Summary: This study evaluates the efficacy of CPM following focal anterior impingement (FAI) surgery of the hip in children as well as the cost-comparison and implications to the health-care system. Introduction: The clinical concept of CPM is based on the premise that post-operative stiffness in a joint can be avoided if full range of motion is applied to the joint immediately following surgery, and is continued until the joint is no longer at risk of developing stiffness. This study hypothesizes that use of CPM following FAI surgery in the pediatric population improves clinical outcomes in terms of Harris hip score. This study further hypothesizes that usage of CPM decreases the length of stay in the hospital (LOS), number of physical therapy visits, number of physician visits, need for pain medications and decreases the cost to the payer. Methods: Twenty-nine adolescents that underwent FAI surgery by a fellowship trained, pediatric orthopedic surgeon were reviewed. Patients were divided into one of three groups; control (no CPM), group I (2 days of inpatient CPM), group II (2-week CPM). Harris hip score was used pre-operatively and post-operatively at 6 weeks, 3 months, and 6 months in all cases. The cost assessment was linked to the length of stay in the hospital, the rental of the CPM device, the number of physician visits, the number of physical therapy visits, and the use of pain medications. Costs were evaluated from the point of view of the payer. Kruskal-Wallis (KW) analysis was performed to determine statistical differences in Harris Hip Score, length of stay in the hospital, PT visits, MD visits, and medication usage for each group. These parameters were then re-evaluated using the Mann-Whitney test with the Bonnferoni correction (p value acceptable at < 0.0167). Results: Mean age was 15 y 2m (11y 4m to 18 y 8 m). There were no statistically significant differences in hip scores between the three groups pre-operatively. There were statistically significant differences in median hip scores between the three groups postoperatively at 6 weeks, 3 months, and 6 months. The group that received 2 weeks of CPM had the best outcome scores. There were no differences in the scores between the control group and group I (2 days CPM) at 6-months follow-up. The results of this study suggest that the use of CPM had a positive impact on the costs to the payer primarily due to decreased LOS. Both CPM groups had an average LOS that was lower than the control. Discussion: The results of this study suggest that post-operative CPM use for FAI patients decreases length of stay, as well as consumption of MD and PT visits, while simultaneously increasing clinical outcomes. Not only does post-operative CPM use appear to make a positive difference in clinical outcomes of adolescents; the improvement seems to be related to the dose of CPM. Those patients that had two weeks of CPM had higher hip scores than the patients that only had two days of CPM and the patients that had two days of CPM had higher hip scores than those that had no CPM. CPM usage had a positive impact on the costs to the payer.