Influence of Isokinetic and Ergometric Exercises on Oxygen Partial Pressure Measurement in the Human Knee Joint

We conducted the first in vivo investigation on the influence of joint movement on intraarticular oxygen partial pressure. The development of a special flexible microcatheter allowed measurements of intraarticular oxygen partial pressure under both physiological and pathological conditions. The aim of this study was to evaluate the influence of different knee joint stresses on intraarticular oxygen partial pressure under physiological (healthy patients) and pathological (patients with osteoarthritis) conditions. The results show that the different exercise patterns influence the intraarticular oxygen partial pressure. Patients with osteoarthritis showed a lower increase of intraarticular oxygen partial pressure compared with healthy patients. This phenomenon is directly correlated to the degree velocity of the isokinetic exercises. We found the same results under ergometric conditions. This method allows functional, intraarticular in vivo measurements under different exercise patterns. For the first time, we were able to measure the influence of joint movement on the intraarticular process of nutrition under physiological and pathological conditions. Also, to evaluate for the first time in vivo different concepts for osteoarthritis therapy.