Hi
@Aunt Angus , i tried to reply here back in July when you posted Twiggy's picture, but my severely dehydrated summer brain woudn't form the words. First off I want to say that Twiggy is stunningly cute/adorable/beautiful. She is the cutest frizzle polish I've ever seen!
Second, I wanted to caution you re considering amputation. Yes amputation would "fix" the slipped tendon problem, but amputation brings it's own potential problems. Twiggy would have to learn to walk all over again, and getting a properly fitted and functioning prosthetic to improve her current stance and gait will be very difficult. I understand you want Twiggy's gait to be as perfect as the rest of her is, but she (and you) have adjusted to overcome her handicap very well. The video you posted of her walking/running is exactly the way my handicapped hen deals with her missing feet. She decides where she wants to go, then flutter-flies to her intended destination as fast as she can. She spends more time resting on the ground than she does standing, and spends more time standing than moving. Like you I have been concerned about compensatory injuries due to her unnatural stance (she rocks back on her shanks for better balance while standing, and the bottoms of her shanks have flattened out, essentially giving her new "paddle feet." And I have been concerned over the fact she doesn't move around nearly as much as a normal hen does, and this may shorten her life. Common sense says these are valid concerns, but like Twiggy my hen has adjusted to her handicap as best as she can, and is leading a good chicken life despite her handicap My point is be cautious over trading one handicap for another.
If in the future you decide to consider amputation, read up on/look into the incredible advances that have been made re human prosthetics, including in the u.s. military. It's not farfetched to believe you may find someone willing to accept Twiggy as a charity case.. I would love to see a chicken be fitted using the latest technology, but until then I would letTwiggy continue to be her beautiful self just as she is. I think you are both doing great!