Causes of Knee Pain

Knee injuries are one of the most common reasons patients consult an orthopedic physician.  Injuries to the knee joint are especially common among patients active in sports.  Since knee pain can originate from a variety of causes, it is vital to have a complete evaluation and specific diagnosis prior to treatment.  Knee injuries can be acute (sudden) caused by a trauma or injury or can happen over time due to over use or disease.

Acute injuries include:

• Breaks or fractures - Breaks of the kneecap, femur, tibia, or fibula are usually caused by a fall, a severe twisting movement, or forcefully hitting the knee against an object.
• Kneecap dislocation - The kneecap can be dislocated and interfere with movement.  This type of damage is most common in teenage girls.
• Ligament injuries - Ligament injuries are typically caused by extreme forces on the knee resulting in a strain, sprain, or tear.
• Meniscus injuries - Meniscus injuries can be caused by an acute tear of the meniscus or in combination with tears of the cruciate ligaments.

Examples of over use or disease conditions include:

• Bursitis—Bursitis is the inflammation of the small fluid sacs around the knee.
• Chondromalacia—Chondromalacia describes the softening and deterioration of the cartilage which often occurs at the underside of the kneecap.
• Meniscus injuries - Meniscus injuries can also be caused by a tear that develops over time from twisting, sudden starts or stops, or impact.
• Osteoarthritis—Osteoarthritis is very common among baby boomers and athletes.  Caused by a gradual wearing away of cartilage in the joint, it is a degenerative disease with no known cure.
• Osteochondritis dissecans—When a piece of bone, cartilage, or both loses blood supply and dies within the knee joint it causes pain and decreased mobility.  These pieces of tissue are known as osteochondritis dissecans.
• Other types of arthritis—Other types of arthritis include rheumatoid arthritis, gout, and lupus.  These conditions are not caused by trauma or overuse, but can also cause pain, swelling, and stiffness in the knee.
• Popliteal cysts—A popliteal cyst causes swelling in the back of the knee.
• Tendonitis—Tendonitis refers to irritation or inflammation of a tendon, and is often caused by excess use.