Ingemar Sernbo

Long-term risk of osteoporotic fracture in Malmö.

Abstract: The objectives of the present study were to estimate long-term risks of osteoporotic fractures. The incidence of hip, distal forearm, proximal humerus and vertebral fracture were obtained from patient records in Malmo¨, Sweden. Vertebral fractures were confined to those coming to clinical attention, either as an inpatient or an outpatient case. Patient records were examined to exclude individuals with prior fractures at the same site. Future mortality rates were computed for each year of age from Poisson models using the Swedish Patient Register and the Statistical Year Book. The incidence and lifetime risk of any fracture were determined from the proportion of individuals fracture-free from the age of 45 years. Lifetime risk of shoulder, forearm, hip and spine fracture were 13.3%, 21.5%, 23.3% and 15.4% respectively in women at the age of 45 years. Corresponding values for men at the age of 45 years were 4.4%, 5.2%, 11.2% and 8.6%. The risk of any of these fractures was 47.3% and 23.8% in women and men respectively. Remaining lifetime risk was stable with age for hip fracture, but decreased by 20–30% by the age of 70 years in the case of other fractures. Ten and 15 year risks for all types of fractures increased with age until the age of 80 years, when they approached lifetime risks because of the competing probabilities of fracture and death. We conclude that fractures of the hip and spine carry higher risks than fractures at other sites, and that lifetime risks of fracture of the hip in particular have been underestimated.

Fracture risk following an osteoporotic fracture

The aim of this study was to examine the pattern of fracture risk following a prior fracture at the spine, shoulder or hip. We studied 1918 patients with fractures at these sites identified from the Department of Radiology in Malmo who were followed for 5 years. Poisson regression was used to compute fracture rates immediately after the initial fracture and at 5 years thereafter in men and women aged 60 or 80 years. Immediate fracture risk was higher than that of the general population, more markedly so at the age of 60 than at 80 years. At the age of 60 years, the risk of hip, forearm and spine fractures were significantly increased following a prior spine, hip or shoulder fracture in men. A similar pattern was seen in women, except that the increase in risk of forearm fracture following a spine or hip fracture was not statistically significant. The incidence of further fractures at the shoulder, spine or hip fell with time after the first fracture, a fall that was significant for all fractures after a shoulder fracture, hip fracture after a spine fracture, and hip and spine fractures after a hip fracture. We conclude that the risk of a subsequent fracture immediately after an osteoporotic fracture is highest immediately after the event. This provides a rationale for very early intervention immediately after fractures to avoid recurrent fractures.

Increasing age-adjusted risk of fragility fractures: a sign of increasing osteoporosis in successive generations?

The age-adjusted incidence of fragility fractures is increasing. This is the outcome of almost all epidemiologic studies that have been done throughout the world during the last 40 years. However, a few studies that have shown an unchanged incidence of hip fractures are as often cited in recent literature, which motivates a discussion of the issue. There are signs that favor the fact that the increasing incidence of fractures in the elderly is evidence of a deterioration of the skeleton in successive generations. Its possible reasons are discussed. The epidemiology of fractures has been studied more thoroughly in Malmr, Sweden than in any other place. The favorable conditions for such investigations in our city have been used in many studies since the beginning of this century [1, 2], up to the present, where all the fractures from those occurring at birth [3] to the fractures sustained by already hospitalized elderly [4] have been investigated. These investigations together with all other studies on fracture epidemiology (to our knowledge) are reviewed in the first part of this article. In the second, possible reasons for the increasing ageadjusted incidence of fragility fractures are discussed.

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.

Incidence of hip fractures in Malmö, Sweden, 1992-1995. A trend-break.

The incidence of hip fractures in Malmö, Sweden, has been studied since 1924. Predictions based on material from the 1950s to the 1980s have shown an almost exponential increase in incidence. During 1992-1995, 2,268 patients aged 50 and older, with hip fractures, were admitted to Malmö University Hospital, the only hospital in the city treating hip fractures. 76% were women with a mean age of 81 (SD 8) years, and the mean age of men was 78 (SD 9) years. 47% of the fractures were cervical. The annual incidences per 10,000 inhabitants were 36 in men and 85 in women. The corresponding numbers of subjects over 80 years were 170 men and 297 women. These findings show that the incidence is no longer increasing. The causes of such a trend-break could be successful osteoporosis prevention, an increasing proportion of non-Scandinavian immigrants with a lower genetic risk of osteoporotic fractures, or a healthier elderly population. Increasing number of the population at risk already have two operated hips, due to previous fractures or arthrosis. Other causes may be fewer prescriptions of sedatives and higher winter temperatures.

