Continuous passive motion in the postoperative treatment of patients with total knee replacement. A retrospective study.

The purpose of this study was to evaluate the effects of adding three 1-hour sessions of continuous passive motion (CPM) each day to the entire postoperative program of patients who received a total knee replacement (TKR). A retrospective chart review was completed for 55 patients (8 with bilateral involvement, totaling 63 knees) who received a TKR between 1981 and 1984. The data analysis compared the following variables for 32 patients who received CPM and 23 patients who received no CPM: the length of hospital stay (LOS), the number of postoperative days (PODs) before discharge, the frequency of postoperative complications, and the knee range of motion at discharge. The CPM Group showed significant decreases in the frequency of complications (p less than .05), the LOS (p less than .01), and in the number of PODs (p less than .001). No difference was demonstrated in the ROM of the two groups. These results support the use of postoperative applications of CPM, but not as strongly as those reported from studies that used longer periods of CPM. Further research is indicated to delineate the minimum dosage of CPM needed to obtain the maximum beneficial effects.