Knee pain is a common reason that people visit their doctors’ offices or the emergency room. Often, knee pain is the result of an injury, such as a ruptured ligament or torn cartilage. But some medical conditions can also bring you to your knees, including arthritis, gout and infections.
Depending on the type and severity of damage, knee pain can be a minor annoyance, causing an occasional twinge when you kneel down or exercise strenuously. Or knee pain can lead to severe discomfort and disability.
Many relatively minor instances of knee pain respond well to self-care measures. More serious injuries, such as a ruptured ligament or tendon, may require surgical repair.
Although every knee problem can’t be prevented — especially if you’re active — you can take certain steps to reduce the risk of injury or disease.
What causes Knee Pain?
In the simplest terms, a joint occurs wherever two bones come together.
But that definition doesn’t begin to convey the complexity of joints, which provide your body with flexibility, support and a wide range of motion.
You have four types of joints: fixed, pivot, ball-and-socket and hinge.
Your knees are hinge joints, which, as the name suggests, work much like the hinge of a door, allowing the joint to move backward and forward. Your knees are the largest and heaviest hinge joints in your body. They’re also
the most complex. In addition to bending and straightening, they twist and rotate. This makes them especially vulnerable to damage, which is why they sustain more injuries on average than other joints.
Your knee joint is essentially four bones held together by ligaments. Your thighbone (femur) makes up the top part of the joint, and two lower leg bones, the tibia and the fibula, comprise the lower part. The fourth bone, the patella, slides in a groove on the end of the femur. Ligaments are large bands of tissue that connect bones to one another. In the knee joint, four main ligaments link the femur to the tibia and help stabilize your knee as it moves through its arc of motion. These include the collateral ligaments along the inner (medial) and outer (lateral) sides of your knee and the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL), which cross each other as they stretch diagonally from the bottom of your thighbone to the top of your shinbone.
Normally, all of these structures work together smoothly. But injury and disease can disrupt this balance, resulting in pain, muscle weakness and decreased function. Many knee injuries are due to overuse, problems with alignment, sports or physical activities, and failure to warm up and stretch before exercise. But they can also result from trauma, such as a car accident, a fall or a direct blow to your knee.
What are the Symptoms of Knee Pain?
A knee injury can affect any of the ligaments, tendons or fluid-filled sacs (bursa) that surround your knee joint as well as the bones, cartilage and ligaments that form the joint itself. Because of the knee’s complexity, the number of structures involved, the amount of use it gets over a lifetime, and the range of injuries and diseases that can cause
knee pain, the signs and symptoms of knee problems can vary widely.
Severe knee pain that comes on suddenly (acute pain) is often the result of injury. Sometimes an injury can lead to ongoing (chronic) knee pain.
Often, chronic pain results from a medical condition such as:
Chondromalacia of the patella, or patellofemoral pain