Re-Displacement Of Closed Diaphyseal Forearm Fractures In Children Treated By Above Elbow Cast At Kenyatta National Hospital

Abstract

Background Diaphyseal forearm fractures are the third most common paediatric fractures and are mostly managed conservatively. Following casting, re-displacement is the most common short term complication. Lack of correction of the re-displacement leads to maluinon of the fractured forearm bones, with limitation of function. Maintenance of acceptable reduction after casting is difficult and various predictive factors have been previously identified, however, no literature exists on the forearm shafts Re-displacement in Kenya to date. Knowledge of re-displacement and predictive risk factors will enable prompt identification of high risk patients and initiate alternative methods of treatment. Objective To determine the Re-displacement rate and risks in casted diaphyseal forearm fractures in childhood. Design Prospective observational study Setting KNH A&E, orthopaedic clinic and paediatric orthopaedic wards Patients and Methods Children aged between 2 and 13 years with consenting legally acceptable representative (LAR) presenting in KNH with closed diaphyseal forearm fractures were recruited for the study at KNH. Information was obtained from interviews with the children and their LAR, patients’ files and patients’ x-rays. Radiographic information was obtained from pre-reduction, immediate post reduction and two weeks post reduction x-ray films. Data collected was analysed using SPSS version 23. Data management/analysis All questionnaires were checked and assessed for completeness before data entry. These questionnaires were stored under lock and key in a cabinet. Data was entered into a password 10 coded database accessible only to the Data Clerk and the Principal Investigator. Once data entry was complete, the entered data was assessed for accuracy and identified entry errors corrected. Exploratory data was thereafter analysed to identify any irregularities and extreme values. For description of the study population, fractures and re-displacement, categorical variables were summarized by means of counts and percentages using frequency tables while continuous variables were summarized by use of measures of central tendency and dispersion (mean, standard deviation, median, minimum, maximum, range, IQR). Determination of factors associated with redisplacement, chi-squared tests were applied for categorical variables and analysis of variance (ANOVA) tests were done for continous variables. Logistic regression was thereafter applied to determine independent factors associated with redisplacement. Presentation of results was by use of tables, graphs, charts and text narratives. Results Fifty-two patients were recruited into this study. These were 40 males and 12 females with a male female ration of 3.5:1 (Figure 1). The mean age of the patients was 9±2years. Most (80.8%) of the patients were right hand dominant. The most common cause of the injury was a fall onto a level ground during playing (N=44), the rest fell from a height. At two weeks post casting, the re-displacement rate was 29% (N=15). Most fractures were complete (69%) and involved the middle segment (70%) of the bones. The cast index of 0.7 - 0.81 was observed in 70% of the cases. Most (85%) of the patients who had redisplacements had a cast index of > 0.81. Taller, older, heavier patients redisplaced their fractures compared to their counterparts. Most redisplaced fractures were in the distal segment of the bones. Higher precasting translation of both bones predicted redisplacement. Conclusion The total rate for redisplacement was 28.8% in this study. Factors found to be significant contributors towards redisplacement of diaphyseal forearm fractures in children include: age of the patient, height of the patient, weight of the patient, quality of the plaster mold for immobilization as measured by the cast index and initial translation of the radius and ulna.