150 patients, between the ages of 50 and 75, who were scheduled to undergo primary TKA due to degenerative arthritis of the knee, were randomly assigned into 1 of 3 groups to test the effect of muscle relaxants on pain following TKA surgery. One group was given non-steroidal anti-inflammatory drugs (NSAIDs) in combination with muscle relaxants, while another was given only NSAIDs, and the final group was given only placebos. Results demonstrated that patients who received muscle relaxants in combination with NSAIDs were more likely to experience less resting and ambulation pain. The combination of NSAIDs and muscle relaxants did not result in an increase in postoperative complications, and was in fact comparable to the placebo group in this measure.