A torn meniscus is a rip in one of the two crescent-shaped pads of cartilage that sit between your thighbone and shinbone, cushioning and stabilizing your knee joint. It’s one of the most common knee injuries, affecting athletes and older adults alike, though for very different reasons. Each knee has two menisci: one on the inner side (medial) and one on the outer side (lateral). When either one tears, it can cause pain, swelling, and a frustrating sensation that your knee is catching or locking up.
What the Meniscus Actually Does
Your menisci are made of tough, rubbery cartilage that act as shock absorbers between the two largest bones in your leg. Every time you walk, run, or squat, they distribute your body weight across the knee joint so no single point takes too much force. They also help stabilize the joint, keeping the rounded end of your thighbone from sliding around on the flat top of your shinbone.
One important detail about the meniscus explains a lot about why tears can be so tricky to treat: only the outer third has a blood supply. Surgeons call this the “red zone.” The inner two-thirds, the “white zone,” has no blood flow at all. Since blood delivers the nutrients and cells needed for tissue repair, tears in the inner portion generally cannot heal on their own.
How Meniscus Tears Happen
In younger, active people, meniscus tears usually result from a forceful twist or pivot while the foot is planted and the knee is bent. Think of a soccer player cutting sharply, a basketball player landing awkwardly, or a wrestler getting their leg trapped. The sudden rotational force shears the cartilage apart.
In people over 40, the cause is often much less dramatic. Cartilage weakens and thins with age, and even something as ordinary as squatting to pick something up can be enough to cause a tear. MRI studies of people with no knee symptoms at all show just how common this degeneration is: about 28% of middle-aged and older adults have a medial meniscus tear without knowing it. That prevalence climbs steadily with age, from roughly 32% in 65- to 70-year-olds to over 52% in people past 80.
Types of Meniscus Tears
Not all tears are the same, and the pattern matters for treatment. The main types include:
- Horizontal tear: Splits the meniscus into an upper and lower layer, running parallel to the surface of the shinbone.
- Longitudinal tear: Runs along the length of the meniscus, following its curved shape. When this type is severe enough that a piece flips into the center of the joint, it becomes a bucket-handle tear, which often locks the knee.
- Radial tear: Cuts from the inner edge outward, perpendicular to the curve. These are common and can compromise the meniscus’s ability to distribute weight.
- Flap tear: Creates a loose piece that can catch or fold during movement.
- Root tear: Occurs where the meniscus anchors to bone. Though technically a type of radial tear, it has more serious implications because it destabilizes the entire structure.
Symptoms to Recognize
A torn meniscus often announces itself with a popping sensation at the moment of injury. In the hours and days that follow, you may notice swelling, stiffness, and pain that sharpens when you twist or rotate the knee. Some people can still walk on it, which leads them to assume it’s minor.
The more telling symptoms are mechanical. Your knee might feel like it’s catching or clicking during movement. You may have difficulty straightening it fully, or it might lock in place so you temporarily can’t bend or extend it at all. Some people describe a feeling of the knee “giving way,” as though it could buckle at any moment. These mechanical symptoms generally indicate that a torn fragment is interfering with the joint’s normal motion.
How It’s Diagnosed
A doctor will typically start with a hands-on exam. Two common tests involve manipulating the knee while feeling and listening for signs of a tear. In the McMurray test, you lie on your back while the examiner bends and rotates your knee. In the Thessaly test, you stand on one leg and twist your knee inward and outward while the examiner supports your arms and watches for pain, clicking, or a sensation of locking.
If a tear is suspected, an MRI is the standard imaging tool. For tears on the inner (medial) side of the knee, MRI detects about 91% of tears and correctly rules them out about 94% of the time. It’s somewhat less reliable for the outer (lateral) meniscus, catching roughly 73% of tears. X-rays won’t show a meniscus tear since cartilage doesn’t appear on them, but they can rule out other problems like fractures or arthritis.
Treatment Without Surgery
Many meniscus tears don’t need surgery, especially smaller tears in the outer zone or degenerative tears in older adults. If your knee isn’t locking, the swelling is manageable, and you can get through daily activities, your doctor will likely recommend starting with rest, ice, compression, and anti-inflammatory medication to bring down swelling and pain. Physical therapy to strengthen the muscles around the knee, particularly the quadriceps, helps take stress off the joint and can resolve symptoms for many people.
This approach works best for stable tears that don’t produce mechanical symptoms. Your age, activity level, and what you need your knee to do all factor into the decision.
When Surgery Is Needed
If conservative treatment doesn’t relieve your symptoms, or if your knee is locking or giving way, surgery is the next step. It’s done arthroscopically, meaning through small incisions using a tiny camera. There are two main options.
Meniscus Repair
When possible, surgeons prefer to stitch the torn pieces back together. This is most viable for tears in the outer third of the meniscus where blood supply supports healing, and for certain tear patterns like longitudinal tears. The advantage is that you keep your meniscus intact, which matters enormously for the long-term health of your knee.
Partial Meniscectomy
For tears in the inner two-thirds where there’s no blood supply, or for complex tears that can’t be stitched, surgeons trim away the damaged portion. This relieves symptoms faster and has an easier recovery, but it removes cartilage that won’t grow back.
The long-term tradeoff is significant. Research tracking patients over time found that 17% of people who had a partial meniscectomy later developed symptomatic knee arthritis, compared to 10% of those who had a repair and just 2.3% in the general population. When researchers excluded arthritis that appeared within the first two years after surgery (which may have been developing before the procedure), meniscus repair cut the risk of later arthritis roughly in half compared to removal.
Recovery After Surgery
Recovery looks very different depending on which procedure you had.
After a partial meniscectomy, most people are walking within days and return to normal activities within a few weeks. The damaged tissue is simply removed, so there’s nothing that needs time to heal inside the joint.
After a meniscus repair, recovery is slower because the stitched tissue needs to heal. For the first three weeks, you’ll be on crutches with a brace, bearing only partial weight. That partial weight-bearing phase typically continues through about six weeks, at which point most people can ditch the crutches and brace once they’ve regained enough muscle control to walk normally. Sport-specific training begins around three to five months after surgery, but only after meeting strength benchmarks: the repaired leg needs to reach at least 90% of the strength of the other leg. Full, unrestricted return to sport generally happens around six months or later.
Why Preserving the Meniscus Matters
Every bit of meniscus you keep protects the smooth cartilage coating the ends of your bones. When meniscal tissue is removed, the remaining cartilage bears more concentrated force with every step. Over years and decades, that extra stress accelerates wear and raises the risk of osteoarthritis. This is why orthopedic thinking has shifted strongly toward repairing tears whenever the location and pattern allow it, even though repair requires a longer, more demanding recovery. For younger and more active patients especially, the short-term inconvenience of a longer rehab can pay off in a healthier knee for decades to come.