<prompt> A middle aged woman with history of backache underwent a Schober test and came as positive. She had hyperpigmented nose and ears. Looking at this radiograph, most likely diagnosis is:AIIMS 2017Ankylosing spondylitisDegenerative disc diseaseOchronosisFluorosis  <response>: Ans. C OchronosisImage shows Intervertebral disc calcification commonly seen in alkaptonuria due to deposition of homogentisic acid. Schobers test is non-specific test that denotes loss of elasticity of spine. Hyperpigmented cartilage is another clue that points towards AlkaptonuriaOchronosis. 