not recommended for degenerative spondylolisthesis.

Conflicts of Interest: None

Source of Funding: Zimmer Spine sponsored research fellowship at the Conquest hospital between 2005–2007. The funds were paid direct to the hospital for follow up and maintenance of Dynesys database. No researcher received direct fund by the company.