system
Given the following post, respond as if you're commenting on Reddit:
human
[Kingsman:TSS] How practical are Gazelle's Prosthetic Leg Blades?
gpt
You can sharpen a prosthetic limb. If the person using that prosthetic is a gymnast and gets whirling around fast, you could kill someone with it. It's unexpected and strange. Even trained guys wouldn't be expecting it. It would take a lot of practice and work; you'd essentially have to be self-taught. But you could do it.

The problem is... everything else *except* killing. Walking on any kind of soft ground would be an undignified mess; on hard surfaces the tiny contact patch of the blade tip would skid and scratch. It would be like wearing spike heels with a ball bearing on the spike. Not to mention the bizarre drawback of the sharp point leaving tracks in hardwood floors and vinyl, enabling enemies to know where you've been.

tl;dr, they're practical in that you could kill someone, but walking around on sharp points has a lot of disadvantages.