A 12 year old boy was brought with pain in the right lower limb and difficulty in walking and standing since two years.
The skull vault is thickened with hyperostosis of both tables. The frontal sinus is hyperpneumatised. The external occipital protuberance is prominent. The sella is deep and large - shows the double floor sign. The terminal phalanges are short and stubby. In the metacarpals, the muscle attachment areas are prominent. The iliac crests are thickened. Enthesopathic calcification is seen in this region and around the acetabula. The knee joint spaces are widened. The heel pad is tall and wide. There are large calcaneal spurs.