Epidemiology and Associated Injuries in Paediatric Femoral Shaft Fractures Treated at a Limited Resource Zonal Referral Hospital in Northern Tanzania

Background: Femoral shaft fractures contribute up to 40% of paediatric orthopaedic admissions with the World Health Organisation data showing youth are particularly vulnerable and road trac injuries are the leading cause of death for children and young adults. The mechanism of injury varies with age and geographical location of the patient and involves a variety of mechanisms from falls to road trac injuries. Understanding the incidence, mechanism and pattern of these injuries allows planning for preventive measures and treatment to meet modern day patient demands, generation of appropriate and timely protocols with minimum social and economic burden to the patient and family. Objectives and Methods: A hospital based cross sectional study was conducted using the orthopaedic department patient registry among children aged under 18 years admitted from 2014 - 2018. Our research question was to determine the epidemiology of femoral shaft fractures and coexisting associated injuries among admitted paediatric orthopaedic patients. Patient les were reviewed from the medical records department and a data collecting sheet was used to record demographics and injury data. Odds ratios with 95% condence intervals for associated injuries in paediatric femoral shaft fractures were estimated using multivariable logistic regression model. Results: We found the prevalence of femoral shaft fracture among paediatric orthopaedic admissions was 18% with the majority 111 (68.5%) being males. The most common injury mechanism was a fall (57.4%) followed by road trac injuries with 35.8% of which 48.3% resulted from pedestrian vs motorcycle accidents. Traumatic brain injury (TBI) was the most common associated injuries accounting for 69% of these injuries with the majority 79% occurring in patients aged 6 years and older. When comparing 6-12 years and 13-18 years age groups to those younger ≤ 2 years, they had 8 and 11 times higher odds for associated injuries (OR 8.25, 95% CI, 1.04 - 65.31) p=0.046 and (OR 10.54, 95% CI, 1.26 -88.31) p=0.031 respectively with road trac related injuries having 17 times higher odds of associated injuries when compared to fall (OR 16.73, 95% CI, 6.28 - 44.57) p<0.001. 112 (69.1%) were treated by non-operative method out of this 90 (55.6%) by traction with delayed Spica application. The overall mean duration of hospital stay was 18.5 ± 11 days, ranging from 3 – 68 days. Conclusion: Pedestrian vs motorcycle injuries was the leading specic cause of paediatric femoral shaft fractures with TBI being the common associated injury. Non-operative management was the most utilized treatment plan and contributed to ten times higher odds for a longer duration of hospital stay. Initiatives to insure children safety on roads should be strengthened in order to reduce/eliminate this burden. Application and practice of current evidence based clinical guidelines and recommendations is paramount for timely and appropriate treatment of these injuries.


Introduction
The World Health Organization (WHO) endorse injury as the leading cause of morbidity and mortality in children after their rst year of life. 1 Femoral shaft fractures account for up to 40% of paediatric orthopaedic admissions in low and middle income countries. 2 The mechanism of injury for these fractures vary with patient age; falls from standing height or playground equipment are more in younger children while high energy injuries are more commonly seen in adolescents and older children. 2,3 Recent studies report the signi cant rise in road tra c injuries (RTI) as the major cause of these fractures. [3][4][5] Associated bodily injuries are common in children that sustain a femoral shaft fracture. High energy injury mechanisms increase the risk of associated injuries; and the presence of an associated injury portends a two-fold increase in the hospital length of stay (LOS) irrespective of the treatment modality employed. 6-8 Understanding the mechanism of injury and the resulting pattern of paediatric femoral fractures is essential to determine the risk of associated injuries among children. Currently, limited information is available regarding the magnitude and trends of this clinical scenario in sub-Saharan Africa.
We conducted a retrospective audit of over ve years to determine the mechanism of injury of paediatric femoral shaft fractures and associated injuries at a zonal referral-teaching hospital in northern Tanzania. Our research question was to determine the prevalence of femoral shaft fractures and coexisting associated injuries among admitted paediatric orthopaedic patients. De ning the magnitude of this problem will be a platform for initiating preventive measures, planning interventions and allocating resources to deliver the best evidence-based patient care. [9][10][11] Material And Methods The institutional review Ethical and Research Committee approved the study with certi cate number 2333. We performed a retrospective, cross-sectional study of all paediatric orthopaedic patients with femoral shaft fractures from January 2014 to December 2018 admitted to the Orthopaedic ward at a zonal referral teaching hospital in northern Tanzania. Located in Moshi district-Tanzania, it is the third largest hospital in the country with 700 o cial inpatient beds often stretched to accommodate about 100-150 more patients on canvas beds as it servers the country's northern corridor with an estimated catchment population of 15 million people per the national census data. 12 The Orthopaedic ward admission registry was reviewed for all patients admitted during the study review period. All patients aged 18 years and younger were identi ed by their diagnosis and further classi ed by name and le identi cation number if diagnosed with a femur fracture. Files for patients with a femur fracture were retrieved from the medical records department and were sub-categorized based on fracture location and type of fracture (pathological versus traumatic). All patients with incomplete data were excluded from the study.
A standardized data extraction form was designed to record all demographic and pertinent injury data including age and gender of the patient, admission date, injury mechanisms, site of the fracture, type of associated injury, fracture type, fracture location, treatment type and duration of hospital stay. Collected data were processed and analysed using SPSS (Statistical Package for Social Sciences) software version Page 4/17 22 (IBM Corp., Armonk, NY, USA). Frequencies, percentages, mean and median were calculated and summarized by narration, frequency tables, histograms and pie charts. Multivariate analysis and Fisher exact tests were computed to determine the risk factors for associated injuries and their corresponding 95% con dence intervals were also calculated. A P-value less than 0.05 was considered statistically signi cant.

