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Biomedical subjects

J Parkkari

Publications and source records attributed to J Parkkari.

46 records · Page 3Linked to original sources
PubMed1996

Secular trends in osteoporotic pelvic fractures in Finland: number and incidence of fractures in 1970-1991 and prediction for the future.

To improve the knowledge of the current trends in the number and incidence of osteoporosis-related pelvic fractures, patients who were admitted to Finnish hospitals in 1970, 1975, 1980, 1985, 1988, and 1991 for primary treatment of first osteoporotic pelvic fracture were selected from the National Hospital Discharge Register. The overall incidence (per 100,000 inhabitants) of osteoporosis-related pelvic fractures (high energy traumas were excluded) in a population aged 60 years or more was 20 in 1970 and 63 in 1991. The increase was most pronounced in the older age groups (patients aged 80 years or more) and was observed in both sexes. The proportion of these osteoporotic pelvic fractures of all pelvic fractures increased from 18% in 1970 to 52% in 1991. Similarly, the proportion of patients over 60 years of age increased from 28% in 1970 to 62% in 1991. In 1991, 78% of the patients with an osteoporotic pelvic fracture were women. Across the study period, the age-adjusted total incidence of osteoporotic pelvic fractures also increased in both women and men 60 years of age and over. The proportional increase was more pronounced in men. We conclude that the number of osteoporotic pelvic fractures in Finland is increasing more rapidly than can be accounted for by the demographic changes only and that effective preventive measures are urgently needed to control the increasing number of these age-related fractures.

Accidental Falls↗
PubMed1996

Epidemiology of hip fractures.

There were an estimated 1.66 million hip fractures world-wide in 1990. According to the epidemiologic projections, this worldwide annual number will rise to 6.26 million by the year 2050. This rise will be in great part due to the huge increase in the elderly population of the world. However, the age-specific incidence rates of hip fractures have also increased during the recent decades and in many countries this rise has not leveled off. In the districts where this increase has either showed or leveled off, the change seems to especially concern women's cervical fractures. In men, the increase has continued unabated almost everywhere. Reasons for the age-specific increase are not known: increase in the age-adjusted incidence of falls of the elderly individuals with accompanying deterioration in the age-adjusted bone quality (strength, mineral density) may partially explain the phenomenon. The growth of the elderly population will be more marked in Asia, Latin America, the Middle East, and Africa than in Europe and North America, and it is in the former regions that the greatest increments in hip fracture are projected so that these regions will account for over 70% of the 6.26 million hip fractures in the year 2050. The incidence rates of hip fractures vary considerably from population to population and race to race but increase exponentially with age in every group. Highest incidences have been described in the whites of Northern Europe (Scandinavia) and North America. In Finland, for example, the 1991 incidence of hip fractures was 1.1% for women and 0.7% for men over 70 years of age. Among elderly nursing home residents, the figures can be as high as 6.2% and 4.9%. The lifetime risk of a hip fracture is 16%-18% in white women and 5%-6% in white men. At the age of 80 years, every fifth woman and at the age of 90 years almost every second woman has suffered a hip fracture. Since populations are aging worldwide, the mean age of the hip fracture patients are increasing rapidly, too. Between 1970 and 1991, the mean age of male Finnish patients increased dramatically from 52.9 years to 69.0 years. In women, the corresponding figures were 71.6 and 78.9 years. This change is likely to cause increasing problems in the treatment and rehabilitation of the patients. In 1990, 72% of the hip fractures worldwide occurred in women. All over the world, the hip fracture incidences are about two times higher in women than in men. Women's overrepresentation has been explained by women's lower bone mass and density and higher frequency of falling. Epidemiologic studies show that trochanteric fractures are an increasing problem since compared with cervical fractures their relative number increases progressively with age in women after the age of 60 years and since their incidence has been shown to increase in both sexes and all age groups during the recent decades. This may have direct public health implication since mortality, morbidity, and costs caused by trochanteric fractures are higher than those of the cervical fractures. Reduced bone density (strength) by age and over the recent decades has been the most frequently mentioned reason for the increase of trochanteric fractures. Also, the fall characteristics of the elderly may have changed during the recent decades resulting in increasing numbers of this type of hip fractures since the type of the hip fracture (cervical or trochanteric) also depends on the impact angle of the greater trochanter at the moment of the floor contact.

