The present study shows that the incidence of hand injuries among the elderly was 21.3/10000 inhabitants and year. Hand injuries occurred to men and women equally, but men were younger than women at the time of injury. Interestingly, the type and severity also differed, with women sustaining fractures and men saw/cut/avulsion/crush injuries; the latter more frequently requiring admission to hospital and surgery and reflected in higher MHISS. Only 13% of the patients were healthy, with hypertension and cardiovascular disease being the most frequent in those who had one or several diseases. Twenty-seven percent of the patients were prescribed ≥5 drugs.
An earlier study, evaluating all age groups in our region, reported an incidence for hand injuries of 70/10000 inhabitants and year, where fractures were the most common injury (49%) and falling was the most common mechanism (41%) . When only the injuries among patients aged 65 years or older in this earlier study were analysed, 55% were found to be fractures and women were more often injured than men. In contrast, the present study shows, when weighted for the number of men and women in this age group in the general population (which was not done in the previous study), that the same proportion of injuries occurred in elderly men and women. A study of 50,272 patients of all age groups in Denmark showed that only 19% of the patients had fractures, but, unlike the present study, it also included contusions, which made up 19% of the injuries . In both of these studies, men sustained the largest number of injuries and the number of wounds was of the same magnitude as in the present study. The studies also showed a reduction in incidence with age. The findings to date show that the elderly do not injure their hands as often as younger patients, but they seem to experience a higher proportion of falls and related fractures.
The most common injury mechanism for fracture, especially in women, was a fall and in 63/153 falls (41%) tripping, stumbling or slipping was the cause. A previous study concerning all kinds of fall-related injuries  presents similar findings, where the same causes were also most common (28%). In our study fall-related hand injuries affected twice as many women as men and a similar pattern has been observed in earlier studies . In most cases no specified reasons are given for the rest of the falls. However, some patients fell due to standing on a bus that was braking or were pulled by a dog on a leash. Since fractures from falling constitute the most common injury, their further prevention using proven means, i.e. strength and balance training and vitamin D and calcium supplementation according to a large review of prevention of fall injuries , could possibly reduce the number of hand injuries in the elderly.
More men than women sustained injuries from powered wood splitters and circular saws, both of which caused more severe injuries [18,19,20]. Circular saw injuries occur in both experienced professionals and elderly patients, as recreational work is common also among older adults [18, 19]. Professionals, e.g. carpenters, injure their hands despite years of experience . Traditionally, activities involving various power tools are more common among men, which may explain the present observed difference. Such an argument is also valid for the crush injuries caused by heavy objects, e.g. farming equipment and heavy machinery, since men still engage more often in heavy work than women. Thus, as pointed out in earlier studies , the exercise of caution and more safety measures when working with these kinds of equipment cannot be stressed enough if hand injuries among older men are to be reduced.
A majority of the patients had minor or moderate injuries and could be treated as out-patients. Even when the data for out-patients were analysed separately, men had a higher MHISS, required surgery more often than women, required more nurse visits and consumed more prophylactic antibiotics, which is reasonable in light of the more severe and open injuries. More men than women were also admitted to hospital among the patients from the Malmö/Lund regions and from the other regions. However, when the data for the in-patients were analysed separately, men and women did not differ regarding MHISS, operating time, days on the ward and number of out-patient visits. Taken together, these overall data indicate that hand injuries among men are more expensive to treat than those among women.
The observed age difference, with men being younger than women at time of injury, could possibly be explained by the fact that men may still be more active using e.g. power tools during their leisure time or still in a partial professional life in spite of their age. At a higher age one may anticipate that most men decrease their use of hazardous equipment. A consequence of aging, e.g. osteoporosis, especially among women may contribute to observation that women had a higher age at injury. The decrease in overall incidence with age is probably, for several reasons, a result of reduced activity and, thus, less exposure to potentially injurious mechanisms. Osteoporosis was, as expected, more common among women than men. One extensive study on hand fractures concludes that, until retirement, men have a higher relative risk of sustaining hand fractures due to a riskier lifestyle, but after the age of 65 the relative risk is higher for women . That study also found that the most common fractures of the hand are to the metacarpals and phalanges . This is confirmed by the present findings, where women had more fractures than men and the most common damage was to the phalanges and metacarpals. A nationwide study of fall-related injuries from the Netherlands shows that, in comparison with hand/finger fractures, hip fractures were more than four times as common, and wrist fractures 40% more common .
