What knee X-rays do we need? A survey of orthopaedic surgeons in the United Kingdom

Amongst orthopaedic surgeons there is often debate about which plain X-rays are required in the assessment of knee disorders. To determine which plain knee X-rays are routinely requested by orthopaedic surgeons in the United Kingdom, a postal survey of the 1287 members of the British Orthopaedic Association was conducted, with a response rate of 70.8%. There was broad agreement on the use of anteroposterior and lateral X-rays, despite the fact that 18% do not appreciate the potential value of weight bearing posteroanterior films in older patients. There was less consensus as to the need for skyline X-rays, despite evidence for their value in demonstrating the patellofemoral joint. In arthritis and after knee replacement, over 75% of surgeons do not use this view. The study also revealed various opinions about the most appropriate flexion angle of the knee when taking X-rays. Despite the frequency with which orthopaedic surgeons request knee X-rays, this study suggests that potentially useful information might often be missed. We would recommend that by routinely obtaining weight bearing PA, lateral and skyline views this problem could be addressed. At the same time it would be helpful if there was more awareness of the best methods of taking these views.