How much does my hardware weigh?

[debbei]

I have an appt with Dr. Neuwirth on December 4th, and I will definitely ask there. I am now weighing less than when I started, but I know the T3 to L3 hardware (stainless steel) has some significant weight. Last I was on the scale was a few days after I came home, and I think I had some water weight I was holding, it was about 5 lbs higher.

Does anyone have an idea? You see, I worry about the IMPORTANT things.

BTW, today is 3 weeks from surgery, and last night I stayed up watching the election results (YEAH!!!!) and took 2 pain pills at 11:00 PM. I slept all night and woke up at 7:30 to take another pill. That's the longest I've ever gone between pills, and I feel really good this morning.

[Carmell]

Debbe,

Sounds like you are doing GREAT! Keep up the good work - slow and steady wins the race.

I'll bet Dr. Neuwirth has "sample" hardware he'd let you see and hold. My Braydon has adjustable titanium rods. We were able to see and feel them before his surgery so we could get an understanding of what was going on inside. His titanium system weighs less than half a pound, total. Stainless may be heavier, especially since there is more of it (T3-L3 is a significant fusion area).

Let us know what Dr. Neuwirth says about the weight of the rods you have. I love interesting trivia like this.

[Qikdraw]

I wonder if I can blame my weight gain on my hardware getting heavier? But then how do I explain my pot belly?

*sigh*

Glad to hear you are well enough to concentrate on the important issues Debbe!

Brad

[titaniumed]

Debbe

6mm dia 316L stainless weighs 1.78474# per 12 foot length/12=.1487283# per foot.

Assuming you have about 20 screws at 2" long ea that equals 40 total inches for the screws.

Assuming you have 2 rods 6mm dia x 18" long ea x 2= 36 total inches for the rods.

This totals 76 inches. 76 inches=6.33 total feet

6.33 total feet X .1487283=.94145# Or 94% of 1lb or 15.04ounces

This is without calculating the stock removal from the threads and the possibllity of the drilled holes through the screw.
My screws from Synthes are hollow. They have a small hole drilled down through the screw which aids with alignment for screw placement.

This is also without calculating the increased dia of the screw head assy which is larger in dia.

With both factors, my best assumption would be 1lb.

titanium weighs 40% less than steel.

Brad, the pot belly is due to lead. (lead belly) lead and gold are close to one another as far as weight is concerned, about 1200 lbs per cubic foot. sorry.

I have the same problem

Ed

[Susie*Bee]

Yep, it weighs hardly anything. Last time I was in to see my scoli doc, he showed me a hunk and let me hold it, and it probably weighed a few ounces at most. It was stainless steel... So our hardware does not give us an excuse for gaining weight. Some of you are sooooo lucky to have lost. Oh well!

[amae28]

I have stainless steel rods and my doctor told me that the two of those and (for me) the 26 screws together weigh around 2-2 1/2 pounds. I think they were estimating, but when I picked up the hardware in the office before my surgery it definitely felt like more than a pound. Obviously it probably depends on how many screws and how long of a fusion you have though.

[Susie*Bee]

I should have said the hunk I held was only about 8 inches long. I have two rods about 20" long plus a shorter (8"?) rod, plus all the screws. My doctor said it wouldn't be more than about a couple of pounds total. Hope that helps better...

[Carmell]

Nice to have an engineer/mathematician in the group, Ed. Glad someone else has the brain cells to take the time to figure all the calculations... helps make us feel better (or worse, if YOU want to be the one who is numerically driven). Also makes me feel my UNeducated guess was semi-accurate - hehe

[debbei]

Thanks everyone,

a couple of pound is a couple of pounds! My husband teases me and says that at the rate prices are going up, he can sell me for scrap if we need $$. LOL

I'll be sure to ask Dr. N this question next month.

Thanks!

[titaniumed]

scrap and screw analysis

Debbe

Supply and demand dictates pricing on all sorts of things like gasoline and metals. We are seeing gasoline prices lowering due to the drop in the demand. The same has happened with the metals sector. Here are the spot prices for some metals like copper,aluminum,nickle, etc. Most metals have cut in half in the last 3 months due to our current economic scenario.

http://www.kitcometals.com/charts/co...istorical.html

So, Im sorry to say that our scrap values are dropping and thats kind of sad. Show this to your husband so hes aware that that "trip" to the scrap yard might not yield his expectations.

You are like a T3-L3 right? Ohh, he would probably get about $5
Im a T2- Pelvis with the long screws, I might get about $6

If he gives you any guff, just tell him your worth $5 more than him. LOL

Carmell

Calculations and cost analysis in precision machining and metalworking is what I do for a living. When I saw the Ti guess at .5 lb I knew it was close and did some very simple math, not even using any of my software for estimation purposes. I just wanted to see, glad I could be of some assistance here on this.

