ACL reconstruction

Because a fully torn ACL usually cannot simply be stitched back to its original strength, the standard surgical approach rebuilds it. In an ACL reconstruction, the surgeon replaces the torn ligament with a graft — a piece of tendon that serves as a new ligament — positioned to restore the knee's stability.

The procedure is typically done arthroscopically, using small incisions and a camera. It is followed by a rehabilitation program that is a central part of the treatment, not an afterthought.

Surgery tends to enter the conversation when a torn ACL leaves the knee unstable for the things a person wants to do, when instability affects daily life, or when there are associated injuries that may benefit from being addressed. Many people considering a return to pivoting or cutting sports discuss reconstruction for that reason.

It is not the right answer for everyone. Some people meet their goals with rehabilitation alone. The decision is made together with your surgeon after weighing your injury, your goals, and the trade-offs — the condition page covers how that decision is approached.

These terms describe two different ideas. Reconstruction rebuilds the ligament with a graft and is the most common surgical approach for a torn ACL. Repair refers to reattaching or preserving a person's own ligament rather than replacing it.

Repair is a distinct option that is appropriate only in specific situations, and whether it applies depends on the individual injury. Which approach fits — if surgery is chosen at all — is something to discuss with your surgeon based on your evaluation.

When reconstruction is chosen, one of the decisions is which graft to use. Broadly, a graft can come from your own body (an autograft, often from a tendon around the knee) or from donor tissue (an allograft). There is more than one reasonable option, each with its own considerations.

There isn't a single “best” graft for everyone — the choice is individualized and is part of the planning conversation with your surgeon, based on your injury, age, activity, and preferences. This page intentionally does not recommend a specific graft.

Sometimes a previously reconstructed ACL fails — from a new injury or other reasons — and a second, or revision, reconstruction is considered. Revision surgery is generally more complex than a first-time reconstruction because it has to account for what was done before.

If you're facing a revision, the evaluation and planning are individualized, and the trade-offs are worth discussing carefully with your surgeon.

Recovery after ACL reconstruction unfolds in stages. Early on, the focus is usually on calming swelling, restoring the knee's motion, and reactivating the muscles. From there, rehabilitation progressively rebuilds strength, control, and confidence, moving toward more demanding activities over time.

This is a longer process measured in months rather than weeks, and the specifics are individual. A structured rehabilitation program with a physical therapist guides each stage. A general overview of how ACL rehabilitation is organized — with the downloadable rehabilitation protocol — is linked below.

Return to sport is based on recovery milestones — including strength, movement quality, functional testing, confidence, and healing — not time alone. A full return to sport typically takes approximately 9–12 months, although recovery is individualized. The final decision is made with the surgeon and rehabilitation team.

Returning too soon, before the knee and the rest of the body are ready, is something the process is designed to avoid. The Return to Play area explains this criteria-based approach in more depth.

Like any surgery, ACL reconstruction carries risks, and no operation guarantees a particular result. Blood clots in the leg are among the risks after this surgery, and your care includes steps to lower that risk. Outcomes vary from person to person based on the injury, the surgery, the rehabilitation, and individual factors.

A candid conversation about the potential benefits, the risks, and the commitment rehabilitation requires is part of deciding whether reconstruction is right for you. Your surgeon can explain what the specific risks and expectations are in your situation.