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Sunday, January 8, 2017

Dance


Every month or so I have this recurring dream. It goes something like this: I’m sitting in an examination hall with other students. I’m aware that I am about to sit an exam. I flip open the first page and find, to my horror, that I can’t understand the question. I guess that it’s a maths or physics question with complex diagrams and equations but I don’t know what I am looking at much less what I am asked to do. I look up at the other students and see them with their heads down, pens afire; or tapping their chins, pondering. I get a horrible feeling that I am sitting the wrong exam. Then I wake up.

A month later I get the same dream but in a different setting and with a different question. 

It’s vivid and unsettling.

Last night was slightly different. The setting is still an examination hall but this time it starts out with desks and chairs and somehow ends up with coffee tables and sofas. The question appears to be the calculation of the energy level of a string of elementary particles (elementary particles drawn literally like beads on a string). There is a worksheet with the energy levels of other combinations of elementary particles (2x + y + 4z + 3k = 762; x + 3y + 6k = 465; etc). Ignoring the many incongruencies that dreams have with reality I actually, for once, understand the question and so set out to answer it. As I pick up my pen the guy next to me leans right over to the point that I cannot place my hand on the paper to do my calculations. Thinking back on the dream this was the time that the setting changes from chairs and desks to sofas and coffee tables. The guy on the other side of me also leans over pushing me back into the sofa. I push back but other people start leaning over. The perspective changes from my point of view to me looking at myself struggling as even more people pile on top of me. My work sheet, examination paper, and answer booklet go their separate ways. Then I wake up.

WTF?!

I mean seriously, WTF?!

I’ve had these dreams for years - probably the better part of a decade - and, finally, when the question actually makes (some) sense my brain conjures a ridiculous scenario to thwart any attempt to answer it. 

I clearly have some unresolved issues.

Don’t you smirk. I bet you have some too.  

If I could dissect my brain anatomically, biochemically, or metaphorically, I would expect to see something quite different to what I would find if I dissected anyone else’s brain. In particular - for the purpose of an easy comparison - if I dissected the homunculus of my motor and somatosensory cortices it would show a relatively large representation for my hands and a smaller representation for my feet. 



Motor homunculus 



Sensorimotor homunculus



My work requires good fine motor skills and, for as long as I can remember, I’ve always had an ability to “see” well using my hands. Nothing otherworldly or such, just a good tactile sense for materials and a good ability to coordinate my motor response accordingly. Regular practice probably enhances these capabilities. 

My feet, on the other hand, are terrible. I literally have no idea where they are at any particular point in time. And without decent sensory input I am unable to modulate an appropriate response. It could be a lack of appropriate sensory end-organs, a problem with the neurological connections, or a problem at the level of the brain. The motor output to my feet does not appear to be any better. As a matter of fact my lack of gross motor skills makes me wonder whether every part of my sensorimotor anatomy - with the exception of my hands - is structurally underrepresented. Sadly, I am no dancer.



There are two types of beings in the universe: those who dance, and those who do not.




I was never compelled to make up for these natural deficiencies. And, thankfully, there is a good living to be made furthering other skills. But I wouldn’t mind being able to dance. Maybe not of anyone else. Just for myself.





Sunday, December 4, 2016

Percutaneous reduction and fixation of the flexed fractured scaphoid


Here’s a neat technique..


17yo male with scaphoid waist fracture


CT reveals comminution










And a humpback deformity


You get the impression there is a pre-existing bone cyst through which the fracture occurred






Lunate extension secondary to scaphoid flexion





This is not the typical case for percutaneous fixation but:
1. a Matti-Russe approach and fixation with screws or a scaphoid plate is not without its problems
2. there is good evidence that stable fixation can obviate the need for bone grafting
3. ask yourself “Can this be done better?”

Well, maybe..



Traction applied


K wire is passed through the lunate


Lunate flexed relative to RCJ (extending scaphoid at the fracture site)




Two guide-wires passed across the fracture site


Scapholunate angle corrected on lateral view


Percutaneous screws




Lateral view to confirm acceptable SLA