What is the probable diagnosis?
Ans. A. Ankylosing spondylitis* Involvement of the lumbar spine and the classical Bamboo spine appearance points towards the diagnosis of Ankylosing spondylitis.* A close differential diagnosis remains to be DISH. See the table below to differentiate the two conditions. Ankylosing spondylitisDiffuse idiopathic skeletal hyperostosisSex/ageCommon in males of 15-40 years of ageCommon in males in 5th to 6th decadeEtiologyIt is chronic progressive inflammatory seronegative spondyloarthropathyIt is a form of degenerative arthritisPathogenesisThe primary site of pathology in ankylosing spondylitis is the enthesis (site of attachment of tendons and ligaments to bone). Ossification also occurs in the ligaments that are ending up as enthesis, especially the ligaments of the spine that gradually get ossified, progressively leading to stiffnessCharacterized by ossification at sites of tendon, ligaments and joint capsule insertion (enthesitis) anterior longitudinal ligament of the spine is most commonly involvedDistributionSI joint, lumbar spine (eventually whole spine), the hip joint is commonly involvedMarked predilection to the axial skeleton; mainly involve thoracic spineCourseAll patients invariably present early with pain and stiffness of backIt is usually asymptomatic and discovered incidentallySI jointBilateral, symmetrical involvement (sacroiliitis)In late cases, erosion may cause pseudo widening of the SI jointsNot involvedESRElevatedNormalHLA B27Positive in 90% casesNegativeDisabilityMarked disability of the spine and hip joints in advanced casesUsually no disabilityX-ray featuresBamboo spine, squaring of vertebrae, syndesmophytesCandle wax appearance due to calcification along the anterior and lateral portion of the vertebral bodies (separated from vertebral bodies)TreatmentNSAIDs, TNF inhibitorsUsually not required
Ankylosing spondylitis
Diffuse idiopathic skeletal hyperostosis (DISH)
OA spine
Osteopetrosis
Arthritis