Personal statements aren't used to shortlist applicants, just as a way to screen for red flags, such as National Front membership or being the founder of the Harold Shipman Fan Club or something. Writing a strong PS is a good way for you to get your thoughts into coherent order for interview, and that's about the extent of its usefulness. Presumably you have reasons for wanting to study medicine other than having good dexterity, or else you'd be considering a career as a plumber or a concert pianist, so you can talk about those instead.