A simple pressure dolorimeter for the quantification of joint tenderness in inflammatory arthritis

A simple pressure dolorimeter for the detection and quantification of joint tenderness is described and evaluated. The pressure dolorimeter was more sensitive than a modified Ritchie Index in measuring degree of joint tenderness and as sensitive in detecting tender joints. The interobserver error of the pressure dolorimeter was low, and in a drug withdrawal study, the pressure dolorimeter was able to detect change in joint tenderness whereas the conventional Ritchie Index was not. These results suggest that the pressure dolorimeter is a simple, reliable and sensitive instrument for measuring joint tenderness in patients with inflammatory joint disease. It is also inexpensive and readily available.