A group of physiotherapists from Brazil and Spain recently conducted a trial of cryotherapy for knee osteoarthritis. Sixty people with painful knee osteoarthritis were randomised to undergo four days of either: daily cold-pack application with compression, or daily sand-pack application with compression.
The study's estimate of the effect of cryotherapy on the primary outcome - pain - was small. The treatment reduced pain by an average of 0.8 on a 10-point scale, which was below the threshold that the authors nominated would make the intervention worthwhile.
The secondary outcomes included patient-reported function and quality of life related to their knee, and functional mobility tests. The estimates on these outcomes were unclear, with mean estimates that favoured the experimental group but wide confidence intervals that did not exclude the possibilities that cryotherapy might be helpful, ineffective or harmful.