INTRODUCTION: The adequate extent of preoperative degenerative disc disease (DDD) for total lumbar disc replacement (TDR) remains controversially debated. The numbers of previously published studies are scarce and the limited data available reveal contradictory results.
METHODS: Preoperative DDD was determined by histological, X‐Ray and MRI evaluation. Nucleus pulposus (NP) and annulus fibrosus (AF) changes were evaluated according to a quantitative histological degeneration score (HDS). X‐Ray evaluation included assessment of the disc space height (DSH). MRI investigation of DDD was performed on a 5‐scale grading system. Clinical outcome assessment included the satisfaction rates, VAS and ODI scores.
RESULTS: Data from 51 patients with an average FU of 50.5 months were included. A significant correlation was established between multiple parameters of DDD preoperatively (p<0.05). Degeneration of NP tissue samples were significantly more pronounced in comparison to those of AF (p<0.001) with no significant correlation between each other (p>0.05). The degree of DDD was not significantly correlated with the patient's symptomatology preoperatively (p>0.05). There was no significant correlation between the degree of DDD preoperatively and postoperative outcome parameters following TDR (p>0.05).
CONCLUSION: Histological, X‐Ray and MRI evaluation demonstrated a significant correlation among the investigated parameters of (DDD) preoperatively, however without any correlation with the patients symptomatology. Increasing stages of DDD did not negatively impact the outcome following TDR, and, although not statistically significant, revealed a trend for improved results postoperatively. Combined advantageous effects of progressive morphological structural rigidity of the index segment and restabilizing effects from larger distraction in degenerated segments may compensate for increasing axial rotational instability, one of TDRs perceived disadvantages.