One of my Dc has had bone lengthening for a congenital condition which left him with one leg much shorter than the other.
This can cause lifelong issues with spine, internal organs etc as well as mobility problems.
The bone is cut right through. In the traditional current method pins go through the bone either side of the cut. Attached to metal rings that go round the outside of the leg.
Every day, whichever the method, the gap between the bone ends is forced apart by about 1mm for new bone to go across the gap. Weeks of this. And every day the tendons, ligaments and muscles are being forced to lengthen too. Months and months of, in effect, having permanent muscle pain.
Bones, muscles, tendons, skin… it is way beyond surgery like breast enlargement etc.
The new bone takes time to harden, so more plaster / crutches once the actual lengthening is done. It takes about 9 months, and then months of physio.
Once you have had to listen to your 18 yo boy crying in pain time and time again the inconvenience of standard clothing might seem less significant.
It makes me feel ill to think of people doing this for cosmetic reasons or people bullying over height to the extent that anyone would consider it.