Bynum's injury

NEW YORK -- Andrew Bynum's knee injury is a common one suffered by athletes in sports such as basketball and football. He tore the medial collateral ligament (MCL) in his right knee Saturday in Memphis. The MCL is one of four ligaments that wrap around the knee and are critical to its stability. A tear in any of the four can result in an extended layoff for an athlete.

However, a more common tear or sprain often occurs in the anterior cruciate ligament (ACL). Surgery is frequently necessary to repair the damage to the ACL. Injuries to the other two ligaments are seen less frequently than the MCL and ACL, but are not unheard of in athletes.

The Lakers expect Bynum to be sidelined for roughly eight to 12 weeks. Surgery is not necessary, however. He was injured when Kobe Bryant crashed into his leg after missing a driving layup midway through the first quarter of Saturday's game.