As a biological scientist who has extensively studied the human body with regard to diseases, injuries and patterns of recovery, I have my doubts about Drew Brees(notes) ability to fully recover from playing the entire NFL regular season with an MCL sprain.
The MCL (Medial Collateral Ligament) is a ligament that is located on the inner side of the knee and links the thigh bone to the shin bone. Any damage that occurs to the MCL is termed a sprain and can range in its degree of severity. In a first-degree sprain, only a few ligament fibers are damaged or broken. A second-degree sprain involves more extensive damage to the ligament fibers; however, the entire ligament remains intact. A third-degree sprain means that the entire ligament has ruptured.
Typical injury advice for an MCL sprain is what is popularly referred to as RICE (rest, ice, compression, elevation). When started immediately after an MCL injury, RICE alleviates the pain resulting from the injury and also starts the healing process for the knee. If such treatment is not employed immediately, as might be the case with Brees, one or several of the following consequences may result:
Pain medication addiction: The New Orleans Saints quarterbacks MCL injury may have been only first degree; however, continual use of his knee during the season probably exacerbated his pain. This pain may have been temporarily alleviated by pain medication. Playing an entire season with knee pain could lead someone in his position to take pain medication on a regular basis, putting the injured person at risk of addiction.
Further MCL injury: An MCL that is torn has a greater chance of being further injured during use. There would have been a high risk of Brees MCL sprain going directly to third degree if he twisted his knee or took a hit to the area. While a first-degree MCL sprain may require no more than three weeks of recovery via RICE, a third-degree sprain usually requires surgery and an extensive recovery period.
Degenerative Arthritis: A ligament that is under constant insult after injury is prone to arthritic degeneration in later life. Even though Brees did not end up with a ruptured MCL, his knee may eventually succumb to arthritis due to its prolonged state of inflammation, swelling and pain during the season in which he continued to play.
Knee replacement: If sufficient deterioration occurs to a knee because of arthritis, a knee replacement may become necessary in later life.