Why is the age-standardized incidence of low-trauma fractures rising in many elderly populations?

Low-trauma fractures of elderly people are a major public health burden worldwide, and as the number and mean age of older adults in the population continue to increase, the number of fractures is also likely to increase. Epidemiologically, however, an additional concern is that, for unknown reasons, the age-standardized incidence (average individual risk) of fracture has also risen in many populations during the recent decades. Possible reasons for this rise include a birth cohort effect, deterioration in the average bone strength by time, and increased average risk of (serious) falls. Literature provides evidence that the rise is not due to a birth cohort effect, whereas no study shows whether bone fragility has increased during this relatively short period of time. This osteoporosis hypothesis could, however, be tested if researchers would now repeat the population measurements of bone mass and density that were made in the late 1980s and the 1990s. If such studies proved that women's and men's age-standardized mean values of bone mass and density have declined over time, the osteoporosis hypothesis would receive scientific support. The third explanation is based on the hypothesis that the number and/or severity of falls has risen in elderly populations during the recent decades. Although no study has directly tested this hypothesis, a great deal of indirect epidemiologic evidence supports this contention. For example, the age-standardized incidence of fall-induced severe head injuries, bruises and contusions, and joint distortions and dislocations has increased among elderly people similarly to the low-trauma fractures. The fall hypothesis could also be tested in the coming years because the 1990s saw many research teams reporting age- and sex-specific incidences of falling for elderly populations, and the same could be done now to provide data comparing the current incidence rates of falls with the earlier ones.     

Fracture repair during external fixation: Torsion tests of rabbit osteotomies

Bone repair was studied in the rabbit tibiofibular bone after a midshaft transverse osteotomy stabilized by external fixation and heavy compression. Both subendosteal and subperiosteal callus formation with concomitant contact healing were observed within 3 weeks, and were further succeeded by subendosteal resorption and increased porosis resulting in atrophy of the cortical bone. Subjected to the torsion test, the bones exhibited restoration of strength within 3 weeks, with maximal energy absorption and elasticity at 6 weeks. The failure of the osteotomy in the torsion test, with radiographic visibility of the osteotomy, characterized the soft-tissue type of behavior of the bones. Hard-tissue like behaviour of the bones with resistance to torsion at the osteotomy site and radiographic obliteration of the osteotomy line occurred by 12 weeks, indicating complete union of the osteotomy. Our experiments demonstrate that elastic external fixation is preferable to the rigid compression plate.     

The effects of training, immobilization and remobilization on musculoskeletal tissue

Compared with the knowledge on immobilization, the effects of remobilization on musculoskeletal tissues have not been well established. What is sure is that remobilization and rehabilitation of any component of the musculoskeletal tissues require much more time than the time needed to cause the immobilization atrophy. With intensive rehabilitation, the functional properties of skeletal muscles can be improved significantly even years after the injury and following immobilization, but no study has shown whether full recovery is possible and whether these rehabilitated muscles are able to respond normally to further training. Experimental studies have given evidence that slow-twitch muscle fibres have better capacity for recovery than fast-twitch fibres, most likely due to better circulation and higher protein turnover. Also evidence has been given that fibre regeneration is possible through satellite cell activation and myotube formation. Very little is known, however, about the effects of age, gender or the level of preimmobilization muscle performance on the restoration capacity. Also the fate of the marked structural changes (for example, connective tissue accumulation) induced by immobilization is unknown. Tendon and ligament tissues are likely to respond appropriately to remobilization, resulting in acceleration of collagen synthesis and fibril neoformation. However, there is a strong suspicion that remobilized tendons and ligaments will not achieve all the biochemical and biomechanical properties of their healthy counterparts. Specifically, the amount of weak type III collagen has been shown to be overrepresented in these tissues instead of mature, strong type I collagen. It is not known whether this is an important risk factor for ruptures during later activity. The effects of remobilization on muscle-tendon junction and proprioceptive organs are not known. It would not be surprising if the serious structural changes induced by immobilization were unrestorable. In the literature dealing with immobilization and remobilization, cartilage degeneration is always a major concern, because not only too strenuous training or immobilization, but also unskilful remobilization may activate this process leading finally to osteoarthrosis. Bone may be one of the best components of musculoskeletal tissues to respond to remobilization, probably because the immobilization atrophy of bone is largely quantitative (osteoporosis) only. The prerequisites for bony recovery are that the follow-up time is long enough (months) and that immobilization has not exceeded about 6 months, the time limit between active and inactive (irreversible) osteoporosis. Prevention of the atrophying effects of immobilization can be very successful if performed properly. According to present knowledge, there are many methods for the purpose, including preimmobilization training early, controlled mobilization; optimal positioning of the immobilized joint; muscular training during immobilization; early weightbearing; exercise with the nonimmobilized extremity; and electrical stimulation. Lots of education and information will be needed, however, before these methods are deeply rooted in the daily routines of the attending physicians, physical therapists, athletic trainers and other persons involved in the treatment of musculoskeletal problems.     

