Knee Ligament or Meniscus Tear

First aid for a knee ligament or meniscus injury

• Protect: stop the activity and avoid putting weight on the knee if it hurts. Use crutches if needed.
• Ice: 15 to 20 minutes every 2 to 3 hours for the first 48 to 72 hours, wrapped in a cloth.
• Compress: an elastic bandage to limit swelling.
• Elevate: keep the leg above heart level.
• Pain relief: acetaminophen (paracetamol) or ibuprofen at the label dose.
• Do not force a locked knee straight.

Knee anatomy in brief

Four main ligaments connect the thighbone (femur) to the shinbone (tibia):

• Anterior cruciate ligament (ACL): stops the shin sliding forward and controls twisting.
• Posterior cruciate ligament (PCL): stops the shin sliding backward.
• Medial collateral ligament (MCL): on the inner side, resists the knee bending inward.
• Lateral collateral ligament (LCL): on the outer side, resists the knee bending outward.

The medial and lateral menisci are rubbery C-shaped discs that cushion and stabilize the joint.

Types of tears compared

Grades of ligament sprain

• Grade 1: stretched with microscopic tears. Knee stable. Recovery 1 to 3 weeks.
• Grade 2: partial tear with some looseness. Recovery 3 to 6 weeks.
• Grade 3: complete tear. Knee unstable. Recovery 6 weeks to over 6 months depending on the ligament.

Meniscus tear vs ligament tear

• Swelling: ligament tears (especially ACL) swell within hours from bleeding; meniscus tears often swell gradually over 24 to 48 hours.
• Pain location: meniscus pain is along the joint line on the inner or outer side; MCL pain is slightly above or below the joint line on the inner side.
• Mechanical symptoms: catching, clicking and locking point to the meniscus.
• Instability: giving way with turning points to a ligament, usually the ACL.

They often occur together.

Degenerative meniscus tears

In people over about 40, the meniscus weakens with age, and tears can occur with minor twisting or no injury at all. These are often part of early knee osteoarthritis. Strong evidence shows that arthroscopic trimming for degenerative tears without locking gives no better long-term results than physical therapy, so rehab is the first choice.

Diagnosis

1. History and examination: ligament stress tests (Lachman for ACL, posterior drawer for PCL, valgus and varus stress for MCL and LCL) and meniscus tests (joint-line tenderness, McMurray and Thessaly tests).
2. X-rays: to check for fractures, especially using the Ottawa knee rules.
3. MRI: the best test for ligaments and menisci.
4. Arthroscopy: a camera inside the joint, used mainly for treatment rather than diagnosis.

Treatment

Non-surgical

• RICE and pain relief early on
• Hinged knee brace for MCL and some LCL injuries
• Physical therapy: restore motion, then build quadriceps and hamstring strength, balance and control
• Gradual return to activity over weeks to months

Surgical

• ACL reconstruction with a tendon graft for active people with instability
• Meniscus repair (stitching) for tears in the outer part, which has a blood supply, usually in younger patients. Recovery is longer but it protects the knee from arthritis.
• Partial meniscectomy (trimming) for torn flaps causing locking that cannot be repaired
• Reconstruction of PCL, LCL or posterolateral corner for severe or combined injuries

Outlook

Most MCL and grade 1 to 2 injuries heal fully with rehab. ACL reconstruction allows return to sport in most people after 9 to 12 months. Meniscus damage, and loss of meniscus tissue, raises the long-term risk of osteoarthritis, which is why surgeons try to repair rather than remove when possible.

Frequently asked questions

How do I know if I tore a ligament or my meniscus?

A ligament tear typically causes a pop, rapid swelling and later the knee giving way. A meniscus tear usually causes pain on one side of the knee, swelling that builds over a day or two, and catching or locking. An examination and MRI confirm which structure is damaged.

Can a torn meniscus heal on its own?

Small tears in the outer edge of the meniscus, which has a blood supply, can heal. Tears in the inner part rarely heal, but many become painless with physical therapy. Degenerative tears in older adults are usually treated without surgery.

How long does an MCL tear take to heal?

Grade 1 MCL sprains heal in about 1 to 3 weeks, grade 2 in 3 to 6 weeks, and grade 3 in 6 to 12 weeks with a hinged brace and rehab. Surgery is rarely needed unless other ligaments are torn.

Can I walk on a torn meniscus?

Usually yes, though it may hurt with twisting, squatting or stairs. If the knee locks and will not straighten, see a doctor promptly, because a torn flap may be caught in the joint and need surgery.

When does a knee ligament tear need surgery?

Surgery is usually recommended for complete ACL tears in active people, multi-ligament injuries, some severe LCL and PCL injuries, and knees that lock from a meniscus tear. Most MCL tears and partial tears heal with bracing and rehabilitation.