A knee injury that prevents unaided walking for more than a week is a strong predictor of knee OA. Such injuries often involve rupture of the anterior cruciate ligament (ACL), which may be associated with a tearing of the meniscus or the medial collateral ligament. Both ACL damage and meniscus tears are strongly linked to early OA development.22, 23 Because the incidence of ACL injury is two to eight times higher among female compared with male athletes, the rising number of women participating in sports can be expected to result in higher rates of knee OA in women.22, 23 Early ACL reconstruction with meniscal preservation may help to protect against knee OA. The poorest postoperative outcomes have been seen following meniscectomy.3, 5