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Summary
Your knee joint is made up of bone, cartilage, ligaments and fluid. Muscles and tendons help the knee joint move. When any of these structures is hurt or diseased, you have knee problems. Knee problems can cause pain and difficulty walking.
Knee problems are very common, and they occur in people of all ages. Knee problems can interfere with many things, from participation in sports to simply getting up from a chair and walking. This can have a big impact on your life.
The most common disease affecting the knee is osteoarthritis. The cartilage in the knee gradually wears away, causing pain and swelling.
Injuries to ligaments and tendons also cause knee problems. A common injury is to the anterior cruciate ligament (ACL). You usually injure your ACL by a sudden twisting motion. ACL and other knee injuries are common sports injuries.
Treatment of knee problems depends on the cause. In some cases your doctor may recommend knee replacement.
NIH: National Institute of Arthritis and Musculoskeletal and Skin Diseases
Diagnosis and Tests
- Direct Arthrography (American College of Radiology; Radiological Society of North America) Also in Spanish
- Knee MRI (American College of Radiology; Radiological Society of North America) Also in Spanish
- Knee Problems (American Academy of Family Physicians) Also in Spanish
- X-Ray Exam: Knee (Nemours Foundation)
Treatments and Therapies
- ACL Injury: Diagnosis and Treatment (Mayo Foundation for Medical Education and Research)
- Knee Arthroscopy (American Academy of Orthopaedic Surgeons)
- Knee Replacement: MedlinePlus Health Topic (National Library of Medicine) Also in Spanish
Living With
- Knee Bracing: What Works? (American Academy of Family Physicians) Also in Spanish
- Knee Rehabilitation Exercises (American Academy of Orthopaedic Surgeons)
- Mobility Aids: MedlinePlus Health Topic (National Library of Medicine) Also in Spanish
Specifics
- ACL Injury (American Academy of Family Physicians)
- Baker Cyst (Mayo Foundation for Medical Education and Research)
- Osteochondritis Dissecans (American Academy of Family Physicians) Also in Spanish
- Patellar Tendinitis (Mayo Foundation for Medical Education and Research) Also in Spanish
- Patellofemoral Pain Syndrome (American Academy of Family Physicians) Also in Spanish
- Pigmented Villonodular Synovitis (American Academy of Family Physicians) Also in Spanish
- Swollen Knee (Water on the Knee) (Mayo Foundation for Medical Education and Research) Also in Spanish
Images
- Anterior cruciate ligament repair - series (Medical Encyclopedia) Also in Spanish
- Knee arthroscopy - series (Medical Encyclopedia) Also in Spanish
Test Your Knowledge
- Knee Pain Myths & Facts Quiz (Medical Encyclopedia) Also in Spanish
Clinical Trials
- ClinicalTrials.gov: Anterior Cruciate Ligament (ACL) Injuries (National Institutes of Health)
- ClinicalTrials.gov: Anterior Cruciate Ligament Reconstruction (National Institutes of Health)
- ClinicalTrials.gov: Articular Cartilage Disorders (National Institutes of Health)
- ClinicalTrials.gov: Knee Injuries (National Institutes of Health)
- ClinicalTrials.gov: Menisci, Tibial (National Institutes of Health)
- ClinicalTrials.gov: Patella Disorders (National Institutes of Health)
Journal Articles References and abstracts from MEDLINE/PubMed (National Library of Medicine)
- Article: The applied study to improve the treatment of knee sports injuries...
- Article: The advantages of using tranexamic acid in anterior cruciate ligament reconstruction:...
- Article: Comparison of surgical or non-surgical management for non-acute anterior cruciate ligament...
- Knee Injuries and Disorders -- see more articles
Find an Expert
- Find a Doctor in American Association of Hip and Knee Surgeons (American Association of Hip and Knee Surgeons)
- National Institute of Arthritis and Musculoskeletal and Skin Diseases Also in Spanish
Children
- Osgood-Schlatter Disease (For Parents) (Nemours Foundation)
- Osteochondritis Dissecans (For Parents) (Nemours Foundation) Also in Spanish
Teenagers
- Anterior Cruciate Ligament (ACL) Injuries (Nemours Foundation) Also in Spanish
- Jumper's Knee (Nemours Foundation) Also in Spanish
- Knee Injuries (Nemours Foundation) Also in Spanish
- Medial Collateral Ligament (MCL) Injuries (Nemours Foundation) Also in Spanish
- Meniscus Tears (Nemours Foundation)
- Osgood-Schlatter Disease (American Academy of Family Physicians) Also in Spanish
- Osgood-Schlatter Disease (Nemours Foundation) Also in Spanish
- Runner's Knee (Nemours Foundation) Also in Spanish
Patient Handouts
- ACL reconstruction (Medical Encyclopedia) Also in Spanish
- Anterior crucate ligament (ACL) injury (Medical Encyclopedia) Also in Spanish
- Anterior cruciate ligament (ACL) injury -- aftercare (Medical Encyclopedia) Also in Spanish
- Anterior knee pain (Medical Encyclopedia) Also in Spanish
- Baker cyst (Medical Encyclopedia) Also in Spanish
- Broken kneecap - aftercare (Medical Encyclopedia) Also in Spanish
- Collateral ligament (CL) injury -- aftercare (Medical Encyclopedia) Also in Spanish
- Getting your home ready - knee or hip surgery (Medical Encyclopedia) Also in Spanish
- Knee arthroscopy (Medical Encyclopedia) Also in Spanish
- Knee MRI scan (Medical Encyclopedia) Also in Spanish
- Knee pain (Medical Encyclopedia) Also in Spanish
- Meniscus tears - aftercare (Medical Encyclopedia) Also in Spanish
- Osgood-Schlatter disease (Medical Encyclopedia) Also in Spanish