Results
Over the study period, a total of 1,092 paediatric patients were admitted to the orthopaedic ward of which 192 (17.6%) were diagnosed with a femoral shaft fracture (Fig. 1). Of this group, 162 (84.4%) femoral shaft fractures met the inclusion criteria to be in the nal patient cohort for analysis, resulting in a femoral shaft fracture prevalence of 18%.
Of this cohort, the median age was eight years and 72 patients (44.4%) were aged between 6-12 years. Most fractures were seen in males 111 (68.5%) with more than half of the patients being primary school children (Table 1). In addition, one-hundred forty-four (88.9%) patients had no health insurance, and 64 patients (39.5%) had fractures that occurred while along the road-side.  All children under one-year of age sustained a femoral shaft fracture from a fall at heights less than 2 meters. Toddlers (1-2 years) had most of their fractures result from falls of less than 2 meters followed by falling objects as the second most common mechanism of injury. Fractures resulting from RTIs were predominantly seen in older children, the 6-12 and 13-18 years of age categories, respectively. There was a signi cant number of children aged within 3-5 years age group whom sustained femoral shaft fractures as a pedestrian versus a motorcycle accident (MCA). Pedestrian RTIs was the leading mechanism of injury for this cohort of paediatric femoral shaft fractures (Table 3). MCA -Motorcycle Accident.

MVA -Motor vehicle Accident.
A total of 38 (23.5%) femoral shaft fracture patients presented with associated injuries, with traumatic brain injury (TBI) seen in 26 (69%) patients in this group; and was the most common associated injury across all age groups. Most associated injuries were seen in the 6 -12 year-old group. Combined TBI, abdominal injury and femur fracture (Waddell's triad) was present in three (8%) patients with associated injuries (Figure 2).
Children in the older age categories were more at risk of an associated injury compared to younger children. When comparing the age categories, the 6-12 year-old and the 13-18 year-old groups had 8 and 11 times higher odds for associated injuries, respectively. Females were 18% more likely to sustain associated injuries, although this was not statistically signi cant (p = 0.679).
Patients with an open fracture had statistically signi cant more associated injuries (p < 0.001), while having a spiral fracture was protective against an associated injury (Table 4). Children with fractures because of a RTI exhibited 17 times higher odds of associated injuries compared to a fall. We also found that males were more likely to sustain a femoral shaft fracture, as they represented 111 (68.5%) patients in the cohort with a M:F ratio of 2.2:1. Our ndings are similar to previous studies that showed male patients accounting for 62-73% of femur fracture patients. 2,5,18 This result re ects the typical high risk behaviour exhibited by boys in Tanzanian society and requires an aggressive preventive strategy for this subset of the population.

Mechanism of Injury
In our study, the most common injury mechanism was a fall accounting for 57.4% (93) of all fractures and nearly half of these falls were in children in their home environment. Earlier studies also demonstrated falls as a common mechanism of injury. 6, 14,15,19 We found that most falls were from trees (25%, 23), while other studies have documented that most occurred during playground activities. 18, 19 Regional variation in childhood recreational activities in addition to the habit of harvesting fruits and rewood from trees which is observed in our society might explain this difference.

