A medial meniscus tear is a common knee injury where the C-shaped cartilage on the inner side of your knee joint gets damaged. This cartilage acts as a shock absorber and stabilizer between your thighbone and shinbone, and when it tears, you typically feel pain along the inner edge of your knee, often with swelling, stiffness, or a sensation that the knee is catching or locking during movement.
What the Medial Meniscus Does
Your knee has two menisci, one on each side. The medial meniscus sits on the inner side, and the lateral meniscus sits on the outer side. These are tough, rubbery wedges of cartilage that distribute your body weight across the knee joint, absorb impact when you walk or run, and help keep the joint stable. Without them, the forces of everyday movement would concentrate on small areas of bone, wearing down the joint surface much faster.
The medial meniscus is less mobile than the lateral one, which makes it more vulnerable to injury. It’s anchored more tightly to surrounding structures, so when the knee twists or absorbs a sudden load, the medial side takes more of the strain.
How These Tears Happen
In younger, active people, medial meniscus tears usually result from a forceful twist of the knee while the foot is planted. This is common in sports that involve pivoting, cutting, or sudden direction changes, like soccer, basketball, and football. A deep squat or an awkward landing can also do it.
In people over 40, tears often develop gradually. The meniscus loses water content and becomes more brittle with age, so even minor movements like getting up from a chair or stepping off a curb can cause a tear. These are called degenerative tears, and they sometimes develop without a single memorable injury.
Types of Medial Meniscus Tears
Not all tears look the same, and the pattern matters because it affects whether the tear can heal on its own or needs surgery.
- Longitudinal tear: Runs vertically along the length of the meniscus, parallel to its curved shape. If this type extends far enough, the torn flap can flip into the center of the joint, creating what’s called a bucket-handle tear, which often locks the knee.
- Horizontal tear: Splits the meniscus into an upper and lower layer, running parallel to the flat surface of the shinbone. These are more common in older adults with degenerative changes.
- Radial tear: Cuts perpendicularly across the body of the meniscus, disrupting its ability to distribute load effectively.
- Oblique (parrot-beak) tear: Runs at an angle through the meniscus. A loose flap from this type of tear can catch between the bones during movement.
What It Feels Like
The hallmark symptom is pain along the inner joint line of the knee, right in the crease where the bones meet. Swelling usually develops within a day or two of the injury. Many people can still walk on a torn meniscus, especially in the first few days, but certain movements make the pain worse: twisting, squatting, or going up and down stairs.
Two sensations are particularly characteristic. One is mechanical locking, where the knee physically gets stuck and you can’t straighten it fully. This happens when a flap of torn cartilage wedges between the bones. The other is a feeling of the knee “giving way,” where the joint suddenly feels unstable, as though it might buckle. You might also notice a clicking or popping sensation when bending the knee.
How It’s Diagnosed
A doctor will typically start with a physical exam, pressing along the inner joint line for tenderness and performing specific maneuvers to stress the meniscus. During the McMurray test, you lie on your back while the examiner bends and rotates your knee, feeling for a click or pain that suggests a tear. The Thessaly test takes a different approach: you stand on one leg with a slight knee bend and twist your body inward and outward three times while the examiner supports your arms. Pain or a catching sensation during either test points toward a meniscus injury.
MRI is the standard imaging tool for confirming the diagnosis. For medial meniscus tears specifically, MRI has a sensitivity of about 95% and a specificity of about 94%, meaning it catches nearly all tears and rarely flags a healthy meniscus as torn. X-rays won’t show a meniscus tear since cartilage doesn’t appear on X-ray, but they can rule out fractures or arthritis.
When Surgery Isn’t Needed
Many medial meniscus tears, particularly degenerative tears and small stable tears, respond well to conservative treatment. The goal is to reduce pain and swelling first, then rebuild strength in the muscles that support the knee.
Strengthening the quadriceps (the muscles at the front of your thigh) is one of the most important parts of rehab, because strong quads reduce the stress your meniscus has to absorb. Exercises targeting the glute muscles also help by improving control during single-leg movements like walking and climbing stairs. A typical program starts with non-weight-bearing exercises like stationary cycling to build muscle without stressing the joint, then progresses to weight-bearing exercises like squats and stair climbing as symptoms allow. Pool-based exercises work well too, since the water supports your body weight while letting you move freely.
Regular aerobic exercise, roughly two and a half hours per week, supports recovery by improving circulation and helping with weight management, both of which reduce knee stress. With consistent effort, most people see meaningful improvement within three to six months.
When Surgery Is Recommended
Surgery becomes the better option when the knee locks frequently, when symptoms don’t improve with physical therapy, or when the tear pattern is unlikely to heal on its own. Two main procedures exist, and the choice between them depends heavily on where the tear sits within the meniscus and how old you are.
Only about 25% of the meniscus receives blood flow. This outer rim, called the red zone, can heal when stitched back together because blood delivers the oxygen and nutrients needed for tissue repair. Tears in this zone are candidates for meniscus repair, where the surgeon sutures the torn edges together. The remaining 75% of the meniscus has no blood supply (the white zone), so repairs in that area tend to fail. Tears here are usually treated with partial meniscectomy, where the surgeon trims away the damaged portion and leaves the rest intact.
Younger patients are more likely to get a repair when possible, because preserving as much meniscus as you can protects the joint long-term. Both procedures are done arthroscopically through small incisions.
Recovery After Surgery
Recovery from a partial meniscectomy is relatively quick. Most people return to normal activities within a few weeks because the meniscus doesn’t need time to heal together, just to settle down from the procedure.
Meniscus repair requires a longer, more structured recovery. For the first three weeks, you’ll be on partial weight-bearing with crutches and limited to bending the knee less than 90 degrees. That restriction continues through about week six, when most surgeons allow you to ditch the crutches and brace, provided your quadriceps are strong enough and your walking pattern looks normal. By nine to twelve weeks, the goal is full range of motion matching your other knee. Sport-specific training starts around three to five months, and unrestricted return to sports, including hard cutting and pivoting, typically happens at six months or later, progressing from non-contact practice to full practice to full play.
Long-Term Joint Health
One of the most important things to understand about a meniscus tear is its relationship to osteoarthritis down the road. Losing meniscus tissue, whether from the original injury or from surgical trimming, changes how forces are distributed across the knee. A study tracking patients aged 16 to 45 in Sweden found that the absolute risk of developing symptomatic knee osteoarthritis was 17% after partial meniscectomy, 10% after meniscus repair, and just 2.3% in the general population. That’s a significant gap, and it’s a major reason surgeons prefer repair over removal when the tear location and blood supply allow it.
Keeping the muscles around your knee strong, maintaining a healthy weight, and staying active with low-impact exercise are the most effective ways to protect the joint after any meniscus injury, whether you had surgery or not.