Aged↗
PubMed1995

Energy-shunting external hip protector attenuates the peak femoral impact force below the theoretical fracture threshold: an in vitro biomechanical study under falling conditions of the elderly.

The first objective of this study was to design a hip protector that would effectively attenuate and shunt away from the greater trochanter the impact energies created in typical falls of the elderly. As the shock absorption material, the protector included the 12 mm-thick Plastazote, which was found to be the most efficient energy-absorbing material in our previous in vitro biomechanical tests. With an anatomically designed semiflexible outer shield of the protector (high density polyethylene), the impact surface was increased and the impact energy shunted away from the greater trochanter. In the second phase of the study, we determined the force attenuation capacity of this device in realistic (in vitro) falling conditions of the elderly. With the impact force of 6940 N used (a typical hip impact force measured in in vitro falling tests), the trochanteric soft tissue (25 mm-thick polyethylene foam) attenuated the peak femoral impact force to 5590 N and the tested protector to 1040 N. In the second series of this experiment, the peak femoral impact force was set to be so high (13,130 N) that the protector, if effective, should prevent the hip fracture in almost all cases. The trochanteric soft tissue attenuated this peak impact force to 10,400 N and the tested protector to 1810 N. Thus, the force received by the proximal femur still remained clearly below 4170 N, the average force required to fracture in vitro the proximal femur of the elderly in a fall loading configuration. In conclusion, our test results suggest that an anatomically designed energy-shunting and energy-absorbing hip protector can provide an effective impact force attenuation in typical falling conditions of the elderly. However, the efficacy of the protector in the prevention of hip fractures can only be evaluated in randomized clinical trials.

Accidental Falls↗
PubMed1994

Force attenuation properties of various trochanteric padding materials under typical falling conditions of the elderly.

The purpose of this study was to determine and compare the force attenuation properties of various external trochanteric padding materials under in vitro conditions simulating characteristic falling of the elderly. The selected materials had to be practically suitable for external hip padding so that the main criteria for the materials were good energy absorbing capacity, good durability, low weight, good recovery after compression, easy availability, and reasonable price. Eight materials met these requirements. The first six were flexible cross-linked polyethylene foams with densities from 30 to 200 kg/m3. The seventh material was Plastazote polyethylene foam, and the eight foam was made of ethylene-vinyl acetate (EVA) copolymer. With a pendulum effective mass of 39 kg, impact velocity of 3.0 m/s, and impact force of 8.2 kN, the force attenuation provided by the 20 mm thick hip-padding materials was quite small, ranging from 22 to 38%. With all these materials the peak femoral force remained above 5 kN, more than two times above the femoral fracture threshold (2 kN). In the second set of experiments, the impact force was gradually reduced until the tested materials lowered the impact force below the fracture threshold. With the most efficient material this critical falling velocity was found to be 1.6 m/s. To go below the fracture threshold with the realistic impact velocity of 3.0 m/s, the padding materials had to be 100-140 mm thick.(ABSTRACT TRUNCATED AT 250 WORDS)

Accidental Falls↗
PubMed1994

Increasing age-adjusted incidence of hip fractures in Finland: the number and incidence of fractures in 1970-1991 and prediction for the future.

Hip fractures in the elderly are a worldwide epidemic, and aging of the populations is increasing the burden of these fractures on the health care systems. To improve the knowledge of whether the number of hip fractures is increasing even more rapidly than can be accounted for by the demographic changes only, all patients who were admitted to Finnish hospitals in 1970, 1975, 1980, 1985, 1988, and 1991 for primary treatment of first hip fracture were selected from the National Hospital Discharge Register. There was a steady, average 7.7% annual increase in the total number of hip fractures in Finland during this period so that the number of fractures was 2239 in 1970 and 6071 in 1991. The proportion of patients aged 60 years or more increased steadily from 75% in 1970 to 91% in 1991. In 1991, 74% of the patients were women. Across the study period, the age-adjusted total incidence of hip fractures also increased in both women and men 50 years of age and over. This increase was more pronounced in men. Thus, the increasing incidence of hip fractures in Finland was not only due to the fact that the population was aging but also due to the increasing age-adjusted incidence. We conclude that the number of hip fractures in Finland is increasing more rapidly than can be accounted for by the demographic changes only and this will seriously challenge the Finnish health care system in the future.

Age Factors↗