@grapau27 Another topical gel to consider is one I first secured from a pharmacist in Scotland when I broke a toe. It's also helped my downhill skiing damaged bum knee, too.
A similar gel is now available OTC in the USA but, prior to that, I'd been able to restock this Scotland secured gel in Canada. So, I'm guessing you'd find it in the U.K.
(But, do heed its label warnings.)
Good luck! Bum knees are the worst!
-Melisa