Casting in finger trap traction without reduction versus closed reduction and percutaneous pin fixation of dorsally displaced, over-riding distal metaphyseal radius fractures in children under 11 years old: a study protocol of a randomised controlled trial

INTRODUCTION: Distal radius is the most common site of fracture in children, comprising 23%–31% of all paediatric fractures. Approximately one-fifth of these fractures are displaced. Completely displaced distal metaphyseal radius fractures in children have traditionally been treated with closed reduction. Recent evidence suggests that correcting the shortening in over-riding distal metaphyseal radius fractures is not necessary in prepubertal children. To date, no published randomised controlled trial (RCT) has compared treatment of these fractures in children by casting the fracture in bayonet position to reduction and pin fixation. METHODS AND ANALYSIS: We will conduct an RCT to compare the outcomes of casting the fracture in bayonet position in children under 11 years of age to reduction and percutaneous pin fixation. 60 patients will be randomly assigned to casting or surgery groups. We have two primary outcomes. The first is ratio (injured side/non-injured side) in the total active forearm rotation and the second is ratio (injured side/non-injured side) in total active range of motion of the wrist in the flexion–extension plane at 6 months. The secondary outcomes will include axial radiographic alignment, passive extension of the wrists, grip strength and length of forearms and hands, patient-reported outcome QuickDASH and pain questionnaire PedsQL. Patients not willing to participate in the RCT will be asked to participate in a prospective cohort. Patients not eligible for randomisation will be asked to participate in a non-eligible cohort. These cohorts are included to enhance the external validity of the results of the RCT. Our null hypothesis is that the results of the primary outcome measures in the casting group are non-inferior to surgery group. ETHICS AND DISSEMINATION: The institutional review board of the Helsinki and Uusimaa Hospital District has approved the protocol. We will disseminate the findings through peer-reviewed publications. TRIAL REGISTRATION NUMBER: NCT04323410. PROTOCOL: V.1.1, 29 September 2020.