I just became aware that Ed McPherson, MD, is now offering limb lengthening: https://www.uclahealth.org/providers/edward-mcpherson

Dr. McPherson is a master surgeon who is well known for taking and fixing those cases others could not fix.  My wife had a botched knee replacement 20 years ago--about 7 surgeons tried to fix it over the years--Ed McPherson actually fixed it in one go.  The OR nurse told me he watched Dr. McPherson successfully replace all the bones in a patient's leg with titanium rods.

I cannot vouch for Dr. McPherson with respect to limb lengthening per se; only as to his orthopedic surgery skills--he is quite literally the best surgeon I ever encountered.  I can say that during my spouse's appointments, he talked with me several times about my procedure and even viewed my xrays when I returned from Russia.  Based on those conversations, he plainly knew stuff and told me he had done non-cosmetic lengthening in the past.

If you are considering limb lengthening, in my opinion, he is worth a look.