In this Article


The knee joint is the largest joint in the human body. It connects your thigh bone (femur) to the bones in your lower leg (tibia and fibula), and also includes the kneecap (patella). There is cartilage between the femur and tibia that provides cushioning in your knee. This cartilage is called the medial and lateral menisci.

The bones in your knee are joined by ligaments that provide stability as you move. These ligaments include:

  • The anterior cruciate ligament (ACL)
  • The posterior cruciate ligament (PCL)
  • The medial collateral ligament (MCL)
  • The lateral collateral ligament

Tendons connect the knee joint to the muscles in your leg.

Like any joint in your body, the knee is vulnerable to injuries, especially if you play sports. The knee joint can also develop osteoarthritis, a painful condition caused by normal wear and tear on the joint.

Some factors can increase your risk of having knee problems. These factors include the following:

  • Obesity
  • Older age
  • Having previous knee injuries
  • Playing sports
  • Lack of strength or flexibility in your knees and legs

Things You Need to Know

Orthopedics is the branch of medicine that treats injuries and other problems with the bones, joints, and muscles in your body. The Intermountain Healthcare Orthopedic Specialty Group works with patients to treat many different knee problems, including the following:

  • ACL injuries and reconstruction
  • Kneecap bursitis (inflammation of a fluid-filled sac that cushions the knee joint)
  • Knee replacement surgery
  • Meniscus tears and repair
  • Patellar (kneecap) fracture
  • Patellar tendon rupture
  • Tendonitis (inflammation of a tendon)
  • Tibia fractures

When to See a Doctor

See your doctor if you notice any of the following:

  • Pain in one or both knees
  • Swelling or stiffness of the knee joint
  • Weakness or instability of the knee
  • Popping or cracking noises while you are walking or exercising
  • Dislocation of the knee joint
  • You can’t straighten your knee all the way

Your doctor will perform a physical exam and discuss your symptoms with you. Depending on the cause of your pain, they may order one or more of the following imaging exams:

  • X-rays to look for fractures and degenerative joint disease
  • Computed tomography (CT) scans to diagnose problems with your knee joint, tendons, and ligaments
  • Ultrasound to evaluate the soft-tissue structures around your knee
  • Magnetic resonance imaging (MRI) to look for injuries to ligaments, tendons, cartilage, and muscles surrounding the knee

Treatment for some knee problems might include rest, stretching exercises, pain medicine, or injections of steroids. If surgery is needed, your doctor will refer you to an orthopedic surgeon (a specialist in surgical correction of bone, joint, and muscle problems).

Support and Resources

American Academy of Orthopaedic Surgeons