Fig. 3.

Subsidence and intraoperative endplate destruction (iED). Subsidence is measured as the change in the distance between the upper endplate of upper vertebra and the lower endplate of lower vertebra of index level using lumbar spine lateral X-ray films, comparing the distances checked immediate postoperatively to those at 6 months postoperatively. iED is checked on the immediate postoperative simple X-ray films, usually around the anterior and posterior sharp edges of DLIF cage.