Wafer-like calcification of the spine in ochronosis

Images in Medicine Wafer-like calcification of the spine in ochronosisA 45-year-old male presented with a history of inflammatory low back ache of 10 years duration, with early morning stiffness for approximately 30 minutes.On examination, there was marked restriction in the movement of the lumbar spine (modified Schober 2.5 cm).However, there was no synovitis; crepitus was noted in both knees.There was brownish black discolouration of the sclera, radial borders of the fingers of both hands, and the pinna (Fig. 1a,b).On revisiting the history, he also had blackish discolouration of urine on prolonged standing.His acute phase reactants were normal, and HLA B27 by polymerase chain reaction was negative.X-ray of the lumbar spine showed intervertebral disc calcifications at multiple levels, anterior ligament calcification, and disc space narrowing (wafer-like calcification).No sacroiliitis was noted on the X-ray of the pelvis (Fig. 1c,d).He was diagnosed with ochronotic arthropathy of the spine.'Wafer-like calcification' is the dense disc calcification of the spine seen in Ochronosis. 1 Ochronotic arthropathy develops in 50% of patients after 40 years. 2It affects the spine and large joints, especially the knees.Clinical and radiological findings can closely mimic ankylosing spondylitis.A careful history, tell-tale signs like discolouration of cartilaginous structures and absence of sacroiliitis on pelvic X-ray can avoid the misdiagnosis.