Like most things in life, the answer to this question can be found after a careful understanding of both the risks and benefits. It is certainly possible that skiing on a smooth surface without significant changes in direction may be successfully executed without a pivoting episode of the knee. Braces can sometimes help the ACL-deficient knee to feel more stable, although they probably can not truly stabilize a knee in aggressive pivoting activities. While it may be possible to avoid injury for a few runs on the slopes in this fashion, the danger lies in what can occur with a change in direction, on the moguls, or if the skis happen to catch in deep snow. Under these circumstances, the knee can pivot and result in an abnormal shifting of the femur on the tibia. Without the ACL to control the translation at the knee, the menisci (“shock absorbers”) and cartilage on the ends of the bone are at-risk for significant injury with instability episodes. Unfortunately, meniscal tears are frequently not salvageable with repair and result in a significant loss of the shock absorbers that normally protects the knee. Like driving a car “with no shocks,” the ACL and meniscal-deficient knee “feels every bump in the road,” damaging the articular cartilage on the ends of the bone and precipitating a rapid downward progression towards osteoarthritis of the knee at a relatively young age. Once arthritis has developed, it is an irreversible process that is managed with salvage rather than restorative procedures.
To make a long story short, skiing without an ACL is certainly possible, but a decision that must be made with a careful understanding of the risk and benefits. Ranawat adds “While a fortunate individual may escape injury, the young knee could suffer significant injuries with a recurrent instability event such as irreparable meniscal and cartilage damage.” If you have suffered an ACL injury, it is critical that you seek the attention of a sports medicine specialist promptly to understand the indications, risks, and benefits of ACL reconstructive surgery.