Fractures are prevalent in the pediatric population, with rough estimates of at least one in every three individuals experiencing a fracture before adulthood [1]. Upper-limb fractures, specifically distal metaphyseal radius fractures, are the most frequent, with up to 35% of the fractures occurring during childhood and a significantly increasing trend during the past decades [2-5]. Unimodal age distribution and seasonal association linked to physical activity have been hypothesized [6]. Treatment options include in situ cast immobilization or fracture reduction with or without fixation with Kirschner wires (K-wires); however, deciding on either procedure has long been controversial [7]. As stated by Ploegmakers and Verheyen [8], the decision to accept, reduce, or operate on these kinds of fractures relies on the physician’s experience and gut feelings. Hence, tolerated age-dependent angulation limits were systematically reviewed and presented as the sole criterion used to determine treatment. Alas, the authors declared methodology limitations due to the lack of adequately designed trials. Consequently, even between experienced pediatric orthopedic surgeons, treatment agreement has merely been considered as fair [9].

Distal radius fractures have a remarkable remodeling potential. It has been a long time since Friberg [10] described the intrinsic ability of epiphyseal plates to change inclination in relation to the forearm axis. Remodeling rate is related to angulation: higher rates occur with more severe deformities, and they progressively decrease as the alignment approaches to normality [11]. Observational designs have shown that fractures up to 29° of angulation and 19 mm of shortening immobilized in situ regain complete alignment after a year of follow-up [12]. In another series of children whose fractures were immobilized without restoring the length of the radius, neutral ulnar variance at final follow-up for the whole sample was reported [13].

Furthermore, usual radius morphology is present within 3 years when alignment is lost, even when the fracture is immobilized without any attempt to regain alignment [14]. In contrast, the effect of age on remodeling potential is doubtful. Shorter times to complete alignment have been reported in younger children, while it is believed that remodeling potential decreases toward skeletal maturity [12,15]. Remodeling potential has been recognized in children up to 14 years of age [16].

Percutaneous K-wire fixation has been recommended, but indications vary [17,18]. Classically, wiring should be considered when perfect reduction is not achievable or in the presence of instability or an intact ulna [19,20]. Recent research suggests that operative interventions are the treatment of choice when some angulation and shortening criteria are not met. Nonetheless, more research is needed to identify those who would benefit the most from fixation [21]. Some specialized centers reserve distal radius corrective osteotomy solely for fracture malunion in children approaching the end of growth or associated physeal arrest. It is also the treatment of choice for children with congenital dysplastic conditions of the bone [22].

Upper-extremity functionality is the ability to reach, grasp, and manipulate objects to perform daily life activities [23]. Functionality is a major concern in these fractures, as residual angular deformities of the distal forearm decreases the range for pronation and supination [24,25]. Most of the instruments that assess upper-extremity functionality in the pediatric population are specifically designed for children with longitudinal deficiencies, amputations, or neurodevelopmental delay. Nonspecific instruments and questionnaires have been used as functional outcomes in clinical trials comparing interventions for wrist fractures in children [26-28]. Specific instruments for the adult population have also been published; however, several items refer to tasks that a 5-year-old might not properly execute [29,30].

The physical functioning domain of the Patient-Reported Outcomes Measurement Information System (PROMIS) has been available since 2011 for assessing children’s functionality among those without any disability. It is a precise and easy-to-administer outcome measurement instrument suitable for children with orthopedic conditions. Children who are 8 years of age or older are able to effortlessly answer the questionnaire unaided. A parent-proxy version is also available for younger children. Upper-extremity functionality is a subdomain of the physical functioning domain. It comprises 29 Likert-type questions that inquire about the difficulty of performing activities during the past week [31].

We propose a noninferiority clinical trial where children who sustained a distal fracture of the radius will be randomly allocated, in the acute setting, to either in situ cast immobilization or closed reduction and cast immobilization, with or without K-wire fixation. The trial’s primary goal is to establish whether upper-extremity functionality at 6 months follow-up, measured using the PROMIS physical functioning domain, has not become worse for the former group compared with the latter. Secondarily, range of motion (ROM), alignment, complications, and additional needed treatments will be contrasted.

The authors’ institution will fully fund the trial and all related expenses. No external sources of funding are associated with this trial. The trial was registered at ClinicalTrials.gov (NCT05008029). Recruitment commenced in July 2021. As of January 2022, 23 children have been randomized. At the time of enrollment, the principal researcher personally interviews parents and children, and the trial’s general characteristics are explained fully. Benefits, such as a closer follow-up (eg, radiographs, pain, and functionality), are also presented. Authors expect an average of 5 patients to be recruited monthly; therefore, recruitment and analysis should be complete by October 2024.

This is the protocol for the first randomized trial that compares functional outcomes of nonreduced versus reduced distal radius fractures in children. To the authors’ knowledge, medical literature lacks experimental designs that account for shortening and angulation of this type of fracture in this age group. Cadaveric studies have documented the effects on the motion of the distal radioulnar joint caused by angular deformities related to distal fractures of the radius [25,36]. Necessary pronation and supination ROMs for functional tasks in children and adolescents have also been ascertained with 3D-motion analysis systems [37]. A randomized clinical design would strengthen the evidence of secure shortening and angulation boundaries in terms of functional outcomes and would aid clinicians in the decision-making process in everyday practice.

A strength of this trial is the objective evaluation of the functional outcomes. The PROMIS scale was envisioned with modern measurement theory, which guarantees meaningful statistical results from a Likert-type scale. Further, the PROMIS was explicitly designed for the pediatric population, including previously healthy children who have sustained a wrist fracture [29].

The limitations of this trial are the lack of blinding for evident reasons and generalizability. Children will be recruited and treated in a specialized center. In most institutions in the authors’ country that deal with fractures in children, a pediatric orthopedic surgeon is not accessible. The allocation will be open-labeled for patients, parents, and medical staff. This scenario may affect participants’ feelings of well-being. However, analyses will be blinded. Finally, cost analyses were never an objective for this trial. The expected results may be relevant in terms of costs to health systems.