Frontal X-ray of the lumbar (lower) spine of a 41 year old female patient with two intervertebral disc implants (white). The implants are replacing slipped (herniated) intervertebral discs between the L4 and L5, and the L5 and S1 vertebrae. Slipped discs can lead to the herniated tissue pressing on the spinal cord, causing severe pain and other neurological symptoms.