Continuous passive motion (CPM) is widely used as part of rehabilitation following knee surgery and there is evidence that its use following total knee replacement can lead to a reduction in both hospital stay and analgesic requirements and an increase in early range of motion. In many centres, the use of CPM machines is limited by the cost of the equipment. We present the results of a pilot study to evaluate a new design of CPM machine (CPMlite) which is inexpensive, portable and quick to set up.
Forty-two patients were randomised to receive CPM therapy following total knee replacement using either a conventional machine or CPMlite. Rehabilitation results (39 patients) showed no statistically significant difference in analgesic requirement, early range of movement or the length of hospital stay between the two groups of patients.
We conclude that this new type of CPM machine compares well with conventional machines, and its significantly lower cost should make CPM more widely available in the post-operative rehabilitation of patients following knee surgery in hospital and at home.