Methods Study type and approvals The study was a randomized controlled non-inferiority clinical trial of patients based on a parallel-group type with an allocation ratio of 1:1.
Sittings The study was done in the emergency reception unit and the orthopedic unit of Duhok Emergency Teaching Hospital (single-center study), Duhok city, Iraq during the period extending from October 2021 to August 2022.
The study was conducted by a team from the hospital composed of a consultant Orthopedic surgeon (person 1), a permanent resident orthopedic doctor (person 2), and a radiologist (person 3). Person 1 generates the random allocation sequence, assessed the outcome clinically, analyzed the results, and drafted the article. Person 2 enrolled the participants in the study, assigned the interventions, and drafted the article. Person 3 assessed the outcome radiologically.
Interventions The participants included received one of the modalities of treatment planned for this study. The first modality was by application of a short arm cast from just below the elbow to the finger's knuckles. The cast was from a Plaster of Paris bandage over a cotton pad. The participants received this modality of treatment considered as group 1 (control group). The second modality was the modified RJ bandage (firmly applied two layers of bulky cotton layers alternating with three layers of elastic bandage in the following order: bandage - cotton - bandage - cotton - bandage)\[17\]. It was applied from below the elbow to the finger's knuckles. The participants received this modality of treatment considered as group 2 (trial group).
The participants and their companions were instructed to keep their modality of treatment clean and dry. Both groups asked for frequent follow-up (at the end of the 2nd, 4th, 6th, and 12th week) until the fracture unit. At each follow-up visit, the participant was checked for possible complications. The final assessment was done at the end of the 12th week by the consultant orthopedic doctor in collaboration with the radiologist.
Sample size calculation The assumed sample size was calculated by using the G\*Power 3.1.9.7 computer software program. A minimum of 148 participants (74 for each group) was required to have a power of 80% chance of detecting the difference between the groups, and a two-sided 95% level of confidence (0.05 level of significance) to avoid the type 1 -alpha- error, with a probable hypothetical effect size of about 0.3 and a degree of freedom of 1 in the contiguity table.
Randomization The allocation of the participants into the modalities of the treatment was done by a simple randomization method with an allocation ratio of 1:1. It was generated by using the website program www.randomization.com. The first generator of the program was used to randomize 148 subjects into both modalities of treatment blocks (74 casts, 74 RJ bandages) (seed 7180). The random allocation sequence was generated by person 1 from the team of the study. It was concealed from the rest of the study team. Person 2 enrolled the participants in the study (assessed the eligibility of the cases, obtained the informed consent) and assigned the interventions.
Blinding The team of the study (apart from person 3 - the radiologist) was not blinded to the modality of treatment that they provided to the patients. The radiologist who assessed the radiological outcome of the cases was blinded to the modalities of treatment. The participants were blinded to the result of the treatment of the other patients included in this study.
The data collection
The data was collected in a special paper for each patient separately. The data included were divided into two parts:
Part 1 included the basic demographic data of the patient and injury like name, age, gender, place of living, date of a wrist injury, type of wrist injury (proved by the radiographic film), type of treatment (group), the time interval between the injury and beginning of treatment, duration of treatment, dates of each follow up. Part 2 included the outcomes during each follow-up visit and at the final assessment like complications of treatment, patient comfortability, and family satisfaction.
Statistical analysis The data analysis was done by admitting the collected data into the Statistical Package for Social Sciences (SPSS) software computer program (IBM Corp. Released 2015. IBM SPSS Statistics for Windows, Version 23.0. Armonk, NY: IBM Corp.). The statistical analysis included the standard descriptive statistics used to describe the basic descriptive data of the patients and injuries. The means and standard deviations (SD) or medians and interquartile ranges were used for the continuous variables, while frequencies and percentages were used for the categorical variables. The comparison between the outcomes of the treatment modalities in both groups was done by finding the difference between the summary statistics in the chi-squared test. The difference was considered statistically significant when the p-value was less than 0.05.
