Analysis of Spinal Kinematics Following Implantation of Lumbar Spine Disc Prostheses versus Fusion: Radiological Study

Study design: Th is is a prospective controlled study comparing lumbar spine disc replacement versus fusion for monosegmental degenerative disc disease (DDD). Sum- mary of Background Data and Objective: Fusion has been reported to be the standard therapy by DDD of the lumbar spine. Due to unsatisfactory long-term results of fusion by progressive adjacent level degeneration, disc replacement was developed and thought to reduce pain while restoring disc height and motion at the aff ected level. Th e expected long- term advantage of disc replacement over fusion is the preservation of motion. Th is again is very diffi cult to judge; therefore the aim of the current study was to analyze segmental mo- tion following disc replacement versus fusion. Methods: Patients meeting inclusion criteria were consented for the study. Th is analysis includes data up to 12 months from the fi rst included patients. Th ere were 13 patients who underwent disc replacement, and 11 patients had fusion procedures. Radiostereometric analysis was done 1 and 6 weeks and 3, 6, and 12 months after surgery. Results: Th e mobility provocation RSA showed a signifi cant seg- mental motion in the disc replacement group in comparison to fusion. Conclusions: Disc replacement using Active L prostheses preserves segmental motion during the period ex- amination time of 12 months.