Meniscus Tear

The menisci are two C-shaped pads of cartilage in your knee, one on the inside (the medial meniscus) and one on the outside, that cushion the joint between your femur and tibia. They deepen the contact between the bones, spread the load evenly, and help the knee feel stable. A tear disrupts all of that. The inner meniscus tears about about twice as often as the outer one. Tears come in different shapes, and they are grouped by what caused them, either a sudden injury or gradual wear.

In younger patients, tears usually happen with a twisting or cutting injury, often alongside an ACL rupture. In middle-aged and older patients, tears are usually degenerative: the cartilage has gradually worn down with age, and the tear coexists with underlying osteoarthritis.

The meniscus has three blood-supply zones. The outer third, the "red zone," gets enough blood flow to heal reliably. The middle third heals inconsistently. The inner third gets almost no blood flow and heals poorly on its own. Where the tear sits on this map matters enormously: a tear in the outer red zone in a young patient is worth repairing; a tear in the inner zone in an older patient is usually better trimmed out cleanly. Your age, your activity demands, and the tear pattern all factor in.

Sudden (acute) tears happen when the bent knee is loaded and twisted hard, pivoting in soccer, landing wrong from a jump. Gradual (degenerative) tears creep in over years as the cartilage loses its tough fiber structure with age.

• Medial or lateral joint-line pain, localized to one side of the knee
• Mechanical symptoms: catching, locking, or a sense of something moving inside the joint
• Pain with squatting, twisting, or rising from a chair
• Delayed swelling developing over 24-48 hours (unlike an ACL tear, which causes the knee to fill with blood almost immediately)
• A palpable click with deep flexion in some patients

Tenderness right along the joint line on the affected side, plus specific moves that load the meniscus and reproduce pain. Standard X-rays rule out a fracture and check for arthritis. That last point matters: in patients who already have arthritis with a degenerative meniscus tear, arthroscopic surgery to clean up the tear is no better than structured physical therapy. Knowing that going in changes the conversation.

MRI defines the tear pattern, length, and location relative to the blood-supply zones, and shows any associated ligament or cartilage damage. Your provider will order one when the diagnosis is uncertain, when surgery is being planned, or when symptoms are not improving with initial care.

Not every meniscus tear needs surgery. For degenerative tears and for most stable tears without true mechanical locking, the right starting point is a structured nonoperative program, not the operating room. The steps below are introduced together, each one building on the others rather than replacing them.

When surgery is the right call, the guiding principle is simple: save the meniscus whenever we can. Arthroscopic surgery is considered for acute tears with true locking, unstable tear patterns that are likely to propagate, or persistent mechanical symptoms after a structured nonoperative trial.

Whenever tear pattern, tissue quality, and vascular zone allow, repair is preferred over removal, because preserving the meniscus preserves the knee. Repair is most successful in younger patients, in the peripheral (red-zone) tear, and when performed alongside concurrent ACL reconstruction.

Recovery depends on which procedure was performed. After a partial meniscectomy (removal of the unstable torn piece), weight-bearing is permitted as tolerated and most patients resume daily activities quickly; return to cutting and pivoting sport follows once strength and confidence return. After meniscus repair or root repair, protected weight-bearing and restricted flexion are required while the repair heals, this is not optional, and adherence directly affects the durability of the result. Return to sport after repair is later and more deliberate than after meniscectomy.

Preserving the meniscus, when feasible, lowers the lifetime risk of knee osteoarthritis compared with partial meniscectomy. Your OSI provider sets activity targets based on imaging, exam, and how the knee is responding, not on a fixed calendar.

External patient-education references and related OSI pages for additional background:

• AAOS OrthoInfo, patient education library
• OSI glossary, orthopedic terminology in plain language