The steroid is a drug called "DepoMedrone." This drug is already widely used to treat CTS. In this study, one injection will be given. The splint is made of elastic and has an aluminium bar which sits on the palm of the hand. In this study, the splint will be worn at night for 6 weeks. Each participant will receive either a single steroid injection or a splint, and will be asked to complete up to 5 questionnaires over 2 years.