Health and social service use among old people in the last 2 years of life

This study focuses on differences in health and social service use in the last 2 years of life among Finnish people aged 70–79, 80–89, and 90 or older and on the variation in service use in the various municipalities. The data set, derived from multiple national registers, consists of 75,578 people who died in 1998–2001. The services included hospitals and long-term-care facilities, use of regular home care, and prescribed medicines. General hospital and public long-term care were the services most commonly used: general hospitals for younger age groups and public long-term care for older groups. The number of inpatient days in hospital was lower with increasing age, but older age groups used long-term care more frequently. Men had more hospital inpatient days than women, but women used more long-term care. The number of hospital inpatient days increased rapidly in the last months of life, almost doubling in the final month. Days in public long-term care increased regularly in the last 2 years of life. Variation in both hospital and long-term care by municipality was remarkable. The results indicate that, among people aged 70 years and older, age is a major determinant of care in the last 2 years of life. The variation in the use of care by municipality and the differences between men and women deserve more detailed analysis in future.     

Cost-effectiveness analysis of guidelines for antihypertensive care in Finland

Background  

Hypertension is one of the major causes of disease burden affecting the Finnish population. Over the last decade, evidence-based care has emerged to complement other approaches to antihypertensive care, often without health economic assessment of its costs and effects. This study looks at the extent to which changes proposed by the 2002 Finnish evidence-based Current Care Guidelines concerning the prevention, diagnosis, and treatment of hypertension (the ACCG scenario) can be considered cost-effective when compared to modelled prior clinical practice (the PCP scenario).     

Increased GABAergic transmission aggravates nucleus basalis magnocellularis lesion-induced behavioral deficits

Quisqualic acid NBM lesions had no effect on water maze performance, but slightly impaired passive avoidance acquisition. GammavinylGABA treatment alone had no effect on the passive avoidance and water maze performance, but aggravated acquisition deficit in rats subjected to NBM lesioning. However, gammavinylGABA-treated NBM-lesioned rats reached control level of performance.     

The association of sensitive systemic inflammation markers with bronchial asthma.

BACKGROUND: Airway inflammation is a characteristic feature of bronchial asthma. Previous studies have shown an increased local inflammatory activity in the airway mucosa of asthma patients. OBJECTIVES: To analyze the association of asthma with three sensitive markers of systemic inflammation, C-reactive protein, serum amyloid-A (SAA), and plasma fibrinogen. METHODS: A cross-sectional, population-based study including 1,513 Finnish men aged 45 to 74 years, who participated in a chronic disease risk factor survey in 1997. Of the participating men, 97 were classified as asthma patients. The odds ratios of asthma were analyzed by quartile of each inflammation marker. RESULTS: In logistic regression models the age-adjusted odds ratios (second, third, and fourth quartile as compared with the first quartile) of asthma increased gradually with increasing quartile of C-reactive protein (1.28, 1.19, 1.96, P for trend = 0.039), SAA (1.20, 3.00, 3.49, P for trend < 0.001), and fibrinogen (1.22, 1.79, 3.16, P for trend < 0.001). The associations were independent of smoking. Further adjustment for waist-to-hip ratio, a marker of central obesity, and symptoms of chronic bronchitis weakened the observed association, but the increasing trend in the association of SAA and fibrinogen with asthma remained highly significant. CONCLUSIONS: Sensitive markers of systemic inflammation, particularly SAA and fibrinogen, were positively and significantly associated with asthma prevalence. These findings support the hypothesis that not only local, but also systemic, inflammation exist in bronchial asthma.     

