Management controversy and clinical equipoise exist in treatments of long bone fractures and traumatic hip dislocation in paediatric patients due to the lack of high-quality clinical evidence. This protocol describes the effort of a large prospective global multicentre cohort study (registry) aiming at providing quality data to assist evidence-based treatment decision-making.

Eligible paediatric patients (N=750–1000) with open physes suffering from proximal humerus fractures, distal humerus fractures, proximal radius fractures, forearm shaft fractures, traumatic hip dislocations, femoral neck fractures or tibial shaft fractures will be recruited over a period of 24–36 months. Hospitalisation and treatment details (including materials and implants) will be captured in a cloud-based, searchable database. Outcome measures include radiographic assessments, clinical outcomes (such as range of motion, limb length discrepancies and implant removal), patient-reported outcomes (Patient Reported Outcomes Of Fracture, Patient-Reported Outcomes Measurement Information System (PROMIS) and EuroQol-5D (EQ-5D-Y)) and adverse events.

Aside from descriptive statistics on patient demographics, baseline characteristics, types of fractures and adverse event rates, research questions will be formulated based on data availability and quality. A statistical analysis plan will be prepared before the statistical analysis.

Ethics approval will be obtained before patients are enrolled at each participating site. Patient enrolment will follow an informed consent process approved by the responsible ethics committee. Peer-reviewed publication is planned to disseminate the study results.

NCT04207892.