[Extra Point]

[quote author=OutsiderFan link=topic=6741.msg72081#msg72081 date=1382458719]
Never heard of a knee injury actually being a broken bone with no knee ligament damage.  Any doctors in the house who can comment or make sense of this?

It can happen.  It's unclear exactly happened in the article, but it sounds like he either fractured the articular surface of his femur or fractured his femur right above the joint.  It's less common then knee soft-tissue injuries, and is relatively rare to occur in isolation.  Usually it happens in a higher energy impact (e.g. car accident) that also would cause knee soft tissue damage.  I'm not an orthopedist so that's the best I can do for now.
[/quote]

The femur is the bone between the hip and knee. If his femur is fractured it is a stress fracture. A complete fracture is actually a very scary injury. The thigh muscles are very strong and broken bones are very sharp. When the femur completely fractures the muscles pull the bones segments together 4 to 6 inches. In the process the femoral artery is often severed and if not treated quickly the victim can bleed out. A fat embolism is another possible outcome that can kill someone. Bones protruding through skin is also common.

When my son was 13 his leg muscles split his knee cap in two while he was running. There was no nerve, ligament, muscle, artery, or tendon damage.

[Extra Point]

[quote author=OutsiderFan link=topic=6741.msg72081#msg72081 date=1382458719]
Never heard of a knee injury actually being a broken bone with no knee ligament damage.  Any doctors in the house who can comment or make sense of this?

It can happen.  It's unclear exactly happened in the article, but it sounds like he either fractured the articular surface of his femur or fractured his femur right above the joint.  It's less common then knee soft-tissue injuries, and is relatively rare to occur in isolation.  Usually it happens in a higher energy impact (e.g. car accident) that also would cause knee soft tissue damage.  I'm not an orthopedist so that's the best I can do for now.
[/quote]

The femur is the bone between the hip and knee. If his femur is fractured it is a stress fracture. A complete fracture is actually a very scary injury. The thigh muscles are very strong and broken bones are very sharp. When the femur completely fractures the muscles pull the bones segments together 4 to 6 inches. In the process the femoral artery is often severed and if not treated quickly the victim can bleed out. A fat embolism is another possible outcome that can kill someone. Bones protruding through skin is also common.

When my son was 13 his leg muscles split his knee cap in two while he was running. There was no nerve, ligament, muscle, artery, or tendon damage.