A Prospective Long-term Follow-up Study of the Posterior Dynamic Stabilizing System to Treat Back Pain Associated With Degenerative Disc Disease

STUDY DESIGN: Prospective cohort study. OBJECTIVE: To evaluate the long-term effectiveness of a posterior dynamic spine stabilization (PDS) System called PercuDyn system as a treatment for low back pain (LBP) in patients with degenerative disc disease who have failed conservative treatment. METHODS: Thirty-five patients (21 males, 14 females, mean age 36 years) with chronic LBP due to degenerative disc disease underwent percutaneous facet augmentation with the PercuDyn system. Indications for implanting the PercuDyn device were chronic LBP without sciatica, significant disc degeneration, and who failed conservative treatment. Follow-up after surgery ranged from 4 to 8 years. Patients were clinically evaluated using visual analogue scale (VAS), Oswestry Disability Index (ODI) questionnaire, and the EQ-5D3L. RESULTS: The VAS scale and ODI scores improved at 6 months, 1 year, 2 years, and 4 to 8 years in comparison with the baseline values (P < .001 and P < .01, respectively). Equally, data from the EQ-5D-3L questionnaire suggested improvements in all domains, including pain and discomfort, over the follow-up period. However, during follow-up, 16 patients (46%) have had unsatisfactory outcome including failure of implant to resolve symptoms (n = 8), developed symptomatic disc protrusion (n = 4), and loosening of the screws (n = 4). CONCLUSION: Our clinical experience highlights the rather high overall failure rate of this system. Although, some patients show significant improvement in their symptoms, we believe that patients with LBP related to degenerative disc disease are a poor indication for this PDS device.However, large scale studies, with optimised selection criteria are needed to demonstrate the exact role of this device in spinal patients.