[Intra-articular oxygen partial pressure measurements under functional conditions].

Oxygen partial pressure is directly related to the vascularisation of different tissues. Different investigations in tissue (muscle, kidney, brain, heart, bone etc.) proved this correlation. The development of a special flexible microcatheter named Licox enables us to do measurements of intraarticular oxygen partial pressure under physiological and pathological conditions for the first time. The aim of this study was to examine the influence of different knee joint stresses on the intraarticular oxygen partial pressure under normal conditions and in osteoarthritis. The results showed that the different exercise patterns influence the intraarticular oxygen partial pressure. Patients with osteoarthritis showed a lower increase of the intraarticular oxygen partial pressure compared to the control group. This phenomenon is directly correlated to degree velocity of the isokinetic exercises. The same findings occur under ergometric conditions. The method permits functional, intraarticular in vivo measurements under different exercise patterns. For the very first time we were able to measure the influence of the joint movement on the intraarticular process of nutrition under physiological and pathological conditions. Different therapy concepts in osteoarthritis can be evaluated directly in vivo for the first time.