Biomedical subjects

O Johnell

Publications and source records attributed to O Johnell.

At least 145 records · Page 8Linked to original sources

PubMed1997

Bone mineral density in adolescents. Higher values in a rural area--a population-based study of 246 subjects in southern Sweden.

We performed, in a cross-sectional study, dual energy X-ray absorptiometry (DXA) among 15-16-year-old boys (n 58) and girls (n 44) living in an urban area and among boys (n 82) and girls (n 66) of the same age from a rural area. We measured bone mineral density (BMD) of the total body, the lumbar spine and the hip. In the rural population, we found significantly higher BMD levels in the lumbar spine (14% for the boys and 12% for the girls) and the total body (6.9% for the boys and 3.4% for the girls). We detected no significant differences in the hip BMD. Adolescents in rural areas seem to develop a higher peak bone mass and thereby presumably have a lower risk of developing fragility fractures.

Absorptiometry, Photon↗

PubMed1997

Bone mineral density, muscle strength and physical activity. A population-based study of 332 subjects aged 15-42 years.

The aim of this population-based study was to find out whether differences in levels of physical activity have an influence on bone mass quantity and whether quadriceps muscle strength is a reliable determinant of bone mass. Included were 175 men and 157 women, aged 15-42 years. Bone mineral density (BMD) was measured at various sites by dual X-ray absorptiometry (DXA) and single photon absorptiometry (SPA). Muscle strength was assessed using an isokinetic muscle force meter. A questionnaire was used to estimate the level of physical activity. We found a positive correlation between physical activity and BMD for boys at the distal forearm and for girls at the trochanter (age group 15-16 years). Active men (age group 21-42 years) had up to 9% higher BMD levels at the hip than those who were less active. Quadriceps muscle torque was not an independent predictor of BMD. Our data suggest that a higher level of physical activity-within the limits of a "normal life style"-may have a positive effect on BMD in the proximal femur of young adults, which in turn may lessen the subsequent risk of fracture.

Absorptiometry, Photon↗

PubMed1996

Meta-analysis of how well measures of bone mineral density predict occurrence of osteoporotic fractures.

OBJECTIVE: To determine the ability of measurements of bone density in women to predict later fractures. DESIGN: Meta-analysis of prospective cohort studies published between 1985 and end of 1994 with a baseline measurement of bone density in women and subsequent follow up for fractures. For comparative purposes, we also reviewed case control studies of hip fractures published between 1990 and 1994. SUBJECTS: Eleven separate study populations with about 90,000 person years of observation time and over 2000 fractures. MAIN OUTCOME MEASURES: Relative risk of fracture for a decrease in bone mineral density of one standard deviation below age adjusted mean. RESULTS: All measuring sites had similar predictive abilities (relative risk 1.5 (95% confidence interval 1.4 to 1.6)) for decrease in bone mineral density except for measurement at spine for predicting vertebral fractures (relative risk 2.3 (1.9 to 2.8)) and measurement at hip for hip fractures (2.6 (2.0 to 3.5)). These results are in accordance with results of case-control studies. Predictive ability of decrease in bone mass was roughly similar to (or, for hip or spine measurements, better than) that of a 1 SD increase in blood pressure for stroke and better than a 1 SD increase in serum cholesterol concentration for cardiovascular disease. CONCLUSIONS: Measurements of bone mineral density can predict fracture risk but cannot identify individuals who will have a fracture. We do not recommend a programme of screening menopausal women for osteoporosis by measuring bone density.

Aged↗

PubMed1996

Effect of transforming growth factor-beta and platelet-derived growth factor-BB on articular cartilage in rats.

The short-term and long-term effects on the growth zone in articular cartilage of transforming growth factor-beta 1 and platelet-derived growth factor-BB injected intraarticularly into the knee joint of growing rats were investigated. The changes induced by five injections of 0.5 micrograms of transforming growth factor-beta 1 included a rapid decrease in the size and number of hypertrophic cells and an enhanced subchondral bone formation. The changes were most marked in the patella but were also apparent in the tibia and femur. The proliferating cells became swollen and lost their normal organization. From the seventh day of the experiment to about 3 weeks, the matrix stained intensely with safranin O for proteoglycans. The alterations induced by transforming growth factor-beta also included synovial fibroplasia and synovitis, consisting predominantly of mononuclear cells. Localised necroses in the cartilage sometimes appeared after 21 days. In long-term studies, destroyed cartilage was found in three of six rats and partial ossification of the joint cartilage was found in two after 90 and 180 days. Ossicles developed in the tendons in all six patellae. Injection of platelet-derived growth factor-BB resulted in an early and transitory minor increase in the osteogenic activity in the zone between cartilage and red bone marrow and later produced an ossicle in one of four tendons. None of the other changes noted after injection of transforming growth factor was observed.

