In this paper, a social health support system is developed to assist both ACL (anterior cruciate ligament) patients and clinicians on making better decisions and choices for ACL reconstruction and rehabilitation. By providing a good platform to enable more effective sharing of personal expertise and ACL treatments, our social health support system can allow: (1) ACL patients to identify the best-matching social groups and locate the most suitable expertise for personal health management; and (2) clinicians to easily locate the best-matching ACL patients and learn from well-done treatments, so that they can make better decisions for new ACL patients (who have similar ACL injuries and close social principles with those best-matching ACL patients) and prescribe safer and more effective knee rehabilitation treatments.