The article is published in the Journal of Neuropsychiatric Disease and Treatment although some who have these desires would probably disagree that it is a disease or disorder and are more likely to compare it to something akin to being transgender.
The article also discusses the two main themes in the research literature: an association with sexual fetish for limb aputation (most associated with the use of the name apotemnophilia) and an alteration in body image linked to differences in the function of the parietal lobe in the brain (most associated with the use of the name xenomelia).
It’s a fascinating review of what we know about this under-recognised form of human experience but it also has an interesting snippet about how this desire first came to light not in the scientific literature, but in the letters page of Penthouse magazine:
A first description of this condition traces back to a series of letters published in 1972 in the magazine Penthouse. These letters were from erotically-obsessed persons who wanted to become amputees themselves. However, the first scientific report of this desire only appeared in 1977: Money et al described two cases who had intense desire toward amputation of a healthy limb. Another milestone was a 2005 study by Michael First, an American psychiatrist, who published the first systematic attempt to describe individuals who desire amputation of a healthy limb. Thanks to this survey, which included 52 volunteers, a number of key features of the condition are identified: gender prevalence (most individuals are men), side preference (left-sided amputations are most frequently desired), and finally, a preference toward amputation of the leg versus the arm.
If you want a more journalistic account, Matter published an extensive piece on the condition last year.