Knee Pain Causes and Treatment Options

Runner holding knee in pain
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Knee pain is an extremely common complaint, and there are many causes. It is important to have a doctor evaluate you in order to get an accurate diagnosis so that appropriate treatment can be provided. Take a look at some of the most typical causes of knee pain, below. 

Sudden Injuries

  • Ligament injuries: Ligament injuries commonly occur during athletic activities and can cause discomfort and instability. One of the most well-known types is tearing the ACL or anterior cruciate ligament. There are three other ligaments that may also be torn, such as the posterior cruciate ligament (PCL), the medial collateral ligament (MCL), or the lateral collateral ligament (LCL).
  • Cartilage injuries | Meniscal tearCartilage tears are seen in young and old patients alike. Cartilage is a type of connective tissue in the body. The knee has two types of cartilage: articular cartilage (which forms the smooth layer of the joint that covers the bone ends) and the meniscus (which serves as a shock absorber or cushion between bones).
  • Dislocated kneecapdislocated kneecap—where the patella comes completely out of its groove on the end of the femur or thigh bone and rests on the knee joint—causes acute symptoms during the dislocation, and can also lead to chronic knee pain.

Wear-and-Tear/Overuse Injuries That Progress Over Time

  • Knee arthritisArthritis, specifically osteoarthritis, is among the most common causes of knee pain, and there are many treatments available. It's also called wear-and-tear arthritis or degenerative joint disease. Cartilage in the joint is worn down over time, causing pain and swelling. This tends to occur in older patients, especially those who are overweight.
  • Patellar tendonitisTendonitis around the joint is most commonly of the patellar tendon, the large tendon over the front of the knee that connects the kneecap (the patella) to the shinbone. This tendon is what helps the knee straighten and kick. Patellar tendonitis happens when the tendon becomes irritated and inflamed. It's usually seen in athletes who jump a lot, like those who play basketball or volleyball. 
  • Chondromalacia patellaChondromalacia patella (also known as "runner's knee") causes knee pain under the kneecap and is due to a gradual softening of the cartilage. It is most common in younger patients (15 to 35 years old).
  • Baker's cystA Baker's cyst is a fluid-filled sac that's caused by excess fluid in the knee joint and can lead to swelling in the back of the joint. It can occur in those who have osteoarthritis or rheumatoid arthritis, or in those who have had a knee injury (like a meniscal tear) or have a chronic knee condition. It tends to happen after the joint capsule becomes damaged or weakened. 
  • BursitisThe most common bursa affected around the joint is just above the kneecap. This is most common in people who kneel over and over again for work, such as gardeners, plumbers, or carpet layers.

In Adolescents

  • Osgood-Schlatter diseaseOsgood-Schlatter disease is a condition that's seen in adolescents and is due to the irritation of the growth plate just at the front of the joint.
  • Osteochondritis dissecansOsteochondritis dissecans is another condition that's seen in adolescents and causes a loosening of cartilage and its supporting bone. 

Uncommon Causes

  • Plica syndromePlica syndrome can be difficult to diagnose. It's irritation of the inner lining of the knee joint. The diagnosis is usually made at the time of arthroscopy.
  • GoutGout occurs when there is an accumulation of uric acid (a waste product of many foods that you eat) in the fluid of your joints. 

When to See a Doctor

If you are unsure of the cause of your symptoms, or if you do not know the specific treatment recommendations for your condition, seek medical attention. Treatment of knee pain must be directed at the specific cause of your problem. Some signs that you should be seen by a doctor include:

  • An inability to walk comfortably on the affected side
  • Injury that causes deformity around the joint
  • Knee pain that occurs at night or while resting
  • Knee pain that persists beyond a few days
  • Locking of the knee (or an inability to bend the knee)
  • Swelling of the joint or the calf area
  • Signs of an infection, including fever, redness, warmth
  • Any other unusual symptoms

Treatments For Knee Pain

Treatment of knee pain depends entirely on the cause of the problem. Therefore, it is of utmost importance that you talk to a doctor and understand the exact cause of your symptoms before embarking on a treatment program. These are some common treatments for knee pain.

  • Rest: The first treatment for most common conditions that cause knee pain is simply to rest the joint and allow the acute inflammation to subside. Often this is the only step needed to relieve knee pain. For instance, if overuse is one of the causes of your knee pain, exercising or doing a particular activity every other day or every few days—as opposed to every day—may provide relief. Building up exercise intensity slowly over a longer period of time might also be beneficial (for instance, increasing running mileage no more than 10 percent per week). If symptoms are severe, crutches may be helpful.
  • Ice and heat application: Ice packs and heat pads are among the most commonly used treatments for knee pain. Ice is most effective after exercising to limit swelling and inflammation. Heat, on the other hand, can be helpful before exercising to loosen up muscles and increase flexibility. 
  • Stretching: Stretching the muscles and tendons that surround the joint can help with some causes of knee pain. 
  • Physical therapy: Physical therapy is an important aspect of treatment of almost all orthopedic conditions. Physical therapists use different techniques to increase strength and flexibility, reduce pain, regain balance, and help return patients to their pre-injury level of activity.
  • Anti-Inflammatory medication: Nonsteroidal anti-inflammatory medications, commonly referred to as NSAIDs, are some of the most commonly prescribed medications, especially for patients who have knee pain that is caused by problems such as arthritis, bursitis, and tendonitis.
  • Cortisone injections: Cortisone is a powerful medication that treats inflammation, and inflammation is a common problem in patients with knee pain. Discuss with your doctor the benefits and risks of a cortisone injection. Most physicians will not administer more than three cortisone shots to one area of the body in a one-year span as repeated injections may raise the odds of weakening tendons and softening cartilage.

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