The most common site of primary osteoarthrosis is -

In general, weight bearing lower limb joints are affected more commonly than upper limb joints. However, No textbook has mentioned which is the commonest joint : knee or hip. According to me it is knee because of following facts :- I have seen hardly one or two cases of primary OA of hip; while, I have seen hundreds of cases of Primary OA of knee in my OPD. At least 4 to 5 patients of primary OA of knee comes daily to my OPD. "OA commonly affects the knee joint"   —Ebnezar "OA of hip is second in frequency to the knee joint" —Ebnezar