Early Rehabilitation After ACL Surgery: Aim for a “Calm Knee”
Reviewed and Approved by Dr Ritwik Kejriwal (Orthopaedic Surgeon)
The first few weeks after ACL surgery are important. My early priorities are simple:
Get the knee straight.
Get the quadriceps working.
Control swelling.
Approximately 5% of my ACL patients have a delay in achieving full knee extension during the early months of rehabilitation. My goal is to bring this as close to zero as possible.
Why can extension be delayed?
There are often several contributing factors:
More significant surgery, particularly when ACL surgery is combined with meniscus or MCL repair
Fear of moving the knee — “Am I going to undo the operation?”
Too much standing and walking, resulting in increased swelling and pain
Inadequate pain control
Insufficient early focus on knee extension and quadriceps activation
For most patients, protecting the ACL does not mean keeping the knee stiff.
My early rehabilitation priorities
Unless additional procedures require specific restrictions, I encourage:
Immediate knee extension
Immediate quadriceps activation
Early knee flexion
Appropriate time out of the brace for exercises
Early swelling and pain management
The aim is to restore normal movement without repeatedly aggravating the knee.
Aim for a “Calm Knee”
More activity is not always better.
A patient may feel good in the morning, spend several hours standing or walking, and finish the day with a swollen, painful and stiff knee.
That can work against rehabilitation.
Instead, aim for a Calm Knee:
✓ Full extension progressing
✓ Quadriceps activating
✓ Flexion improving
✓ Swelling controlled
✓ Pain controlled
Use ice for pain relief, compression and elevation to help manage the postoperative knee, and avoid excessive standing or walking if this repeatedly causes swelling and stiffness.
If the knee becomes more swollen and stiff as activity increases, reduce the load, calm the knee down, restore movement and then progress again.
Take-home message
Early ACL rehabilitation is a balance between movement and swelling control.
The goal isn't to see how far you can walk in the first week.
Get the knee straight.
Get the quadriceps working.
Restore flexion.
Control swelling and pain.
Above all, aim for a Calm Knee.