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Biomedical subjects

Pekka Kannus

Publications and source records attributed to Pekka Kannus.

At least 19 recordsLinked to original sources
PubMed2007

Fragile external phenotype of modern human proximal femur in comparison with medieval bone.

UNLABELLED: Proximal femur macroanatomy of 118 medieval and 67 contemporary adults, 84 contemporary elderly, and 48 contemporary hip fracture cases was evaluated. Within approximately 1000 years, the femoral neck axis has become longer, and its cross-section has become proportionally smaller and more oval in shape. These changes in the present external phenotype alone account for approximately 50% higher fall-induced stress compared with the medieval situation. INTRODUCTION: Bones, as whole skeletal structures, adapt to mechanical stresses they customarily experience. Because the present, mechanized lifestyle apparently deprives our skeletons of vigorous, habitual physical exertion, we studied whether the proximal femur phenotype has evolved vulnerable to fragility fractures by time. MATERIALS AND METHODS: Proximal femur macroanatomy of 118 medieval and 67 contemporary adults, 84 contemporary elderly, and 48 contemporary hip fracture cases was evaluated. Using direct measurements of external bone dimensions and geometric properties, we estimated the fall-induced stress as an index of hip fragility. RESULTS: Within approximately 1000 years, the femoral axis length has become substantially longer (analysis of covariance, body height adjusted, p < 0.001), whereas the neck circumference has not increased. The macroanatomy was found similar between the contemporary adult and elderly groups. In hip fracture cases, however, the femoral axis length was further lengthened (p < 0.001), but the circumference was somewhat smaller (p = 0.001). Consequently, the estimated fall-induced stress can be approximately 1.5-fold today compared with the medieval times (p < 0.001), and the secular trend seemed to be worse in women (sex-time interaction, p = 0.001). CONCLUSIONS: The modern, relatively slender phenotype of the proximal femur alone seems to increase the fall-induced stress considerably, and when this phenotype coincides the osteoporotic, internally deteriorated femoral neck structure, fracture risk is imminent. This mechanically compromised external phenotype underscores the importance of timely strengthening of the skeleton and its regular maintenance throughout life.

Adaptation, Physiological↗
PubMed2006

Alarming rise in fall-induced severe head injuries among elderly people.

This study assessed the current trend in the number and incidence (per 100,000 persons) of fall-induced severe head injuries among the very old adults in Finland, an EU-country with a well-defined white population of 5.2 million, by taking into account all persons 80 years of age or older who were admitted to our hospitals for primary treatment of such injury in 1970-2004. The number of Finns aged 80 years or older with a fall-induced severe head injury increased considerably between the years 1970 and 2004, from 60 (women) and 25 (men) in 1970 to 745 (women), and 350 (men) in 2004. The relative increases were 1142 and 1300%, respectively. Across the study period, the age-adjusted incidence of injury also showed a clear increase from 1970 to 2004, from 168 to 506 in women (201% increase), and from 172 to 609 in men (254% increase). A similar finding was observed in age-specific incidences. If the age-adjusted incidence of injury continues to rise at the same rate as in 1970-2004 and the size of the 80 year old or older population of Finland increases as predicted (approximately 2.2-fold increase during the coming 25 years), the number of fall-induced severe head injuries in this population will be about 3.4-fold higher in the year 2030 than it was in 2004. In Finnish persons 80 years of age or older, the number of fall-induced severe head injuries shows an alarming rise with a rate that cannot be explained merely by the demographic changes of the population. The finding underscores an increasing influence of falls on well-being of our elderly persons, and therefore, effective fall-prevention actions should be initiated to control this development.

Accidental Falls↗
PubMed2006

Loading modalities and bone structures at nonweight-bearing upper extremity and weight-bearing lower extremity: a pQCT study of adult female athletes.

