Anterior Cruciate Ligament (ACL) is one of the most common knee injury.

Sprain or tear of the ACL is one of the most common knee injury specially for athletes who are playing soccer, football and basketball. Cruciate ligaments are found inside our knee joint. They cross each other to form an "X" with the Anterior cruciate in front and the posterior cruciate ligament in back. These ligaments control the back and forth motion of our knees. The anterior cruciate ligament runs diagonally in the middle of the knee which prevents the tibia from sliding out in front of the femur, as well as providing rotational stability to the knee.

Possible cause of injury:

1. Changing direction rapidly.

2. Stopping suddenly.

3. Slowing down while running.

4. Landing from a jump incorrectly.

5. Direct contact or collision.

Symptoms:

1. Pain and swelling.

2. Range of motion loss.

3. Joint tenderness.

Diagnostic test:

1. Physical examination.

2. MRI or X-ray imaging.

Treatments:

1. Nonsurgical: Recommended for elderly or have a very low activity level.

Bracing and physical therapy.

2. Surgical: Recommended for athletes.

Rebuilding the ligament. Most ACL tears cannot be sutured back together. The ligament must be reconstructed. It will be replaced with a tissue graft. Often, they are taken from the patellar or hamstring tendons at the back of the thigh are common source of grafts. Sometimes a quadriceps tendon, which runs from the kneecap into the thigh is used. Finally, cadaver graft (allograft) can be used. Because the regrowth takes time, it may be six months or more before an athlete can return to sports after surgery.

Rehabilitation: Rehabilitation plays a vital role in getting back to patient's daily activities. A physical therapy program will help them regain knee strength and motion.

If you're a fan of sports, you probably hate to see one of your favorite player goes down with ACL injury. You know that the injury is devastating to the player or it could be a career ending injury for him or her.

Here are 5 current NBA players with ACL injury:

1. Derrick Rose: Too big, too fast, too strong. Former #1 pick and MVP (2010-2011 season).

Image credit: sportskneetherapy.com

During Game 1 of the first round of the 2011-2012 playoffs against the Philadelphia 76ers, Rose injured his left knee while trying to jump. He was immediately helped off the court. The injury occurred when the Bulls were leading by 12 points with 1:22 left to play.

2. Rajon Rondo: Triple double threat and floor general. Boston celtics champion in year 2008.

Image credit: wildcatbluenation.com

January 27, 2013, during a game with the Miami Heat, it was revealed that Rondo had torn his ACL and would miss the remainder of the season.

3. Ricky Rubio: Assist sensation, no look passess. Former 5th pick in 2009 draft.

Image credit: blog.timesunion.com

In a loss to the Los Angeles Lakers on March 9, 2012, Rubio tore his ACL and his lateral collateral ligament defending Kobe Bryant. He missed the rest of the season.

4. Iman Shumpert: Former New York Knicks and now playing with the Cleveland Cavaliers.

Image credit: theleaguenews.us

On April 28, 2012, during a first round playoff game against the Miami Heat, Shumpert suffered a knee injury while dribbling in midcourt and was immediately helped off the court.

5. Jamal Crawford: NBA Sixth Man of the Year Award in both 2010 and 2014.