Can you not replace the grips? Motorbike or cycle come to mind, the NHS won't want them back, they kept giving my Mums Sticks and Zimmers every visit and refused to have then back as it was something to do with liability, ie if they failed in use after being reissued they would be culpable, we donated them all to a charity that helps out others, perhaps there is one similar near you that may have other options?