Fig. 5.

Operated segmental height in fusion versus arthroplasty group (a), and group without ASD versus group with ASD (b). There was a significant difference between fusion and arthroplasty group at postoperatively 1 year and 5 years (a) (*Mann–Whitney test and p < 0.01). About intergroup comparisons between postoperative 5 years with preoperative state, operated segmental height was significantly increased at total, arthroplasty (a) and groups with ASD (b) (^†Wilcoxon signed-ranks test and p < 0.01)