Have you tried putting a clean needle in the hole and try tapping could well be glass don't leave it to long or the pad will seal. if you feel some thing and you are ok with it try and work it from side to side be aware it might be well in but just take your time make sure it's sterilised as u go along. It's important 2 remember wotever is causing the limp needs sorting, limit the walking etc as it cud just be making things worse. Cheers Greg