A method for measuring contact pressures instantaneously in articular joints

A method whereby instrumented pipes are inserted part of the way into articular cartilage from the underlying subchondral bone has been developed for measuring instantaneous contact pressures acting within articular joints. Contact pressures developed between two specimens cut from fresh cadaveric knee joints were measured with this technique and then subsequently with pressure-sensitive paper. Average contact pressures (load/contact area) were also calculated. Comparisons of the three sets of data show that contact pressures measured with the pressure pipe system are linearly related (p less than 0.001) to both the contact pressures measured with the pressure-sensitive paper and the calculated average contact pressures.