Title: British Orthopaedic SCFE Surgery (BOSS) Study: Investigating Slipped Capital Femoral Epiphysis (SCFE) as a childhood precursor to osteoarthritis of the hip in adulthood.
Funder: Department of Health and Social Care

Abstract: Background: SCFE is the most common hip disease of adolescence and causes lifelong morbidity. It always requires immediate surgery to stabilise the hip, and in the longer term often leads to osteoarthritis requiring a hip replacement. Childhood obesity is believed to be the primary risk factor and rising obesity make this an increasing public health concern. SCFE is akin to a fracture through the growth plate of the femoral head, with displacement resulting in a misshapen hip. The femoral head has a tenuous blood supply, which either the disease or the resultant surgery may compromise. Interruption of this blood supply can cause a catastrophic collapse of the femoral head due to avascular necrosis, which invariably leads to severe hip arthritis within months. Widely accepted practice is to stabilise the bone with deformity, however this also precipitates the development of early osteoarthritis. There are numerous surgical techniques to treat SCFE, and prevent SCFE in the opposite (unaffected) hip. However, the evidence that underpins surgery is limited to case reports and case series, therefore a robust evidence base is lacking. The poor quality evidence is attributed to the rarity of cases within individual centres, and the emergency nature of treatment. Aims: A nationwide cohort of SCFE cases will be created to determine the disease incidence, case mix, risk factors, variations in surgical interventions, and understand the safety and efficacy of different surgical strategies and form the basis for future intervention trials. Consent will be sought to link the cohort to other datasets, allowing future determination of long-term outcomes; most notably hip arthroplasty. Linked administrative datasets will also be used to explore the association with obesity. The broader aim, using SCFE as an exemplar paediatric orthopedic condition with significant long term morbidity, is to develop an internationally competitive clinical academic, able to foster a UK-wide collaborative research culture and network in paediatric orthopaedics. Plan: This study utilises two work packages, both are underpinned by the need to assimilate large case numbers to generate high quality evidence. The first follows the IDEAL framework, to collect a consecutive nationwide surveillance cohort of SCFE cases, with case finding supported by linkage to nationwide hospital administrative data. The cohort will be used to determine the case mix, interventions used and collect immediate outcomes, in addition to 2-year radiographic and surgeon-reported outcomes. Consent will also be sought to collect 2-year patient reported outcomes, and to enable future data linkage to determine long-term outcomes; particularly via the National Joint Registry. The second work package uses existing linked administrative databases to investigate the association between SCFE and obesity at a population level.Benefits to patients and the NHS: Using SCFE as exemplar, this study will determine disease incidence, risk factors for SCFE, identify the safety and efficacy of current surgical strategies, and make recommendations to optimise treatment regimens, aiming to reduce both short and long-term morbidity, and forming a robust platform for future clinical trials and translational research, to better improve outcomes and quality of life for this, and related conditions. Preparatory work for this study triggered a review by NICE, with the draft consultation advising formalised outcome monitoring in SCFE (pertaining to stable severe SCFE). The proposed cohort will directly address these recommendations, having provisional endorsement from NICE. Results will therefore have immediate impact through the development of NICE guidelines. This proposal fits within the NIHR research priority, to investigate long-term conditions in children and young people. Paediatric orthopaedic surgery has been highlighted as a priority area by the NIHR HTA. This study offers direct tangible benefits to patients, is timely and well aligned to the national research agenda.

Lay abstract: Slipped Capital Femoral Epiphysis (SCFE) is a childhood hip disease requiring urgent surgery, and a common precipitant of early osteoarthritis in adulthood. There is no good evidence to determine what causes SCFE, or the optimal treatments. The choice of operation is dependent on the beliefs of the treating surgeon, rather than scientific evidence. The infrequency of SCFE, and the emergency nature of surgery are reasons inhibiting progress. This project will establish a national collection of SCFE, collect medium-term outcomes, and use linkage to routine healthcare databases to identify risk factors and facilitate long-term outcomes to determine the best treatment strategies.

Research activity codes: 2.1 BIOLOGICAL AND ENDOGENOUS FACTORS
Health categories: MUSCULOSKELETAL