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.
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:
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 :
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:
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.
Author
Topic: Importance of bone alignment (Read 4941 times)