Efficacy of neuromuscular stimulation of the quadriceps femoris during continuous passive motion following total knee arthroplasty

The effect of neuromuscular stimulation of the quadriceps femoris combined with continuous passive motion (CPM) on the active extension range of motion and force of patients with total knee arthroplasty was investigated. The experimental group received three one-hour periods of electric stimulation per day in the extension cycle of the continuous passive motion. The control group received continuous passive motion without quadriceps electric stimulation. Both groups engaged in physical therapy consisting of active range of motion, quadriceps femoris setting, flexion and extension stretches, and ambulation. Manual goniometry and tensiometry were used to evaluate knee active extension range of motion and quadriceps strength. Upon dismissal, the stimulated group was able to generate more force at 90°, 35°, 20°, and terminal extension of the involved knee, but none of these values was found to be statistically significant. Active extension range of motion of the stimulated group on dismissal showed a significant decrease in active extension lag (degrees) as compared to the control group. The experimental group averaged ten days in the hospital as compared to 12.5 for the control group, and subjectively noted decreased pain during stimulation.