This is the first study to show that cold can be used effectively after total hip replacement (THR) for pain relief. They also showed how local cooling of the hip can relieve stress and result in faster rehabilitation.

Two groups of patients were part of this study. Each group had 23 patients who got a cementless THR for osteoarthritis. The first group had a cooling pad wrapped in a waterproof cover applied over the wound area. A layer of gauze protected the wound first. A computer was used to keep the pad at a constant temperature for four days.

The second group had the same exact treatment including the pad. The pad in the control group was kept on for four days, but it was not cooled below room temperature. Blood loss and pain levels were the two measures used to compare treatment methods.

Both groups had about the same amount of blood loss. The big difference was in pain levels. Pain scores for the group with the cooling pad were much lower than for the control group. Pain was gone by day three for more than half of the cold therapy group. It took up to five days to reduce pain to zero in the control group.

The cold therapy didn't reduce swelling, but it did change the amount of pain pills taken. The cold therapy group used less total amount of the main pain reliever. The authors conclude that using cold the first four days after THR is simple and effective for controlling pain. The patient can start rehab sooner with less risk of blood clots.

Reference:

Naoto Saito, MD, et al. Continuous Local Cooling for Pain Relief Following Total Hip Arthroplasty. In The Journal of Arthroplasty. April 2004. Vol. 19. No. 3. Pp. 334-337.'