Intra-articular temperature measurements after superficial heating.

Superficial heating of the joint is widely used in various rheumatic conditions and is considered as decreasing the intra-articular temperature. This study shows that heating the joint with hot pack significantly increases the articular temperature from 35.2 +/- 1.5 degrees C (mean +/- SD) to 36.4 +/- 1.0 degrees C (p less than 0.001), while intra-cavity temperature of the contralateral unheated knee joint did not change significantly. Since such elevation of temperature of one degree C is liable to enhance the inflammatory process, the use of superficial heating has to be carefully reconsidered in acute and chronic inflammatory joint diseases.