46 YO physician had a degenerative disc 5 years ago. Back pain refractory to conservative therapy. The doctor appropriately checked the facets which you see in the first picture and they are healthy. She is a good candidate for disc replacement. Her facets became arthritic at the index level. L5-S1 over several years and pain returned. The surgeon decided to fuse over the disc from her back. The implant chosen has a mobile core which I personally do not like at L5-S1. Also appropriate however in my experience I find a high incidence where the fusion does not heal. See the videos where I demonstrate why. The implant usually needs to be removed and fused in the front. She also had issues at tbd disc above. So here I used a fixed core implant above at L4-5.