Aetiological factors in severe osteoarthritis of the knee

We interviewed 231 consecutive patients with osteoarthritis undergoing knee replacement surgery and examined them for evidence of risk factors and bilateral disease. Bilateral knee replacement surgery was performed on 17% of patients; 50% of patients had a knee replacement with no radiographic evidence of osteoarthritis in the unoperated knee. There was an increased ratio of women to men undergoing surgery (1.6:1) and the right knee more commonly required surgery than the left (1.3:1). A history of previous meniscectomy on the operated knee was rare (5.2%), as was a history of premorbid deformity (3.3%). Obesity was no more common than in the general population. Most patients undergoing surgery for osteoarthritis of the knee in this series had none of the risk factors identified by epidemiological studies. © 1995.