A multi-centre, randomized, pragmatic, parallel group, non-inferiority trial to compare the clinical and cost-effectiveness of sling immobilization versus surgery in the management of adults with a displaced fracture of the distal clavicle:Protocol for the DIDACT randomized controlled trial

Aims Fractures of the clavicle primarily occur in young males and constitute 2.6–5% of all fractures in adults. Distal clavicle fractures, where the outer end of the collarbone breaks, account for 20-25% of all clavicle fractures. These fractures can be called displaced if the ligaments connecting the collarbone to the shoulder blade (coracoclavicular complex) rupture. Such displaced (Neer’s type II and V) fractures are currently treated with an operation involving fracture fixation or with sling immobilization. This protocol describes a randomized controlled trial that aims to evaluate the clinical and cost-effectiveness of these two types of treatment that are used for displaced distal clavicle fractures. Methods The DIsplaced DistAl Clavicle Fracture Trial (DIDACT) is a pragmatic, parallel, two-arm individually randomized non-inferiority trial of 214 adult patients with a radiologically confirmed diagnosis of a displaced distal clavicle fracture. Participants will be randomly allocated on 1:1 basis to surgery with locking plate fixation (with or without coracoclavicular (CC) sling, or CC reconstruction alone) or sling immobilization. In the sling immobilization group, if symptomatic non-union occurs, participants would be offered surgical fixation (typically at the 3 month follow-up). The primary outcome and endpoint will be the self-reported Disability of Arm, Shoulder and Hand (DASH) at 12 months. The DASH will also be collected as a secondary outcome at baseline, 6 weeks, 3, and 6 months after randomization. Other secondary outcomes include shoulder pain, EQ5D-5L, complications (e.g. infections, re-operations), fracture healing, healthcare costs, patient treatment preferences, satisfaction with appearance of their shoulder and sensitivity or pain to touch, and range of movement. Conclusion There is uncertainty as to whether a sling immobilization pathway is non-inferior to surgery and which of these two treatments is cost-effective. The DIDACT Trial is a sufficiently powered and rigorously designed study to inform clinical decisions for the treatment of adults with this injury. Keywords: Trauma, Distal clavicle, collarbone, orthopaedic surgery, clavicle fracture, randomized controlled trial