Clive, a key issue to regarding your hip is your medical record at the time proving an in-service injury. Better is a continuing or regular entry in your medical records. If you have such ongoing notes then the RBL can advise and assist in claiming an award or pension from SVA.
I remember my first medical complaint after about 12 year's service and then regularly thereafter. A key part of my assessment was recounting how it affected me. Mrs PN was essential here as you forget what you can't do as you adept your life style.