The CAST study protocol: a cluster randomized trial assessing the effect of circumferential casting versus plaster splinting on fracture redisplacement in reduced distal radius fractures in adults

Britt Barvelink,Joost W Colaris,Max Reijman,Erwin Ista,Gerald A Kraan,Vanessa Brown,Niels W L Schep,Taco Gosens,Suzanne Polinder,Jan A N Verhaar

doi:10.1186/s12891-021-04238-0

Abstract

BackgroundThere is no consensus concerning the optimal casting technique for displaced distal radius fractures (DRFs) following closed reduction. This study evaluates whether a splint or a circumferential cast is most optimal to prevent fracture redisplacement in adult patients with a reduced DRF. Additionally, the cost-effectiveness of both cast types will be calculated.Methods/designThis multicenter cluster randomized controlled trial will compare initial immobilization with a circumferential below-elbow cast versus a below-elbow plaster splint in reduced DRFs. Randomization will take place on hospital-level (cluster, n = 10) with a cross-over point halfway the inclusion of the needed number of patients per hospital. Inclusion criteria comprise adult patients (≥ 18 years) with a primary displaced DRF which is treated conservatively after closed reduction. Multiple trauma patients (Injury Severity Score ≥ 16), concomitant ulnar fractures (except styloid process fractures) and patients with concomitant injury on the ipsilateral arm or inability to complete study forms will be excluded. Primary study outcome is fracture redisplacement of the initial reduced DRF. Secondary outcomes are patient-reported outcomes assessed with the Disability Arm Shoulder Hand score (DASH) and Patient-Rated Wrist Evaluation score (PRWE), comfort of the cast, quality of life assessed with the EQ-5D-5L questionnaire, analgesics use, cost-effectiveness and (serious) adverse events occurence. In total, 560 patients will be included and followed for 1 year. The estimated time required for inclusion will be 18 months.DiscussionThe CAST study will provide evidence whether the type of cast immobilization is of influence on fracture redisplacement in distal radius fractures. Extensive follow-up during one year concerning radiographic, functional and patient reported outcomes will give a broad view on DRF recovery.Trial registrationRegistered in the Dutch Trial Registry on January 14th 2020. Registration number: NL8311.

Highlights

There is no consensus concerning the optimal casting technique for displaced distal radius fractures (DRFs) following closed reduction
This study aims to clarify if type of cast immobilization influences maintaining fracture alignment in reduced adult distal radius fractures
The primary objective is to assess which type of cast, a splint versus a circumferential cast, is most optimal to prevent fracture redisplacement in adult patients with a reduced DRF

Summary

Introduction

There is no consensus concerning the optimal casting technique for displaced distal radius fractures (DRFs) following closed reduction. This study evaluates whether a splint or a circumferential cast is most optimal to prevent fracture redisplacement in adult patients with a reduced DRF. Displaced distal radius fractures (DRF’s) are very common in the adult population and their incidence is still increasing because of the ageing population [1, 2]. Two-thirds of DRFs in adults are displaced and require closed reduction [4]. DRFs are generally immobilized using a non-circular splint or a circumferential cast. A large number of reduced DRF’s (32–64%) redisplace during cast immobilization in the first treatment weeks [5,6,7]. Whereas redisplacement of DRFs was previously accepted or reduced in a second attempt, nowadays these redisplaced fractures are generally treated surgically [8, 9]

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