A Review of Surgically Treated Distal Radius Fractures in a University Hospital

Introduction: Distal radius fracture (DRF) is the most common orthopaedic injury with a reported incidence of 17.5%. It is commonly seen in young males and elderly females. Over the last two decades, there is an increasing tendency to treat DRF surgically by open reduction and internal fixation (ORIF) with plate and screws owing to improved device design, better fixation and operative technique. The purpose of this study was to evaluate the demographic characteristics, type and method of fixation, and outcome in all surgically treated DRF cases from 2014 to 2018 in a university hospital. Materials and methods: A retrospective review of all surgically treated DRF cases with one year follow-up in a tertiary hospital in Malaysia was done. Patients who left the follow-up clinic before one-year post-surgery or before fracture union were excluded. A total of 82 patients with 88 DRF were finally included into the study and outcome in terms of union time and need of multiple surgeries were analysed along with the predictors. Results: In this study, mean age of the patient was 46.2 years. Motor vehicle accident was the commonest cause of the fracture and AO Type C fracture was the commonest fracture type. Seventeen (19.3%) out of 88 fractures were compound fracture. Open reduction and internal fixation with volar plate was the most common surgical technique done in this series (93.2%). Three (3.5%) out of 88 fractures required multiple surgeries and eighty-three (94.3%) DRF cases were united before nine months of the surgery in this study. There was statistically significant association between clinical type of the fracture and the union time (p-value <0.05). Conclusion: There was a 1.7:1 male-female ratio with AOC fracture being the most common type of fracture. The most common method of fixation was ORIF with volar locked plate. Patients with closed fractures have a higher rate of union compared to open fractures at nine months.


INTRODUCTION
Distal radius fracture (DRF) is the most common orthopaedic injury with a reported incidence of 17.5% 1 . They are commonly seen in young males and elderly females 1 . Traditionally, DRF among the elderly have been treated nonoperatively by casting. However, it has been shown that casting alone for the treatment of unstable, osteoporotic DRF can result in collapse of the fracture fragments and hence, malunion 2 . That's why, recently there has been an interest in more aggressive fracture fixation in the elderly too, in the hope of speeding up the recovery time and to preserve the ability of the patients to live independently. And due to difficulty in closed reduction, instability after reduction, and high prevalence of complications following conservative management, surgical treatment is usually preferred in young patients 2 .
Over the last two decades, open reduction and internal fixation (ORIF) with plate and screw became the treatment of choice in DRF owing to improved device design, better fixation, and operative technique. Volar locking plate has become the most common surgical technique due to its superior biomechanical properties 3,4 .
However, there is lack of data of surgically treated DRF cases in Malaysia. The purpose of this study was to evaluate the demographic characteristics, type of fracture, mechanism of injury, method of fracture fixation, outcome of the fracture in terms of fracture union time and need of multiple surgeries, and associated predictors in all surgically treated DRF cases in a tertiary university hospital of Malaysia.

MATERIALS AND METHODS
This study included all surgically treated DRF cases from January 2014 to December 2018 (total five years) with oneyear follow-up of a single tertiary university hospital in Kuala Lumpur, Malaysia. Patient medical records were reviewed retrospectively, and pre and post-operative radiographic images were retrieved. Patients who left the follow-up clinic before one-year post-surgery or before fracture union were excluded from this study.
Along with the patients' demographic characteristics, hand dominance, Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification of the fracture, clinical classification of the fracture, causes and mechanism of injury, associated other injuries, types of surgical management, time interval between the injury and the surgery, and follow-up at 3, 6, 9 and 12 months' post-surgery were evaluated.
Two outcomes were set to evaluate the result. One was complete radiological union before nine months' postsurgery. As a fracture that does not unite within six to nine months of time is referred as non-union 5 , nine months was set as satisfactory radiological union time in this series. Radiological union was confirmed looking into the bridged cortices as well as the absence of fracture line visibility on radiographs 6 . Another outcome was the number of surgeries carried out. If the fracture was not united before nine months of the surgery or if more than one surgery were done along the course of the treatment of the DRF, the outcome was considered as unsatisfactory.
The factors influencing the fracture type and outcome were evaluated. These factors were divided into three groups, patient related factors, trauma related factors and treatment related factors. Patient-related factors were age, gender; trauma-related factors were type of fracture, mechanism of injury; and treatment-related factors were time interval before the surgery, type of the surgery. Patients were grouped into three age groups, young adult (below 40-year age), middle-aged (41-60 years) and old-age (61 years and above) 7 .
Data were analysed by using IBM SPSS version 27. The association between age, sex, mechanism of injury versus clinical and AO classification of DRF was done by using Pearson Chi-square test. And the association between the predictors influencing the outcome was analysed by using the Fisher exact test. The level of significance was set at p <0.05 at 95% confidence interval.