This cross-sectional study of adult female athletes assessed whether the apparent loading-related differences in bone structure are primarily associated with the loading type or the muscle performance-related joint moments. Several structural variables at shaft sites of the tibia, radius and humerus, and distal sites of the tibia and radius were measured with peripheral quantitative computed tomography (pQCT) among 113 female national level athletes (representing hurdling, volleyball, soccer, racket-sports and swimming) and their 30 nonathletic referents. For the weight-bearing lower extremities, the loading modalities of the above sports were classified into high-impact (hurdling, volleyball), odd-impact (soccer, racket-sports) and repetitive, nonimpact (swimming) loadings; and for the nonweight-bearing upper extremities into high magnitude (functional weightlifting in hurdling and soccer), impact (volleyball, racket-sports) and repetitive, nonimpact (swimming) loadings. As expected, athletes' bone mass was substantially higher at loaded bone sites compared with the nonathletic referents, but more pertinently to the locomotive perspective, the loading-induced additional bone mass seemed to be used to build mechanically strong and appropriate bone structures. Compared with controls, the weight-bearing bone structures of female athletes (swimmers excluded) were characterized by larger diaphysis, thicker cortices and somewhat denser trabecular bone. The athletes' bones at the nonweight-bearing upper extremity were generally larger in cross-sectional area. The estimated indices of joint moment (muscle force x estimated lever arm) were explained from 29% to 50%, and the loading modalities from 8% to 25%, of the variance in most bone variables (P < 0.05) of the tibia (shaft and distal site). In contrast to the weight-bearing tibia, only the estimated joint moment was positively associated (P < 0.05) with the structural characteristics of the radius and humerus, accounting for 6% to 26% of the variance in bone variables of the shafts of these bones. Such association was not observed at the distal radius. In conclusion, at the weight-bearing lower extremity, the strong bone structure of the female athletes was attributable to muscle performance-related estimated joint moments and impact loading modality. At the shaft sites of the nonweight-bearing upper extremity, the strong bone structure was mainly attributable to the estimated joint moments. Thus, different loading history and other features of loading seemed to govern the skeletal adaptation at the upper and lower extremity.

Absorptiometry, Photon↗
PubMed2006

Renal insufficiency-induced bone loss is associated with an increase in bone size and preservation of strength in rat proximal femur.

Chronic renal insufficiency (CRI) results in phosphate retention and secondary hyperparathyroidism, the treatment of which is largely based on the use of calcium salts as phosphate binders. Advanced CRI causes bone fragility, but information about bone geometry and strength in moderate CRI is scarce. We assigned 39 8-week-old male Sprague-Dawley rats to sham-operation (Sham) or 5/6 nephrectomy (NTX). Four weeks later, the rats were randomized to 0.3% calcium (Sham, NTX) or 3.0% calcium diet (Sham + Calcium, NTX + Calcium). After 8 weeks, the animals were sacrificed, plasma samples collected, and femora excised for neck and midshaft analyses: dual-energy X-ray absorptiometry, peripheral quantitative computed tomography, and biomechanical testing. The NTX increased plasma urea and PTH 1.6-fold and 3.6-fold, respectively, whereas high calcium intake suppressed PTH to 30% of controls. Total femoral bone mineral content decreased (-6.3%) in the NTX group, while this deleterious effect was reversed by high calcium diet. In the site-specific analysis of the femoral neck, the volumetric bone density (-6.5%) was decreased in the NTX group but not NTX + Calcium group. However, in the nephrectomized rats, there was also a concomitant increase in the cross-sectional area (+15%), and, despite the decrease in bone density, the mechanical strength of the femoral neck was maintained. In the midshaft, NTX decreased cortical volumetric bone density (-1.2%), but similar to the femoral neck, no differences were found in the mechanical strength. In conclusion, a decrease in bone mass in moderate experimental CRI was associated with a concomitant increase in bone size, and maintenance of mechanical competence. Although high calcium diet suppressed plasma PTH to under normal physiological levels, it prevented the CRI-induced loss of bone mass without an adverse influence on bone strength.

Absorptiometry, Photon↗
PubMed2006

A sideways fall and hip fracture.

A sideways fall onto the hip is known to be a clear risk factor for hip fracture of elderly people, but it has remained unclear how severe injury such a fall can be. This retrospective patient file survey of young adults aged 15 to 49 years suggested that a fall onto the hip is indeed a serious high-impact injury possessing energy to fracture the proximal femur even in young healthy men. This being the case, it is evident that sideways falls can be very dangerous and thus a natural target for fracture prevention.

Accidental Falls↗
PubMed2006

Prevention of hip fracture with hip protectors.

