Just do 8 cm on femurs and see if that is adequate for your needs. DR Rozbruch reports that 80% of his patients are content with only that amount. If it proves insufficient, you can consider 5 cm on tibias. Nonetheless, exceeding 10 cm at that level (as I have done myself) can lead to disproportionate limbs and a very noticeable change in appearance. Therefore, I recommend aiming for a maximum of 8 cm on femurs and 5 cm on tibias if you truly desire increased height. With 8+ cm on femurs alone, you would already reach a height of around 175 cm, which falls within the normal range.