Abstract
Introduction: In this study we have studied the range of motion within Dynesys treated discs and levels adjacent to flexible stabilisation.
Dynesys was designed to offer physiological motion at the lumbar spine. An advantage which is superior to abolishing movements through spinal fusion.
Methods: A cohort of 75 post-Dynesys patients had weight-bearing lateral lumbar spine x rays in flexion/extension positions. Evaluation was done through PACS™ digital software. Flexibility at individual disc level was measured as the differences between flexion/extension angles accurate to within 1°. Motion was evaluated at the index and immediate adjacent levels.
Results: Patients with single level Dynesys had an average ROM of (3+/−4.7) at L5-S1 and (5.1+/−2.9) at the immediate adjacent level. Two levels Dynesys was associated with a ROM of 5+/−3.6 at L5-S1 & L4–5 and 3.5+/−1.8 at their immediate neighbour disc. Across three levels, Dynesys favoured a ROM of 5.3+/−2.5 at the operated sites and 1.6+/− 2 at the adjacent level.
Discussion & Conclusion: This study is the first radiological research to confirm the flexibility of Dynesys. Controlled motion at the dynesys treated disc levels share to distribute global spinal movements. This will advantage the next disc segments and protects them from risk of developing “accelerated adjacent segment disease”.
Correspondence should be addressed to BASS/BCSS c/o BOA, at the Royal College of Surgeons, 35–43 Lincoln’s Inn Fields, London, WC2A 3PE, England.
