In postmortem examinations 26 hip joints of 23 adult individuals were filled with Ringer's solution in order to furnish data on the relationship between intra-articular pressure, capsular content, and joint position A tube system was connected to an 18gauge needle and to a pressure transducer After instillation of 2 5, 5 0, 7 5, and 10 0 ml of Ringer's solution, intra-articular pressure was recorded in six different joint positions (extension, 45 Β°and 90 Β°flexion, 40 Β°internal and 40 Β°external rotation, and 45 Β°abduc- tion in extension) Intra-articular pressure depends mainly on the position of the joint, with highest values in external and internal rotation and lowest values in 45 Β°flexion In this last position, the pressure was zero in two of four cases after injection of 10 ml, whereas with external rotation and instillation of 2.5 ml almost 60 k Pa was recorded In extension and after filling with 10 ml the pressure exceeded the level of normal systolic blood pressure in all cases Under pathologic conditions intra-articular pressure of the hip joint can rise well above arterial pressure and thus eventually compromise vascular supply to the femoral head, even in the presence of only minimal intra-articular effusion.