The knee is a hinge joint that connects the thigh bone (femur) to the lower leg bones (tibia and fibula) and the kneecap (patella). Like other joints in the body, the knee is made up of tendons and ligaments, as well as cartilage structures like menisci and bursae. The tendons and ligaments provide strength and stability and allow the knee to evenly carry the weight of the body, while the cartilage structures allow for smooth, fluid movements.
The knee may become injured as a result trauma, overuse or degeneration that occurs naturally over time. Injuries can affect any structures within the knee, resulting in a bruise, sprain, strain or fracture. After a knee injury, patients may experience knee pain that varies in frequency and severity, as well as difficulty walking or standing, stiffness and loss of motion.
While knee injuries can affect patients of all ages and activity levels, they are most common in those who participate in high-risk sports, are obese, are older and who lack muscle strength and flexibility.
The ACL (anterior cruciate ligament) is one of the most commonly injured ligaments in the knee. Running diagonally through the middle of the joint, the ACL works together with three other ligaments to connect the femur (upper leg bone) to the tibia (lower leg bone). People who play sports that are likely to damage the knee -- such as basketball, football, skiing and soccer -- are at greatest risk for injuring the ACL. Only about 30% of ACL injuries result from direct contact with another player or object. The rest occur when the athlete decelerates while cutting, pivoting, or sidestepping; lands awkwardly; or plays recklessly. About half of ACL injuries are accompanied by damage to the meniscus, cartilage, bone or other ligaments in the knee.
Signs that you may have injured your ACL include pain, swelling and instability immediately after the injury, followed hours later by greater swelling and pain, limited motion, tenderness and an inability to walk comfortably.
A torn meniscus is a common injury often caused by forcefully twisting or rotating the knee. It can also be a result of degenerative changes in older adults. A meniscus tear can be repaired through arthroscopic surgery.
The menisci are C-shaped pieces of tough cartilage that rest on either side of the knee, between the thigh bone and shin bone. They help to distribute body weight across the knee so it can be properly supported by the bones in the leg, and also provide stability to the knee joint. A meniscus tear is common after a traumatic injury, and most frequently occurs when the knee joint is bent and the knee is then twisted. Torn menisci are common in athletes and older adults whose cartilage may have worn away.
A torn meniscus causes pain and swelling, and may also be accompanied by a frequently locking joint and the inability to completely straighten the knee. Some people experience a popping or clicking sensation within the knee as well.
Treatment for a meniscus tear often begins with conservative methods such as rest, ice or over-the-counter medication. If these treatments are not effective and symptoms continue, you may benefit from meniscus repair surgery. Meniscus repair is an arthroscopic procedure in which the torn segment of the meniscus is removed and the torn edges are sutured together, which allows them to heal properly.
Patellofemoral syndrome, also known as chondromalacia patella, is a pain condition involving a degeneration of the cartilage in the kneecap, which may be caused by overuse, injury, obesity or malalignment of the kneecap. While this condition can affect anyone, it is most common in athletes and those who engage in frequent manual labor.
Patients with patellofemoral syndrome experience knee pain that is worse when the knee is bent, such as while sitting, using stairs or jumping. A buckling or popping sensation within the knee, as well as feelings of tightness or fullness, is also possible.
While patellofemoral syndrome is a chronic condition with no real cure, there are several basic treatment options available to relieve symptoms, most of which focus on avoiding triggering activities. Treatment for patellofemoral syndrome may involve rest, simple life changes, avoiding certain movements and anti-inflammatory medications.
Customized physical therapy exercises, including stretching to improve flexibility and relieve tightness, may also be utilized. More severe cases may require surgery, but this is considered rare. Your doctor will determine the most appropriate treatment option for your individual condition.
