Proportions aside, is 4+4 twice safe? Assuming you did 4 cm femurs, then once that’s done do 4cm tibias, then wait a year and rebreak femurs for another 4cm then after rebreak tibias for another 4cm. 16cm total. It sounds pretty safe and in a video with cyborg 4 life he said it’s a really good option. Thoughts?
I see you are referring to option 5 here
https://limblengthening.org/lengthening-strategies/$275,000 for the 16cm (8cm femurs + 8cm tibias) you mentioned
16cm = 6.30 inch
Better option would be option 4
$201,500 for 13cm (8cm femurs + 5cm tibias) and no rebreaking of bones
13cm = 5.12 inch
Also, 5cm for tibias is far more safer than 8cm. With +8cm tibias, you'll get major arthritis pain at the knees. And remember, the average tibia is 80% of the length of the femur, so +8cm tibias is overboard.
Option 4 gives you 5.12 inch for the best safety. If +5.12 inches will not satisfy you, then it's unlikely anything will satisfy you. Plus is paying over $70k for a little more than one inch really worth it when you can gain 5.12 inches with option 4?