Dynesys versus Dynamic Hybrid System in the treatment of Multi-Segmental Lumbar Degenerative Disease: a retrospective study

Abstract

Abstract Background Of all the spinal diseases, lumbar degenerative disease (LDD) is a common and frequently-occurring disease and often develops into multi-segmental LDD over time. When multi-segment LDD occurs in middle-aged people who love sports, dynamic internal fixation, which can preserve the range of motion (ROM) and prevent adjacent segment degeneration (ASD), is more suitable for such people than interbody fusion. Nowadays, researchers have mainly focused on comparing the effectiveness of hybrid fixation versus rigid fusion, or Dynesys fixation versus rigid fusion, whereas Dynesys fixation and hybrid fixation have not been adequately compared in multi-segmental LDD in terms of clinical and radiographic evaluations. Methods We included 35 patients with multi-segmental LDD from January 2015 to August 2019, divided into Dynesys (only used Dynesys system, n = 22) and Hybrid (used Dynesys system and an intervertebral cage, n = 13) groups. Clinical outcomes were evaluated using perioperative data, Oswestry Disability Index (ODI), and Visual Analogue Scale (VAS). Radiologic evaluations included lumbar spine X-ray, MRI, and CT. Furthermore, different complications were analyzed. Results At the last follow-up, ODI and VAS of each group were significantly improved (p < 0.05), and the ROM of operating segments decreased. However, Dynesys group preserved a larger extent of ROM than that of Hybrid group at the final follow-up (p < 0.05). ROM of the upper adjacent segment was increased in both groups (p < 0.05), while the disc heights were significantly decreased at the final follow-up than those one-week post-surgery (p < 0.05). Besides, Dynesys group had a more obvious decrease in the disc height of dynamic segments than Hybrid group (p < 0.05). No significant difference existed in complications between both groups (p > 0. 05). Conclusion Dynesys and hybrid fixations can preserve ROM of stabilized segments. Dynesys fixation can preserve a larger extent of ROM than that of Hybrid fixation. However, hybrid fixation can better preserve the disc height of the non-fusion level. Overall, both surgical procedures can be employed as effective treatments for middle-aged and physically active patients with multi-segmental LDD.