For most of Sunday and part of Monday morning, wide receiver Randall Cobb's injury left the Green Bay Packers faithful holding their breath. A GIF of the injury, courtesy of Fox Sports via Bleacher Report, is below:
According to Tyler Dunne of the Milwaukee Journal Sentinel, Cobb sustained a fractured fibula and will miss the next six to eight weeks.
Though a broken fibula is a significant injury in any light, it could have been much worse. A possible ACL tear undoubtedly crossed the minds of many, and Cobb likely has his fitness level to thank.
While any knee structure can suffer damage during a contact hyperextension injury such as Cobb's, the ACL—short for "anterior cruciate ligament"—is particularly vulnerable.
Just like all ligaments, the ACL is a tough band of tissue that connects two bones in order to stabilize and coordinate their motion. In this case, those bones are the femur (the thigh bone) and tibia (shin bone).
Specifically, the ACL prevents the tibia from slipping forward relative to the femur.
During forceful hyperextension—where the knee over-straightens, so to speak—an outside tackle can overwhelm the ACL's ability to prevent the tibia from moving forward, resulting in a tear.
Fortunately, it appears Cobb's strong surrounding musculature (such as his quadriceps and hamstrings) absorbed enough of the stress of the hit and prevented the ACL from taking too much of the blow on its own.
However, that stress still had to go somewhere, and that somewhere was his fibula.
The fibula is a bone of the lower leg that runs from the knee to the outside of the ankle alongside the weight-bearing tibia. It supports the tibia and does not bear much weight in its own right.
Dunne had more info about Cobb's specific fracture via Twitter:
Though exact details are not available, Dunne's tweet suggests the fracture is not significantly displaced and not quite even a full break. In other words, the general alignment of Cobb's fibula likely remains intact.
Why does that matter?
Depending on where it takes place, a complete, displaced or unstable fibular fracture could threaten other structures within the leg, something Cobb likely avoided.
For instance, a displaced proximal fracture—meaning one close to the knee rather than close to the ankle—could injure the common peroneal nerve. Common peroneal nerve damage compromises dorsiflexion (pointing of the toes toward the head), among other actions.
A complete fibular fracture may also require surgical intervention—such as an open reduction internal fixation (ORIF) procedure—for proper repair. During an ORIF, orthopedic surgeons visualize the fracture, manipulate the broken bone back into place and use metal hardware to reinforce the bone in its proper anatomical position while it heals.
On the other hand, an isolated, non-displaced fracture does not require surgery. In fact, it usually only needs somewhere in the neighborhood of six weeks to return to full activity, and initial reports predict a similar scenario for Cobb.
Generally speaking, rehab for a fibular fracture is not terribly complicated, at least compared to an ACL tear, for example.
During initial stages, doctors will likely place an athlete's leg in a cast and advise him or her to avoid activities that require bearing weight.
In Cobb's case, additional stress on the fibula too early could complete the already near-complete fracture, thereby setting him back quite a bit.
Once an athlete can tolerate the pain, however, he or she can slowly resume weight-bearing activity, along with strength and agility training to make up for lost time.
In the best-case scenario, the cast comes off after a handful of weeks, and rehab takes only a few more.
Then again, even with the best medical care—which Cobb is surely receiving—complications, setbacks and delayed healing are always possible.
Nevertheless, unless reports of such outcomes surface, it's reasonable to expect a return by Week 14 or so.
Hopefully that comes to pass, as with the injuries piling up, the Packers will certainly need their star for the final stretch of the 2013 regular season if they are to make another playoff push.