A Comparative Multicenter Study on the Epidemiology of Traumatic Fractures During the COVID-19 Early Emergency Response Period in Yogyakarta Special Region, Indonesia

Background: The changes of lifestyle and mobility during the Coronavirus Disease 2019 (COVID-19) pandemic may inuence the epidemiology of traumatic fractures. This study aimed to investigate the epidemiology of traumatic fractures in Yogyakarta Special Region (Daerah Istimewa Yogyakarta/DIY) during the COVID-19 emergency response period and compare the data with the similar period in the previous year. Methods: This was a retrospective study involving ve secondary referral hospitals and one tertiary referral hospital. We included all patients who presented to the emergency departments or orthopedic clinics who were then diagnosed with new onset fractures. We compared the data during the emergency response period (COVID group) with a similar period in 2019 (control group). Results: There were 1,249 patients with 1,428 fractures included in this study. There was almost half reduction of patients during the emergency response period. There was no signicant difference in proportion of gender and mean of age between patients in the control group and the COVID group. During the emergency response period, there was signicant increases in the proportions of patients experiencing low energy injuries (38.0% vs. 30.8%), injuries occurring at home (34.0% vs. 23.8%), and surgically treated closed fractures (51.8% vs. 45.3%), along with decrease of patients’ referrals (1.6% vs. 4.1%). The difference in proportions of fracture type, osteoporotic fractures, and multiple trauma was not signicant across the groups. Conclusions: During the COVID-19 emergency response period in DIY, there were nearly half reduction (47.68%) of patients with fractures, increased proportion of patients injured at home, reduced proportion of patients referred to another hospital, and increased proportion of surgically treated closed fractures. The knowledge about this epidemiological trend may help in developing preventive programs and treatment policy for fractures and other injuries during the current pandemic.


Introduction
In the end of 2019, a new coronavirus was identi ed as a cause of a severe respiratory system disease in Wuhan, China [1]. The World Health Organization (WHO) named the disease as Coronavirus Disease 2019  and later, declared it as a global pandemic on March 11 th , 2020 [2,3]. On March 13 th , 2020, the rst con rmed case in Yogyakarta Special Region (Daerah Istimewa Yogyakarta/DIY) was announced [4]. Shortly thereafter, the governor of DIY announced the COVID-19 emergency response period, lasting from March 20 th until May 29 th , 2020 which could be extended whenever required [5].
To reduce the disease transmission, people were appealed to do some preventive measures, such as hand hygiene, postpone unnecessary travel, stay at home, and physical distancing [6,7]. The schools were closed and people should work from home whenever possible [8].
The changes of lifestyle and mobility during the COVID-19 pandemic have been proven to in uence the epidemiology of traumatic fractures. Worldwide, many studies had reported signi cant reduction in fracture or trauma cases [9][10][11][12][13][14]. The epidemiological characteristics of traumatic fractures were changed during the COVID-19 pandemic: there were higher patients' average age, with an increase in the proportion of home/domestic accidents, osteoporotic fractures, and fractures caused by low energy trauma [9,10,15,16]. The surgeries performed for fractures or other trauma cases was also seen decreased during COVID-19 pandemic period [12,16].
Even though it is useful for developing preventive measures and treatment strategies, the epidemiological information and studies of traumatic fractures in Indonesia are still rare. Moreover, there were still no data found during the COVID-19 pandemic emergency period in DIY. Therefore, this study aimed to investigate the traumatic fractures' epidemiology in DIY during the COVID-19 early emergency response period and compare the data with the similar period in the previous year.

