Twisted Limbs in Kittens

There is a video of a sweet little kitten, born with deformed hind legs, playing. Her name is Murcy. She is enjoying her playing and she is playing well but oblivious to the fact that she does not have hind legs that work. Cats compensate marvellously for disability.
It got me thinking. What causes a kitten to be born with twisted, deformed limbs? How common is it?
Well the answer is that a kitten can be born with twisted limbs anywhere and his or her mother can be any sort of domestic cat, purebred pedigree or otherwise. The condition is not limited to a specific location and neither is it defined by poor welfare or poor nutrition because it’s cause is nearly always developmental and not genetic.
Cause
In other words it appears that the position of the kitten in the womb, especially within large litters, can cause the unborn kitten to be in a cramped position preventing her limbs from developing normally. A specific condition called “Twisty Cat” and related conditions can also cause twisted limbs. The medical term for Twisty Cat is radial hypoplasia. Another cause is umbilical cord strangulation.
Both hindlegs and forelegs together with paws can be affected. Sometimes the condition is what is called “bilateral” (meaning both fore or hind limbs) or unilateral. More than one kitten in a litter can be affected. The degree and type of deformity varies.
Treatment
Can it be treated? Yes, sometimes, if the treatment starts very soon after birth. Treatment includes: splints, hot compresses, massage and physiotherapy treatment – stretching and flexing the leg.
Sometimes the treatment does not work and the longer it takes to work the greater the chance that the limb will atrophy and become permanently useless. Perhaps amputation is an option because two legged cats cope marvellously well.
Sometimes treatment to correct twisted limbs is inadvisable because the kitten will have internal organ abnormalities as well. Under these circumstances euthanasia seems to be the preferred choice, sadly.
Declawing
An interesting side topic concerns the declawing of a cat with twisted forelegs. Clearly this will be exceptional but Sarah Hartwell refers to a tabby cat whose name is Ellie. Because of her disability the claws of the fore paws were not naturally worn down during use. This caused them to grow too long. Her caretaker, Nicole Rutledge, was unable to trim them because Ellie refused to comply. Although Nicole is against declawing she agreed to have Ellie’s paws declawed.
Is this one of those exceptionally rare occasions when declawing is morally acceptable? Perhaps Nicole could have asked her vet to do it under anaesthetic or sedation? I don’t know. I am just suggesting that there might be no occasions when declawing is acceptable because there is always an alternative. Am I right or wrong?
Source of information on twisted cat limbs: Messybeast.com. Thanks Sarah. Here is the page (opens new window). Photo at top of page (framed by Michael) by Josh Norem of The Furrtographer and Saving Grace Rescue.