Knee problems happen when you injure or develop disease in your knee and it can’t do its job. Your knee is the joint where the bones of the upper leg meet the bones of the lower leg, allowing hinge-like movement while providing stability and strength to support the weight of your body. Flexibility, strength, and stability are needed for standing and for motions like walking, running, crouching, jumping, and turning.


The point at which two or more bones are connected is called a joint. Several kinds of supporting and moving parts, including bones, cartilage, muscles, ligaments, and tendons, help the knees do their job.

  • In all joints your: 
  • Bones are kept from grinding against each other by a lining called cartilage. 
  • Bones are joined to bones by strong, elastic bands of tissue called ligaments.
  • Muscles are connected to bones by tough cords of tissue called tendons. Muscles pull on tendons to move joints. 

Although muscles are not technically part of a joint, they’re important because strong muscles help support and protect your joints.

Each of these structures is subject to disease and injury. When a knee problem affects your ability to do things, it can have a big impact on your life. Knee problems can interfere with many things, from participation in sports to simply getting up from a chair and walking. 


  • Like any joint, the knee is composed of: 
  • Bones. 
  • Cartilage. 
  • Ligaments. 
  • Tendons. 
  • Muscles. 

Take a closer look at the different parts of the knee in the illustration below.


The type of knee problem you have depends on what part of the knee is injured or affected by disease. Here are some of the most common types of knee problems:


There are some 100 different forms of arthritis, rheumatic diseases, and related conditions. Virtually all of them have the potential to affect the knees in some way; however, the following are the most common. 

  • Common Forms of Arthritis:
  • Osteoarthritis is a form of arthritis. In this disease, your cartilage gradually wears away and changes occur in the adjacent bone. Osteoarthritis may be caused by joint injury or being overweight. It is associated with aging and most typically begins in people age 50 or older. A young person who develops osteoarthritis typically has had an injury to the knee or may have an inherited form of the disease. 
  • Rheumatoid arthritis, which generally affects people at a younger age than does osteoarthritis, is an autoimmune disease. This means it happens because your immune system attacks areas of your body. In rheumatoid arthritis, the primary site of the immune system’s attack is your synovium, the membrane that lines the joint. This attack causes inflammation of your joint. It can lead to destruction of your cartilage and bone and, in some cases, muscles, tendons, and ligaments as well.

Meniscal Injuries 

The menisci can be easily injured by the force of rotating the knee while bearing weight. A partial or total tear may occur when a person quickly twists or rotates the upper leg while the foot stays still. For example, when dribbling a basketball around an opponent or turning to hit a tennis ball. If the tear is tiny, the meniscus stays connected to the front and back of the knee; if the tear is large, the meniscus may be left hanging by a thread of cartilage. The seriousness of a tear depends on its location and extent.

Tendon Injuries

Knee tendon injuries range from tendinitis, which is inflammation of a tendon to a ruptured or torn tendon. If a person overuses a tendon, it can stretch and become inflamed. This can happen during activities such as: Dancing. Cycling. Running. 

Tendinitis of the patellar tendon is sometimes called “jumper’s knee” because in sports that require jumping, such as basketball, the muscle contraction and force of hitting the ground after a jump strain the tendon. After repeated stress, the tendon may become inflamed or tear. 


  • Some symptoms of knee problems include:
  • Pain. 
  • Stiffness. 
  • Swelling.
  • Redness.
  • Hot to the touch.
  • Clicking sound in the knee.
  • Locking of the knee joint.
  • Weakness.


Doctors diagnose knee problems based on the findings of a medical history, physical exam, and diagnostic tests. 

Medical History

During the medical history, the doctor asks how long symptoms have been present and what problems you are having using your knee. In addition, the doctor will ask about any injury, condition, or health problem that might be causing the problem. 

Physical Examination 

The doctor bends, straightens, rotates (turns), or presses on the knee to feel for injury and to determine how well the knee moves and where the pain is located. The doctor may ask you to stand, walk, or squat to help assess the knee’s function. 

Diagnostic Tests 

Depending on the findings of the medical history and physical exam, the doctor may use one or more tests to determine the nature of a knee problem. Some of the more commonly used tests include: MRI. CT Scan. X-ray. Ultrasound. Arthroscopy. Joint Aspiration. Biopsy.


At Avala, our team of world-class orthopedic surgeons and sports medicine specialists provides patients with the most innovative orthopedic treatment options from physical therapy to minimally invasive surgery.

Our goal is to reduce your pain and get you moving again. Learn more about robotic knee replacements here

National Institute of Arthritis and Musculoskeletal and Skin Diseases. “Knee Problems.” https://www.niams.nih.gov/health-topics/knee-problems/advanced