Physical Therapist Examining A Cracking Knee After ACL Surgery

Why Does My Knee Crack During My ACL Surgery Recovery?

Knee Crack | If you’re recovering from ACL surgery and worried whether the noises from your knee are a warning sign that your surgery hasn’t gone well, or that you’ve done too much, too soon, you aren’t alone!

Hearing your knee crack, click or pop after your ACL surgery is a very common experience among those who have gone through an ACL reconstruction.

And we understand that it’s a very scary thing.

The last thing you want is for something to go wrong, and end up battling an injury you’d hoped would be in the past.

We know you want to get back to sports, workouts, and running, and we are here to help get you there!

Woman running outdoors for exercise

1. Why Are My Knees Clicking During My ACL Surgery Recovery?

There are a few reasons your knees may be clicking that are completely normal.

A. Scar Tissue

Following ACL surgery, there is typically some scar tissue that develops within the knee joint and surrounding structures.

When you first start moving the knee around, this scar tissue will start to break up causing an audible crack or pop – this is okay!

B. Swelling

Oftentimes after surgery, the knee joint and affected structures will experience swelling.

This is a normal part of the healing process.

When there is swelling in the knee joint, this can cause the knee cap to track differently along the thigh bone when bending and straightening the knee.

When the knee cap gets off its normal track, this can cause an audible crack or pop.

Again, this is not something to be overly concerned about as once the swelling is resolved, this motion should return to normal.

In addition to ice and elevation, safe and gentle range of motion at the knee can help to decrease post-operative swelling.

An example of a simple range of motion exercise to increase knee flexion is heel slides along the floor while sitting with legs stretched out in front of you.

Other examples include low-intensity stretching for the hamstrings and calf muscles.

All range of motion and stretching should follow the prescribed guidelines of immediate post-operative care set by the surgeon in order to protect the healing ACL graft.

Specific instructions on these exercises are linked below!

B.1. Range of Motion and Stretching Exercises For ACL Surgery Recovery

– Heel Slides

– Hamstring Stretch

– Calf Stretch

C. Weak Quadricep Muscles

Similar to joint swelling, a weak quadriceps muscle can cause the knee cap to track differently and may result in a crack or pop.

Following an ACL reconstruction, it is normal to experience quadriceps weakness.

Regaining quadriceps strength is something your physical therapist will begin working on with you early in your rehab.

Much like swelling, once quadriceps strength returns the knee cap will track normally again.

A safe quadriceps strengthening exercise to do after ACL surgery is isometric quadriceps setting.

This exercise will help to wake up the quadriceps muscle that has likely lost some strength since surgery.

Again, all exercises should follow the guidelines set by the surgeon in order to protect the healing ACL graft.

Specific instructions on these exercises are linked below!

C.1. Quadriceps Strengthening Exercise:

– Isometric Quad Setting


2. What If I’m Still Worried About My Knee Clicking?

While hearing a crack or pop is completely normal following surgery, it can be reassuring to speak to an expert physical therapist – like our team at our Chicago clinic.

Our advice would be to get help from knee pain specialists who work with athletes and active people recover from knee injuries on a daily basis.

At PREP Performance Center, you can get drug-free knee pain relief, whilst helping speed up recovery and improve your performance when running and playing sports.

To find out how we can help you recover from ACL surgery, or any other knee injuries you are struggling with, arrange a Free Discovery Visit.

Right now, the demand at our clinic is very high, so arrange your Free Discovery Visit or call us on (773) 609-1847 now.


Dealing with knee cracking during ACL surgery recovery? Our guide to ACL reconstruction can help – download it today.

Download Your Guide to ACL Reconstruction


3. Other Free Resources To Prevent and Treat Sports Injuries

Read Our Blog – How To Prevent Knee Pain When Running

Read Our Blog – 11 Steps To Improve Knee Flexion After ACL Surgery

Read Our Blog – 6 Best Exercises To Eliminate Your Knee Pain

Follow Us On Social Media – Prep Performance Center Facebook, Prep Performance Center Twitter and Prep Performance Center YouTube


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