User question about Precice and Stryde ERC

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A fellow member of this community sent me a private message asking me about ERC. I thought It would be cool to answer publicly so everyone can benefit.

QuoteHi Dr. Thanks for reply
These are my Questions

1. can we use  ERC of stryde on Precice too or vice versa?
2. How can we know dr. is implemented Stryde nail not precice?
3. Why stryde ERC machine  mentioned in Nuvasive company's website is different in turkey or Athens?

Those are all very good questions. Here are my answers:

1) all generations of Nuvasive ERC work on Precice of all generations (1 thru 2.5) Stryde , and Precice Bone Transport. Remember, Stryde is nothing but a Precice made from BioDur (sturdy stainless alloy). The internal mechanism is the same as designed by Dr. Herzenberg, Standard and Green.

In my opinion, the best ERC of all is the ERC1 as it is the most reliable. It does not look as neat, but if your surgeon gives you access to an ERC 1, you know for a fact that it will perform properly. (as long as you keep the skin mark intact, and that it is remarked frequently during followups, as the skin tends to stretch distally as lengthening goes on).

The ERC 4 is good as well because it has a longer distance of communication (soft tissue gap) with the rod. It is good for patients with more Girth to their limb. However it has been shown to fail sometimes and you will need a responsive sales representative or surgeon to troubleshoot problems.


2) You have to trust your surgeon. PRECICE is only a partial weight bearing implant. no CLL surgeon in their right mind would implant a PRECICE instead of a STRYDE and tell you to walk on it. PRECICE will break if weight bearing restrictions are not respected. oooh yes they do.
To differentiate the implant On XRAY: with a normal amount of XRAY kVP, you will see the inside of the precice mechanism (gears) very well. With the same amount of kVP, you will not see the Stryde mechanism well at all. it will look very uniform.

3) Nuvasive had a limited amount of ERC 4 during launch and only made them accessible to a few centers such as ours (ICLL of Baltimore), Paley Center, LimbPLastx, maybe Giotikas, and a select few group. The reason is that they use centers who are VERY experienced with limb lengthening to troubleshoot problems with their new products. It decreases the potential variables. I had the chance to work with all generations of ERC, including the 4, and they all work just as well (with a few differences)

 Also, they do business differently in certain part of the world and it is possible that in Turkey, certain distributors only have access to certain ERC versions. However, it does not matter. ERC 1, 3 and 4 are equivalent and work just as well one another.


Let me know if that makes sense and If you need clarifications .

Also guys: feel free to reach out via PM if there is any other topic you would like covered. I would be happy to write a capsule about anything of interest.

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They can break if the weight bearing restrictions are not respected.

Also, always remember that walking creates forces equivalent to 2x body weight on the implant, and climbing steps, up to 4x body weight.  so even if you only weigh 150lbs, walking fast or climbing stairs may be too much for the implant.

Be critical of marketing. Always keep an assistive device (cane, crutches, walker) during ambulation to offload your legs as you walk.

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More: kVP is the peak kilovoltage, which is basically the amount of energy emitted to obtain the xray image. The denser the object, the more KvP needed to penetrate it.


A: Ballerina syndrome is called equinus contracture, on medical terms. It can occur from many causes in life, but to put simply, in the world of limb lengthening, it is mainly a complication of tibia lengthening.

It is preventable through gastrocnemius recession at the time of initial lengthening surgery, and it is preventable and fixable via aggressive physical therapy rehabilitation . The best remedy is prevention .

Lengthening is lengthening no matter the method. The implant is just a vehicle for length. LON in tibia is very safe. The only added risk is fracture through a pin site and pin site infection. Precice and Stryde are equivalent but stryde ha thé added benefit of weight bearing.

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I have thought about it, especially since Stryde nail came on the market, But my allegiance to my patients does not allow me to take the months necessary for the recovery. They need treatment and close followup.

Also, I do not suffer from height dysphoria and do not feel a strong need to be taller . My necessity is to hit the gym. That is what makes me feel better personally.

I hope this makes sense!