Miriam Nakamoto faced Lauren Murphy on last Saturday's Invicta FC 7 card for the bantamweight championship. That fight was stopped in the 4th round as Nakamoto's right knee gave way to injury. Nakamoto has tweeted news confirming that she tore her ACL.
Good news: No collateral damage to my knee! MCL, PCL, meniscus, cartilage etc. Everybody's OK! Except the Bad news: My ACL is kaput. RIP :-(— Miriam Nakamoto (@MiriamNakamoto) December 11, 2013
Furthermore she appears well-informed on the topic of ACL injuries, having apparently suffered the same injury to her left knee.
The best news from this tweet is that she is having the ACL repaired with a patella tendon autograft, which is the "gold standard" for ACL reconstruction, rather than a cadaver allograft.
The injury to her knee occurred in the third round, and can be seen at the beginning of this GIF, courtesy of ZombieProphet.
In the first slow motion sequence, you can see Miriam's right knee give way, buckling anterior and medially as she was taken down by Murphy. The second slow motion sequence clearly shows her right tibia shearing anteriorally as she shifts her weight back on the leg. This shearing movement is what the intact ACL resists.
Female athletes may be at higher risk for ACL injuries than their male peers. There are probably many reasons for this, from anatomical and hormonal differences to differences in the way females jump and land. (Further information on the topic of female ACL injuries can be found here.)
Nakamoto's record with the Invicta organization is now 1 win, 1 loss and 1 no contest.