Patella Femoral Pain Syndrome (PFPS) occurs most
often from walking on stairs, kneeling, sitting for long periods
of time and even overuse with running.
PFPS 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 on the under side of
Symptoms include pain around the patella and swelling.
Osgood-Schlatter Disease occurs during puberty
and generally resolves on its own once growing has ceased,
usually at age 18 or 19.
All long bones have a growth plate - made of a cartilaginous
material which is not as strong as bone - at each end of the
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
This stress, over time, causes the tibial tubercle to enlarge.
Symptoms of Osgood-Schlatter Disease include swelling and
increased pain below knee cap especially with running, jumping
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.
The repetitiveness of these motions 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 (jumper's knee).
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.
When an individual plants his foot, decelerates and cuts or
changes direction, the thigh rotates inward and the lower leg
When the body tries to compensate for this misalignment, the
quadriceps can produce a force great enough to displace the
patella laterally - on the outside of the knee, causing a
condition known as patella subluxation and
Subluxation refers to when the patella pops out and in on its
own. When the patella stays displaced, the injury is considered a
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 and is
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.
The iliotibial band is a band of tissue - fascia - which begins
at the hip and cross and insert into the lateral aspect of the
With activities like biking and running, irritation develops at
the insertion point, where friction is created over the lateral
condyle of 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.
The medial collateral ligament (MCL) is located on the medial
(inside) aspect 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
This injury most often occurs from a direct blow to the lateral
(outside) aspect 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.
A meniscus on both the medial and lateral aspects of the knee
sits connected to the top of the tibia and below the femur.
It acts as a shock absorber between the two bones. A
meniscus (cartilage) 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
- Pain with squatting and a feeling of "locking" or "giving
Such symptoms often warrant surgical intervention to repair or
The anterior cruciate ligament (ACL) is the
ligament associated with the phrase "blew out the knee."
This ligament 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 to the ACL.
The patient will often hear a loud pop or snap, which is the
ligament tearing. This can happen as an isolated incident or can
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.