“…12,16,19,20,23 , 26-36 , 38,39 Generally only 1 knee is affected but 11 studies reported bilateral involvement. 13,16,20,21,23,27,28,34,37,40,41 Men are more commonly affected than women with ratios ranging from 2:1 to 9:1 (mean 4:1), 16,18,23,24,26,30,31 , 33-36 , 39 and 2 studies reported only on male patients. 18,24 Mechanical pathomechanism such as repetitive shearing stress and overuse is reported by 12 studies, 13 , 15-17 , 20-22 , 24,25,29,36,41 while only 3 studies report a possible biological etiology.…”