Microdisc. Microdiscectomy implies that the major part of the disc is removed thru a small incision and usually with an operating mircoscope. The posterior structures namely the facet joint, various ligaments etc. Provide the supporting elements.
Disc and joints. Microdiskectomy removes up to half of the disk at most leaving some disk behind to keep space between the vertebra. Disk removal ideally won't weaken the joints that support the spinal column which includes the vertebra. The vertebra are separate from the disk so are not affected by removal of it alone.