Knee pain is an extremely common complaint among older men and women. There are many causes, not the least of which is osteoarthritis which affects over 27 million Americans. Some of the more common causes of knee pain include the already mentioned arthritis, ligamental injuries, cartilaginous injuries, patellar tendinitis, dislocated kneecap, bursitis and Baker’s cyst. Less common conditions such as gout, Osgood-Schlatters and osteochondritis – the previous two seen almost exclusively in adolescence- will cause knee pain. (1)
The knee is a hinge joint formed by two bones and held together by four ligaments. The kneecap covers the ventral side of knee, enabling a friction free pain free movement. The joint is surrounded by a membrane that produces a fluid which helps to nourish the cartilage and keep the area slippery. Between the bones in the upper leg and the lower leg, which meet at the knee, is cartilage. This cartilage also helps to cushion the joint and create a friction free motion.
Even if you are only moderately overweight, it can put excessive forces on the knee causing significant wear and tear that can result in osteoarthritis. Research has shown that during walking the hips, knees and ankles will bear up to five times a person’s total weight in force. This means that for every pound of extra weight a person carries another 5 pounds is an added to each knee during walking. Contrast this with a 10 pound weight loss being equivalent to 50 pounds of extra stress relieved from the joints.
Arthritis in the knee will typically affect people over the age of 50 and is more common in those who are overweight or who have suffered significant knee injuries in their earlier years. Researchers have also found a genetic predisposition, which means that it tends to run in families. (2)
The pain of knee arthritis will progress as the condition worsens. Interesting, the arthritis does not always progress steadily over time. Individuals may report that symptoms fluctuate with the weather and that they have good months and bad months.
The most common symptoms that individuals report is pain increases with activity, they have limited range of motion, they experienced swelling in the joints, it feels as if the knee “gives out”, they have stiffness in the joints, there is tenderness when they press on the knee and the knee may become deformed. (3,4)
According to a study done at the University of Iowa researchers found that women who had strong thigh muscles, quadriceps, were 50% less likely to develop knee pain compared to those who had the weakest muscles. This supports previous research that found strong quadriceps muscles protect against cartilage loss. However, the increased muscle strength did not prevent osteo arthritis but actually decreased the pain and symptoms that the woman experienced. X-ray evidence showed that 10% of those individuals with strong muscles who had no pain did have evidence of arthritis on x-ray. (5)
The goal of treatment is to decrease pain in the joints through a multidisciplinary team approach. Patients are often evaluated and treated by physical therapists, who help develop programs to improve muscle strength, function and range of motion. Physicians and pharmacists work together to find adequate medical pain control while social services are brought into play to help individuals find support in the community and act as a liaison in the workplace. (6)
Individuals who have arthritis in the knee will also find benefit from using a cane held in the hand opposite from the side with the arthritis. The cane should be of correct height which any medical supply company can adjust. Weight loss is another significant portion of treatment in order to decrease load bearing on the knee.
Some individuals find relief from mild to moderate pain using cortisone injections into the joints. It is not recommended more than every two to three months. While an ace bandaged may be helpful to control swelling and give some psychological benefit knee braces are generally not helpful. However, recent special braces developed specifically for individuals with osteo arthritis in the knee as well is wedged shoes have been found to decrease the load bearing on the joints and therefore the pain and degeneration of the cartilage.
Individuals who suffer from osteo arthritis of the knee often find that their lifestyle changes over time and as the disease progresses they lose more and more function. However, with some minor dietary changes, weight loss, exercise and support using a cane many are able to continue to function well in their daily lives with only minor adjustments.
(1) Medline Plus: Knee Pain
(2)Trends in Molecular Medicine: Recent Advances in the Genetic Investigation of Osteoarthritis
(3) NHS Choices: Osteoarthritis – Symptoms
(4) Johns Hopkins Medicine health Library: Osteoarthritis
(5) American College of Rheumatology: Women with Strong Thigh Muscles Protected from Symptomatic Knee Osteoarthritis
(6) Annal of Rheumatic Diseases: Aerobic Walking or Strengthening Exercise for Osteoarthritis of the Knee