Clinical outcomes of the Dynesys dynamic neutralization system: 1-year preliminary results

Abstract

<jats:sec> <jats:title>Object</jats:title> <jats:p>In this study the authors present the preliminary clinical outcomes of dynamic stabilization with the Dynesys spinal system as part of a multicenter randomized prospective Food and Drug Administration (FDA) investigational device exemption (IDE) clinical trial.</jats:p></jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>This study included 101 patients from six IDE sites (no participants were omitted from the analysis) who underwent dynamic stabilization of the lumbar spine with the Dynesys construct. Patient participation was based on the presence of degenerative spondylolisthesis or retrolisthesis (Grade I), lateral or central spinal stenosis, and their physician's determination that the patient required decompression and instrumented fusion for one or two contiguous spinal levels between L-1 and S-1. Participants were evaluated preoperatively, postoperatively at 3 weeks, and then at 3-, 6-, and 12-month intervals. The 100-mm visual analog scale was used to score both lower-limb and back pain. Patient functioning was evaluated using the Oswestry Disability Index (ODI), and the participants' general health was assessed using the Short Form-12 questionnaire. Overall patient satisfaction was also reported.</jats:p> <jats:p>One hundred one patients (53 women and 48 men) with a mean age of 56.3 years (range 27–79 years) were included. The mean pain and function scores improved significantly from the baseline to 12-month follow-up evaluation, as follows: leg pain improved from 80.3 to 25.5, back pain from 54 to 29.4, and ODI score from 55.6 to 26.3%.</jats:p></jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>The early clinical outcomes of treatment with Dynesys are promising, with lessening of pain and disability found at follow-up review. Dynesys may be preferable to fusion for surgical treatment of degenerative spondylolisthesis and stenosis because it decreases back and leg pain while avoiding the relatively greater tissue destruction and the morbidity of donor site problems encountered in fusion. However, long-term follow-up care is still recommended.</jats:p></jats:sec>

Mid‐term evaluation of the effects of dynamic neutralization system on lumbar intervertebral discs using quantitative molecular MR imaging

“…These results are in agreement with Welch et al (32), that reported the same level of improvements in a larger population (101 patients) but after only 1-year follow-up of the Dynesys system, with Stoll et al (33), where a consecutive series of 83 patients was studied for different follow-up times (range, 11.2-79.1 months), and with the recently published work of Cienciala et al (34) where 102 patients were followed for a 3-year period.…”

The effect of design parameters of dynamic pedicle screw systems on kinematics and load bearing: an in vitro study

“…Clinical data for posterior pedicle screw-based dynamic stabilization show mixed outcomes ranging from comparable to fusion [10,11,[13][14][15]42] to worse than fusion [16,17], which could be attributed to the different clinical indications. Obviously, the latter (e.g., disc degeneration, spinal stenosis with or without degenerative spondylolisthesis, etc.)…”

“…In clinical use since 1994 [9], Dynesys has shown mixed results, strongly dependent on the clinical indication [10][11][12][13][14][15]. Apparently, a complication attributed to its inadequate stabilization in the transversal plane may be the disability to eliminate radicular pain [16,17].…”

Posterior dynamic stabilization of the lumbar spine with the Accuflex rod system as a stand-alone device: experience in 20 patients with 2-year follow-up

“…Welch et al [25] in a multicentric study reported 101 patients with lumbar spinal stenosis and degenerative spondylolisthesis with a 12-month follow-up. Fifteen of 101 patients required 18 reinterventions at the time of the 1-year follow-up evaluation, from these, 11% underwent 13 procedures related to the spine or the index surgery.…”