Persistent Knee Pain after Knee Arthroscopy

Persistent Knee Pain after Knee Arthroscopy


By Steve A. Mora, MD
Orange County Knee Specialist

You Had Knee Arthroscopy But Your Knee Still Hurts?
I see patients with this situation on a daily basis. They are one of the most challenging groups.

The usual scenario is one where a patient had arthroscopic knee surgery for a torn meniscus.  The patient was told that it was a minor surgery and that recovery would be fast. The expectations were high. However the patient is now 3 months out from surgery and they are still having pain. The patient is now frustrated and concerned.  Adding insult to injury is the fact that almost every patient has had a neighbor or co worker who had the “same” surgery and who was back doing everything in “2 weeks”.  Or even worse a pro athlete had a similar surgery and was back on the field scoring touchdowns 4 weeks later.
I find these types of cases very challenging. What makes these problems even more challenging is the fact that often times they cannot be solved in a single 15 minute second opinion consult.

The good news is that a majority of patients just need more time to heal  or more therapy and rehabilitation.  In many cases that joint is simply tight secondary to the post surgical swelling.

If a patient had surgery less than 3 months ago, I usually find that they are incompletely healed and need more time or maybe therapy aimed at particular deficits. Sometimes the rehabilitation requires releasing scar tissue with “active release” or “deep tissue work” type of rehabilitation. Sometimes the key is improving flexibility of the patellofemoral joint with a good physical therapist.  The latter is one of the most common causes of persistent pain. Those are the easy cases.  The goal of the therapy is usually to loosen up the patella femoral joint, maximize quadriceps flexibility, improve extension, and break up scar tissue.

The challenge is trying to figure out when things are fine and moving a little slow or if indeed a real un diagnosed or new problem exists.

In order to understand what might be causing pain after a knee arthroscopy I need to start with a good history and examination.   These problems cannot be solved over email or telephone. I spend a lot of time trying to understand the current as well as the pre operative symptoms. I do a detailed exam looking at leg lengths, alignment, flexibility, strength and evaluation of the joints above and below the knee.   Details are important.  It is also helpful when a patient brings in their old op report, pre-operative MRI and surgical pictures of the knee joint. These pictures allow me to see the state of the articular cartilage and remaining meniscus after the surgical procedure.   I also look for conditions that might be causing referred pain such as spine or hip problems. My exam also focus on the exact area of pain and tenderness.

High quality up to date X-rays and an MRI are essential for a thorough evaluation. Appropriate X-Rays include standing weight bearing views of both knees (Rosenberg views), Lateral and Patellofemoral Sunrise views. These X-rays are very important because they tell you information that the MRI does not. An MRI may also show “subchondral bone edema” (a.k.a. a insufficiency fracture) under the arthritic area.  Bone marrow edema causes pain therefore these findings cannot be ignored.

MRI reports are not always correct in identifying the cause of pain.  It is not unusual for a new MRI to say “meniscus tear” in the area that was already treated with meniscectomy. It is very hard if not impossible for an MRI to distinguish surgical changes/scar from a persistent or new meniscus tear.  In addition the radiologist reading the MRI does not have all case details therefore they are at a disadvantage when reading the new MRI.

To improve accuracy after surgery an MRI with the addition of contrast injection into the joint (Arthrogram) is often necessary.  The contrast will help me differentiate between scar and true pathology.  The contrast is injected into the joint and not injected into the veins.

In some cases I order full length X-Rays to evaluate lower extremity alignment.  If the leg has significant bowing or knock knees deformity the joint is more prone to one sided joint wear or arthritis.

If a patient reports morning stiffness of their hands or they have multiple joints with inflammation or pain, I will send them for a rheumatology blood tests and refer them to a rheumatologist for a detailed evaluation.

Once I have all the above information I put together a differential diagnosis and present it to the patient. Like I mentioned at the top, sometimes the problem is simply being incompletely healed and more time is needed. Other possibilities as mentioned in my examples above may include include poor rehabilitation, cartilage defects, sub chondral edema from degeneration/arthritis (common), poor patella mechanics, poor range of motion, AVN (rare), IT band syndrome, pes bursitis, intra-articular ganglions, plica bands/synovitis, persistent tear that was incompletely treated (unusual). Other problems that I consider  include rheumatoid disease, hip arthritis, and neurological disease such as a L4 radiculopathy. I then spend a few minutes writing down my diagnostic plan and the treatment plan. Patients appreciate it when you write down the plan as well as “the next step”. For example I might say “lets try a steroid injection today, more therapy aimed at improving quad flexibility and 10 days of NSAIDs. If this does not work in 6 weeks I will recommend hyaluronate injections”.