The prevention of fractures amongst older people consists of (i) prevention and treatment of osteoporosis, (ii) prevention of falling and (iii) prevention of fractures using injury-site protection. As the great majority of hip fractures are caused by a sideways fall with direct impact on the greater trochanter of the proximal femur, one approach to prevention is the use of an adequately configured padded, firm-shield external hip protector. With this type of two-part design, the impacting force and energy are, at the time of the fall-impact, first weakened by the padding part of the protector and then diverted away from the greater trochanter by the shield part of the same. Following this line, a series of consecutive studies by the Accident & Trauma Research Center at the UKK Institute, Tampere, Finland, found that a padded, strong-shield hip protector was effective in preventing hip fractures. In the context of the wider literature on hip protectors, these more encouraging results suggest the need for a more rigorous regulation of protector design and characteristics. Alongside inadequacies of design, the other most frequent general problem with hip protectors is compliance. Not all elderly people with a high risk of hip fracture will agree to use hip protectors and in those who do, long-term adherence may decrease. Caregiver motivation and involvement appear therefore to be crucial.

Accidental Falls↗
PubMed2006

Update in the epidemiology of proximal humeral fractures.

UNLABELLED: We sought to determine current trends in the number of fall-related and osteoporosis-related proximal humeral fractures in elderly Finns during last three decades. We collected data from the National Hospital Discharge Register on all patients 60 years or older who were admitted to Finnish hospitals from 1970 to 2002 for primary treatment of proximal humeral fractures. Fractures induced by traffic accidents or other high-energy traumas were excluded. The number and incidence (per 100,000 patients) of fractures increased from 208 (number) and 32 (incidence) in 1970 to 1120 (number) and 105 (incidence) in 2002. The age adjusted incidence of proximal humeral fractures also showed an increase, from 51 (1970) to 129 (2002) in women, and from 14 (1970) to 48 (2002) in men. In women 80 years or older, the age specific incidence of fracture increased from 90 (1970) to 294 (2002), while in the other age groups trend changes were less extensive. The mean patient age also increased, from 73 years (1970) to 78 years (2002) in women and from 70 years (1970) to 73 years (2002) in men. If these trends continue, the number of fractures in elderly Finns will triple during the next three decades. LEVEL OF EVIDENCE: Prognostic study, Level IV (case series). See the Guidelines for Authors for a complete description of levels of evidence.

Aged↗
PubMed2006

Paricalcitol [19-nor-1,25-(OH)2D2] in the treatment of experimental renal bone disease.

UNLABELLED: Paricalcitol is a less hypercalcemic vitamin D analog that has been shown to suppress secondary hyperparathyroidism and to prevent the associated histomorphometric changes in bone. In this study, we show that paricalcitol also ameliorates the renal insufficiency-induced loss of bone mineral and the mechanical competence of bone. INTRODUCTION: Renal bone disease is a common consequence of chronic renal insufficiency and the associated secondary hyperparathyroidism (SH). Paricalcitol [19-nor-1,25(OH)(2)D(2)] has been shown to ameliorate SH and prevent renal failure-induced histomorphometric changes in bone with minimal calcemic and phosphatemic activity. However, information about its efficacy on restoration of bone structural strength is lacking. In this study, we explored the effects of paricalcitol treatment on bone structure and strength in a model of advanced renal disease. MATERIALS AND METHODS: Forty-five 8-week-old rats were randomly assigned to either surgical 5/6 nephrectomy (NTX) or Sham-operation. After a 15-week postoperative disease progression period, the NTX rats were further allocated to uremic control (NTX) and treatment (NTX + paricalcitol) groups, the latter of which received paricalcitol for the subsequent 12 weeks. After 27 weeks, the animals were killed, plasma samples were collected, and both femora were excised for comprehensive analysis of the femoral neck and midshaft (pQCT and biomechanical testing). RESULTS: High mortality that exceeded 30% was observed in both NTX groups. NTX induced over a 13-fold increase in plasma PTH, whereas this increase was only 5-fold after paricalcitol treatment. At the femoral neck, NTX was associated with an 8.1% decrease (p < 0.05) in vBMD and a 16% decrease in breaking load (p < 0.05) compared with the Sham group, whereas paricalcitol treatment completely prevented these changes. At the femoral midshaft, the NTX resulted in a 6.6% decrease in cortical BMD (p < 0.01 versus Sham), and this change was also prevented by paricalcitol. CONCLUSIONS: Paricalcitol administration prevented renal insufficiency-associated decreases in BMD in the femoral neck and the femoral midshaft and restored bone strength in the femoral neck. Therefore, paricalcitol can efficiently ameliorate renal insufficiency-induced loss of bone mineral and mechanical competence of bone.

