Overview
Each knee has two menisci: C-shaped wedges of fibrocartilage that sit between the femur and tibia on the inner (medial) and outer (lateral) sides. They spread load across the joint, absorb impact and add stability. A tear is a split in that wedge, and the pattern of the split matters as much as the fact of it — a longitudinal tear near the outer rim in a 22-year-old has a blood supply and can be stitched; a frayed degenerative tear in the inner third of a 58-year-old's meniscus has none and cannot.
Meniscus tears are the most common reason for knee arthroscopy, and also one of the most common findings on MRI in knees that do not hurt. Deciding which tears need treatment, and which treatment, is the purpose of the visit. Dr. O'Donnell's bias is toward preserving meniscus tissue whenever it can be preserved, because the meniscus is the knee's protection against arthritis.
Common Symptoms
- Pain along the joint line on the inner or outer side of the knee, worse with twisting, squatting, kneeling or climbing stairs
- Swelling that develops over a day or two after a twisting injury, rather than within hours
- Catching, clicking or a sense of something moving inside the joint
- Locking — the knee gets stuck short of full extension and has to be wiggled free — which indicates a displaced fragment
- In degenerative tears, pain that comes on without a clear injury, often first noticed getting up from a low chair or out of a car
Pain on the joint line with twisting separates a meniscus tear from most other knee problems. Pain behind or around the kneecap with stairs and sitting points toward patellofemoral pain; pain with giving way after a pop points toward the ACL, which is torn alongside the meniscus in a large share of sports injuries.
Causes & Risk Factors
In younger patients the mechanism is a twist on a planted foot with the knee bent — a cut in soccer or football, a pivot in tennis, a deep squat under load, or a ski fall. These are traumatic tears and are often repairable. After 40 the meniscus loses water content and elasticity and can tear with trivial load: standing from a squat, stepping off a curb, gardening. These degenerative tears are usually horizontal or complex, sit in the poorly vascularized inner zone, and frequently accompany early knee arthritis. Prior ACL injury, a previous partial meniscectomy, and occupations that involve prolonged kneeling and squatting raise the risk.
How It Is Diagnosed
The exam localizes the tear. Dr. O'Donnell checks for joint-line tenderness, performs the McMurray test (rotating the bent knee while extending it to reproduce a click or pain) and the Thessaly test (twisting on a slightly bent, weight-bearing knee), and examines the ligaments and kneecap because meniscus tears often occur with other injuries. Whether the knee fully extends is checked at every visit; a knee that cannot is treated as a bucket-handle tear until proven otherwise.
Weight-bearing X-rays are taken to assess joint space and alignment — in a patient over 45 with a degenerative tear, the amount of arthritis on the X-ray predicts the outcome of surgery better than the MRI does. MRI confirms the tear and describes its pattern, location and size, which together determine whether it is repairable. It is ordered when the exam suggests a tear and treatment will depend on the answer, and is not needed for every sore knee.
Treatment Options
Non-operative care
Degenerative tears without locking are treated without surgery first, and most improve. The program controls swelling, restores full motion and quadriceps control, then rebuilds strength in the hip and thigh over about 6 to 12 weeks while avoiding deep squatting and pivoting. A corticosteroid injection can reduce pain and swelling in a knee that is too irritable to exercise. Several large trials have shown that physical therapy matches arthroscopic trimming for degenerative tears in middle-aged patients, so surgery on this group is reserved for those who fail a proper course of rehabilitation or have mechanical locking.
Meniscus repair
When a tear is in the vascular outer zone, is longitudinal or radial, and the tissue is healthy — the typical traumatic tear in a younger patient — Dr. O'Donnell performs an arthroscopic meniscus repair, suturing the torn edges together so the tissue heals. Repair has a longer recovery than trimming and a healing rate that is not 100%, but a repaired meniscus keeps functioning for decades, and the long-term arthritis risk after losing meniscus tissue is well documented. Repair is strongly favored when the tear accompanies an ACL reconstruction, because the healing environment is better.
Partial meniscectomy
Tears that cannot heal — inner-zone, complex, degenerate or flap tears that are catching or locking — are treated by partial meniscectomy, an arthroscopic procedure that removes only the unstable fragment and leaves as much of the rim as possible. Recovery is fast: walking the same day and most activity within a few weeks.
Recovery & What to Expect
The two operations have very different timelines, and that difference is part of the decision.
| Milestone | Partial meniscectomy | Meniscus repair |
|---|---|---|
| Weight bearing | As tolerated from day one; crutches only until walking is normal | Brace locked in extension for walking; flexion under load limited to 90° for 4–6 weeks |
| Full motion | Weeks 1–3 | Weeks 6–12, progressed gradually |
| Strengthening | From week 1 | Weeks 6–16; no deep loaded flexion |
| Running | Weeks 3–6 as tolerated | Late in months 3–4 if criteria met |
| Pivoting and cutting | Weeks 4–6 | Not before about 4 months |
| Return to sport | Typically 4–6 weeks | Typically 5–6 months, on symmetric strength and hop testing |
Patients managed without surgery generally return to full activity over 6 to 12 weeks. All three protocols are available as PDFs: nonoperative management, partial meniscectomy, and meniscal repair.
Frequently Asked Questions
Can a meniscus tear heal on its own?
Only tears in the outer third of the meniscus have a blood supply, and small stable tears there can heal with protection. Tears in the inner two-thirds do not heal. Many degenerative tears stop hurting with rehabilitation even though the tear itself remains, which is a good outcome.
Do I need surgery for a meniscus tear?
Most degenerative tears in patients over 40 do not, and are treated with 6 to 12 weeks of physical therapy first. Surgery is recommended for tears that lock the knee, for traumatic tears in younger patients that can be repaired, and for tears that keep catching or swelling after a proper course of rehabilitation.
What is the difference between meniscus repair and meniscectomy?
Repair stitches the torn edges together so the tissue heals and keeps protecting the joint; it takes 5 to 6 months to return to sport. Partial meniscectomy trims out the torn fragment; recovery takes 4 to 6 weeks, but the removed tissue does not regrow and the joint is left with less cushioning. Dr. O'Donnell repairs whenever the tear pattern and tissue allow it.
Can I walk after meniscus surgery?
After a partial meniscectomy, yes — the same day, with crutches only until your gait is normal. After a repair you walk in a brace locked straight and avoid bending under load for the first 4 to 6 weeks so the sutured tissue can heal.
Will a meniscus tear lead to arthritis?
Losing meniscus tissue raises the long-term risk of arthritis in that compartment, which is why preserving the meniscus is the priority when a repair is possible and why trimming removes as little as possible. A tear that is managed non-operatively and stops causing symptoms does not by itself cause arthritis.
How quickly can I be seen for a locked knee?
A knee that will not straighten is treated as urgent. Call (305) 393-8810; same-week appointments are kept for acute injuries, and out-of-town athletes can send imaging ahead through mymedicalimages.com.
This page is for general education and is not a substitute for a medical evaluation. Treatment recommendations depend on your individual diagnosis and goals. Kevin O'Donnell, MD sees patients from Coral Gables, Miami, Brickell, Pinecrest and Coconut Grove at 475 Biltmore Way, and out-of-town patients by telemedicine.