Hi Rana
I think no accurate diagnosis could be done without all investagation procedures&tools inluding blood tests,x-ray,clinical assessments,past and presnt history,.... in order to be able to rollout other causes/diseases!!
any way u may have to note gait pattern(waddling gait),age, body weight,sex, knee click(crepitations),tenderness medially(as usually),nature of job,...
Regards