Anterior cruciate ligament (ACL) injuries are among the most common knee injuries, especially in athletes and active individuals. Traditionally, the approach to ACL tears has included a period of waiting before surgery—allowing inflammation to settle and the knee to regain mobility. But new findings from the Hospital for Special Surgery (HSS) suggest that early surgical intervention could play a key role in preventing knee osteoarthritis (OA) down the line.

These findings were recently presented at the 2025 Annual Meeting of the American Academy of Orthopaedic Surgeons and are generating fresh discussion about how best to manage ACL injuries with the future in mind.

Key Findings: Early Surgery, Less Inflammation

In a preclinical study, HSS researchers explored the biological impact of performing ACL reconstruction shortly after injury, compared to delaying surgery. The results were compelling:

• ✅ Lower immune cell activity in the joint

• ✅ Reduced inflammatory response

• ✅ Fewer degenerative joint changes typically associated with the development of osteoarthritis

According to Dr. Scott Rodeo, senior author of the study, “Immediate ACL reconstruction may lower the risk of developing knee arthritis.” His team’s research indicates that prolonged inflammation following ACL injury—especially when surgery is delayed—may contribute to joint deterioration over time.

Challenging Traditional Protocols

Historically, orthopaedic surgeons have often waited several weeks after an ACL injury before performing surgery, largely to allow inflammation to subside and to reduce the risk of post-operative stiffness. However, this new research challenges that approach by emphasizing the long-term effects of inflammation on joint health.

Persistent inflammation not only affects pain and mobility in the short term but may also accelerate cartilage breakdown and structural changes in the knee. These factors are well-known contributors to the development of osteoarthritis, a chronic condition that causes joint pain, stiffness, and reduced function.

Implications for Osteoarthritis Prevention

Knee osteoarthritis is a leading cause of disability, particularly among those who have experienced sports injuries or trauma to the joint. Studies have shown that up to half of individuals with ACL injuries eventually develop knee OA, even after undergoing reconstructive surgery.

If further clinical research supports the HSS findings, early ACL surgery could become an important preventative strategy—not just to restore stability to the knee, but also to protect long-term joint integrity and reduce the risk of chronic arthritis.

What This Means for Patients

It’s important to note that the recent findings are based on preclinical models, and additional human studies will be needed to confirm these outcomes in broader patient populations. However, the research highlights an important shift in thinking: timing matters when it comes to joint injury recovery and arthritis prevention.

For patients with ACL injuries, these insights may inform discussions with orthopedic surgeons about the best timing for surgery—particularly for younger, active individuals who may be at higher risk for post-traumatic osteoarthritis.

The connection between early ACL reconstruction and reduced arthritis risk offers promising new directions in joint preservation. As our understanding of inflammation, injury, and arthritis continues to grow, timely intervention may become a more central component of comprehensive care.

At the American Arthritis Foundation, we’re committed to sharing the latest scientific insights that can help individuals protect their joints and prevent long-term complications. If you’ve experienced a knee injury or are considering ACL reconstruction, speak with your healthcare provider about the best options for preserving your joint health today—and for years to come.