Animals↗

PubMed1996

Prevention of osteoporosis: cost-effectiveness of different pharmaceutical treatments.

The cost-effectiveness of different pharmaceutical programmes to prevent osteoporosis has been compared. The following pharmaceutical treatments were analysed and compared: calcium supplementation, etidronate and calcitonin. As a benchmark for comparison, oestrogen replacement therapy, in the form of both pills and plaster, was also included in the analysis. The cost-effectiveness of different strategies for particular age groups was analysed. Finally, the cost-effectiveness of population-based prevention programmes was compared with the cost-effectiveness of programmes based on screening followed by treatment of women with low bone mineral density (BMD). A cost-effectiveness analysis (CEA) was carried out. The cost/effectiveness ratio computed was net costs per hip fracture avoided. The evaluation was based on a simulation model in which 1000 women were followed from the age of 50 years. The model was based on Danish epidemiological data and Danish health care cost figures. Assumptions concerning the health effect of the pharmaceutical methods of prevention were based on results from existing studies. As different results have been reported, 'optimistic' and 'pessimistic' alternatives were simulated in the model. The analysis revealed large differences in the cost-effectiveness of different pharmaceutical methods; however, the cost-effectiveness is highly sensitive to the treatment effect assumed. Treatment will be more cost-effective the higher the fracture risk of the group treated, so cost-effectiveness will therefore increase the later in life the intervention takes place, and if only women screened for low BMD are treated. However, the overall effect from a general screening programme will be low and highly sensitive to compliance. As compliance with pharmaceutical treatment seems to be low, and as the effectiveness--and thereby the cost-effectiveness--is encumbered with much uncertainty, prevention of osteoporosis through screening for low BMD should not be recommended at present.

Aged↗

PubMed1996

Bone mineral density in female junior, senior and former football players.

The purpose of this study was to examine the bone mineral densities (BMD) of female junior and senior football (soccer) players with different training regimens and histories, female former football players, and their respective controls. Active junior (age 13-17 years, n = 62) and senior (age 18-28 years, n = 34) players, representing three teams with different levels of performance and training, were compared reciprocally and with matched controls (n = 90). Former players (age 34-84 years, n = 25) who had ended their careers on average 9.7 years previously and their matched controls (n = 57) were also studied. Body composition and total body, lumbar spine and proximal femur BMD were measured with dual-energy X-ray absorptiometry. Former players and their controls were asked in a questionnaire to specify their current level of physical activity. In a control for differences in age, weight and body mass index, football players had significantly greater BMD than controls at all sites measured. This difference appeared to be site-specific, with greater differences in BMD at the proximal femur sites (10.5-11.1%) than at the lumbar spine (4.8%) or for the total body (3.5%). Further, differences were greater for senior than for junior players. However, no BMD differences were found between teams representing different levels of performance and training. Female former football players had retained their proximal femur and total-body BMD advantage over controls. In conclusion, training in female football, which is an impact-loading activity, has a site-specific, positive effect on bone formation that is not increased over a certain level of physical activity. The BMD advantage attained appears to be preserved to some extent after the termination of the athlete's active career, which may have a positive effect on future fracture risk.

Absorptiometry, Photon↗

PubMed1996

Changes of bone mineral mass and soft tissue composition after hip fracture.

The aim of this prospective longitudinal study was to measure prospectively the bone mineral density (BMD) and anthropometric variables after a hip fracture. In particular, we studied changes in the BMD in both the injured and uninjured hips, and examined if the postoperative mortality rate and complications, including pseudarthrosis of the fracture and late segmental collapse of the head of the femur, could be predicted by early bone mass measurements. The bone mineral density and the body composition were measured with dual energy X-ray absorptiometry in 102 consecutive hip fracture patients, 31 men and 71 women, with a mean age of 74 and 79 years, respectively. All cases were operated on within 3 days. The measurements were undertaken within 10 days after the fracture, after 4 and after 12 months. The BMD of the hip fracture cases decreased, especially in the lower extremities where the patients lost 7%, during the first year after the fracture. The patients also lost lean body mass (5%) but gained fat (11%) during the same period. They lost significantly more bone mass in the fractured hip than in the uninjured hip (p < 0.05). No difference was found between those patients who survived and those who died within 2 years after their hip fracture in neither the initial measurement nor in the follow-up measurements. Also, we found no difference between those patients whose hip fracture healed and those who developed late segmental collapse or pseudarthrosis. In conclusion, osteoporotic hip fracture cases lose bone mass at an increased rate, especially in the fractured hip. Also, their soft tissue composition changes, gaining fat while losing muscle mass. Furthermore, it seems that early bone mineral measurements cannot predict postoperative failures or postoperative mortality.

