Background: Primary knee osteoarthritis (KOA) is one of the most widely studied diseases in medicine.
Objectives: To study the frequency and risk factors of primary knee osteoarthritis in Qena governorate patients.
Patients and Methods: Assessment of 200 primary knee osteoarthritis patients was done through clinical , radiological findings and evaluation of risk factors as age, sex, family history, and weight. In addition to, Severity of knee osteoarthritis according to Kellgren-Lawrence Grading Scale which was classified severity of knee osteoarthritis depending on size of knee joint space ,developing of osteophyes, bone sclerosis and bone deformity  .
Results: The primary knee OA was increased with aging . Frequency of primary knee OA was more in females, rural areas and in average and heavy workers .There was positive family history with majority of our cases (85% ) . Overweight and obesity contributed to develop primary knee OA in 67.5% in our study. Knee pain, swelling, stiffness and cripitus were the most common manifestations of primary knee osteoarthritis in nearly 75% of our cases.
Conclusion: Aging, female sex,  positive family history, high BMI, and increased physical activity are risk factors in osteoarthritic patients of Qena governorate .