I was fitted for my first finger splint by a physical therapist. To get the best size, you might ask your orthopedic doctor to recommend a PT center with a hand specialist on its staff, then call to ask if they can fit a plastic finger splint. Still you may fall between sizes, in which case you may have to apply hand lotion to help slip the splint on at night, then soap suds to get it off in the morning. A splint may not cure you; at best it might put off surgery.