Aged↗

PubMed1996

Femoral neck geometry and radiographic signs of osteoporosis as predictors of hip fracture.

A total of 125 consecutive hip fracture patients were investigated regarding hip geometry. There were 33 men of mean age 76 +/- 10 years, and 92 women of mean age 78 +/- 9 years. Patients with previous hip surgery were excluded. Hip geometry (hip-axis length, width of collum femoris, and femoral shaft and neck-shaft angle) were registered on both plain radiographs and DEXA scans performed within 2 weeks after fracture. On the radiographs, the calcar femorale, the Singh index, and the femoral neck index (FNI) were also calculated and compared with earlier published values of bone mineral density hip in the hip fracture patients. The fracture cases were compared with controls, 192 DEXA scans and 163 radiographs, in patients without hip surgery or known hip disease. As measured on the DEXA scans we found a wider collum femoris and a wider femoral shaft in both the male and female fracture cases, compared to controls. Also, the fracture cases showed signs of osteoporosis as measured by the calcar femorale, the Singh index, and the femoral neck index. These measurements showed good correlation with bone mineral density of the hip as measured by the DEXA scans.

Absorptiometry, Photon↗

PubMed1996

Influence of surrounding soft tissues on onlay bone graft incorporation.

OBJECTIVES: This investigation aimed to evaluate the influence of three different soft tissue environments on onlay bone graft incorporation into the craniomaxillofacial skeleton and to follow this process immunohistochemically by staining for some bone and cartilage matrix proteins and proteoglycans. STUDY DESIGN: Femoral and tibial bone grafts, either uni- or bicortical, were placed subperiosteally, submuscularly, and intramuscularly in 36 identically sized and aged isogeneic rats. The results were evaluated after 4, 12, and 20 weeks. RESULTS: Corticocancellous grafts showed a more extensive incorporation and more pronounced local resorption. Bicortical grafts produced more resorption of the recipient site, which oftentimes resulted in the graft being almost level with the surrounding bone. The marrow space of both graft types was sealed off by compact bone formation. Intense labeling of tested bone matrix proteins at various parts of the graft-host area was demonstrated. Ultimate graft height was significantly reduced for most groups, but no major differences between groups were registered. Intramuscularly positioned control grafts ultimately showed signs of lacking viability and reduced labeling of cartilage matrix proteins. CONCLUSIONS: These findings indicate that either type of graft had its drawbacks and that further studies to enhance integration and size maintenance are necessary to improve overall graft persistence. Immunolabeling may help to identify essential mechanisms in and find markers of graft incorporation.

Animals↗

PubMed1996

The relationship between anthropometric measurements and fractures in women.

In a population-based, retrospective study involving postmenopausal women, we investigated the relation between fracture prevalence (risk) and present as well as previous body height and weight. A questionnaire was mailed to 46,353 postmenopausal women aged 50-80 years and there were 29,802 (64.3%) responses. Questions were asked about body height and weight and fractures after the age of 25 and at what year they had occurred. The fractures were grouped according to whether they had occurred within 5 years or 10 years prior to responding to the questionnaire. Main outcome was relative risk (RR) of having sustained a fracture of the hip, radius, or spine within 5 years or within 10 years prior to responding to the questionnaire. RRs for hip and spine fractures were negatively associated with current body mass index, current weight, and weight gain since the age of 25 years. Moreover, the RRs of these fractures were positively associated with current height, height at the age of 25, and height loss since the age of 25 years, with the exception of fracture of the spine and current height. RRs for radius fracture were negatively associated with current body mass index and height loss since the age of 25. Moreover, the RRs for radius fracture were positively associated with current weight and height, weight gain since the age of 25, and weight and height at the age of 25. Height at the age of 25 was a consistent risk factor for all fracture types. The RR of the highest quartile (greatest height) vs. the lowest was 2.5 for having a hip fracture during the past 5 years and 2.3 during the past 10 years, which corresponds to a RR of 1.4 for an increase in 1 SD (5.4 cm) in height at age 25. The RR for spine fracture increased about fivefold in women having sustained > or = 3 cm height reduction compared with those who had maintained height. We conclude that tall women have a greater relative risk of experiencing fragility fractures. By using height, women at risk of a later fracture can be selected already at the age of 25 years for later follow-up. Height loss, being strongly associated with fragility fractures, indicates the presence of an already existing osteoporotic condition that should receive evaluation and treatment.

