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

Abstract

Decompression surgery for lumbar spinal stenosis is a common procedure. After surgery, segmental instability sometimes occurs, therefore, different methods for restabilization have been developed. Dynamic stabilization systems have been designed to improve segmental stability. In this study, clinical results of patients with lumbar spinal stenosis that underwent decompression and stabilization with the Accuflex dynamic system are presented; clinical, radiographic, and magnetic resonance imaging (MRI) findings are fully described. Improvements in all clinical measurements, including visual analog scale for back and leg pain, Oswestry disability index, and SF-36 health status survey were noticed. At a 2-year follow-up, 22.22% of patients required hardware removal due to fatigue while in 83% of them no progression of disk degeneration was observed after implantation of the Accuflex system. Additionally, as demonstrated by the MRI images at follow up, three patients (16%) showed disk rehydration with one grade higher on the Pfirmann classification. Although a relatively high hardware failure was observed (22.22%), the use of the dynamic stabilization system Accuflex posterior to decompression procedures, showed clinical benefits and stopped the degenerative process in 83% the patients.

Complications associated with the Dynesys dynamic stabilization system: a comprehensive review of the literature

“…34,40,41,51,59 Recently, a nonfusion stabilization system with motion preservation (Dynesys system, Zimmer Spine) has been explored as an alternative to fusion in an effort to reduce adjacentsegment disease (ASD) and maintain greater physiological movement and function. 31,32,47,61 Dynesys is a pedicle screw-based dynamic stabilization system that has been used since 1994 and consists of pedicle screws, flexible spacers, and cords.…”

Effect of posterior dynamic instrumentation on high-intensity zones in lumbar degenerative disc disease

“…In their prospective study using various dynamic stabilization systems in the treatment of degenerative discopathy and instability of the lumbar spine, Zagra et al showed a change in Pfirrmann grade from 4 to 3 in 8 of 32 patients at an average of 12 months of follow-up (27). Similarly, in their study, Reyes-Sánchez et al reported research on 20 patients who underwent posterior dynamic stabilization of the lumbar spine and were monitored for 2 years (22). Three of those patients had a change in Pfirrmann grade from 3 to 2.…”

“…An HIZ was present in 27 of 31 levels (87.09%) in the control group, and the HIZs did not disappear during the follow-up period. Disc rehydration and improvements in Pfirrmann grades may be a feature of dynamic stabilization systems, as explained by Schnake et al and Reyes-Sánchez et al (22,24).…”

“…Reyes-Sánchez et al in their prospective study, reported clinical and radiological data for patients treated with microsurgical decompression and stabilization with the AccuFlex dynamic rod device (22). A total of 20 consecutive patients at 2 years of follow-up had a mean VAS score for back pain that improved from 7.9 to 2.8 and a mean ODI value that improved from 55% before surgery to 24% at final evaluation.…”

A Short History of Posterior Dynamic Stabilization

“…This system received FDA clearance for single level dynamic fusion. In a study conducted by Reyes-Sánchez et al, 20 consecutive patients underwent dynamic stabilization surgery with the Accuflex rod system to treat lumbar spinal stenosis and dysfunctional segment motion [35]; the clinical, radiographic, and magnetic resonance imaging (MRI) findings were fully described. During a 2-year followup period, 22.22% of the patients required device removal due to fatigue, while there was no progression of disk degeneration observed after implantation of the Accuflex system in 83% of the patients.…”