Methods
This was a comparative-retrospective study, involving ve secondary referral and one tertiary referral hospitals in Yogyakarta Special Province: Yogyakarta Regional Public Hospital, Wates Regional Public Hospital, Wonosari Regional Public Hospital, Panembahan Senopati Bantul Regional Public Hospital, Universitas Gadjah Mada Academic Hospital, and Dr. Sardjito General Hospital. This study was approved by the Medical and Health Research Ethics Committee Faculty of Medicine, Public Health and Nursing Universitas Gadjah Mada.
We included all patients who presented to the emergency departments or orthopedic clinics who were then diagnosed with new onset (< 1 week) fractures based on history clinical, and radiological examinations. The fractured bones included in this study were: clavicle, scapula, humerus, radius, ulna, hand, spine, pelvic, femur, tibia, bula, and foot. For the COVID group (during the pandemic period), we included all patients who presented to the hospital from 20 th March -29 th May 2020. For the control group, the period was from 1 st April -10 th June 2019.
We excluded the patients with pathological fractures due to bone tumors (primary and metastatic), genetic bone abnormalities, unhealed previous fractures (poor union or non-union), periprosthetic fractures, and patients with data missing from their medical records.
The collected data included the sociodemographic characteristics of the patients (age and gender), mechanisms of injury, injury location, fractured bone, type of fracture (closed/open fracture), concurrent fracture, osteoporotic fracture, multiple trauma, hospital stay duration, referral, treatment, and patients who refused recommended surgery or inpatient care. The data were obtained from the medical records.
We categorized the mechanisms of injury as fall from standing height, fall from height <1 m, fall from height >1 m, bicycle injury (not involving collision with motor vehicle), motor vehicle accident/MVA (any injuries involving collision with motor vehicle, as the vehicle rider or hit by motor vehicle), others (any speci c mechanisms of injury such as being hit, trapped, cut, machine-related, etc., not classi ed in the other groups), and unknown (unspeci c mechanisms of injury). We considered fall from standing height, fall from height <1m, and the bicycle injury as low energy trauma; where fall from height >1m, MVA, and others as high energy trauma. The injury locations were grouped as at home (in the house/living place and the surroundings), road (including the sidewalks), others (school, workplace, sports elds, and other speci ed places), and unknown.
The fractured bone was documented as clavicle, scapula, humerus, radius and/or ulna, hand, spine, pelvic, femur, tibia and/or bula, foot, and patella. The patients were stated to have concurrent fracture when they had more than one fracture based on the mentioned bone group. We considered a fracture as an osteoporotic fracture when it ful lled all the following criteria: 1. The patient age was more than 50 years old (female)/more than 60 years old (male); 2. Occurred in proximal humerus, distal radius, thoracic/lumbar vertebrae, or proximal femur; and 3. Caused by a low energy trauma [17,18]. The patients were classi ed as having multiple trauma when they had any injuries involving more than one body region and required treatment from more than one specialist for the injuries [19].
We grouped the treatment as conservative and surgical treatment. For analyzing the treatment, we excluded patients who were referred to another hospital. The patient was classi ed to receive the surgical treatment for the speci ed fracture when they received the treatment involving incision with an instrument, performed by orthopedic surgeon, in the operating theatre.
The statistical analysis was performed using SPSS 23.0 (IBM Corp., Armonk, New York). We tested all the numeric variables with Kolmogorov-Smirnov test for the normality of distribution. The difference of mean was analyzed with t-tests for data with normal distribution, and with Mann-Whitney tests for data with abnormal distribution. For categorical variable, we conducted chi-squared and used Fisher exact tests when the expected count was less than ve. The p-value of <0.05 was considered signi cant.

Results
During the speci ed period, we found 1,249 patients presented with fractures of the de ned bones: 820 (65.65%) patients in the control group; 429 (34.35%) patients in the COVID group. The patients' age ranged from <1 year old to 100 years old (mean: 42.49 ± 19.96). There was no signi cant difference in mean of age between patients in the control group and the COVID group (control group: 42.64 ± 24.03 years; COVID group: 42.20 ± 23.34 years; p=0.886). Three patients from the COVID group were suspected to be affected by COVID-19. However, all of them were negative on PCR swab test.
There was reduction in the number of all cases caused by any mechanism of injury during the pandemic, although the difference in proportion between the groups was not signi cant (Table 1). When grouped as low or high energy injury, the proportion of low energy injuries increased during the pandemic period (38.0% vs 30.8%; p=0.012). However, the high energy injuries were still the main cause of fractures in both groups. The COVID-19 pandemic has signi cantly in uenced the injury location, where the proportion of injuries at home increased and the injuries outside home decreased (p=0.001) (Fig 1.). The road remained the main location where the injuries occur.  There were almost 60% decrease of patients who presented with multiple trauma during the COVID pandemic period, compared to the pre-pandemic period (30 patients in the COVID group; 74 patients in the control group). The proportion of patients experiencing multiple trauma with fracture were also less in COVID pandemic period although the difference was not signi cant (7.0% in COVID group; 9.0% in control group; p = 0.217).
During the pandemic period, 295 (68.8%) patients received inpatient care. The proportion was slightly higher compared to the control period (64.1%, 526 patients), although the difference was not signi cant (p = 0.102). For the patients receiving the inpatient care, the mean of hospital stay duration was slightly higher in the control group than in the COVID group (4.91 ± 3.75 days vs 4.39 ± 3.45 days, p = 0.008). In the control period, the proportion of patients who needed to be referred to another hospital was signi cantly higher than in the COVID period (4.1% vs 1.6%; p = 0.018).
About 10% of the patients (82 patients in control group, 46 patients in COVID group) refused to receive recommended inpatient care and/or to receive operative treatment. The proportion was not statistically different between the control and the COVID groups (10.0% in control group; 10.7% in COVID group; p = 0.689).
There were more fractures treated surgically during the COVID period compared to the control period, although the difference was not signi cant (56.2% vs 52.7%, p = 0.212). However, the difference of the proportion of closed fractures treated surgically vs. conservatively was signi cant, with more proportion of fractures treated surgically during pandemic period (51.8% vs 45.3%, p = 0.038).