RESULTS
The total number of patients were initially included into this study was 152. Among them only 82 patients were attended the out-patient clinic until the fracture was united. Therefore, the total number of patients were finally included into this study were 82. As 6 of them had bilateral DRF, total number of evaluated fractures were 88. Patients' age range was from 16 to 83 years. The highest incidence was noted in below 40year age group (42.7%). Male-female ratio was 1.7:1. Among the six bilateral cases, three were from less than 40 years' age group. One of these six patients was female and other five were male. Majority of the patients in this series were Malay (44, 53.7%) followed by Chinese and Indian. Summary of the characteristics of this study is shown in Table I Twenty-eight (31.8%) cases were associated with another fracture. Associated ulnar styloid fracture was noted in 21 (25.6%) cases, metacarpal fractures were noted in five (6%) cases and scaphoid fracture in two (2.4%) cases.
Mechanism of injury of the fractures were divided into two groups. Majority of the cases were the result of high energy trauma (HET) (63, 71.6%). Among the causes motor vehicle accidents (MVA) was the most common cause of injuries (50, 56.8%) followed by fragility fracture (18,20.5%), fall from height (10, 11.4%). Detail of the causes and mechanism of injury is mentioned in Table I   There was no statistically significant association between the mechanism of injury and AO type of the fracture.
Open reduction and internal fixation (ORIF) with volar plate was the most common surgical technique done in this series (82 cases, 93.2%), followed by ORIF with K-wire (4, 4.5%) and closed manipulative reduction (CMR) with K-wire (2, 2.3%). External fixator was applied as temporary management of open AO Type C fractures which were subsequently converted to ORIF with plate or K-wires.
In this series, three (3.4%) patients required multiple surgeries for the management of DRF. Among these, wound debridement of the surgical site infection was done in one case, revision of plating and bone grafting was done in another case and only bone grafting was done in another one case.
Association between six predictors, (age, sex, mechanism of injury, AO type of fracture, Clinical type of fracture, Time before the surgery) and two outcomes, healing within nine months of surgery and need of multiple surgeries were analysed.
In this series, in 83 (94.3%) cases union occurred within nine months of the surgery and in five cases, union occurred after nine months. Among these five late union cases, one case belonged to ≤40 years' age group, two cases from 41 -60 years' age group and another two cases were from ≥61 years' age group. All these five cases were males and sustained DRF following HET. There was no statistically significant association between the union time and age group, sex, mechanism of injury.
Among 26 type A DRF cases, 24 fractures were united within nine months of the surgery and two cases were united after nine months. All 26 Type B cases were united within nine months' post-surgery. Thirty-three type C DRF cases were united before nine months and three cases were united after nine months' post-surgery. There was no statistically significant association found between AO type of the fracture and union time.
Among 17 open DRF cases, 13 cases were united within nine months of surgery, while four were united after nine months. Whereas 70 of closed DRF cases were united before nine months and one was united after nine months. There was statistically significant association between the clinical type of the fracture and union time (see Table II).
In this series,71 cases were treated surgically within first three weeks of the trauma. Sixty-eight of them were united within nine months' post-surgery and three were united after nine months. Thirteen DRF cases were treated in between 4-6 weeks of the trauma, 12 of them were united within nine months and one was united after nine months. Four cases were treated after six weeks of trauma. Three of them were united within nine months of surgery and one was after nine months. There was no statistically significant association found between the timing of the surgery and union time.
Multiple surgeries were done in three cases. Two of them were from 41-60 years of age group and one case was from ≥61 years' age group. Two of them were males and one female patients. All three of multiple surgery cases were from HET group. There was no statistically significant association between the multiple surgeries and age group, sex, mechanism of injury.
Multiple surgeries were done in two open DRF and in one closed DRF case. There was no statistically significant association between the clinical type of the fracture and the need of multiple surgeries (see Table III).
All three multiple surgeries were done in AO Type C group. There was no statistically significant association between the AO type of the fracture and the need of multiple surgeries. Among 71 DRF cases operated within three weeks of the trauma; multiple surgeries were done in two cases. Among 13 DRF cases where surgery was done in between 4-6 weeks of time, there was no incidence of multiple surgery and among the last four cases where surgery was done late, in between six weeks to six months, multiple surgeries were performed only in one case to manage the fracture. There was no statistically significant association between the time of the surgery and the need of multiple surgeries.

