How does a medial meniscus tear happen?
A medial meniscus tear can occur due to many mechanisms of injury. These tears often occur in sports. Medial meniscus tears commonly happen with an ACL tear and are part of the unhappy triad involving the MCL, ACL, and medial meniscus. This is because the medial meniscus acts as a secondary stabilizer to prevent the knee from slipping forward, and when the ACL tear occurs, it puts extra stress on the medial meniscus which leads to it tearing. In addition, deep squats put extra stress on the back of the knee and can cause a medial meniscus tear to occur. Other causes include turning, twisting, or pivoting activities where extra stress is placed on the inside of the knee, which are all mechanisms that a medial meniscus tear can occur.
What does a medial meniscus tear feel like?
Most of the time people can point to a specific injury to the knee when they tear the meniscus, but this is not always the case. The pain usually is associated with the tear, joint swelling, joint line tenderness, and pain in the back of the knee (popliteal space) particularly with deep squatting movements is associated with a meniscus tear. Frequently people also lack terminal knee extension due to the swelling or the lesion causing the limitation in ROM. Some have pain with descending stairs or walking downhill on a hike or while hunting especially on uneven surfaces. Popping and clicking are often involved as well.
What does treatment look like?
Physical therapy will attempt to control knee effusion (swelling) and pain by promoting good movement patterns, strengthening those patterns, and providing advice for activities to avoid further injury. Many patients respond well with rest, ice, and motor control training that prevents accessory knee movements with functional activities. Ideally, we would be able to keep as much of our meniscus intact because it is the primary shock absorber at the knee and without it, it increases your risk for knee osteoarthritis.
Do you need surgery? Not all meniscal tears require surgery, however, there are many reasons to consult with a surgeon about meniscus surgery. If you have significant pain, swelling, popping, and clicking, and your knee gets locked up, you should consult with a surgeon about your symptoms. If you are having occasional pain and swelling in your knee and it responds to physical therapy you may be able to get along without surgery. If the patient has a complex tear, a radial tear, or a meniscus root tear, and is a good candidate with relatively younger age and good cartilage surfaces, a meniscus repair would be indicated to address the tear and prevent further progression of osteoarthritis.
What is the difference between a meniscus repair and a meniscectomy?
Didn’t know there was a difference? There is a significant difference between the surgery and the rehab. A meniscectomy is the removal of part of the meniscus that was damaged or appears to be causing the patient’s complaints. A meniscus repair is done to larger tears that occur in the outer 1/3 of the meniscus. Tears that occur in the outer 1/3 have blood flow and are able to heal slowly provided the correct environment with rehab. Your surgeon will sometimes consider performing a repair to a tear in the middle 1/3 of the meniscus if you are a good candidate, but the blood supply to the meniscus diminishes as you progress towards the thinner and more internal portion of the meniscus. Ultimately, we want to keep as much meniscus as we can to prevent knee OA.
Rehab for a meniscectomy is typically immediate weight-bearing as tolerated and return to sports activities when swelling, pain, strength, and stability has been restored to the prior level of function.
Rehab for a meniscus repair typically involves 4-6 weeks of nonweight bearing (NWB) which allows the repair to start to heal. Weight-bearing causes compression and rotation on the meniscus surface and can damage the repair if not gradually progressed during the right time frames as recommended by the surgeon. Compliance is critical for a successful surgery. The eventual return to sports activities requires control of knee swelling, pain-free ROM, restored strength and stability at the knee.
Meniscus injuries range from insignificant and asymptomatic to significant in nature. Rehab is a significant factor in a patient’s success. To learn how we can help you stay active click here.
Pain and swelling
Medial Meniscus Tear
Meniscus diagram