Aged↗

PubMed1996

Advances in osteoporosis: better identification of risk factors can reduce morbidity and mortality.

Osteoporosis is a common disease of postmenopausal women and the elderly. Low bone mass results from genetic, nutritional and lifestyle factors, decreased oestrogen levels, certain medical conditions, and the use of certain drugs. The overall incidence and age- and sex-related incidences of osteoporosis are increasing worldwide. Osteoporotic fractures can cause considerable pain, disability, loss of independence and deterioration in quality of life. Many patients lose the ability to perform the activities of daily living. Mortality and morbidity after hip fracture increase with age. Prevention of osteoporosis and osteoporotic fractures is an urgent priority to reduce the burden placed on health care and social welfare systems.

Activities of Daily Living↗

PubMed1996

Importance of participation rate in sampling of data in population based studies, with special reference to bone mass in Sweden.

OBJECTIVE: To study the effects of participation rate in sampling on "normative" bone mass data. DESIGN: This was a comparison between two randomly selected samples from the same population. The participation rates in the two samples were 61.9% and 83.6%. Measurements were made of bone mass at different skeletal sites and of muscle strength, as well as an assessment of physical activity. SETTING: Malmö, Sweden. SUBJECTS: There were 230 subjects (117 men, 113 women), aged 21 to 42 years. RESULTS: Many subjects participated in both studies (163). Those who took part only in the study with the higher participation rate (67) almost invariably had higher values for bone mass density at the sites measured (up to 7.6% for men) than participants in the study with the lower participation rate. No differences in muscle strength were recorded. CONCLUSION: A high degree of compliance is important to achieve a reliable result in determining normal values in population based studies.

Adult↗

PubMed1996

Onlay bone graft behaviour after marrow exposure of the recipient rat skull bone.

This study aimed to evaluate the effects on incorporation of onlay grafts after exposure of the marrow of the skull recipient bed. Tibial or femoral uni- and bicortical bone grafts were positioned subperiosteally or submuscularly in the parietal and temporal region, respectively, of 28 adult rats. The recipient bed was ground to remove the external cortical layer and expose the underlying marrow. The outcome was assessed after four, 12, and 20 weeks by routine histology and immunohistochemical labelling for various bone and cartilage proteins. Marrow exposure resulted in an explosive bone formation, prompt graft incorporation, earlier onset of bone remodelling, but also localized resorption at the host bed due to increased vulnerability to pressure. Graft height loss was similar relative to previous observations by us using the same experimental model but without exposure of the marrow. The investigated proteins were identified at various locations and with different temporal sequences; the technique contributed to a diversified appreciation of graft behaviour. The findings emphasize the essential role of the bone marrow constituents to bone graft incorporation.

Animals↗

PubMed1996

Falls and hip fracture. A reasonable basis for possibilities for prevention? Some preliminary data from the MEDOS study Mediterranean Osteoporosis Study.

UNLABELLED: The Mediterranean Osteoporosis Study (MEDOS), a multicentre study on incidence, risk factors, and means of prevention of hip fracture in the Mediterranean region, started in 1986 and involved 14 centres, in Portugal, Spain, France, Italy, Greece, and Turkey. The design includes a case-control study comparing 8,185 individuals in age groups above 50 (2,816 cases and 5,369 controls; two controls per case). Information on falls was only collected for a small fraction of the controls. In a questionnaire including 160 main questions eleven referred to circumstances around the fall. Falls were classified according to a) high risk environment, e.g. occurred in darkness and b) high risk fallers, e.g. confusion, reduced functional ability. There was great variation between centra for a majority of the results. However, 2/3 of fractures happened during daylight. 9% of fractures, same for both males and females, took place in darkness. Females have more indoor fractures than males. Around 15% of fractures took place in connection with going to the toilet. Mental factors play a minor role as reported immediate cause to the fall. Before the fall that caused the hip fracture between 28-84% could get up from a chair without any difficulties. Of the males 0-26% lived alone as against 0-37% or females. CONCLUSION: The data on circumstances around the fall shows a complex pattern with substantial variation between different cultures, but where a, however, minority took place under risk circumstances that have a clear preventive potential.

Accidental Falls↗

PubMed1996

The development of a European questionnaire for quality of life in patients with vertebral osteoporosis.

