Growing Screws in Slipped Capital Femoral Epiphysis (SCFE) (hip disorder where the growth plate of the femur bone slips out of place)

Free Gliding SCFE Screw System from Orthopediatrics (FG screw). The study will compare the traditional treatment for mild-moderate stable SCFE which is a fully threaded cannulated screw (traditional screw) with the FG screw. This will be inserted as a surgical procedure into the proximal femoral epiphysis of the affected hip and sometimes as a prophylactic measure dependent on individual patient risk. This will be inserted in a single setting under general anaesthesia shortly after patient presentation to a secondary/tertiary hospital. The screw that the patient is randomised to will be inserted by an orthopaedic surgeon trained in the usage of both the traditional and FG screws. The screw takes approximately 1-2 hours to insert in a single surgical procedure. The FG screw has a telescopic design with 'medial and lateral threaded fixations, connected through a trilobe self-extending shaft' as per Orthopediatrics. The screw is designed to provide stabilisation of the slipped growth plate whilst theoretically allowing continued growth of the hip. if the hip is allowed to continue to grow this should theoretically improve hip function and pain in the future. The screw is placed with the intention of not being routinely removed unless there is a complication in the future e.g. osteonecrosis of the femoral head resulting in screw penetration of the hip joint, breakage of the screw causing pain and therefore necessitating removal of the screw, etc. The screw is not routinely removed because if the screw is removed prior to skeletal maturity there is the chance that the slip will recur.