Sports Injury Roundup

LA Lakers center Andrew Bynum was sidelined with a knee injury last night in their game against the San Antonio Spurs. In the second quarter, Bynum fell after stepping on Spurs DeJuan Blair’s foot. This caused Bynum to hyperextend his right knee, and he left the game. According to LA coach Phil Jackson:

“There’s always concern… We’ve seen him go down a couple of times that have been debilitating, so there’s a concern. It was kind of a freaky play, but they usually are, and that’s what basketball is.”

Jackson acknowledged Bynum could be out for at least a few games. This is not the first knee injury of Bynum. Last June, he played in the NBA finals with a torn meniscus.

Knee hyperextension is a condition in which the knee is straightened beyond the normal limits of the joint. Hyperextension frequently is a mechanism of knee injuries in gymnastics, basketball and volleyball. It can damage ligaments, cartilage and other stabilizing structures in the knee. Symptoms of injury due to hyperextension include bruising, swelling and pain with straightening of the knee. Forceful hyperextension can tear one of a knee ligaments, most frequently the anterior cruciate ligament (ACL).

The knee is essentially a modified hinge joint located where the end of the thigh bone (femur) meets the top of the shin bone(tibia). Four main ligaments connect these two bones:

• Medial collateral ligament (MCL) — runs along the inner part of the knee and prevents the knee from bending inward.
• Lateral collateral ligament (LCL) — runs along the outer part of the knee and prevents the knee from bending outward.
• Anterior cruciate ligament (ACL) — lies in the middle of the knee. It prevents the tibia from sliding out in front of the femur, and provides rotational stability to the knee.
• Posterior cruciate ligament (PCL) — works with the ACL. It prevents the tibia from sliding backwards under the femur.

The ACL and PCL cross each other inside the knee, forming an “X.”

For more information about ACL injury see our story about Soledad O’Brien.

Meanwhile in MLB, Texas Ranger outfielder and 2010 AL MVP Josh Hamilton has been put on the DL because of an arm injury. He is expected to miss six to eight weeks after sustaining a fracture in his upper right arm which occurred when he dove headfirst into home plate.

According to Hamilton:

“I listened to my third-base coach. That’s a little too aggressive. The whole time I was watching the play I was listening. [He said] ‘Nobody’s at home, nobody’s at home.’ I was like, ‘Dude, I don’t want to do this. Something’s going to happen.’ But I listened to my coach. And how do you avoid a tag the best? By going in headfirst and get out of the way and get in there. That’s what I did.”

The fracture was small enough that it was not detected on X-ray, but it was caught on an MRI exam, which revealed a non-displaced fracture of the humerus bone.The humerus is the bone of the upper arm. Non-displaced means that the two segments of the bone involved in the fracture remain next to each other, in good alignment.

All fractures can be broadly described as:

Closed (simple) fractures are those in which the skin is intact
Open (compound) fractures involve wounds that communicate with the fracture. This break in the skin can expose the bone to contamination. Open injuries carry a higher risk of infection.

Other considerations in fracture care are displacement (the gap between the bone fragments) and angulation. If angulation or displacement is large, reduction (manipulation) of the bone may be required and, especially in adults, may require surgical care. These injuries may take longer to heal than injuries without displacement or angulation.

Compression fractures usually occurs in the vertebrae, for example when the front portion of a vertebra in the spine collapses due to osteoporosis (a medical condition which causes bones to become brittle and susceptible to fracture, with or without trauma).

Other types of fracture are:

Complete fracture: A fracture in which bone fragments separate completely.
Incomplete fracture: A fracture in which the bone fragments are still partially joined. In such cases, there is a crack in the osseous tissue that does not completely traverse the width of the bone.

Linear fracture: A fracture that is parallel to the bone’s long axis.
Transverse fracture: A fracture that is at a right angle to the bone’s long axis.
Oblique fracture: A fracture that is diagonal to a bone’s long axis.
Spiral fracture: A fracture where at least one part of the bone has been twisted.
Comminuted fracture: A fracture in which the bone has broken into a number of pieces.
Impacted fracture: A fracture caused when bone fragments are driven into each other.
Torus fracture: A greenstick, buckle or torus fracture is a fracture in a young, soft bone in which the bone bends and partially breaks.