Types of knee cartilage damage
- Meniscus tears: the most common cartilage injury. Acute tears happen with twisting on a bent knee in sport; degenerative tears develop with age, sometimes from a simple squat.
- Articular cartilage injuries (chondral or osteochondral lesions): damage to the smooth surface of the bone ends, from a fall, a dislocated kneecap or ligament injury.
- Chondromalacia patellae: softening of the cartilage behind the kneecap; see runners knee.
- Osteoarthritis: gradual, widespread thinning of cartilage over years.
Symptoms
- Pain on the inner or outer side of the knee joint, or behind the kneecap.
- Swelling, often developing over 24 hours after an injury.
- Catching, clicking or a feeling that something is moving in the joint.
- Locking: the knee gets stuck and cannot fully straighten.
- Giving way or instability.
- Pain with squatting, twisting, stairs or kneeling.
Fluid in the knee is common; see joint effusion.
Causes and risk factors
- Twisting injuries in football, basketball, skiing and other pivoting sports.
- Ligament injuries such as an ACL tear, which often damage the meniscus or cartilage too.
- Kneecap dislocation.
- Age-related wear and osteoarthritis.
- Excess weight, previous knee surgery and misalignment of the leg.
- Repetitive kneeling and squatting at work.
How it is diagnosed
A clinician asks how the injury happened and examines swelling, joint line tenderness, movement and ligament stability, using specific tests for the meniscus. MRI is the main imaging test for cartilage and meniscus damage. X-rays show bone alignment and osteoarthritis. In older people, MRI often shows degenerative meniscus tears even in knees without pain, so findings are interpreted together with symptoms.
Physiotherapy: the first-line treatment
- Early phase: control swelling and pain, restore full straightening and bending, and reactivate the quadriceps.
- Strengthening: progressive exercises for the quadriceps, hamstrings, hip and calf, such as sit-to-stand, step-ups, bridges and leg press.
- Balance and control: single-leg balance and movement control to protect the knee in twisting.
- Load management: temporarily reduce deep squatting, pivoting and running, then return gradually.
- Return to sport: running drills, jumping and change of direction once strength is near that of the other leg.
For degenerative meniscus tears, studies show that exercise therapy gives results similar to keyhole surgery for most people. A knee support or tape may help in the short term; see KT tape for the knee.
When surgery is considered
- A locked knee that cannot straighten, usually from a displaced meniscus fragment.
- Meniscus repair for suitable tears, mainly in younger people, to preserve the shock absorber.
- Partial meniscectomy to trim an unstable torn piece when repair is not possible and symptoms persist.
- Cartilage restoration (microfracture, osteochondral grafts or cell-based techniques) for selected focal cartilage defects.
- Ligament reconstruction when instability from an ACL tear coexists.
- Knee replacement for advanced osteoarthritis; see knee replacement recovery.
Recovery times
- Physiotherapy for degenerative tears: improvement over 6 to 12 weeks.
- Partial meniscectomy: return to normal activities in 4 to 6 weeks.
- Meniscus repair: protected weight bearing and limited bending for several weeks; return to sport in 4 to 6 months.
- Cartilage restoration: 6 to 12 months before full return to sport.
Protecting the knee in daily life
- Choose low-impact activities such as cycling, swimming and walking while symptoms settle.
- Avoid deep squatting, kneeling and twisting on a planted foot during flare-ups.
- Use the handrail on stairs and lead with the stronger leg going up and the painful leg going down.
- Maintain a healthy weight: every kilo lost reduces the load across the knee with each step.
- Keep up strengthening exercises two or three times a week even after symptoms improve.
- Use ice after activity if the knee swells, and heat for stiffness.
For pain relief choices, see ice or heat for knee pain.
When to see a doctor
- The knee is locked and you cannot straighten it.
- Major swelling within hours of injury, or inability to bear weight.
- The knee repeatedly gives way.
- A hot, red, swollen knee with fever: emergency.
- Pain that does not improve after several weeks of exercise and self-care.
Key points to remember
- Knee cartilage damage includes meniscus tears and articular cartilage injuries.
- Pain, swelling, catching and locking are the main symptoms.
- Physiotherapy is the first-line treatment for most people.
- Surgery is reserved for locked knees, repairable tears and persistent mechanical symptoms.
Questions about knee cartilage damage
These answers are general information and do not replace an examination or individual medical advice.
Can knee cartilage heal on its own?
Cartilage has a limited ability to heal, but symptoms often improve with physiotherapy as the muscles around the knee get stronger.
How do I know if I have damaged my knee cartilage?
Pain on the joint line, swelling, catching or locking after a twisting injury suggest it. Examination and MRI confirm.
Can I walk with knee cartilage damage?
Usually yes, within comfort. A locked knee that cannot straighten needs prompt assessment.
Is surgery always needed for a meniscus tear?
No. Most degenerative tears improve with exercise therapy. Surgery is for selected cases.
What exercises are good for knee cartilage damage?
Quadriceps and hip strengthening, step-ups, bridges, cycling and balance exercises, progressed gradually.
How long does knee cartilage damage take to heal?
From 6 to 12 weeks with physiotherapy to 4 to 12 months after repair or restoration surgery.
Sources
This guide is for general information and does not replace medical advice. How a problem is diagnosed and treated depends on your examination and medical history. If you think you have an emergency, contact your local emergency services.