The complaints of vertebral osteoporosis usually result from wedge or crush fractures and biconcave deformities. These are caused by a decrease of bone mass and deterioration of bone structure leading to loss of strength. Treatment of osteoporosis should result in an increase of bone mass, and the incidence of new vertebral fractures should diminish. However, new vertebral fractures are not always accompanied by pain, and disability does not well correlate with the number of vertebral fractures. Patients with osteoporosis often have other problems e.g. with taking a shower, preparing meals, gardening, walking stairs, visiting friends and attending social activities. In addition, pain and disability may influence mood and lead to depression. The assessment of quality of life should be a primary endpoint in clinical trials in patients with osteoporosis and in individual patients care. Recently, the European Foundation for Osteoporosis (EFFO) has decided a develop a questionnaire for patients with vertebral osteoporosis, i.e. patients with vertebral deformities. The questionnaire is meant for use in clinical trials. A questionnaire was made including 48 questions and 6 visual analogue scales. The questions concern the following domains: pain, activities of daily living, jobs around the house, moving, leisure and social activities, general health perception and mood. The questionnaire ("Qualeffo") has now entered the validation phase. The first study in 8 centres concerns the within-subject reproducibility, the internal coherence, and the specificity by comparing osteoporotic patients with a control group not suffering from osteoporosis or backpain.

Humans↗

PubMed1996

Social function after cervical hip fracture. A comparison of hook-pins and total hip replacement in 47 patients.

47 patients with a cervical hip fracture Garden 3 or 4 and fully ambulatory before the fracture, were randomized to either fixation with Hansson hook-pins (24 patients, median age 79 years) or to a Charnley hip replacement (23 patients, median age 80 years). The patients were followed for 2 years. Social function was evaluated using a standard questionnaire. There were no postoperative deaths and no significant differences in hospital stay. 9/24 patients treated with hook-pins developed healing complications and 2 dislocations occurred in the THR group. After 1 and 2 years, fewer patients treated with hip replacement used outdoor walking aids; they were also more likely to do their own shopping. Hip replacement is a good choice when treating healthy older people with displaced cervical hip fractures, when primary mortality is expected to be low and the risk of healing complications after nailing is high.

Activities of Daily Living↗

PubMed1996

Cost-effectiveness of fracture prevention in established osteoporosis.

This study presents the results of a computer simulation model for calculating the cost-effectiveness and cost-utility of treating patients with established osteoporosis in order to reduce the risk of fractures. The results are based on Swedish data for risk of fracture and costs. The treatment intervention modelled is based on treatment of a 62-year-old woman with established osteoporosis. The cost per hip fracture avoided is 350,000 SEK, assuming a 50% reduction in the risk of fracture due to 5 years of treatment. A sensitivity analysis for changes in the cost and effectiveness of treatment, the risk of fracture and the discount rate is performed. The cost per life-year gained and the cost per quality-adjusted life-year (QALY) gained is presented to enable comparison of the cost-effectiveness of treating osteoporosis with that of other health care interventions. A comparison between treating the same woman for osteoporosis and mild hypertension shows a cost per life-year gained of 220,000 SEK and 128,000 SEK respectively. Cost per QALY gained is very similar for the two interventions: 105,000 SEK and 103,000 SEK respectively. This model provides a tool to enable clinicians, administrators and health policy makers to analyze and understand the economic aspects of a major health policy issue.

Computer Simulation↗

PubMed1995

Conservative treatment of acute low back pain. A 5-year follow-up study of two methods of treatment.

STUDY DESIGN: Prospective, randomized trial. OBJECTIVES: To compare the McKenzie method of treatment of acute low back pain with patient education in "mini back school" after 5 years; the 1-year results have already been published. SUMMARY OF BACKGROUND DATA: The 5-year results after the initial treatment are presented in this study of 89 subjects. Included in the study were 22 women and 67 men with an average age of 39.6 +/- 10.5 years (range 22-66 years). METHODS: Sixty-two subjects (70%) were interviewed by telephone, while the remaining 27 subjects (30%) were examined and interviewed personally. Information of sick leave was obtained from the Swedish National Health Insurance Office. RESULTS: The results showed that subjects who received treatment according to the McKenzie principle 5 years earlier had significantly less recurrences of pain and fewer were on sick leave compared with the subjects who received education in mini back school. The other variables did not show any statistically significant differences. CONCLUSIONS: The difference between the two treatments was much less after 5 years compared with the 1-year results.

Acute Disease↗