Complex injuries

I broke the car cable to my IPhone 5 the other day.  As I suspect is the case for many people, even though I intend to unplag the cable by grabbing the little black nubbin (.... I'm assuming "nubbin" is the technical term), in reality I probably yank on the cable more often than not.

Not surprisingly, it is starting to break, as you can see above.  To me, what is most interesting is wear it broke- at the interface between the nubbin and the casing.  It didn't have to break there- it could have broke in the cable itself, or the end of the nubbin that attaches to the casing, or the nubbin itself, or where the nubbin interfaces with the lightning plug.  It happened to break where it did, because along the chain that was the weak point.

It struck me that this was a perfect analogy for many of the musculoskeletal injuries Garrett and I see in clinic. Someone engages in some physical activity that causes an abnormal force across their body, and the body gets injured.  The place of injury can vary, though, depending on the specifics of their injury.

For example, the patellar ligament connects the patella (knee cap) to the tibial tuberosity (the little bump on the front of the shin bone), and this ligament complex can be injured from abnormal loading.  In this context, I am using complex to mean a linkage of things to one another, rather than as a synonym for complicated.  In 11 year old boys, the patellar ligament complex usually fails where the ligament attaches to the patella, something called Sinding-Larsen-Johansson syndrome.  In 14 year old boys, it usually fails where the ligament attaches to the tibia, called Osgood Schlatter syndrome, and in adolescents and young adults, it usually fails in the proximal 1/3 of the patella, called Jumper's Knee or patellar tendinopathy.

One of my job as a physician is to be familiar common loading patterns, and also recognize how things like age, gender, and common activities affect their different complexes, because they often have different injuries.

In the meantime .... fortunately my car cable still works.