Imaging and Knee Pain
Whether at home, work or play, you depend on your knees to get you where you need to go. These workhorse joints can take a lot—none of the body’s other joints can match the knees’ size or strength—but even they have their limits. Pain is often the first clue that your knees have reached those limits. Knee pain can affect nearly every aspect of your life, and when it occurs, the road to relief often starts with imaging. Let’s take a look at three common causes of knee pain and the important role imaging plays in diagnosing them.
A chronic condition that causes joint inflammation, arthritis typically affects the knees
by attacking the cartilage that protects the bones as they rub against each other during movement. This type of arthritis is known as osteoarthritis, and over time, it can destroy all cartilage in the knee, leaving bone to grind against bone. In addition to pain, osteoarthritis can cause stiffness, swelling and weakness.
After a physical exam to look for swelling and other signs of arthritis, some of the first diagnostic tests your physician is likely to order are X-rays
of the knee, which can reveal telltale markers of arthritis, such as bone spurs and narrowing in the joint. If your physician wants a more detailed view of the joint, especially of the connective tissues, you may need to have an MRI
or CT scan
. These tests can help your physician gauge the condition of ligaments, tendons and other tissues.
Bursitis occurs when the overuse of a joint causes inflammation of the bursae—small pouches of fluid that help joints move smoothly. You’re more likely to develop bursitis if you subject your knees to the same repetitive movements day after day without giving them time to recover, such as kneeling to garden. Like arthritis, bursitis causes pain, tenderness and swelling. Bursae aren’t visible on X-rays, but your physician may order them to rule out other potential causes of your symptoms, such as bone-related conditions. To check the bursae, your physician may order an MRI, which can show whether the sacs are inflamed.
Unlike arthritis and bursitis, which are chronic conditions, tears of the menisci—two pieces of cartilage in each knee that help keep bones from rubbing together—tend to be acute injuries that occur because of a sudden twist or blow, often during sports. If you tear a meniscus, you may feel a sudden pop in the knee, followed by instability, pain, swelling and stiffness. The menisci don’t show up on X-rays, but these tests can be useful to help your physician rule out other conditions. An MRI will allow your physician to see your menisci and determine whether there’s a tear in one or both.