A season ending injury is not a diagnosis. Igor Shesterkin is out for the season after his right skate jammed into the post and his leg folded underneath him. The Rangers have announced a lower body injury, not a specific torn structure. The differential depends on where the force went: MCL injury if the knee collapsed inward. A trapped skate can create that load in hockey. [1] ACL or meniscus injury if the body rotated over a fixed foot. PCL injury with trauma through a bent knee. These are possibilities, not diagnoses from a replay. [2] Fracture or cartilage injury also belongs on the list. If he cannot actively straighten the knee, the patellar and quadriceps tendons need assessment. [2,3] Not bearing weight is a reason to investigate, not proof of an ACL tear. [3] The protocol is assessment before prediction. Protect the leg, assist him off, check circulation and nerve function, then examine the ligaments and extensor mechanism. Radiographs assess for fracture. MRI helps def...