Why does ACL repair have to be done soon after the injury?

What happens to the torn ligament over time

After the ACL comes away from the thigh bone, the free end is bathed in joint fluid. It tends to retract, lose its shape and sometimes scar down onto the PCL or the floor of the notch. Within a few weeks it may no longer reach its attachment or hold sutures firmly.

There is no exact cut-off that applies to everyone. Many surgeons prefer to operate within roughly the first three weeks, while accepting that each knee is judged on what is seen.

The usual advice to wait, and when it differs

For ACL reconstruction, waiting until swelling settles and movement returns is often sensible, because operating on a stiff, angry knee raises the risk of stiffness later. Repair is the exception: the biological window can be short.

The balance is to see a knee surgeon early, get an MRI quickly and plan surgery once the knee can move reasonably, rather than waiting months by default.

What to do in the first days

• Rest, ice and elevate the leg, and use crutches if needed
• Work gently on straightening the knee fully
• Avoid returning to football, padel or the gym to test it
• Arrange an MRI and a consultation within days rather than weeks
• Seek urgent care for a locked knee, numbness, a cold foot or severe swelling

If you are not a repair candidate

Many people are not, and that is not a failure of timing. Mid-substance tears, chronic tears and knees with poor tissue are usually better served by reconstruction, which can be planned without the same urgency. At Aman Hospital, Dr. Gelber will explain which group you are in and why.