Our finding that 58% of the injuries affected the left hand contradicts previous studies in all age groups, where the right hand was more commonly injured, except in cases of work-related hand injuries to right-handed patients . Injuries at work, as well as when engaged in carpentry and handling firewood, were common among men. These latter injuries are comparable to work-related injuries, which might explain the high incidence of left-hand injuries occurring in men. Other studies of severe hand injuries, mainly from saws and machines, also reported an over-representation of left-hand injuries [24, 25]. In older women, the dominant handgrip strength is significantly reduced after the age of 60, and that of the non-dominant handgrip after the age of 50 . The dominant hand is used more often in activities of daily living and hence is stronger and may not fracture as easily as the non-dominant. In older women, reduced handgrip strength is an independent risk factor for osteoporotic fractures . Another study shows that the correlation between non-dominant handgrip strength and frailty is stronger than that between the dominant handgrip strength and frailty , indicating that the dominant hand is stronger than the body in general. This might explain the high incidence of left-hand injuries in women. Notably, handedness was poorly documented, making it difficult to draw conclusions from a correlation between handedness and injured side.
The population of older adults in society is increasing as are the numbers of medicines they take. The increase in medication for treatment of various diseases is partly due to more widespread use of cardio-protective medicines and anti-depressants . Patients prescribed more medicines are more likely to have more co-morbidities, more limitations in the activities of daily living and less mental capacity as well as to consume more healthcare than those taking fewer medicines . The influence of side effects of the various medications cannot be excluded, e.g. the risk of orthostatic hypotension in connection with antidepressant treatments. Twenty-seven percent of the present patients took ≥5 drugs, involving the risk of interaction between the different medicines and of side effects. Forty-five per cent of the patients suffered from hypertension and 34% from cardiovascular disease, which is in line with previous findings of co-morbidities in older trauma patients . Considering co-morbidities, medicines and the biological repair processes, repair and reconstruction after a hand injury may be more challenging in elderly patients.
Hand injuries potentially leave the patients with long-term disabilities and functional limitations. Since older people already suffer from a decline in physical and mental capacity they are vulnerable to these consequences and may be in need of additional support after hand injuries. Previous studies have researched the outcome of hand injuries and conclude that a higher severity grade of hand injury correlates with greater costs, longer sick leave and reduced hand function, but that even minor injuries can be debilitating [24, 25, 29]. The outcomes of hand injuries among the elderly have not yet been studied, but the consequences for older patients are likely to affect their ability to engage in daily living and leisure activities. Hence, there is a potential gain from conducting more studies on the topic both in terms of improving the quality of life for the elderly with hand injuries and reducing the costs to society.
There are a number of limitations to this study. The retrospective design precludes any completion of missing data. Some patients with minor hand injuries may have been treated by their general practitioners without referral, despite an established routine for the following up of all hand injuries at our department, meaning that we cannot be sure that all hand injuries were included. As many hand injuries can be treated without knowledge of the patients’ co-morbidities or medicines; thus, documentation of these was sometimes scarce. We believe that it is important for healthcare providers to improve the recording of patient demographics, co-morbidity, handedness etc. with respect to planning of the resources in the health care system. The administrative system for medical records in the primary healthcare and hospital sectors differs and without access to medical records from the primary care sector some co-morbidities and medicines may have been missed. There might be a potential bias when calculating the incidence, which might be underestimated. However, in the present region there is an agreement and specific routines for long with GPs, A&E units and department of Orthopaedics how to refer patients with hand injuries, resulting in that most injuries are treated at the present department.