If you have rickets your skeleton could be said to be rickety, perhaps. I wonder whether "rickets" comes from "rickety" or vice versa.
The Merriam Webster entry for rickety says only:
1 : affected with rickets
2 a: lacking stability or firmness: SHAKY sense 2a
// a rickety coalition
b: in unsound physical condition
// rickety veterans
// rickety stairs
But in the ordering of the senses there is hint, at the very least, that "rickety" first meant afflicted with rickets. If so I guess it parallels "lousy" which originally meant afflicted with lice.
The same site defines "rickets" like this:
"Definition of rickets
: a deficiency disease that affects the young during the period of skeletal growth, is characterized especially by soft and deformed bones, and is caused by failure to assimilate and use calcium and phosphorus normally due to inadequate sunlight or vitamin D" and the entry says nothing about the word "rickety".
From the site BMJ Journals:
The discovery of this new disease, rickets, in the middle of the 17th century was probably due to the increasing urbanisation taking place at the time, as well as to misguided practices in infant feeding. Within a very short time early obstetricians like Willughby in England and van Deventer in Holland were describing the problems of delivering infants through women’s rickety pelvises. Perhaps it was no coincidence that the Chamberlen family also introduced the forceps into their practice at this time and that in the 17th century man midwives increasingly invaded the previously jealously guarded female province of childbirth.
