Dynamic Stabilization for Degenerative Spondylolisthesis and Lumbar Spinal Instability

Abstract

Lumbar interbody fusion is a widely accepted surgical procedure for patients with lumbar degenerative spondylolisthesis and lumbar spinal instability in the active age group. However, in elderly patients, it is often questionable whether it is truly necessary to construct rigid fixation for a short period of time. In recent years, we have been occasionally performing posterior dynamic stabilization in elderly patients with such lumbar disorders. Posterior dynamic stabilization was performed in 12 patients (6 women, 70.9 ± 5.6 years old at the time of operation) with lumbar degenerative spondylolisthesis in whom % slip was less than 20% or instability associated with lumbar disc herniation between March 2011 and March 2013. Movement occurs through the connector linked to the pedicle screw. In practice, 9 pairs of D connector system where the rod moves in the perpendicular direction alone and 8 pairs of Dynamic connector system where the connector linked to the pedicle screw rotates in the sagittal direction were installed. The observation period was 77–479 days, and the mean recovery rate of lumbar Japanese Orthopedic Association (JOA) score was 65.6 ± 20.8%. There was progression of slippage due to slight loosening in a case with lumbar degenerative spondylolisthesis, but this did not lead to exacerbation of the symptoms. Although follow-up was short, there were no symptomatic adjacent vertebral and disc disorders during this period. Posterior dynamic stabilization may diminish the development of adjacent vertebral or disc disorders due to lumbar interbody fusion, especially in elderly patients, and it may be a useful procedure that facilitates decompression and ensures a certain degree of spinal stabilization.

Dynamization–Posterior Lumbar Interbody Fusion for Hemodialysis-Related Spondyloarthropathy: Evaluation of the Radiographic Outcomes and Reoperation Rate within 2 Years Postoperatively

“…Moreover, dynamic stabilization showed favorable outcomes in older patients with degenerative spondylolisthesis, with better fusion rates in fusion surgery using the dynamic stabilization system than in conventional fusion systems [27]. This finding supported our own system.…”

Short and Medium Term Results of Posterior Segmental Instrumentation and Posterolateral Fusion in Female Patients with Spondylolisthesis: A Clinical Trial

“…However, it was reported that pseudarthrosis may develop in 5-25% of patients who underwent PLF and 50% of patients with pseudarthrosis may be asymptomatic (23). Moreover, it was reported that short-term results of dynamic systems which have been started to be used in degenerative spondylolisthesis in recent times were successful and similar to the results of fixation and PLF (24,25). We think that short-term results of studies related to dynamic system may explain that patients develop pseudarthrosis but are asymptomatic patients.This is because dynamic fixation systems allow partial movement in the sagittal plane although they do not create instability as in the preoperative period.…”

Preliminary Results on Radiological Hypermobility at Upper Adjacent Disc Level in Posterior Lumbar Interbody Fusion Compared to Advanced Dynamic Stabilization

“…As a concept of ADS, the share of increased load at UAD level is expected. 9) We therefore tolerate long-term final fusion at the dynamically stabilized level, but patients more than 50 years who undergo ADS will receive benefits from delayed ASD compared to those who undergo PLIF.…”

“…In 2014, we reported the short- to mid-term clinical and radiological outcomes about our previous dynamic stabilization. 9) In that report, as a concept of dynamization, two types of dynamization were introduced as dynamic stabilization mechanisms for different types of pathophysiology. One is dynamic stabilization that allows perpendicular movement for lumbar degenerative spondylolisthesis, and the other is that allowing sagittal movement for lumbar disc herniation in which postoperative instability is a concern because of an apparent vacuum phenomenon.…”