Guice's Preseason Injury
Derrius Guice, rookie RB for the NFL's Washington Redskins, sustained an ACL injury on August 9th. He was tackled after the end of run, where it appears he was planting his left leg and the weight of the opponent causes his left knee to buckle. His injury is a reminder of how tenuous a professional athletes career can be, as far as injuries are concerned. He was initially felt to have an MCL injury, but an MRI was performed to confirm the diagnosis, which revealed an ACL tear. I have reviewed a general review of ACL tears in another post, but let's take a look at the imaging side of the injury. Many times an ACL tear is associated with other injuries, such as a meniscus tear or lateral collateral ligament tear. Although the diagnosis can be confidently made by physical exam, an MRI is generally accepted as the appropriate test to confirm the presence of an ACL tear.
Inside of Knee (Zoomed View)
First, you need to get yourself oriented to the anatomy of the knee. We have the femur as the upper thigh bone and the tibia as the lower shin bone that meet together to create the knee joint. We then have the ACL that runs directly through the middle of the knee acting as the major stabilizer of the knee joint. We can then compare these structures to the MRI of the exact same area.
MRI Cross Section of Knee (Normal)
Now we can see the anatomy within the knee joint and compare to the model above (note the knee is pointing in the opposite direction). Of note you can see the black line cutting through the central portion of the knee joint that is representative of the ACL.
MRI Cross Section of Knee (TORN ACL)
In contrast, in the picture below there is no clear black line cutting through the central portion of the knee. The lack of this line indicates that the ACL is torn. Keep in mind this is a simplistic explanation of the analysis on an MRI and significant expertise is needed to confirm the diagnosis and any other associated injuries.
Return TO PLAY
The data on return to play is ever-changing in regards to ACL reconstruction. In the past, the general goal for return back to full sports participation was reported between 6 to 9 months. However, recent data suggests that we should potentially be waiting 1 to 2 years for return back to full contact sports participation. The focus has shifted away from a fixed time toward the need to meet functional criteria before returning back to contact sports.
Sports Considerations
An isolated ACL injury will cause significant strength, balance and functional deficits after reconstruction. An athlete should consider a functional assessment, testing such criteria as strength, agility and balance prior to return, even if they have met time criteria for return back to sports. Functional assessments can uncover muscle imbalance, weakness or improper movement patterns that can put an athlete at risk for re-injury.