Dynamic stabilization for degenerative spondylolisthesis and lumbar spinal instability

Area of Science:

• Spine Surgery
• Orthopedics
• Biomedical Engineering

Background:

• Lumbar interbody fusion is standard for active patients with degenerative spondylolisthesis and instability.
• Rigid fixation in elderly patients with short-term needs is debatable.
• Posterior dynamic stabilization (PDS) is an emerging alternative for specific lumbar disorders in older adults.

Purpose of the Study:

• To evaluate the efficacy and safety of posterior dynamic stabilization in elderly patients with lumbar degenerative spondylolisthesis or instability.
• To assess the potential of PDS to mitigate adjacent segment pathology compared to traditional fusion.

Main Methods:

• Retrospective analysis of 12 elderly patients (mean age 70.9 years) undergoing PDS between March 2011 and March 2013.
• Procedures included D-connector (n=9) and Dynamic connector (n=8) systems allowing controlled rod movement.
• Patients had lumbar degenerative spondylolisthesis (% slip < 20%) or instability with disc herniation.

Main Results:

• Mean follow-up was 77-479 days with a mean Japanese Orthopedic Association (JOA) score recovery of 65.6%.
• One case of slippage progression occurred but without symptom exacerbation.
• No symptomatic adjacent vertebral or disc disorders were observed during the follow-up period.

Conclusions:

• Posterior dynamic stabilization may be a useful procedure for elderly patients, facilitating decompression and stabilization.
• PDS may potentially reduce the incidence of adjacent vertebral or disc disorders often associated with lumbar interbody fusion.
• Further long-term studies are needed to confirm the benefits of PDS in this patient population.