244 patients undergoing total knee arthroplasty were randomized to receive a post-operative intervention of either ATP supplements or a placebo. This study was undertaken to evaluate the effects of ATP supplements on pain and function over the first 28 days following surgery. An electromechanical dynamometer was used to assess patients’ quadriceps strength, a visual analog scale (VAS) was used to measure pain scores, and hospital records were used to determine length of hospital stay and analgesic consumption. The study gathered data pre-operatively and four weeks post-operatively, and found that those who received ATP supplementation had a significantly higher level of quadriceps strength, lower pain scores, and lower analgesic consumption when compared to those who received placebo.