40yr old male patient having pain with daily morning stiffness of spine for 30 minutes and reduced chest movements. Most probable diagnosis is

The information in question are 40yr male Morning stiffness in spine Limited chest expansion *****all fit into clinical criteria for diagnosis of Ankylosing spondylitis x ray of ankylosing spondylitis -BAMBOO SPINE AS is a chronic, progressive immune-mediated inflammatory disorder that results in ankylosis of the veebral column and sacroiliac joints . * The spine and sacroiliac joints are the common affected sites -- Chronic spinal inflammation (spondylitis) can lead to fusion of veebrae (ankylosis) . Characteristic Pathologic Features : * Chronic inflammation in: - Axial structures (sacroiliac joint, spine, anterior chest wall, shoulder and hip) - Possibly large peripheral joints, mainly at the lower limbs (oligoahritis) - Entheses (enthesitis) * Bone formation paicularly in the axial joints Axial manifestations: * Chronic low back pain * With or without buttock pain * Inflammatory characteristics: - Occurs at night (second pa) - Sleep disturbance - Morning stiffness * Limited lumbar motion * Onset before age of 40 years Refer maheswari 9th ed