Animals↗
PubMed2006

Nationwide decline in incidence of hip fracture.

UNLABELLED: This epidemiologic study determined the trend in the number and incidence (per 100,000 persons) of hip fracture among older adults in Finland, an EU country with a well-defined white population of 5.2 million, between 1970 and 2004. The results show that the alarming rise in the fracture incidence from early 1970s until late 1990s has been now followed by declining fracture rates. Reasons for this are largely unknown, but a cohort effect toward a healthier aging population and increased average body weight and improved functional ability among elderly Finns could partly explain the phenomenon. INTRODUCTION: Although osteoporotic fractures of older adults are said to be a major public health concern in modern societies with aging populations, fresh nationwide information on their secular trends is limited. MATERIALS AND METHODS: This epidemiologic study determined the current trend in the number and incidence (per 100,000 persons) of hip fracture among older adults in Finland, an EU country with a well-defined white population of 5.2 million, by taking into account all persons >or= 50 years of age who were admitted to our hospitals for primary treatment of such fracture in 1970-2004. RESULTS: The number of hip fractures among >or= 50-year-old Finns rose very constantly between 1970 (1857 fractures) and 1997 (7122 fractures), but since then, the rise has leveled off (7083 fractures in 2004). After this and because of a continuous rise in population at risk, the crude incidence of hip fracture (showing a clear rise in 1970-1997) decreased between 1997 and 2004, from 438 (per 100,000 persons) in 1997 to 374 in 2004. Concerning the age-adjusted fracture incidence, findings were similar. Until 1997, the age-adjusted incidence of hip fracture clearly increased in both women and men, but thereafter, this incidence declined in both sexes: in women, from 494 in 1997 to 412 in 2004, and in men, from 238 in 1997 to 223 in 2004. CONCLUSIONS: The rise in the incidence of hip fracture in Finland from the early 1970s until the late 1990s has been followed by declining fracture rates. Exact reasons for this are unknown, but a cohort effect toward a healthier aging population and increased average body weight and improved functional ability among elderly Finns cannot be ruled out.

Aged↗
PubMed2005

Prevention of falls and consequent injuries in elderly people.

Injuries resulting from falls in elderly people are a major public-health concern, representing one of the main causes of longstanding pain, functional impairment, disability, and death in this population. The problem is going to worsen, since the rates of such injuries seem to be rising in many areas, as is the number of elderly people in both the developed and developing world. Many methods and programmes to prevent such injuries already exist, including regular exercise, vitamin D and calcium supplementation, withdrawal of psychotropic medication, cataract surgery, professional environment hazard assessment and modification, hip protectors, and multifactorial preventive programmes for simultaneous assessment and reduction of many of the predisposing and situational risk factors. To receive broader-scale effectiveness, these programmes will need systematic implementation. Care must be taken, however, to rigorously select the right actions for those people most likely to benefit, such as vitamin D and calcium supplementation and hip protectors for elderly people living in institutions.

Accidental Falls↗
PubMed2005

Achilles tendon disorders: etiology and epidemiology.

The Achilles tendon is the strongest tendon in the human body. Because most Achilles tendon injuries take place in sports and there has been a general increase in popularity of sporting activities, the number and incidence of the Achilles tendon overuse injuries and complete, spontaneous ruptures has increased in the industrialized countries during the last decades. The most common clinical diagnosis of Achilles overuse injuries is tendinopathy. The basic etiology of the Achilles tendinopathy is known to be multi-factorial. Although histopathologic studies have shown that ruptured Achilles tendons have clear degenerative changes before the rupture, many Achilles tendon ruptures take place suddenly without any preceding signs or symptoms.

Achilles Tendon↗
PubMed2005

Injury-related deaths among Finnish adolescents in 1971-2002.