DISCUSSION
Distal radius fracture is more common in young males and elderly females.  4,8,9 . In our study, the ratio of males to females was 1.7:1. Two other studies conducted in Singapore and Indonesia also showed male preponderance 10,11 . However, there are also studies which shows otherwise, two of them were studies conducted in Sweden and Norway 12,13 . The result of racial distribution in our study was merely the reflection of race distribution in Malaysia.
Motor vehicle accident was the commonest cause of fracture in our study. Some other studies also had the similar findings [8][9][10] . As published by World Health Organization (WHO), low and middle-income countries had higher fatalities 10,13 of road traffic crashes (RTC) and males were more likely to get involved in RTC 14 . Males might be riskier and more adventurous while driving or riding. As young males are physically and mentally stronger, they normally are tasked to do heavy chores in the workplace and hence might get injured more. This might be the cause of preponderance of young males in our study. Fragility was found as major cause of fracture in ≥61-year-old age group in our study and most of them were women, which was aligned with two other studies conducted in Singapore and Norway 10,12 . The reason might be that the incidence of osteoporosis rises markedly with age. Thus, the increased bone loss and reduced bone density after the menopause in females, and age-related bone loss in both males and females, predispose to increase bone fragility which subsequently increase the susceptibility to fracture.
Among the AO types of fracture, type C was the most common fracture in our study. Since MVA was the most common mechanism of injuries, it contributed to much higher rate of high energy injuries and subsequently type C fractures. Koh et al mentioned in his study that the likelihood of development of type C fractures was increased when the force of fall got greater 10 .
Open reduction and internal fixation with volar plating was the most popular surgical method used (93.2%) in our centre to treat DRF. Better reduction quality and objective functional scores were reported in ORIF with volar plating, comparing with other surgical techniques 15,16 . In the past, older patients with DRF were treated conservatively with either plaster cast or with external fixation devices, due to concerns of the stability of internal fixation in old patients due to poor bone quality 17 . However, recent studies had shown the benefits of ORIF with volar plates and mentioned it as a safe and effective treatment alternative for patients aged over 60 too 18 .
In our study, we tried to find out the associated factors for the DRF in relation to healing time and need for multiple surgeries. There was no statistically significant association between the union time and age group, sex, mechanism of injury, AO type of fracture and type of surgery and time interval between the injury and date of surgery. But significant association was noted between the healing time and clinical classification of the fracture. Several studies showed that patients with open fractures have a high likelihood of developing infection resulting in prolong hospitalisation, multiple surgical procedures, and prolonged antibiotic treatment 19,20 . In a retrospective analysis of 42 open distal radial fractures (with 7% infections), a significant association between contamination (e.g., faecal matter, tar, dirt, grass, and gravel) and infection was reported 20  There were some limitations in our study. As it was a retrograde study, subjective or objective functional assessment of the hand following DRF was not done as no data was available regarding hand function assessment in treatment files. Among 162 DRF cases done in this 5 years' time, 74 cases were discontinued follow-up before fracture union. This was also another limitation of this study. We recommend doing a follow-up study mentioning the hand function assessment by DASH score of surgically treated DRF in future.

CONCLUSION
In this study, there was 1.7:1 male to female ratio with AO-C fracture being the most common type of fracture. The most common method of fixation was ORIF with volar locking plate. Patients with closed fractures have a higher rate of union compared to open fractures at nine months.