Assessment of a New Axis of Radiation in Hip Joint Radiographies

Introduction & Background: The harmful effects of x-rays on sensitive cells such as those of sex gonads are a well-established fact. Therefore, special care should be taken in hip radiographies to protect the gonads. According to the most recent references, to locate the head of femur and its joint in hip radiographies, a line should be drawn from the ASIS to symphysis pubis. To locate the head of the joint, we had to move 2.5cm inferior and laterally from the middle of the men-tioned line. The outer end of this new line indicates the position of the femur head. However, due to the lack of accurate instruments in wards and the variety of diseases and also to avoid repetitive hip radiogra-phies, we decided to apply an experimental method. Patients & Methods: In this study, hip radiographies with FFD=100 were done for 50 patients of both sex with different ages. In all instances the distances be-tween symphysis pubis and the greater trocanter, the base of the lesser trocanter, and upper edge of acetabulum, and symphysis pubis and the center of femur, were measured on the radiographs by means of a standard ruler. The findings were then statisti-cally analyzed. The radiography apparatus was Phil-lips 500MA model D7. Results: In this study, it was shown that in 27 cases, the distance between symphysis pubis and the center of the head of femur was equal to the distance be-tween the base of the lesser trocanter and the upper edge of acetabulum. There was also a difference of 0.5, 1, and 2.5 centimeters in 14, 10, and 3 cases re-spectively. Conclusion: These findings were statistically signifi-cant and new. This is notable with regard to the ease of locating the hip joint in small radiographs. In addi-tion it has the advantage of a small degree of gonadal protection.