Effect of surface conditioning methods on the bond strength of luting cement to ceramics

OBJECTIVES: This study evaluated the effect of three different surface conditioning methods on the bond strength of a Bis-GMA based luting cement to six commercial dental ceramics. METHODS: Six disc shaped ceramic specimens (glass ceramics, glass infiltrated alumina, glass infiltrated zirconium dioxide reinforced alumina) were used for each test group yielding a total number of 216 specimens. The specimens in each group were randomly assigned to one of the each following treatment conditions: (1) hydrofluoric acid etching, (2) airborne particle abrasion, (3) tribochemical silica coating. The resin composite luting cement was bonded to the conditioned and silanized ceramics using polyethylene molds. All specimens were tested at dry and thermocycled (6.000, 5-55 degrees C, 30 s) conditions. The shear bond strength of luting cement to ceramics was measured in a universal testing machine (1 mm/min). RESULTS: In dry conditions, acid etched glass ceramics exhibited significantly higher results (26.4-29.4 MPa) than those of glass infiltrated alumina ceramics (5.3-18.1 MPa) or zirconium dioxide (8.1 MPa) (ANOVA, P<0.001). Silica coating with silanization increased the bond strength significantly for high-alumina ceramics (8.5-21.8 MPa) and glass infiltrated zirconium dioxide ceramic (17.4 MPa) compared to that of airborne particle abrasion (ANOVA, P<0.001). Thermocycling decreased the bond strengths significantly after all of the conditioning methods tested. SIGNIFICANCE: Bond strengths of the luting cement tested on the dental ceramics following surface conditioning methods varied in accordance with the ceramic types. Hydrofluoric acid gel was effective mostly on the ceramics having glassy matrix in their structures. Roughening the ceramic surfaces with air particle abrasion provided higher bond strengths for high-alumina ceramics and the values increased more significantly after silica coating/silanization.     

Damage mechanics and load failure of fiber-reinforced composite fixed partial dentures

OBJECTIVES: Damage mechanics has been defined as the study of the initiation (initial failure) and accumulation of damage to and including rupture (final failure). This study was designed to evaluate the effect of increasing fiber-reinforced composite (FRC) substructure within a standardized fixed partial denture (FPD) model on the failure performance, in terms of damage mechanics. METHODS: The two FRC restorative systems, Targis/Vectris (TV) (Ivoclar Vivadent) and EverStick (ES) (Stick Tech with Gradia, GC Corp.), were used to restore the molar FPD model (1.5 mm axial and 2.0 mm occlusal reduction). Templates were used to standardize substructure designs with 0, 18, 43, and 66% cross-sectional FRC volume fraction (V(FRC)) of fiber substructure. Specimens (n = 5) were homogenized at 29 points and stored for 1 week at 37 degrees C in distilled water. Specimens were luted with calcium hydroxide, then statically loaded until failure. Initial failure (IF), final failure (FF) and the mode of failure were recorded. RESULTS: The lowest mean load to initial failure was 530 N (TV 18%) and the highest was 1208 N (ES 66%). Linear regression analysis calculated the Pearson's correlation coefficient (r) for the interactions between V(FRC) and IF (ES: r = 0.7879, TV: r = 0.6184), V(FRC) and FF (ES: r = 0.912, TV: r = 0.8152), and between IF and FF (ES: r = 0.892, TV: r = 0.7237). Unreinforced specimens universally fractured instantaneously. SIGNIFICANCE: The highest loads to initial and final failure were yielded by specimens with the highest cross-sectional V(FRC).