I was at a metalworking show a few years ago, "westec" in La and watched one of these screws being made on a Tornos Deco swiss style cnc lathe. It took about 6 minutes to make and I had one in the car for a long time. About a month ago someone mentioned it here and I went out to the car to see if it was still there but it probably was thrown out at the car wash. They cost about $1000 ea. The lathe with tooling $300K engineering,programming, and set-up charges 25K. Other associated costs are pricy also, so there is quite an investment involved in making these. They are tricky little buggers!

Screws sold at Home Depot are made with a process called "cold heading" where wire spool stock is smashed in dies at a rate of 4000-8000 pcs per minute.So you see there is a big difference in engineering, methoding, and production rates and of course cost between spinal screws and deck screws.

So a screw, is just not any old screw.
Oh my cheek hurts.

Regards
Ed

[Carmell]

Thanks again, Ed. Glad you can help us with the technical stuff. Machining and metalworks is interesting.

When Braydon has his expansion surgeries for his VEPTR rods (every 6-8 months) the surgeon lets him keep the locking clips (made if 100% titanium). He also gets to keep the expansion "sleeves" when they replace them with longer rods (when the sleeve has been expanded to the end). He has quite a collection of hardware after 14 expansion surgeries and 2 exchange surgeries. Maybe the metal markets will go up one day and we could cash them in for REAL money. I know the cost billed to my insurance was NOT chump change. His original rods were billed at $25,000+ for two rods, sleeves and locking clips. With each expansion surgery, they replace the locking clip with new ones. Each locking clip is billed at $1500 (yes, that's EACH - Two each surgery) to the ins company. You can't tell me the hospital is paying anywhere CLOSE to that. My surgeon said that they pay Synthes approx $50 for each locking clip. My "non profit" hospital is making a pretty penny on that item alone.

[JoAnn5]

I think it's about 42 pounds

Well that's my story.... and i'm stickin' to it!! lol

[Qikdraw]

Brad, the pot belly is due to lead. (lead belly) lead and gold are close to one another as far as weight is concerned, about 1200 lbs per cubic foot. sorry.

I have the same problem

Ed

LOL Ed!

So are you saying my lead belly may actually be gold? I better not tell my wife or I'll end up as jewelry...

Brad

[txmarinemom]

My husband teases me and says that at the rate prices are going up, he can sell me for scrap if we need $$. LOL

Deb, it is SO awesome to hear how great you're coming along. Carmell's right about slow and steady, and even those who are fortunate enough to seem to zip through early recovery often hit spots where things seem to stall (as I believe was mentioned in the thread rated 5 stars by our "Comedic Therapist", Ed ). The whole process seems to balance out.

My Stryker XIA system (6mm Vitallium rods - which I still haven't seen anyone else wearing - and titanium screws) weighs in at ±6 oz. In comparison, Hanson told me the same XIA system in 316 SS (the XIA is available in 316, titanium and Vitallium) would be slightly over 1 lb.

BTW, I'm sure I've posted snippets of Hanson's answer when I asked about the risk of frx (fatigue fracture) with Vitallium - and the system/material in general, but here's what he had to say:

"... there are two factors that come into play when evaluating the strength of
the material; both the material itself and the overall radius of the rods.

As the radius of the rod increases (SS is only available in 5.5 mm or 6.35 mm
rods, versus 6.0 mm for the Vitallium) the overall strength of the rod goes up by a factor of 4.

I think a 6.0 mm vitallium rod is a good compromise and certainly is quite strong. "

Sure 316/316L SS are heavier, but whether it's noticeable? Who can really say unless they've had 316/316L and then something else ...

I really had to laugh at the scrap metal comments. My family knows I want to donate my body to science (hopefully not anytime soon!), and I actually want to know if it's worth it to have my hardware removed for scrap - LOL.

Macabre? Probably. But as much as I paid for it, it's kind of a valid consideration!

Carmell's mention of the cost vs. consumer retail of Synthes locking clips reminded me of when Hanson started doing VBS (stapling) in June. We were discussing the surgery, and he described the tins used to hold the Nitinol c-clamps in an ice bath (they straighten at ambient temperature). I laughed and said "probably $5,000 muffin tins ...", and he said "Yeah ... pretty much!".

Regards,
Pam

[titaniumed]

Brad, lead not gold. nice try, dream on.

Lead is used as ballast in keels of sailboats, and to bend our rods and spines foward to increase lumbar lordosis through bone remodeling. LOL

I wonder how many men with potbellies have had flatback problems? Probably not too many.

Pam, I love the 'comedic therapist' title! Wow, I need to get a name tag made immediatly! and doctors coat!
Oh this reminds me of Benny R.I.P.

http://www.youtube.com/watch?v=810TQyT2KXI

My hospital experiance was nothing like this. Is it like this in England?

I had a doctor that suggested that I donate my body to science, but I think that we are worth more in the pre-surgical state. I wonder if any of the medical museums actually have a spine on display that has been fused?
It might be of more value to donate with the hardware. You know, someone is going to come along and say
" wow that guy got screwed!"

I wonder if there are any surgeons that still use wires? Interesting to know if "todays modern hardware" has totally replaced the use of luque wires? It was the "gold standard" years ago with extreme paralytic cases.

Enuf fun for today.

Ed