Discussion
We found several impacts of the COVID-19 pandemic on the epidemiology of fractures in our region. As seen worldwide, the total of patients with fractures were reduced. In our study, the reduction was 47.68%. The amount of reduction was similar to a study in China (reduction of 46.74%) but lower than the study in Italy (reduction of 73.8%) [9,10].
While some studies found increases in the patients' mean age during the pandemic period [9,10], our study did not demonstrate a signi cant difference in the patients' age across the period groups. The proportions of osteoporotic fractures were not different as well. These ndings might be caused by the fear of elderly being infected by COVID-19 virus in the hospital, since they have more risks to develop severe disease when getting infected [10,20]. The recommendation to not go to the health facilities unless urgent might also lead to the reluctance of elder people and people with osteoporotic fractures to go to the hospital [21].
This study reveals a transition of the mechanism of injury towards the low energy injury. Additionally, this pandemic contributes to more injuries occurring at home. These ndings can be explained by the facts that people spent more time at home, that contains several hazards to low energy injury such as slip or trip on steps or in the bathroom [22]. Consequently, more social education to increase the safety at home is needed to prevent any injuries at home during the pandemic.
In our study, the MVA was still the number one cause of fractures during the pandemic period, although the number of cases was reduced 52.5%. However, the decrease was much less compared to the previous studies in Italy and China where the reduction of MVA cases was 79.6% and 88.9%, respectively [9,13]. Less reduction of case numbers and the dominance of MVA in the pandemic period might be associated by less restriction in the mobility of people in Indonesia and less compliance of Indonesian people to stay at home and maintain safe social distancing. In contrast to China and Italy, Indonesia was not applying a lockdown due to the economic considerations [23,24]. The domination of MVA even during COVID-19 pandemic necessitates more prevention to decrease the high case number. People should be more educated to drive/ride motorcycle safely, i.e. using helmets, not riding/driving when sleepy, limitation of the speed, etc.

Previous studies demonstrate signi cant reduction in the proportion of open fractures and concurrent
fractures, along with reduction in the Injury Severity Score (ISS) in patients with multiple trauma [9]. However, our study cannot demonstrate similar results. It is known that the occurrence of open fractures, concurrent fractures and multiple trauma were associated with high energy injuries [25][26][27]. In our study, the reduction in percentage of high energy injuries during the pandemic period was relatively small, and the high energy injury remains the main cause of people presenting to the ED with fractures. In contrast, the previous study reported signi cantly more reduction in the proportion of high energy injuries [9].
The current study found that the total number of surgically treated fractures was reduced by 44.2%. This nding was similar to the previous study in China where the surgically treated fractures were reduced to almost 50% [9]. For all trauma cases, studies in London and Pakistan reported the number of surgeries for trauma were reduced about 30% and 40%, respectively [12,16].
This study shows a higher proportion of closed fractures treated surgically during the pandemic. There were several possibilities to explain this nding. First, patients with closed fracture with minimal displacement caused by low energy trauma did not go to the hospital because they thought the injury would not cause fractures. This will decrease the number of fractures which were usually treated conservatively. Second, due to the decrease of the number of surgeries because of the decreased patient number and postponed elective procedures, more staff and facilities were available for surgery.
There are several limitations of this study. First was its retrospective design. Second, for osteoporotic fractures, we did not use the bone mineral density value that would be more accurate to see the extent of osteoporosis. Third, we only included the patients from public and academic hospitals. We had no data from private hospitals.
We recommend future studies to examine the epidemiology of fractures with a longer time period and involving more variety of treatment centers to add to the strength of the study and so that we can see the trends during the year. Because this research only included the acute fractures, further study is recommended to investigate the neglected fractures or injuries other than fractures.

Conclusions
The COVID-19 pandemic has led to several changes in fracture epidemiology. During the COVID-19 early emergency response period in DIY, there was almost half reduction (47.68%) of patients with fractures who presented to the hospital. The proportion of fractures due to low energy injury increased, as well as the proportion of patients being injured at home. There was a reduction in the proportion of patients referred to another hospital and an increase in the proportion of surgically treated closed fractures. The knowledge about this epidemiological trend may help in developing preventive programs and treatment policy for fractures and other injuries during the current pandemic.