Differences in the incidence of hip fracture. Comparison of an urban and a rural population in southern Sweden.

The incidence of hip fracture from 1981 to 1984 inclusive in the urban population of the city of Malmö was compared with three rural municipalities around the city of Ystad in southern Sweden. A higher incidence of hip fracture was found in the urban population, especially among women. Patients with a hip fracture in Malmö had a lower mean age. Women in Malmö lived more often alone or in institutions.

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.

Long-term cost and effect on quality of life of osteoporosis-related fractures in Sweden

Background and purpose Few economic or quality-of-life studies have investigated the long-term consequences of fragility fractures. This prospective observational data collection study assessed the cost and quality of life related to hip, vertebral, and wrist fracture 13–18 months after the fracture, based on 684 patients surviving 18 months after fracture. Patients and methods Data regarding resource use and quality of life related to fractures was collected using questionnaires at 7 research centers in Sweden. Information was collected using patient records, register sources, and by asking the patient. Quality of life was estimated using the EQ-5D questionnaire. Direct and indirect costs were estimated from a societal standpoint. Results The mean fracture-related cost 13–18 months after a hip, vertebral, or wrist fracture were estimated to be €2,422, €3,628, and €316, respectively. Between 12 and 18 months after hip, vertebral, and wrist fracture, utility increased by 0.03, 0.05, and 0.02, respectively. Compared to prefracture levels, the mean loss in quality of life between 13 and 18 months after fracture was estimated to be 0.05, 0.11, and 0.005 for hip, vertebral, and wrist fracture. Interpretation The sample of vertebral fracture patients was fairly small and included a high proportion of fractures leading to hospitalization, but the results indicate higher long-term costs and greater loss in quality of life related to vertebral fracture than previously believed.

Incidence of hip fractures in Malmo, Sweden (1950-1991)

In a 24-year sub-sample taken from a 42-year period of study (1950-1991), hip fracture incidence was analysed from a defined catchment area within one hospital. During this time, 8,256 hip fractures occurred in a generated risk population of 1,915,571 person-years. Crude incidence increased three-fold in women and five-fold in men. In men, the age-specific increase was twice as large as the age drift. In women, the two components were of equal size. The more marked increase in men caused the female:male ratio to decrease from 4.2 in 1950 to 2.4 in 1991. In men, all age classes experienced a significant yearly increase (1.6% in the 50-59 age group, 3.9% over the age of 80). In women, only the 70-79 and 80+ age groups showed a significant increase (1.4%, 2.3%). In the age-standardised curve, a levelling off occurred during the mid-80s. In women, this was attributable to changes in climate during wintertime. In men, no significant association was found with temperature. The age-standardised curve followed an approximate linear trend with an increase of 6.4/100,000/year in women and 4.9/100,000/year in men. The cumulative rate for the age group 50-79 years doubled in men but increased only by one-third in women. The impact of increasing incidence in men compared with women is discussed using an osteoporosis model consisting of base risk, senile risk, and post-menopausal risk.

Bone mineral mass in hip fracture patients

The aims of this study were to measure the bone mineral density (BMD) and some anthropometric variables in patients with hip fracture, to compare these data with those from controls, and to compare the fractured and unfractured hip. Bone mineral measurements with dual energy X-ray absorptiometry (DEXA) were undertaken in 93 consecutive hip fracture patients, 26 men and 67 women, with a mean age of 75 and 78 years, respectively, within 10 days after injury. We found lower BMD in most measurements in both men and women compared with age- and sex-matched controls. The body weight and lean body mass were also significantly lower in the male hip fracture patients; in women only weight was lower. In women there was lower BMD in spine and hip in those who had sustained trochanteric hip fractures compared with those with cervical fracture. No such difference was found in men. There was no difference in BMD in the hip when patients with stable and unstable fractures were compared. In the fractured and nonfractured hips we measured BMD in regions of interest. In women with trochanteric hip fractures the BMD was decreased in the fractured hip compared with the uninjured. No such difference was found for cervical fractures or in men.