Intervertebral fixing. Frontal (left) and lateral (right) x-rays of the lower back and pelvis of a 36-year-old patient, showing internal fixing between the lumbar (L5) and sacral (S1) vertebrae (spinal bones). There is discopathy (disc disease) of the lumbosacral segment of the patient's lower back. Discopathy refers to disorders of the intervertebral discs that separate and cushion the vertebrae. An intervertebral fusion cage with metal screws (white) has been fitted to substitute the affected intervertebral disc between these vertebrae.