Interesting, is this why you are choosing external tibia?
I found a small sample satisfaction quiz on the two and it seems patients prefer internal (very small sample so..): https://www.ncbi.nlm.nih.gov/pubmed/26688988
Yeah, safety and affordability are the main reasons. It's been said to be the least invasive and safest form of LL.
But the paper mentioned "better cosmetic appearence", I disagree (assuming we do femurs if we do internal). Hiding scars is easy, but proportions-wise, longer femur isn't very aesthetic. I just realize raising the knee level is pretty important for the looks.
However, the advantage of internal femur is the possibility of lengthening extra 1-2cm. I'm pretty confused also.
I'm guessing the patients who responded to the questionnaire preferred internal due to convenience and overlooked how invasive and the possible long-term effects. Anyway, those patients made it alive post-LL and obviously couldn't realize the danger they were in.