FEMORAL HEAD - Osteoarthritis

The head has retained its normal shape but the cartilage is irregularly and unevenly thinned almost, in some places, exposing the subchondral bone giving a brownish colour. At the periphery there is osteophytic lipping where there are irregular bony outgrowths covered with cartilage. The cut surface shows a thickwalled multilocular cyst; the cysts are lined by fibrous tissue and are said to communicate with the joint surface. They may be present before other manifestations of osteoarthritis; their genesis is not known.