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What Is Knee Pain? 

Knee pain is one of the most common causes of chronic pain in the U.S., of American adults. Like most joints, the knee is a complex structure involving: 

  • Bones 

  • Cartilage 

  • Ligaments 

  • Muscles 

  • Tendons 

Any one of the many conditions that affect one or more of these can cause pain. The knee is also a weight-bearing joint, which leaves it a high risk for potential pain, with multiple possible causes. 

Causes and Risk Factors 

Knee pain can be caused by both acute injuries and chronic complaints. Some of the more common potential causes of knee pain include: 

  • Chondromalacia: a wearing away of the cartilage on the underside of the kneecap 

  • Dislocation: bones in the knee are out of place 

  • Ligament injuries: these include injury to the anterior cruciate ligament (ACL), medial collateral ligament (MCL), lateral collateral ligament (LCL) or posterior cruciate ligament (PCL) 

  • Meniscus tear: an injury to one of the pads of cartilage between the femur and the tibia 


Risk factors for developing pain in the knee include: 

  • Age: Advancing age raises the risk of many conditions that can cause knee pain, including osteoarthritis 

  • Certain sports: Some sports, such as basketball, skiing and running, place additional stress on the knee, making injury and pain more likely than other sports 

  • Excess weight: Excess weight places additional stress on the knee 

  • Muscle weakness or inflexibility: Weak or stiff muscles around the knee cannot support the joint as well as strong, flexible muscles 

  • Prior knee injury: A former knee injury makes another injury more likely and can lead to chronic conditions that cause knee pain 


Pain in the knee can be felt in different or multiple locations and can have different qualities. Where the pain is felt, how bad the pain is and what other symptoms are also present will depend in large part on the cause of knee pain. 

Pain may be felt: 

  • Behind the knee 

  • Deep within the knee 

  • On the inside of the knee (medial pain) 

  • On the outside of the knee (lateral pain) 

Other symptoms that often accompany knee pain can include: 

  • Bruising 

  • Instability 

  • Popping, grinding or crunching sounds with movement 

  • Stiffness 

  • Swelling 

  • Tenderness 

  • Weakness 


A proper diagnosis for generalized knee pain is crucial because the cause of the knee pain will inform treatment options. Doctors will often start with a medical history and physical exam. A medical history can help determine family history of arthritis or other chronic conditions, as well as any recent injuries to the knee. During a physical exam, doctors will often check for bruising, tenderness or swelling of the knee joint and the knee’s range of motion. 

Imaging tests can often be useful in diagnosing knee pain or confirming a suspected diagnosis. X-rays can detect fractures and other problems with bone, while computed tomography (CT) and magnetic resonance imaging (MRI) scans can check for damage to soft tissue such as cartilage, ligaments and tendons. 


While treatment will depend in large part on the specific condition that is causing the pain, common nonoperative care options can include: 

Surgery, when it is necessary, may be open or arthroscopic, depending on the procedure. Arthroscopic surgeries are done with small tools and a camera called an arthroscope attached to a video monitor, while open surgeries use a comparatively large incision so the surgeon can see directly into the surgical site. 

Common surgeries to treat causes of knee pain include: 

  • ACL reconstruction 
  • Cartilage repair and microfracture, where a surgeon makes small holes in the bone near damaged cartilage to encourage the body to heal itself 
  • Meniscectomy or meniscus repair 
  • Osteotomy, where a surgeon realigns bones in the knee to relieve pain or correct instability 
  • Patella tendon repair 
  • PCL reconstruction 
  • Quadriceps tendon repair 

Severely damaged knees may necessitate a partial or total knee replacement, also known as arthroplasty. 


If you have knee pain, follow the link below and answer a few short questions. Someone will get back to you as soon as possible. Thank you for choosing Summit Health. 

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