Intra-articular Knee Temperature Changes

• Published in: The American journal of sports medicine 2004-03, Vol.32 (2), p.441
• Main Authors: Todd A. Warren, Eric C. McCarty, Airron L. Richardson, Todd Michener, Kurt P. Spindler
• Format: Article
• Language: English
• ISSN: 0363-5465; 1552-3365
• DOI: 10.1177/0363546503258864

Background: Cryotherapy is commonly applied without research documenting the intra-articular (IA) temperature changes or subject discomfort between ice and a cryotherapy device. Hypothesis: The null hypothesis is that no difference would be observed in IA temperature decline or subject tolerance between ice and the cryotherapy device in normal knees. Study Design: Prospective, within-subject controlled clinical trial. Methods: Twelve subjects had IA temperature in suprapatellar pouch and skin recorded bilaterally after application of cryotherapy versus ice. Subject tolerance was recorded by 10-cm visual analog scale (VAS). Statistical evaluation was by Spearman’s correlation analysis and paired, nonparametric Wilcoxon’s signed rank test. Results: Both significantly lowered ( P < 0.001) skin and IA temperature with median decreases (ice/cryotherapy) at 30 (3.3°C/2.2°C), 60 (12.8°C/7.1°C), and 90 (15.2°C/9.7°C) minutes. However, ice lowered the IA temperature significantly more than the cryotherapy device ( P < 0.001) and was more painful by VAS at 30 and 60 minutes ( P < 0.01). Conclusions: Both methods produced large declines in skin and IA temperatures. However, ice was more effective yet resulted in higher pain scores. The authors hypothesize that IA temperatures below a threshold are associated with increased perceived pain. Keywords: cryotherapy intra-articular temperature knee ice