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USC's Kristofer O'Dowd out 3-4 weeks with a dislocated patella

Kristofer O'Dowd was injured last night in USC's opening series during their scrimmage last night at the Coliseum.

Starting center Kristofer O'Dowd, regarded as a linchpin for an experienced line expected to ease the transition of a new quarterback, suffered a dislocated right kneecap during the first series of a scrimmage Monday night at the Coliseum.

O'Dowd, a junior coming off shoulder surgery, went down at the end of a mistake-prone first series on a running play that ended with Joe McKnight's fumble.

Senior Alex Parsons replaced O'Dowd, who is expected to be sidelined three to four weeks.

"We're fortunate that we have depth, but it's just a crusher that he got banged up like that," Coach Pete Carroll.

As a freshman in 2007, O'Dowd also dislocated his right kneecap in the fourth game against Washington and missed four games.

Yes, we have some depth but losing O'Dowd is tough. If we are to believe that he will only be out 4 weeks he could still miss the Ohio State game. That could hurt us tremendously. I would not be surprised though if he was on the field for that game.

We'll see...

This is the same injury he suffered in his freshman season.

This is what I wrote then...

Make no mistake this can be a serious injury. This is not as common as the ACL injury in athletes but an ACL injury must be ruled out and that can be done with a number of different tests. Surgery is not indicated unless the injury is recurrent and is usually a last resort.

Treatment for this injury obviously depends on how severe the injury is, but special care is taken to strengthen the Vastus Medialis of the Quad Muscle structure. This muscle helps to place a medial pull on the patella, reducing the lateral, dislocating force.

Here is a little anatomy and physiology from the Athletic Advisor:

The Dislocated Patella
(Click Here for an MRI of a dislocated patella)
The patella (knee cap) is a sesamoid bone. A sesamoid bone is one that is encased in tendon or ligament. The patella is located inside the quadriceps tendon. The patella acts as a fulcrum to increase the strength of the quad muscle. It is held in place by the quadriceps tendon above, the patellar tendon below, and very thin ligaments on either side. The patello-femoral joint is formed by the patella and trochlear groove of the femur.

Due to the twisting nature of sports, the patella can dislocate (come out of joint) with an awkward twist of the femur (thigh) on the tibia (shin). A twisting motion causes the patella to shift to the side. Usually, the patella moves laterally (to the outside). This occurs because the quadriceps muscle contracts to maintain the stability of the body. The shin has shifted so that the line of pull of the quads causes the patella to shift laterally. The patella is pulled laterally because it wants to remain in line with the muscle.

The patella can dislocate more easily in some people than others. Individuals with a greater "Q-angle" are at a greater risk for patellar dislocations. The "Q-angle" is formed by envisioning a circle around the patella, the line of pull of the quad muscle forms the tail of the "Q." If the tail of the "Q" is more than 25 degrees off of the center of the quad-patella-patellar tendon line of pull, it is considered an abnormally high "Q-angle."

This places the patella at a greater risk to slide off of the femur. The quad-patella-patellar tendon mechanism wants to form a straight line when the quad muscle contracts, due to this, the patella is pulled laterally. This places a person with a high "Q-angle" at a greater risk for patellar dislocations.

Another risk factor for patellar dislocations is a malformed patella or trochlear groove (the groove located between the two heads of the femur) . The back side of the patella should have a peak, like an inverted mountain top. The trochlear groove should look like the valley between mountains. If either the mountain or the groove are not large enough, the patella is more prone to dislocate.

This is demonstrated by the x-ray. The back side of the patella is flat. This accounts for the sideward lean of the patella. This patella is prone to dislocate and is partially dislocated or subluxed in the x-ray. X-rays are necessary to rule a fracture of the patella. In some cases the mountain peak of the patella will be "knocked off" when it impacts with the femur. This piece of bone can cause severe damage to the joint if it is not properly addressed.

The retinaculum is the band of connective tissue that attaches to the medial and lateral structures of the knee joint, including the patella and patellar tendon. In a patellar dislocation this is either stretched or torn. Most surgeons I have discussed this with pretty much agree that this is usually a tear and not a stretch of the retinaculum. The amount of stress placed upon the tissues during this injury usually result in a some sort of a tear.

I am not surprised that he had a recurrence of this injury. With as hard as these guys play this is one of those injuries that can happen repeatedly as more stress is placed on the joint.

I have faith that Parsons will step up but lets not kid ourselves, losing O'Dowd could have some major implications.

More on last nights scrimmage later...