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

Abstract

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.

Keywords: orthopaedic & trauma surgery; paediatric orthopaedic & trauma surgery; paediatric surgery; trauma management.

Figure 1

Finger traction method is used when casting the injured wrist. Dorsal displacement and shortening of the radius are not corrected but a gentle attempt is taken to regain the longitudinal axis of the forearm. A volar below-elbow splint is already in place in this picture.

Figure 2

The splinted upper extremity is supported with a collar and cuff sling.

Figure 3

Photographs for evaluation of forearm movements, length and shape in a 6-year-old boy taken after cast removal (casted in bayonet position in finger trap traction without anaesthesia in emergency room) at 4 weeks from the injury. These measurements are performed in this trial at 4 weeks, 3 and 6 months and 1 year. (A–B) Pronation of the forearms. (C) Supination of the forearms. (D–E) Maximal active extension of the wrists (angle between red lines). (F–G) Maximal active flexion of the wrists (angle between red lines). (H–I) Shape of forearms in medial view. (J) Maximal passive extension of the wrists (angle between red lines). (K–L) Length and shape of forearms dorsally.

Figure 4

Flow chart of the trial with three separate cohorts: randomised cohort, declined cohort including eligible patients whose parent(s) or guardian(s) did not consent to randomisation and non-eligible cohort including patients with an exclusion criteria.

Figure 5

Flow chart of the randomised cohort. ROM, range of motion.

Figure 6

Flow chart of the declined cohort of eligible patients whose parent(s) or guardian(s) did not consent to randomisation. ROM, range of motion.

Figure 7

Flow chart of the non-eligible cohort including patients with an exclusion criteria. ROM, range of motion.