Can’t speak for the NHS in particular but in most organisations, these things are all about the company covering their backs- making sure you’re being supported, there’s no underlying issues, if there’s anything they can do to help you return, that sort of thing, rather than being about hassling you for daring to be injured.
Ironically, in my experience companies deal far better with serious illness/injury than they do with everyday ones- I had constant hassle in my last job due to infrequent absences (below the national average but apparently they set off some sort of alarm bells), then I broke my hip and was off for about 3 months and never had the slightest hassle. Apparently being off for 2 days with the flu is more serious than being off for months with a leg 😉
Speak to your union rep, assuming you’re a member.