A torn meniscus is a rip in one of the two C-shaped pads of cartilage that sit between your thighbone and shinbone, cushioning and stabilizing the knee joint. It’s one of the most common knee injuries, affecting roughly 66 out of every 100,000 people per year, with men injured two to four times more often than women. The injury can happen suddenly during a sport or develop gradually as the cartilage wears down with age.
What the Meniscus Actually Does
Each knee has two menisci. The medial meniscus sits on the inner side of the knee, and the lateral meniscus sits on the outer side. Together, they cover about 60% of the contact area between your thighbone and shinbone and absorb more than half of the force that passes through the joint with every step. Their wedge shape is key: it converts the downward force of your body weight into outward tension that the tissue can handle, while also stabilizing the rounded end of the thighbone as it moves on the flat surface of the shinbone.
Beyond shock absorption, the menisci help lubricate the joint and nourish the smooth cartilage coating your bones. When you bend your knee fully, the lateral meniscus bears 100% of the load on the outer side of the knee, while the medial meniscus handles about 50% of the load on the inner side. Losing part or all of a meniscus shifts that force directly onto the bone surfaces, which is why tears matter for long-term joint health.
How Meniscus Tears Happen
In younger people, meniscus tears typically result from a forceful twist or pivot while the foot is planted, common in sports like soccer, basketball, and football. These acute tears often happen alongside other knee injuries, particularly ligament sprains. Isolated lateral meniscus tears skew younger: 63% occur in patients under 20. Isolated medial tears trend older, with more than half found in people over 30.
In middle-aged and older adults, the meniscus gradually dries out and weakens. A degenerative tear can happen during something as ordinary as standing up from a chair or stepping off a curb. The cartilage has simply worn thin enough that normal forces are enough to cause a rip.
Types of Meniscus Tears
Not all tears are the same, and the type matters for both symptoms and treatment options.
- Horizontal tear: Runs sideways through the meniscus, splitting it into an upper and lower layer, like separating the halves of a sandwich. Common in degenerative knees.
- Radial tear: Cuts inward from the free edge, perpendicular to the long curve of the meniscus. This severs the fibers responsible for distributing load, which can significantly reduce the meniscus’s ability to absorb shock.
- Longitudinal tear: Runs along the length of the meniscus, parallel to its outer edge. Small longitudinal tears sometimes heal on their own if they’re in a well-supplied area.
- Bucket-handle tear: A large longitudinal tear where the inner fragment flips into the center of the joint, like the handle of a bucket. This type frequently locks the knee.
- Flap tear: A piece of torn meniscus folds back on itself, creating a flap that can catch between the bones during movement.
What a Torn Meniscus Feels Like
The hallmark symptoms are pain along the joint line (the crease on either side of the knee where the bones meet), swelling, and mechanical symptoms: clicking, catching, or locking. You might feel a pop at the moment of injury. Swelling often develops over several hours rather than immediately, which distinguishes it from injuries like a torn ACL that tend to swell within minutes.
A locked knee, where you physically cannot straighten the joint all the way, suggests a displaced fragment like a bucket-handle tear is blocking movement. Some people also describe the knee “giving way,” a sudden feeling of instability during walking or turning. Smaller tears may produce only mild, intermittent aching that worsens with squatting, twisting, or climbing stairs.
How a Torn Meniscus Is Diagnosed
A doctor will typically start with a physical exam, bending and rotating your knee to reproduce pain or a click along the joint line. These hands-on tests are useful screening tools, but MRI is the standard for confirming a tear. For medial meniscus tears, MRI has a sensitivity of about 93% and a specificity of 88%, meaning it catches the vast majority of tears and rarely flags a normal meniscus as torn. Lateral tears are slightly harder to detect, with sensitivity around 79% but specificity above 95%.
Why Blood Supply Determines Healing
The outer third of each meniscus receives blood flow from small vessels at the knee’s periphery. This region, traditionally called the “red zone,” has the best chance of healing because blood delivers the oxygen and nutrients that tissue repair depends on. The inner two-thirds, the “white zone,” has little to no blood supply and limited healing capacity.
That said, healing isn’t perfectly predictable by zone alone. Some tears in well-supplied areas fail to heal completely, while some in poorly supplied areas recover unexpectedly. The medial meniscus has fewer blood vessels overall compared to the lateral meniscus, which may partly explain why surgical repairs on the inner side of the knee have a higher failure rate.
Treatment Options
The 2024 guidelines from the American Academy of Orthopaedic Surgeons emphasize preserving as much functional meniscus tissue as possible, because removing it raises the risk of osteoarthritis down the road. Research shows that a partial meniscectomy (trimming away torn tissue) combined with a ligament reconstruction nearly doubles the odds of developing structural arthritis, and a total medial meniscectomy triples those odds.
Nonsurgical Management
For tears that don’t displace or lock the knee, especially degenerative tears in older adults, physical therapy is often the first approach. Strengthening the muscles around the knee, particularly the quadriceps and hamstrings, helps compensate for the lost cushioning. Rest, ice, compression, and anti-inflammatory medication manage pain and swelling in the short term. Many people with small, stable tears improve enough with rehab that they never need surgery.
Surgical Repair vs. Partial Removal
When surgery is needed, repair (stitching the torn edges back together) is preferred over removal whenever the tear has healing potential. A displaced tear that locks the knee, like a bucket-handle tear, generally calls for surgery sooner rather than later. For tears that don’t respond to nonsurgical care, guidelines suggest operating within six months of injury. Waiting longer is associated with more persistent pain and worse functional outcomes.
What Recovery Looks Like
Recovery after a meniscus repair follows a structured timeline. For the first three weeks, you’ll wear a locked brace and use crutches with only partial weight on the leg. Between three and six weeks, you continue partial weight-bearing while gradually unlocking the brace to allow more knee motion. Around the six-week mark, most people can ditch the brace and crutches once they can walk with a normal gait and control their thigh muscles well enough to keep the knee stable.
Sport-specific training typically begins between three and five months, but only after hitting a series of benchmarks: completing a running program without pain or swelling, achieving at least 90% strength in the operated leg compared to the other side, and scoring well on functional hop tests. Full, unrestricted return to sport generally happens at six months or later, progressing from non-contact practice to full practice to game play.
Recovery from a partial meniscectomy (removal rather than repair) is significantly faster. Because the tissue is trimmed away rather than stitched and left to heal, most people bear full weight within days and return to normal activity in four to six weeks. The tradeoff is that less meniscus remains to protect the joint long-term.