Types of Knee Problems
The knee is vulnerable to a variety of problems which vary significantly from a temporary, minor problem to a severe or progressive disability.
The term “acute” means that the problem develops suddenly, typically from a severe twisting or wrenching of the knee or from the impact of a fall or sports collision. The most common acute problems affecting the knee are sprains, strains and tears of the soft tissues of the knee joint — the ligaments, tendons and cartilage or menisci. These structures may be injured as a result of a single incident or by repeated minor trauma, called an “overuse” injury.
Bone fractures are not as common as soft-tissue injuries, but they are more likely to occur in children, especially affecting the more delicate growth plate in a child’s bones. Also at particular risk are older individuals whose bones may be weakened by osteoporosis.
Signs of an acute knee problem usually develop within minutes to a few hours after the injury and include pain, swelling, limited mobility, and abnormal sensations within the knee, such as the feeling of a “pop” or a “giving way.” There may be an audible sound at the moment of impact or a persistent “crackling” of the knee joint even after other symptoms subside. In some cases, the knee will feel as though it is “locked,” without pain or swelling.
An acute injury may respond well to first aid measures, and symptoms may be relieved within 24 to 48 hours. However, if symptoms persist, or if there is any question about the severity of the injury, an evaluation by an orthopedic specialist should be obtained.
The term “chronic” is used to describe problems that develop gradually over time. Chronic knee problems may include minor mechanical problems, such as knee dislocation, or a progressive, degenerative problem such as osteoarthritis or rheumatoid arthritis. Symptoms will vary with the severity of the problem. For example, arthritis is a major source of disability, even though the problem may cause only minor symptoms in its early stages.
Inflammation is a process that can accompany both acute and chronic knee problems. It is a type of pain that is localized in the knee joint and may be accompanied by a sensation of abnormal warmth, redness and swelling. It may be temporary, as in bursitis or synovitis, or the condition may produce recurrent symptoms and progressive disability, as with the different forms of arthritis.
The swelling that accompanies an inflamed joint results from fluid accumulation produced and secreted by the extensive synovial lining of knee structures. The extent of swelling can vary significantly, with both generalized swelling and swelling at specific sites, depending on the severity of the problem and the structure that is inflamed.
Select from the topics below for more information about common injuries to the knee.