Tuesday Extra

Application

If my guess about the application is correct, then your second sentence is carefully worded, but will probably be misread by many.

Re: Application

;-)

Hint

Alex read between the lines of the original question. Although I have personal experience with this jig, I was not aware of it at the time.

Re: Hint

I'll guess it's a jig for inter-cranial work?

Tom

flattery will get you nowhere

The space between my ears is considerably less than 18". But you are right. The jig would be used by a (hopefully) skilled medical professional.

Re: Tuesday Extra

Your answer to Thomas strengthened my confidence in my guess.

I'd start with a cylinder bigger than the objects you are going to drill. I would bore out the axis of the cylinder and cross-bore where I want the crossing drilling to go. Then hollow out the cylinder from one end, leaving enough thickness in the walls and base to support drill guides. I would also bore and tap holes in the cylinder for threaded rods that end in pads shaped appropriately to support the object, or use slings in tension to hold the object in the jig.

But that is just in concept, since the object you will be drilling is probably connected to other things, and can't be disjoined for the drilling. So I suspect the final product, while holding drill guides in the same positions as the described cylinder, won't look much like a cylinder, and will provide more access to the drilled object.

Re: Tuesday Extra

You are correct that it doesn't look much like a cylinder. But also correct in the basic concept of an armature for holding several drill guides in precise alignment.

There is more of a 'freehand' aspect to it than I would have imagined. But one additional design constraint is that it must be radiolucent to facilitate confirmation of the correct alignment.

Whazzit?

I assume some kind of orthopedic device such as a pin for fracture repair or installation of an artificial joint?

Re: Whazzit? *LINK*

Alex 'nailed' it. The jig is for installing intermedullary nails to stabilize and/or repair the femur.

My experience with the jig resulted from hitting a patch of solid-phase dihydrous oxide while riding my bicycle.

Despite a rather complicated subtrochanteric fracture of the right femur, I didn't get a cast. The doctor said he would 'nail' me instead. They cut and drilled and reamed and tapped and hammered and screwed and then sewed me back up. I woke up feeling good as new (at least until the morphine wore off). It took a couple weeks before I could actually turn the pedals again.

The link describes the design and surgical technique.


The Jig