Akinyoola et al. from Nigeria and Mughal et al. in South
Africa reported RTI as the most common mechanism of injury throughout Sub-Saharan Africa. 2,8 We found that RTIs resulting from a pedestrian versus MCA was the most common mechanism for sustaining a femoral shaft fracture accounting for 17.3% of overall childhood femoral shaft fractures. The absence of adequate infrastructure, poor tra c regulations and a lack of adult supervision most likely results in a higher risk of sustaining these injuries in the paediatric population. Child education on road safety and implementation of road safety rules is paramount to prevent a continued rise in the prevalence of fractures.
Our data did not demonstrate the expected variation in the mechanism of injury across age groups. Other studies have shown a transition from falls to RTI as the major mechanism when shifting from younger to older children. Socio-economic activities in our region that involve tree climbing attribute the overrepresentation of falls from a height. 18,19 In addition, 54 (33%) of the femur fractures in our study occurred at home which poses a challenge as children are considered safe while at home due to theoretical adult supervision. This necessitates a need for public health interventions to further understand the risk, design appropriate family level education and prevent these injuries in the future.

Associated injuries
We found a 23.5% prevalence of femur fracture associated injuries that agree with other published studies, demonstrating a prevalence ranging from 28.6% in the USA to 36% in New Zealand. 6,7 Being older than 6 years and being female increased the odds of sustaining an associated injury that is similar to ndings reported in the literature. 6,7 Older children are more likely to sustain a high energy injury mechanism, either a RTI or a fall from a height above 2 meters, which explains the predisposition to these associated injuries.
TBI was the most common associated injury in our patient cohort. Other studies have reported that other long-bone fractures are the most common associated injury followed by TBI. The use of helmets and protective equipment during contact or motorized sports which is mandated and paid attention to it in Western countries partly contribute to this. Sports related falls were the most common mechanism of sustaining a femur fracture in these other studies, while our study saw a higher incidence of RTI with pedestrian versus MCA (17.3%). 16,20 Fractures resulting from RTIs had an increased risk of having an associated injury that is similar to other studies in the literature. 2,17 RTI also increased the risk of Waddell's triad, which was 3 (8%) of those with associated injuries in this study, similar to that seen in Nigeria (8.7%) but signi cantly lower that seen in the USA (25.5%). 6,8 Understanding this association is critical in determining patient care requirements from the injury scene all the way until de nitive hospital treatment as some associated injuries are life threatening if missed.

Limitations and strength
This study being retrospective could not control for the quality of the information found in the patient les and this resulted in 25 (13%) of femoral shaft fractures being excluded from the study. The study established baseline data in paediatric femoral shaft fractures at our centre, which will help improve the management of these injuries.

Recommendations
Childhood femoral shaft fractures address a crucial component in children health and safety as these injuries often times are a result of high energy trauma as in this study pedestrian MCA and falling from trees were the top two leading speci c mechanisms of injury, respectively. The need for a populationbased study exists to obtain a better understanding of this phenomenon, as other children continue to be treated at different facilities or traditional bone setters. More emphasis on road safety measures for drivers and pedestrians is critical as RTI attributed to most those with associated injuries and was the second leading cause of paediatric femoral shaft fractures.

Conclusion
Falls contributed to most femoral shaft fractures sustained in our cohort of paediatric patients, but pedestrian versus MCA was the leading mechanism of injury followed by falling from trees. The 18%femoral shaft fractures prevalence in our settings correlates with injury burden observed in other hospital-based studies within the region. TBI was the most common associated injury with RTI injuries contributing to the majority of them. It was established that being over the age of 6 years and being female increased the odds of having an associated injury.
The dataset(s) supporting the conclusions of this article is(are) included within the article (and its additional le(s).

Declarations
Ethics approval and consent to participate The ethical clearance was obtained from the Kilimanjaro Christian Medical University College Ethical and Research committee with certi cate number 2333. Con dentiality of patients was assured by using name initials and serial numbers. The committee waived the need for patient informed consent in this retrospective review.

Declaration of Helsinki
All procedures were performed in accordance with relevant guidelines' in the manuscript.

Consent for publication
All authors of the manuscript have read and agreed to its content and are accountable for all aspects of the accuracy and integrity of the manuscript in accordance with ICJME and authorize for its publication.

Availability of data and materials
All data generated or analysed during this study are included in this published article and is attached in supplementary information les.   PaediatricFemurfracturesdataset.pdf