"Mighty Mouse" was forced to undergo shoulder surgery back on March 7, 2013 in Seattle, Washington, to repair three tears in his labrum. The procedure, which could keep him sidelined for up to 12 weeks, "went well" according to Johnson.
MMA Fighting has the nitty gritty:
"The type of surgery I had done is the labral debridement [procedure]. When the doctor got in there, he saw my shoulder was stable, which is the most important thing. Then I got a PRP [platelet-rich plasma] shot, which means my blood get puts in the joint which promotes natural healing in the joint where blood flow doesn't go."
The untimely injury (more on that here) forced the cancellation of his upcming title fight against John Moraga at The Ultimate Fighter (TUF 17 live finale next month in Las Vegas; however, the challenger is expected to wait for Johnson's return instead of taking a fight in the interim.
Get well soon, Mr. Mouse.