Spinal osteo-arthritis

1-It affects facet and sacro-iliac joints.

2-It causes changes in the joint and articular surfaces.

3-Regarding joint space, it causes the following

-Disc space narrowing.

-Disc space calcification.

-Vacuum phenomena.

4-Regarding the articular surfaces, it causes the following

-Sub-articular sclerosis.

-Sub-articular cyst formation.

-Osteophytic lipping.

marked osteophytosis and joint space narrowing is noted in the facet joints in this patient with severe osteoarthritis of the lumbar spine -- the osteophytosis is causing significant encroachment on the lateral recesses bilaterally

Osteoarthritis in an 85-year-old woman with breast carcinoma and abnormal left sacroiliac joint uptake on a radionuclide bone scan. Nonenhanced axial CT scan of the sacrum shows a small sacral osteophyte (small arrow) and subchondral sclerosis of the sacral side of the sacroiliac joint (large arrows) due to osteoarthritis.