one thing that really disturbs me about revision surgery

[Guest guest]

the hardware that Bernie showed me is one solid rod that has a curve

in it. It is bolted in place with screws.

I thought a long rod was what got me in trouble in the first place.

Bernie explained that the curve and the multiple screws were the

improvements.

However, I know I have read research studies that suggest that when

they curve the rod at room temperature, there is some possibility

that the higher body temperature will help it attempt to return to

its original straighness at some point in time.

For some reason, I was expecting segmented hardware, or shorter rods

that connect together. I seem to recall watching a video that

showed shorter rods between the vertebrae -- but it could have just

been a one or two level fusion I suppose.

The idea of having long rods and a solid fusion is making me a bit

apprehensive. I like being able to dance to Caribbean music. I

would hate to loose my ability to wiggle (although as I sat in my

chair and wiggled from side to side, I did get a shooting pain down

my leg, but I still enjoyed the wiggle).

Is Dr Rand using a long curved rod, too? What about the other

docs? Is this the standard?

[Guest guest]

Hi...

Segmental hardware refers to the rods being attached to the spine at multiple points (with hooks or screws), as opposed to the Harrington rods, which were attached at the top and bottom.

Can you recall where you read the research about rods losing their curves? I don’t remember ever seeing anything like that. There has been some research about using shape memory metal:

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve & db=PubMed & list_uids=11956914 & dopt=Abstract

Regards,

On 7/31/06 8:29 AM, " SB " <bahadreama@...> wrote:

the hardware that Bernie showed me is one solid rod that has a curve

in it. It is bolted in place with screws.

I thought a long rod was what got me in trouble in the first place.

Bernie explained that the curve and the multiple screws were the

improvements.

However, I know I have read research studies that suggest that when

they curve the rod at room temperature, there is some possibility

that the higher body temperature will help it attempt to return to

its original straighness at some point in time.

For some reason, I was expecting segmented hardware, or shorter rods

that connect together. I seem to recall watching a video that

showed shorter rods between the vertebrae -- but it could have just

been a one or two level fusion I suppose.

The idea of having long rods and a solid fusion is making me a bit

apprehensive. I like being able to dance to Caribbean music. I

would hate to loose my ability to wiggle (although as I sat in my

chair and wiggled from side to side, I did get a shooting pain down

my leg, but I still enjoyed the wiggle).

Is Dr Rand using a long curved rod, too? What about the other

docs? Is this the standard?

[Guest guest]

Hi...

I finally found what you mentioned:

1: Spine. 2005 Feb 15;30(4):375-9. Links

The memory properties of cold-worked titanium rods in scoliosis constructs.

* Burger EL,

* Baratta RV,

* King AG,

* Easton R,

* Lu Y,

* ow M,

* Riemer BL.

Department of Orthopedics, Bioengineering Laboratory, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, USA. EBurge1@...

STUDY DESIGN: Time series monitoring changes in titanium and stainless steel rod curvature kept at a constant temperature of 37 C as a function of time. OBJECTIVES: To assess the possibility of loss of curvature in titanium rods after scoliosis surgery. SUMMARY OF BACKGROUND DATA: Titanium rods have gained use in scoliosis surgery due to their excellent biocompatibility, while allowing medical personnel to obtain undistorted magnetic resonance imaging scans following surgery. However, the impression of several clinicians has been that when screw pullout and/or loss of sagittal balance occurs, it may be due to the rods losing some of their curvature. METHODS: Five 6-mm rods of differing compositions and lengths (titanium 300 and 100 mm, stainless steel 300 and 100 mm, prebent titanium 85 mm) were bent at room temperature with a 3-point rod bender, then placed in an incubator at 37 C. Digital photographs were taken every 2 weeks and analyzed to extract the radius of curvature of each rod. RESULTS: The Ti rods had a significantly decreasing curvature with time. The prebent Ti and stainless steel rods did not exhibit significant change in curvature. CONCLUSIONS: Titanium rods bent at room temperature and then exposed to body temperature over time tend to exhibit " metal memory " ; they gradually revert to their original shape. This may result in loss of sagittal balance and/or proximal screw pullout.

PMID: 15706332 [PubMed - indexed for MEDLINE]

I’m going to have to ask some questions about this, as I don’t understand the results:

RESULTS: The Ti rods had a significantly decreasing curvature with time. The prebent Ti and stainless steel rods did not exhibit significant change in curvature.

Did the titanium rods lose their curves or not? In today’s scoliosis surgeries, all rods are pre-bent.

Regards,

On 7/31/06 8:29 AM, " SB " <bahadreama@...> wrote:

the hardware that Bernie showed me is one solid rod that has a curve

in it. It is bolted in place with screws.

I thought a long rod was what got me in trouble in the first place.

Bernie explained that the curve and the multiple screws were the

improvements.

However, I know I have read research studies that suggest that when

they curve the rod at room temperature, there is some possibility

that the higher body temperature will help it attempt to return to

its original straighness at some point in time.

For some reason, I was expecting segmented hardware, or shorter rods

that connect together. I seem to recall watching a video that

showed shorter rods between the vertebrae -- but it could have just

been a one or two level fusion I suppose.

The idea of having long rods and a solid fusion is making me a bit

apprehensive. I like being able to dance to Caribbean music. I

would hate to loose my ability to wiggle (although as I sat in my

chair and wiggled from side to side, I did get a shooting pain down

my leg, but I still enjoyed the wiggle).

Is Dr Rand using a long curved rod, too? What about the other

docs? Is this the standard?