For many people—especially those who are overweight or lead a sedentary lifestyle—knee pain is practically inevitable—but it doesn’t have to be a lifelong affliction. The first step in combating knee pain is to understand where it is coming from. That means a proper diagnosis from a qualified medical professional is crucial in treating knee pain and preventing it from getting worse.
As a weight-bearing joint, the knee can take quite a beating. In addition to the normal wear and tear experienced by all joints, the knee is also acted upon by the force of gravity, which is compounded by any excess weight a person may be carrying.
Parts of the Knee
The knee is a hinge-type joint—not a ball-and-socket joint like the hip or shoulder. This means it has a fairly limited range of motion, but it doesn’t mean it is not complex.
The knee joint is a meeting of three bones—the tibia (lower leg bone), the femur (thigh bone) and the patella (kneecap). The ends of both the tibia and the femur are wrapped in articular cartilage to enable them to glide smoothly together. The underside of the patella is also surfaced with cartilage, and two more pads of cartilage called menisci (singular meniscus) sit between the femur and tibia and act as shock absorbers.
Four main ligaments keep the bones of the knee in place. They are:
- Anterior cruciate ligament (ACL)
- Posterior cruciate ligament (PCL)
- Lateral collateral ligament (LCL)
- Medial collateral ligament (MCL)
Finally, the quadriceps tendon attaches the quadriceps muscle to the kneecap, and the patellar tendon (actually a ligament since it connects two bones, instead of attaching muscles to bones like a true tendon) attaches the kneecap to the tibia.
Common Knee Pain Sources
With all that bone, cartilage and connective tissue, the potential is high for something to go wrong in the knee. The result of damage to any of these tissues? Typically pain, and often instability of the knee, limited range of motion or inability to bear weight.
Problems affecting different parts of the knee are treated differently, which is why it is so important to know the root cause of knee pain. Learn about some of the most common forms of knee pain—and their treatments.
Knee osteoarthritis is the wear-and-tear damage to articular cartilage. Osteoarthritis is the most common form of arthritis, and the knee is one of the most common sites of osteoarthritis. Cases of knee osteoarthritis have doubled since the mid-20th century.
Over time, the cartilage that wraps the ends of bones breaks down due to osteoarthritis. Eventually the articular cartilage will wear away entirely, leaving bones to grind painfully against each other.
Treatment: There is no cure for knee osteoarthritis, but the condition can be slowed and managed. Treatments include:
- Physical therapy
- Activity modification
- Weight loss
- Pain-relieving medications
- Injections such as corticosteroids, stem cells, viscosupplementation and amniotic tissue
A total knee replacement is the only treatment option for advanced osteoarthritis. Debridement surgery to remove damaged tissue can be an option for cases that are less advanced.
The menisci are crescent-shaped pads of cartilage that act as the knee’s shock absorbers and secondary stabilizers. These tissues can become frayed and torn due to age, weight or injury. Tears can be painful and cause a feeling of instability in the knee. A lack of blood supply to most of the meniscus make tears difficult or impossible to heal on their own.
Treatment: Physical therapy can increase knee function and reduce pain. For particularly painful or debilitating tears, meniscectomies and meniscal repair surgeries may be necessary.
The ACL is the most often damaged ligament in the knee. It is responsible for keeping the tibia from sliding out in front of the kneecap, and for keeping the knee together during rotational movement. It is one of the prime stabilizers of the knee.
Treatment: The goal of treatment for minor ACL injuries (injuries to ligaments are called sprains) is to minimize pain and swelling. Treatments include:
- Activity modification
- Pain relievers
For complete ACL tears, an ACL reconstruction will be necessary. An ACL reconstruction involves placing a similar tissue—either a tendon from a cadaver (called an allograft) or from the patient’s own body (an autograft)—as a scaffold and creating an environment where new connective tissue grows.
Patellofemoral Pain Syndrome and Chondromalacia
Patellofemoral pain syndrome, also known as runner’s knee or jumper’s knee, is a condition that causes pain in the front of or around the knee. Chondromalacia, which is also sometimes called runner’s knee, is a similar condition that can cause patellofemoral pain syndrome. Chondromalacia occurs when the cartilage on the underside of the patella wears away, possibly due to misalignment of the knee joint.
Treatment: Both conditions are usually treated nonsurgically. Surgical treatment can include a tendon release if a tight patellar tendon is pulling the kneecap out of proper alignment, or debridement surgery, where damaged cartilage is surgically removed from the patella.
Knee Pain Prevention
While knee pain is common, especially as you get older, it is not inevitable. Here are some tips to keep knee pain from affecting your quality of life.
Maintain a healthy weight. Being overweight and obese are the main risk factors for many types of knee pain. Your knees have to work harder the more weight they have to carry. Keep your body mass index (BMI) between 18.5 kg/m2 and 24.5 kg/m2 for a healthy weight.
Move more… Counterintuitively, the more you do, the better your knees will feel. There’s a reason why physical therapy is almost always a treatment option for knee pain. Aim to get at least 30 minutes of moderate exercise five times a week, according to the Centers for Disease Control and Prevention.
…but move correctly. For knee pain, aim for low-impact activity like swimming or bicycling, rather than high-impact activity such as running and some forms of aerobics. Low-impact activities stress your knees less, giving you the benefits of exercise without the impact to your knees.
If you are experiencing knee pain, we can help. Request an appointment and one of our orthopedics specialists will diagnose the cause of your knee pain and suggest a treatment plan that’s right for you.