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Author Topic: Importance of bone alignment  (Read 4936 times)

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FDR101

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Importance of bone alignment
« on: September 24, 2017, 03:27:08 PM »

I was reading a research paper on the precision of the PRECISE nail from 2014 by Yatin M. Kirane, MBBS, DOrtho, PhD, Austin T. Fragomen, MD, and S. Robert Rozbruch, MD. (Link to research paper:  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4397804/)

One of the sections of the study was the resulting bone alignment.

It shows that unintentional changes in femoral and tibial alignment during lengthening happen with a few degrees.

Quote
In patients who did not undergo correction of a varus or valgus deformity, there was an unintentional +2° change in lateral distal femoral angle and a +3° change in medial proximal tibial angle, while the unintentional lateral shift in the mechanical axis deviation was 1 mm and 5 mm during femoral and tibial lengthening, respectively (Table 4). Among patients without any procurvatum/recurvatum deformity correction, the unintentional change in the sagittal plane angle was +3º for the femur and 0º for the tibia. A tendency for varus-procurvatum malalignment after proximal femur osteotomies and valgus-procurvatum malalignment after tibia osteotomies was observed. We attempted to minimize malalignment by selecting appropriate osteotomy level, by ensuring adequate length of the thicker nail piece beyond the osteotomy, and by using blocking screws [25] whenever indicated.

Note that when the numbers they are talking about are averages. So when they say 0º for the tibia, it is due to a range from -5º to +4º, the ranges are shown in table 4:



Note that these are small malalignments compared to other devices:

Quote
In summary, based on our initial series of 25 femoral and/or tibial lengthening procedures, the new PRECICE® internal lengthening nail appears to be a valid treatment option for straightforward bone lengthening procedures with mild to moderate deformity correction. The accuracy and precision of nail distraction were 96% and 86%, respectively, frequency of implant failure was 4%, and effects on bone alignment and adjacent-joint ROM were minimal.

Note also that the sample group lengthened an average of about 3.5 cm and that the sample group was small, limited and non randomized (check article for more info).

My question is whether someone here has more knowledge on how important these bone alignments are for athletic recovery post op?

From what I take from the article, the more one lengthens the bigger the chances of malalignments become.

From table 4 we see that the ranges on Femurs are :

Quote
Mechanical axis deviation (mm)   1 [lateral] (2 [medial] to 8 [lateral])
Procurvatum/recurvatum (°)           +3 (0–12)
Lateral distal femoral angle (°)   +2 (0–5)

Has anyone researched or by any chance talked with their doctor about the importance of a 2-8 mm shift of mechanical axis deviation or 0-12° shift of Procurvatum/recurvatum angle and the Lateral distal femoral angle?

It would be interesting to find out if a lot the reduced athletic recovery are due to these bone alignments. It's also interesting that it seems to be larger in Tibias compared to Femurs:

Quote
However, we did observe a tendency for varus-procurvatum malalignment at proximal femur osteotomies and valgus-procurvatum malalignment at proximal tibia osteotomies, which is consistent with past studies [7, 32]. A greater tendency for malalignment was observed during tibial lengthening as compared to femoral lengthening, possibly due to anatomic differences.

So if anyone has some knowledge on the subject of the importance of bone alignment in general either from own research or from talking with a doctor I'd love to hear more.
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Body Builder

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Re: Importance of bone alignment
« Reply #1 on: September 24, 2017, 09:43:10 PM »

Bone alignment is more important to avoid arthritis, at least premature.

Some few degrees (less that 5) of malalignment won't cause a major decrease in athletic abilities but still it wears down joints and could cause arthritis in the future.
If malalignments are major then even gait is not normal and joints will have serious problems but even small malalignments should be avoided as much as possible.
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ub40

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Re: Importance of bone alignment
« Reply #2 on: September 25, 2017, 12:41:19 PM »

It's very important, a few degrees off and you feel your walking is different and your center of balance drastically changes. Some doctors seem to be okay with that but it's not something to be taken lightly.
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sweng

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Re: Importance of bone alignment
« Reply #3 on: July 19, 2020, 06:47:24 AM »

This is probably going over my head, but does this essentially mean that those with a pre-existing knee genu recurvatum can possibly get it fixed due to CLL causing a procurvatum?  Wouldn’t this just cancel out the backwards knee bend?
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Maison

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Re: Importance of bone alignment
« Reply #4 on: October 13, 2021, 09:05:09 AM »

This is probably going over my head, but does this essentially mean that those with a pre-existing knee genu recurvatum can possibly get it fixed due to CLL causing a procurvatum?  Wouldn’t this just cancel out the backwards knee bend?

Theoretically, as you say, surgery can unintentionally correct the genu recurvatum.
In fact, my genu varum was unintentionally corrected by internal tibial lengthening surgery.
However, if you want to correct the genu recurvatum, I think you should consult a doctor who specializes in both correction of malalignment and bone lengthening.

And if a patient without genu varum or genu recurvatum undergoes internal tibial surgery, blocking screws should be used to prevent malalignment.
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Maison

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Re: Importance of bone alignment
« Reply #5 on: October 20, 2021, 10:32:09 AM »

I suspect that many people in this forum may underestimate the risk of malalignment.

As shown in these paper, the use of blocking screws is important for the prevention of malalignment in intramedullary nail surgery.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5069203/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7376586/

Deformation may occur when there is only an intramedullary nail and no blocking screw.

I suffered from malalignment after leg lengthening, so I want many people to know the importance of blocking screws.
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eric.cartman

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Re: Importance of bone alignment
« Reply #6 on: October 20, 2021, 10:55:29 AM »


It would be interesting to find out if a lot the reduced athletic recovery are due to these bone alignments. It's also interesting that it seems to be larger in Tibias compared to Femurs:

So if anyone has some knowledge on the subject of the importance of bone alignment in general either from own research or from talking with a doctor I'd love to hear more.

It’s a very real and prevalent problem, especially with tibias. I ended up with a knee valgus ( knock knees) when my TSF frames were replaced with IM nails. I had to go through another surgery, and had the nail replaced with additional screws to get it corrected. It’s mainly a surgical error as axis alignment wasn’t properly taken into account during the nail insertion. My advice is to be careful which surgeon you choose.
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Mayday

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Re: Importance of bone alignment
« Reply #7 on: January 13, 2022, 01:08:48 PM »

Thanks for sharing your experience. Could you please give more details about your second surgery?
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TheGambitKing

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Re: Importance of bone alignment
« Reply #8 on: January 13, 2022, 01:45:19 PM »

Can malaligment be solved?
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Michael J. Assayag, MD

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Re: Importance of bone alignment
« Reply #9 on: February 03, 2022, 06:42:28 PM »

Can malaligment be solved?

yes.
usually it requires a corrective surgery.

It is rarely needed for a good femoral lengthening, but valgus / pro-curvatum is frequent with tibia lengthening even in the best hands
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Dr. Michael J Assayag MD FRCSC
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sphenopetroclival

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Re: Importance of bone alignment
« Reply #10 on: May 16, 2023, 02:12:44 PM »

with tibia lengthening even in the best hands
A surgeon’s technical skill ultimately determines patient outcomes. If alignment is an issue for the surgeon at tibia perhaps it's best to instead proceed with the femur only.
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