No. 1 Pick Jadeveon Clowney Had The Greg Oden Surgery, And The NFL World Is Worried

Houston Texans linebacker Jadeveon Clowney has undergone microfracture surgery on his injured knee, the team announced on Tuesday.

It's awful news.

The former No. 1 NFL Draft pick had already been ruled out for the rest of the the season. The surgery's nine-month recovery timetable now puts the start of the 2015 season in jeopardy.

But the real worry is further down the road - there's generally not a great track record of players going on to have long, productive careers after microfracture surgery.

Microfracture surgery involves poking tiny holes in the bone near torn knee cartilage. The blood helps repair the tear, but the resulting cartilage isn't as strong as the original and the knee is never the same.

Some big-name athletes have had the surgery - Amare Stoudemire and Greg Oden in the NBA, and Marques Colston and Reggie Bush in the NFL - to varying results.

In 2007 FootballOutsiders' Kevin Pelton took a look how 56 NFL players performed after microfracture surgery. He found a decent number of cases where players returned to form, even some where the players were over the age of 30. But in general the numbers aren't great - only nine of 56 players stayed in the league for five years after microfracture surgery, Pelton found.

A 2013 study on microfracture surgery in the NBA found that 73% of players returned to the league after surgery, but those players "competed in fewer games per season with fewer points and steals."

The anecdotal evidence is a mixed bag. Zach Randolph has had his best years after microfracture surgery, while Penny Hardaway lost his career to it.

In March Sean Deveney of the Sporting News reported that doctors were moving away from microfracture surgery as a solution to knee cartilage tears in elite athletes. One NBA team doctor told him:

"I don't think anyone in 2014 would advise Greg Oden to get microfracture if he had the same issues he showed back then. The thinking has changed. It is still a good surgery in some cases, but not for high-level athletes."

Oden is the cautionary tale here. He was taken No. 1 overall in the 2007 NBA Draft and was considered a once-in-a-generation prospect, only to have his career derailed by a series of medical procedures, including microfracture surgery.

While there's no reason to believe Clowney will be that unlucky, it's fair to say we might never see the long, dominant career who all hoped Clowney would have when he first burst onto the scene.

Ex-NFL team physician David Chao painted a somber picture of Clowney's outlook on Twitter:

Others in the NFL world are rightly concerned.