Patella Femoral Pain Syndrome
Patella Femoral Pain Syndrome (PFPS) occurs most often from walking on stairs, kneeling, sitting for long periods of time and even overuse with running.
It can be caused when the cartilage under the patella (knee cap) becomes damaged or when the patella does not track in the femoral groove properly, causing irritation beneath the patella.
Symptoms include pain around the patella and swelling.
Osgood-Schlatter Disease (OSD) occurs during puberty and generally resolves on its own once growing has stopped, usually at age 18 or 19.
All long bones have a growth plate - made of cartilage which is not as strong as bone - at each end of the bone.
The quadriceps tendon crosses the patella and aides in connecting the patella to the upper shinbone (tibial tubercle) at or near the growth plate.
With the quadriceps muscle highly involved in running and jumping activities, the stress of the contractions cause the tendon to pull at the insertion point on the tibial tubercle, causing micro-trauma.
Over time, this stress causes the tibial tubercle to enlarge.
Symptoms of OSD include swelling and increased pain below the knee cap especially with running, jumping and kneeling.
The patella tendon connects the patella to the shinbone and is relied on heavily for any motion that extends or straightens your knee. Jumping and kicking are two of these activities.
Patella Tendinitis (Jumper's Knee)
The repetitiveness of motions, such as jumping and kicking, causes tiny tears in the tendon. When activity continues, the tears continue to accumulate and the body cannot keep up with the repairs, causing a condition known as patella tendinitis.
Some causes of patella tendonitis include overuse, being overweight, having tight leg muscles or an imbalance of the leg muscles - specifically the quadriceps and the hamstrings.
Symptoms include pain and swelling below the kneecap.
Patella Subluxation and Dislocation
When an individual plants his foot, decelerates and cuts or changes direction, the thigh rotates inward and the lower leg rotates outward.
When the body tries to compensate for this misalignment, the quadriceps can produce a force great enough to displace the patella laterally, causing a condition known as patella subluxation and dislocation.
Subluxation refers to when the patella pops out and in on its own. When the patella stays displaced, the injury is considered a dislocation.
Symptoms include complete loss of knee function, the patella resting in an abnormal position, pain and swelling.
A bursa is a fluid-filled sac located in high-friction areas. High friction areas include where tendon or muscle rub over bone.
Bursitis is an inflammation of a bursa. It can be classified as acute, chronic or reoccurring.
The prepatellar bursa becomes inflamed from increased kneeling. The deep infrapatellar and suprapatellar bursa become inflamed from overuse activities such as running and jumping.
Symptoms include pain and swelling in and around the knee.
Iliotibial Band Friction Syndrome
The iliotibial band is a band of tissue (fascia) which begins at the hip and crosses and inserts into the lateral aspect of the knee.
With activities like biking and running, irritation develops at the insertion point, where friction is created over the femur.
This is an overuse condition known as iliotibial band friction syndrome and can be seen in individuals who have genu varum (bow legged) and/or pronated (flat) feet.
Symptoms include pain on lateral aspect of knee and swelling in and around the knee.
MCL Sprain or Tear
The medial collateral ligament (MCL) is located on the medial (inside) of the knee. It connects the femur to the tibia. In an MCL sprain the ligament stretches but doesn't completely rupture. In an MCL tear, it ruptures.
This injury most often occurs from a direct blow to the lateral (outside) of the knee, forcing the medial joint to stretch apart and cause the MCL to stretch or tear.
Keeping the leg muscles around the knee strong can help to protect against this type of injury. This injury can range from a mild to a severe sprain.
In a sprain the ligament stretches but doesn't completely rupture. In a severe sprain, many fibers of the ligament are torn but it is not completely ruptured.
Symptoms can range from mild to severe with joint stiffness, point tenderness just below the medial joint line, swelling, effusion and instability.
Meniscus (Cartilage) Injury
A meniscus on both the medial and lateral parts of the knee is connected to the top of the tibia and below the femur.
It acts as a shock absorber between the two bones. A meniscus injury is one that affects this "shock absorber."
There is a much higher incidence of medial meniscus injury. The most common mechanism is weight bearing combined with a rotary force while flexing or extending the knee.
Symptoms of meniscal tears include:
- Swelling that can enlarge the knee
- Joint line pain
- Loss of range of motion
- Pain with squatting and a feeling of "locking" or "giving way"
Such symptoms often require surgery.
Anterior Cruciate Ligament
The anterior cruciate ligament (ACL) is the ligament associated with the phrase "blew out the knee." It can sprain or tear.
In a sprain, the ligament stretches but doesn't completely rupture. In a tear, it ruptures.
An ACL injury occurs when there is a direct blow to the knee or from a single-plane force.
An example of a single-plane force is when the lower leg is rotated while the foot is fixed. This can occur when an individual who is running fast suddenly decelerates and makes a hard "cutting" motion, causing a tear.
The patient will often hear a loud pop or snap, which is the ligament tearing. This can happen as an isolated incident or involve more structures such as the MCL and medial meniscus.
When the ACL, MCL and medial meniscus are all injured, the condition is known as "the unhappy triad." Symptoms include a pop sensation, rapid swelling and joint instability.
In a competitive athlete, surgery is a highly recommended option. Non-surgical options are available as well.