Here are some real life examples of patients who had persistent pain after knee arthroscopy.

Example 1, a meniscus tear was missed and not completely treated. 

This is one of my patients who had surgery 3 months prior to seeing me. After his failed knee arthroscopy he was told that he needed a knee replacement. His most recent post op MRI was very difficult to decipher. It turned out that he had large hidden lateral meniscus tear flap that was flipped posteriorly behind the knee in between the meniscus and the bone.

Example 2, Perhaps the meniscus tear was a “root tear” which requires a special type of repair. 

Root tears of the meniscus are difficult to identify on a MRI. They are also difficult to surgically treat. If you don’t repair them the patients will continue to have pain and will develop arthritis.

Example 3, a meniscus tear was “repaired” it might not have healed. 

Patient had undergone meniscus repair. The meniscus did not heal. They continue to tear. Patient required second surgery to remove small meniscus tear fragments and the sutures that were used to repair. This is not a uncommon situation. Anybody who undergoes meniscus “repair” must know that there is a small possibility that they might require a second surgery to clean up the unhealed fragments


Example 4, Often times the cause of pain has to do with “bone marrow edema” a.k.a a insufficiency fracture, that was not addressed at the time of the meniscus surgery. These lesions are often ignored by the surgeon. They are often erroneously called bone bruises. In my experience they are frequent a cause of pain after surgery. These lesions need to be treated with an injection of calcium phosphate into the bone (Subchondroplasty  Procedure).

Classic looking bone marrow edema. These findings are usually called bone bruises. In the past they were thought to be inconsequential. They are associated with degenerative meniscus tears. These lesions need to be addressed with Calcium Phosphate injection into the bone. It’s an easy procedure. Doing a simple arthroscopy to treat the meniscus tear will not eliminate the pain.

Example 5, In some cases the patient had early degenerative joint disease which became painful after the surgery.

Arthritic knee joint that was associated with a meniscus tear. Often times the arthritis becomes the cause for pain. Even if the meniscus tear is properly cleaned up the arthritic condition may continue to cause pain. The focus of future treatment with her for switch to arthritis treatment.

Treatment should be aimed at improving the joint. This is a complex situation. I’ve written an article just on this topic. Just because you’ve been told the you have arthritis does not necessarily mean you need a joint replacement.  If you’ve been told that you have arthritis and that there is nothing else that can be done other than knee replacement please read  my blog article titled “Make Your Knee Great Again” for more info regarding treating knee arthritis without a joint replacement. There are non surgical treatment options for arthritic knee pain following meniscus surgery.  Some of these options include treatment as simple as increasing physical therapy, Hyalurate injections, weight loss and unloading knee braces.

Non surgical treatment for degeneration might also include Regenerative Medicine options including, Platelet Rich Plasma for mild to moderate degeneration,  Bone Marrow Concentrate stem cell injections and Lipogems Regenerative Medicine injections for severe arthritis.

As you can see dealing with a patient that has already had arthroscopy is very challenging. In my practice the key to helping out these folks out is to first listen, examine and review data.

I hope this information was helpful to you.  If you live in Orange County and you need help with your knee you can see me for a consultation.  I will do my best to help you.

Thank you.


Dr. Mora is a board-certified orthopedic surgeon at Restore Orthopedics and Spine Center in Orange County.

He specializes in:

-Sports Trauma -Arthroscopy of the knee, shoulder, hip and elbow.

-Arthritis of the Knee

-Mixed Martial Arts Injuries

-First Responder Injuries

-Regenerative Medicine:Lipogems, Bone Marrow Stem Cells, Plasma therapy.

For a consultation please call Restore Orthopedics and Spine Center in the City of Orange 714-598-1745

Dr. Mora’s family heritage is Peruvian. He speaks fluent Spanish.



Restore Orthopedics and Spine Center

112o W. La Veta Ave, Third Floor

Orange, CA 92868

Office: (714) 598-1745

Fax: (714) 941-9539