The purpose of our study was to examine the nationwide trends in the age- and sex-specific incidence rates of fatal injuries among 10-19-year-old adolescents in Finland, a country with a well-defined white population of 5.2 million. A population-based study was based on Official Cause-of-Death Statistics of Finland. We included adolescents aged 10-19 years who died because of an injury in 1971-2002. During the study period, the incidence of injury-related deaths declined considerably, from 43.0 (per 100,000 persons) (95% confidence interval (CI): 38.5, 47.5) in 1971 to 19.9 (95% CI: 16.5, 23.4) in 2002 (p<0.001). The decrease was seen in both genders. The decline in injury deaths was mainly due to decrease of deaths in traffic accidents. A sharp peak in boys' suicides was found during economic depression. To sum up, the incidence of adolescent injury deaths declined considerably in Finland between 1971 and 2002. The reasons for this positive development are probably multifactorial, including improvements in traffic safety and emergency services. The trend in intentional deaths showed no change during the 32-year study period and therefore prevention of adolescent violence and suicides should also receive attention.

Accidents↗
PubMed2005

Secular trends in rates of unintentional injury deaths among adult Finns.

This study assessed the current secular trends in unintentional injury deaths among persons 15 years of age or older in Finland. For this purpose, we obtained from the Finnish Official Cause-of-Death Statistics (OCDS) the data for persons aged 15 years or older whose deaths occurred in 1971--2003 due to an unintentional injury. Among Finnish men, the most drastic change occurred in road traffic crashes. The age-standardised death rate (per 100,000 person-years) of men's road traffic crashes was 47 in 1971 but only 11 in 2003. In contrast, the rate of fall-induced deaths among Finnish men gradually rose, from 18 in 1971 to 24 in 2003, by which time falls became the leading category of men's unintentional injury death. Also alcohol poisonings seemed to bypass road traffic crashes as the cause of men's injury death. Among Finnish women, the age-standardised rate of fall-induced deaths decreased till 1975, after which the curve was rather flat. The death rate (per 100,000 person-years) of women's falls was 30 in 1971 and 18 in 2003. During the entire period of 1971--2003, traffic caused fewer deaths in women than men, but the declining trend in women's death rates was also clear, from 17 in 1971 to 5 in 2003. Other unintentional causes accounted for few deaths in women during 1971--2003, although it was of interest that the rate of women's deaths due to alcohol poisoning rose from 1 in 1971 to 4 in 2003. In conclusion, during 1971--2003 falls replaced road traffic crashes as the leading cause of unintentional injury death in adult Finns. The rise in men's fall-induced deaths occurred even with a rate that cannot be explained merely by demographic changes, and therefore, systematic fall prevention measures are needed to control the development. The rising incidence of women's deaths due to alcohol poisoning needs close follow-up.

Accidental Falls↗
PubMed2005

Non-pharmacological means to prevent fractures among older adults.

Bone fractures affecting elderly people are a true public health burden, because they represent one of the most important causes of long-standing pain, functional impairment, disability, and death among this population. Compromised bone strength (osteoporosis) and falling, alone, or more frequently in combination, are the two independent and immediate risk factors of elderly people's fractures through which all the other, more distant risk factors, such as aging, inactivity, poor nutrition, smoking, use of alcohol, diseases, medications, functional impairments, and disabilities, operate. Of these two, falling, not osteoporosis, is the strongest single risk factor for a fracture. The most usual occurrence resulting in a fracture of an older adult is a 'simple' fall from standing height or less. Although in general terms this type of trauma is mild or moderate only (compared with, for example, motor vehicle collisions), to the specific injury site these traumas are high-impact injuries often creating forces clearly exceeding the breaking strength of the bone. Therefore, fractures affecting elderly people should be called 'fall-induced high-impact injuries' instead of the commonly used, partly misleading terms of osteoporotic fractures or minimal-trauma fractures. Prevention of elderly people's fractures consists of prevention of osteoporosis and of falling, and prevention of fractures using injury-site protection. Concerning osteoporosis, maximizing peak bone mass and preventing bone loss by regular exercise, calcium, and vitamin D, and, treatment of established osteoporosis with bone-specific drugs, have a strong scientific basis. In fall prevention, regular strength and balance training, reducing psychotropic medication, and diet supplementation with vitamin D and calcium have been shown to be effective. The multifaceted risk factor-assessing and modifying interventions have also been successful in preventing falls among the older adults by simultaneously affecting many of the risk factors of falling. Finally, concerning injury-site protection, padded strong-shield hip protectors whose effectiveness is scientifically proven seem to be a promising option in preventing hip fractures.

Accident Prevention↗