If your knee is severely damaged by arthritis or injury, it may be hard for you to perform simple activities such as walking or climbing stairs. You may even begin to feel pain while you are sitting or lying down.
Knee replacement is the resurfacing of the worn out surfaces of the knee and replacing the lost cartilage and diseased bone with metal and plastic. Knees wear out for a variety of reasons, including inflammation from arthritis, injury, or simple wear and tear.
Cartilage is the substance that lines the surface of all the joints in the body. They provide a smooth, lubricated surface for the joint to move through and provide shock absorption to protect the underlying bone. Damage to the cartilage of the knee can occur from many different causes including twisting injuries, sports trauma, and car accidents. People with damage to the cartilage in their knee experience pain, swelling, popping, or clicking. Depending on the size of the damaged area, this can most often be treated through a minimally invasive arthroscopy, or "knee scope". Treatments include debridement, placing small holes in the lesion to stimulate healing, or even transplantation of cartilage from other, healthier parts of the knee to the damaged area.
The knee has two menisci, an inner "medial" meniscus and an outer "lateral" meniscus. They are C-shaped structures made of "rubbery" cartilage that sit between the shinbone (tibia) and thighbone (femur). They act as shock absorbers in the knee and protect the underlying cartilage. Meniscus tears commonly occur with twisting and flexing injuries of the knee such as in sports, falls, and other accidents. Symptoms of a torn meniscus include pain, swelling, popping, clicking, and locking. These injuries are treated with knee arthroscopy ("knee scope") through 3 to 4 very small incisions. The torn portion is often trimmed out, or in some circumstances, repaired. In rare instances, the entire meniscus must be removed, which also removes the shock absorber that protects the cartilage. This can lead to painful arthritis as the underlying cartilage is damaged and can be a difficult problem to treat in young patients. However, this can be prevented with a new procedure that involves transplantation of a similarly sized donor meniscus into the knee, restoring the shock absorption and protecting the cartilage.
Athletes who participate in high demand sports like soccer, football, and basketball are more likely to injure their anterior cruciate ligaments. If you have injured your anterior cruciate ligament, you may require surgery to regain full function of your knee. This will depend on several factors, such as the severity of your injury and your activity level.
The patella, or "knee cap" is the round bone in the front of the knee. It is suspended in the tendon of the quadriceps muscle and is used to help the thigh muscles straighten the knee. The undersurface of the patella is shaped somewhat like a dome and glides in a similarly shaped groove on the end of the thighbone called the "trochlea". The strong ligaments on either side of the knee cap help keep it centered in this groove while the knee is moving. Some people have ligaments around the knee cap that are too loose or too tight, preventing it from sliding the groove correctly. Patients with arthritis or cartilage problems under the knee cap commonly describe pain in the front of the knee particularly with prolonged sitting, arising from a chair, and climbing stairs. This problems can usually be treated with arthroscopy (knee scope), where the cartilage is repaired and the ligaments are re-balanced.