A torn cartilage is damage to the tough, flexible tissue that cushions and protects your joints. The term most commonly refers to a torn meniscus in the knee, but cartilage tears can also affect the hip, shoulder, and other joints. Cartilage damage is remarkably common: when surgeons look inside knees during arthroscopy, they find cartilage defects in 60% to 66% of cases.
Types of Cartilage That Can Tear
Your joints contain two main types of cartilage, and both can be damaged. Articular cartilage is the smooth, slippery coating on the ends of bones where they meet at a joint. It’s made up of about 80% water and is designed to let bones glide against each other with almost no friction. The meniscus, found only in the knee, is a tougher, more fibrous wedge of cartilage that sits between the thighbone and shinbone. It acts as a shock absorber, converting the downward force of your body weight into outward tension that the tissue can handle.
The shoulder and hip have a similar structure called the labrum, a ring of fibrous cartilage that deepens the socket and helps stabilize the joint. When people say “torn cartilage” without specifying, they usually mean the knee meniscus, which is the most frequently injured.
Why Cartilage Heals Poorly on Its Own
Cartilage is one of the few tissues in your body that has almost no blood supply. It also lacks lymphatic drainage and contains only one cell type. This means it gets very little of the raw material other tissues use to repair themselves. A cut on your skin can heal in days because blood rushes in with immune cells and growth factors. Cartilage doesn’t get that response. Only the outer edge of the knee meniscus (roughly the outer 10% to 30%) has any blood vessels at all. Tears in that outer zone have a reasonable chance of healing. Tears in the inner, avascular zone typically do not heal without intervention.
What Causes a Cartilage Tear
Tears fall into two broad categories: traumatic and degenerative. A traumatic tear happens suddenly, often during a sport or accident. Twisting the knee while your foot is planted, a hard pivot, or a direct blow to the joint can shear the cartilage. These injuries are common in sports that involve cutting, jumping, or quick direction changes.
Degenerative tears develop gradually over time. The cartilage weakens and frays from years of loading, and eventually a minor movement can cause it to give way. Contributing factors include high-impact repetitive stress, abnormal joint alignment, joint instability, and inadequate muscle strength around the joint. Lifelong moderate use of normal joints does not, on its own, increase the risk of this kind of wear.
Symptoms to Recognize
The hallmark symptoms of a torn cartilage in the knee include:
- Pain that worsens with twisting or rotating the joint
- Swelling and stiffness, which may develop over several hours after the injury
- Locking, where the knee feels stuck and won’t straighten fully
- Catching or clicking, a sensation of something getting in the way during movement
- Giving way, a feeling that the knee buckles or can’t support your weight
- A popping sensation at the time of injury
Not everyone experiences all of these. Some people with degenerative tears notice only intermittent pain and mild stiffness that worsens with activity. Others have a dramatic locking episode that makes walking immediately difficult. The pattern often depends on the size and location of the tear and whether a loose flap of cartilage is catching inside the joint.
How Cartilage Tears Are Diagnosed
A physical exam is usually the first step. Your doctor will check for tenderness along the joint line, test your range of motion, and perform specific maneuvers that stress the cartilage to reproduce your symptoms. MRI is the standard imaging tool and is good at ruling out intact cartilage, with specificity of 84% to 100%. However, its sensitivity varies widely, ranging from 0% to 79% depending on the location and size of the lesion. That means MRI can miss some cartilage defects, particularly smaller or partial-thickness ones. In some cases, the full extent of the damage only becomes clear during arthroscopy, when a surgeon looks directly inside the joint with a camera.
Grading the Severity
Surgeons classify articular cartilage damage on a five-point scale. Grade 0 is normal cartilage. Grade I means the surface is soft and swollen but still intact, something you’d only detect by pressing on it with a surgical instrument. Grade II is a partial-thickness defect with small cracks that don’t reach the bone underneath. Grade III involves deeper cracks that extend down to the bone surface, covering an area larger than half an inch across. Grade IV, the most severe, means the cartilage has worn away completely, leaving bare bone exposed.
Meniscus tears are described differently, based on their shape (horizontal, radial, bucket-handle, or complex) and whether they’re in the blood-supplied outer zone or the avascular inner zone. These details determine which treatment options are viable.
Treatment Options
Not every cartilage tear requires surgery. Small, stable tears in a knee that still functions well are often managed conservatively with rest, physical therapy to strengthen the muscles around the joint, and activity modification. Anti-inflammatory measures can help control pain and swelling in the short term.
When surgery is needed, the approach depends on the type and location of the damage. For meniscus tears, the two main options are repair (stitching the torn tissue back together) and partial removal of the damaged portion. Repair is preferred when the tear is in the outer, blood-supplied zone, because the tissue has a chance of healing. Removing the damaged section is faster to recover from but removes a piece of the joint’s shock absorber, which can accelerate cartilage wear over time.
For articular cartilage defects, especially larger ones, there are procedures designed to stimulate new cartilage growth. One common technique involves making tiny holes in the bone beneath the defect to trigger a healing response. A more advanced approach takes a sample of your own cartilage cells, grows them in a lab over several weeks, and then implants them back into the defect on a collagen scaffold. A five-year clinical trial comparing these two approaches found that the cell-based implant produced significantly better pain relief and function for defects 3 square centimeters or larger. Both treatments showed similar improvement on MRI in terms of filling the defect, but patients who received the implant reported better daily function and less pain.
Recovery Timeline After Surgery
Recovery after meniscus repair follows a structured progression. For the first three weeks, you’ll be on crutches with partial weight bearing and a locked brace. The goal during this phase is protecting the repair and managing swelling. Between weeks three and six, weight bearing stays limited, though your surgeon may allow you to start unlocking the brace. Around the six-week mark, most people can ditch the crutches and brace once they’ve regained enough thigh muscle control to walk normally.
Sport-specific training typically begins at three to five months, starting with a return-to-running program and progressing to agility drills. Full, unrestricted return to sport, including hard cutting and pivoting, is generally cleared at six months or later. The timeline stretches longer for articular cartilage repair procedures, where protecting the new tissue while it matures is critical.
Recovery from a partial meniscus removal is considerably faster. Many people are walking without crutches within a week or two and return to normal activities within four to six weeks, since there’s no repaired tissue that needs time to heal.
Long-Term Outlook
The long-term impact of a cartilage tear depends heavily on what was damaged, how it was treated, and what you ask of your joint afterward. A successfully repaired meniscus preserves the knee’s natural shock absorption and reduces the risk of early arthritis. Removing part of the meniscus relieves symptoms effectively but shifts more stress onto the articular cartilage, which is why surgeons prefer repair when possible. Articular cartilage defects, if left untreated, tend to progress rather than improve, since the tissue lacks the biological machinery to rebuild itself. Maintaining strong muscles around the joint, staying at a healthy weight, and choosing lower-impact activities when appropriate all help protect whatever cartilage remains.