There are many causes of knee pain. Below is an illustration of the different parts of the knee and how they relate to or depend upon each other.
Basic Anatomy of the Knee
The knee joint is a junction of three bones. The femur and tibia meet to form a hinge joint. In the front of them is the patella (knee cap). The patella sits over the other bones and slides when the leg moves. The end of these three bones are covered by cartilage. This is a tough elastic material that cushions the joint. These C shaped pads of cartilage are called menisci. There is a lateral (outside) and medial (inside) meniscus. Ligaments help to stabilize the knee. These are strong elastic bands of tissue that connect one bone to another. The four main stabilizing ligaments of the knee are the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL) and lateral collateral ligament. There are two basic groups of muscles at the knee. In the front of the knee are the quadriceps muscles that work to straighten the leg. In the back of the knee are the hamstring muscles which help to bend the knee. The muscles that help stabilize the knee side to side are the abductors (outside) and the adductors (inside).
Most common Causes of Knee Pain
Osteoarthritis (also called degenerative joint disease) is the most common type of knee arthritis. It is characterized by progressive wearing away of the cartilage of the joint. As the proactive cartilage is worn away by knee arthritis, bone is exposed within the joint. The most common symptoms are pain with activity, limited motion, stiffness, swelling, tenderness and deformity of the joint (knock-knees or bow-legs).
Ligament injuries commonly occur during athletic activities. Of the four major ligaments of the knee, the ACL is the most common injured. The ACL prevents the tibia from sliding too far forward. When the ACL is injured, the knee becomes less stable. People with this injury often complain of a sensation that the knee will “give out” from under them. Symptoms also include pain, swelling and decreased motion. Another of the four major ligaments that is often injured is the MCL. The MCL resists widening of the inside of the joint or prevents “opening-up” of the knee. Most common symptoms following injury to the MCL is pain directly over the ligament. The PCL and LCL can also be injured, but not as frequently as the other two ligaments discussed above.
Osgood-Schlatter disease commonly occurs in active boys and girls aged 11-15 during growth spurts where repeated stress from the contraction of the quadriceps passes through the patella tendon to the tibial tuberosity. This stress can cause inflammation of the tendon or small fractures that cause an increase in bone growth in the tuberosity. Once the syndrome develops, common symptoms include intense knee pain with running, jumping, squatting, kneeling or impact to the area.
The medial and lateral menisci distribute weight, cushion the joint and improve stability of the joint. When torn, common symptoms include knee pain, swelling, tenderness, decreased motion, popping and clicking.
This arises when the patellar tendon, which connects from the knee cap to the tibia, and the tissues that surround it become inflamed and irritated. This is usually due to overuse, especially from jumping activities. Patellar tendonitis usually causes pain directly over the patellar tendon. Other symptoms include pain with activities, especially jumping or kneeling.
This develops due to irritation of the undersurface of the knee cap. The most common symptom is pain in the knee cap area.
People who experience patellar Subluxation have a knee cap that does not track evenly within its groove on the femur. Patella dislocation occurs when the knee cap fully dislocates out of the joint. Most commonly, tracking problems cause discomfort with activity and pain over the edges of the knee cap.
Physical Therapy Q & A
What will my treatments consist of?
After an individual plan of care is developed by the physical therapist, your treatments may include manual hands-on techniques to restore optimal tissue function, and therapeutic exercises to increase range of motion and strength. Your exercises will be progressed on an individual basis as determined by the therapist.
How long should I expect my recovery to be?
Time of recovery depends on several aspects including degree/severity of injury, age, type of injury, and activity level. The physical therapist will be able to give you a more specific time frame following your initial evaluation.
How can I prevent this from occurring again?
The therapist will educate you regarding your condition and will be happy to answer any questions you may have. A home exercise program will be issued to promote your independence and prevent further injury.
Bridget Faucher, PT, DPT, OCS looks forward to treating you to help you gain back function and decrease pain.