Texans DE JJ Watt (Lateral tibial plateau fracture): Watt’s left cleat tripped up a bit and resulted in an awkward couple of steps on his left leg. The second step appeared to result in a significant, forceful valgus injury (bending inward like this >|) to his left knee. As TV broadcasters mentioned, the same injury pattern happened to Dez Bryant last season. I wrote about that injury here.
Bryant right knee valgus injury:
Watt left knee valgus injury:
The medial (inner) part of the knee, the MCL, stretches in an injury like this. The lateral (outer) bones of the knee, the lateral femoral condyle and lateral tibial plateau bang together and, if enough force is present, can result in a fracture of the lateral tibial plateau. In Bryant’s case that led to a bruise in the lateral tibial plateau. In Watt’s case, unfortunately, the stress to the knee resulted in a fracture in the lateral tibial plateau that was likely visible on the x-ray obtained at the stadium.
An injury like this needs to be treated aggressively. When the lateral tibial plateau fractures, the overlying cartilage/joint surface can collapse. In order to function normally, the knee joint surface must be smooth. Surgery is performed to attempt to restore the normally smooth joint surface and repair any injury to surrounding structures (the meniscus is commonly also injured). Watt can certainly come back from this type of injury, hopefully by next season, but his performance will depend a lot on the severity of injury to his joint surface, ability to fix it surgically, and risk of post-traumatic arthritis.