Optimization of the fixed-flexion knee radiograph

Purpose: To develop a user-friendly method of achieving optimal radiographs for measurement of joint space width of the knee with minimal radiation exposure. In order to accomplish this the X-ray technologist must (1) be able to identify the anterior and posterior rims of the tibial plateau at a variety of X-ray head angles and (2) be able to choose the direction to adjust the head angle to get a better view based on the criteria for acceptable radiographs. Methods: We have developed a training manual and materials to instruct investigators and radiology technologists in a method that uses a commercially available Plexiglas positioning frame (Synaflexer (TM)) and standard X-ray equipment to achieve optimal X-rays with regard to tibial plateau alignment of the knee. This should be accomplished with four or fewer radiographs. Results: Optimized radiographs for joint space width measurements are achieved without the need for fluoroscopy or foot maps. Conclusions: This method is readily understood and instituted by radiology technologists in the field. (c) 2007 Published by Elsevier Ltd on behalf of Osteoarthritis Research Society International.