<prompt> Bamboo spine with sacroilitis -Anky losing spondylitisRAOAPsoriatic arthritis  <response>: Ans. is a i.e.. Ankylosing spondylitis Radiological features of ankvlosing spondylitiso Radiographic evidence of sacroiliac joint is the most consistent finding in ankylosing spondylitis and is crucial for diagnosis. The findings are :-Sclerosis of the articulating surfaces of SI jointsWidening of the sacroiliac joint spaceBony ankylosis of the sacroiliac jointsCalcification of the sacroiliac ligament and sacro-tuberous ligamentsEvidence of enthesopathy - calcification at the attachment of the muscles, tendons and ligaments, particularly around the pelvis and around the heel.o X-ray of lumbar spine may showr :-Squaring of vertebrae: The normal anterior concavity of the vertebral body is lost because of calcification of the anterior longitudinal ligament.Loss of the lumbar lordosis.Bridging osteophytes syndesmophytesBamboo spine appearance. 