Cryotherapy as an analgetic technique in direct postoperative management of elective joint replacement

The application of crushed ice or hydrogenated silicate, a micro-crystalline substitute has been used as a method to treat posttraumatic and postoperative irritations of the locomotor system for a long time. Closed systems using pumps can be viewed as further development as they enable continous, water-free cooling of operating areas. The analgetic effect of postoperative cold therapy was evaluated in a prospective clinical trial, including 312 patients after total knee or hip arthroplasty. Conventional cold packs, consisting of microcrystalline silicate were compared to a continous applicable closed system. Continous cryotherapy resulted a depression of skin temperature to 12 degrees C, whereas intermittend cooling only caused a mean temerature decrease of 1 degrees C. Clinically continous cold application leads to a more than 50% decrease of analgetic demands in both, systemic and regional application (p < 0,001). This oberservation was found in a significant correlation with patient's pain sensation as well as primary range of motion. Intermittant cryotherapy was found to be ineffective in postoperative pain relieve in hip- an inadaequat in knee arthroplasty patients. We could not report an influence to postoperative blood loss, as dicussed in previous reports.