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Operatively induced, standardized tibia fractures in 42 10-week-old male rats were fixed with intramedullary nails. 21 of the rats were fed liquid containing 15% ethanol. 5 weeks after inducing the fracture, the rats were killed and the total body bone mineral density (BMD) was analyzed with the DEXA technique, and the mechanical properties of the fractured and the unfractured tibiae as well as the ipsi- and contralateral femoral shaft and femoral neck were tested. The rats given a liquid containing 15% ethanol were found to have significantly lower total BMD and total calcium than the controls. We also found a significantly lower bending moment and bending stiffness both in the fractured and unfractured tibiae among rats fed on ethanol. The energy absorption until refracture was less in rats fed on ethanol. Posttraumatic osteopenia was present, as judged by the mechanical tests of the ipsilateral femoral shaft and the femoral neck in all animals. There was no difference in this respect between the animals fed on ethanol and the controls. We found that ethanol disturbs bone metabolism which reduces the mechanical properties of the tibiae and femora of rats, but the healing process of an induced tibial shaft fracture was not affected.

We measured bone mineral density (BMD) in 128 men and 143 women, aged 22-90, by dual energy X-ray absorptiometry (DEXA) and quantitative ultrasound (QUS). We found reduced bone mineral density in relation to age as measured both by DEXA and QUS. There was a correlation between 0.28 and 0.52 in men and between 0.53 and 0.77 in women when comparing DEXA and QUS measurements. When including only persons with low bone mass, the correlation was less.

We studied the ultrastructure of bone tissue around implants of pure titanium inserted into the tibia in 4 patients with arthrosis or rheumatoid arthritis. Three main appearances of the interface were noted. First, a close contact between titanium and calcified bone with living osteocytes inside the newly-formed bone was observed in all samples. Secondly, a close contact was also seen between the implant and osteoid, the newly formed collagenous matrix being either uncalcified or calcifying. Thirdly, a loose extracellular matrix with fibrillar and nonfibrillar materials was sometimes observed between bone mineral and implant. There was no inflammatory reaction at the interface. We concluded that the titanium implants were osseointegrated, but the calcification of the bone tissue was not complete even after 20 months. However, mineralization of osteoid and living bone cells revealed the presence of an active tissue.

Histomorphologic differences of the periarticular bone in rheumatoid arthritis (RA) and osteoarthrosis (OA) may be of importance for long-term prosthetic fixation. We have evaluated bone specimens, obtained during total hip replacement from an acetabular and a femoral biopsy site, in 42 RA-hips and 61 OA-hips. In both groups the bone turnover was increased in the acetabulum compared to that in the femur. In the acetabulums the total trabecular bone volume was equal, but osteoid volume, osteoid surface, resorptive surface, and the appositional rate were increased in RA. On the femoral side, only the osteoid volume was higher in RA. The increased bone turnover with a greater amount of unmineralized tissue, as well as resorptive activity in the acetabulum, may be of importance for the higher rate of acetabular component migration and loosening after total hip replacement in RA.

The bone mineral content (BMC) was determined by dual photon X-ray absorptiometry prior to hip replacement in 22 patients with rheumatoid arthritis and 31 with arthrosis. Compared with the arthrosis patients, the rheumatoids had approximately 20 percent lower bone mineral content in the proximal femur, the lumbar spine, and in the innominate bone superior to the acetabulum.

In 1992 a retrospective case control study was performed, based on all patients with ankle fractures (n 1063) treated at the Department of Orthopedics in Malmö, Sweden, between 1950-1951 and 1961-1965. As all radiographic examinations have been saved in Malmö, we were able to study all subsequent fractures that this group had sustained. 260 patients from 1961-1965 who were still living in Malmö today were also compared with an age- and gender-matched control group regarding the location and type of subsequent fractures. The group with former ankle fractures continued to have a two-fold increase incidence of all sorts of fractures. The same result was found when looking at the upper and lower extremities separately. However, the risk of sustaining new fractures in the once-fractured extremity was not increased compared to the uninjured side.

62 former patients, who had been treated at our department for tibial shaft fracture (n 38) or knee ligament injury (n 24) 15-38 years earlier, were re-evaluated for post-traumatic osteopenia. 62 age- and sex-matched subjects without fracture served as controls. By means of a Lunar DEXA apparatus we measured the bone mineral density (BMD) in the total body, the hips and special regions of interest (ROI) in the lower extremities. We found a difference in the BMD between the injured and uninjured legs, most obvious in the femur condyle. Measurements of bone mineral loss early after the injury did not correlate with the present late measurements. The former fracture patients had at the time of follow-up the same BMD in the rest of their bodies as a whole, compared with controls. We conclude that post-traumatic osteopenia is still evident in the injured leg decades after the injury.

The bone mineral mass was measured in 324 residents of the city of Malmö, Sweden, by dual energy roentgen absorptiometry (DEXA) using the Lunar DPX equipment--total body, hip, and lumbar vertebrae. The bone mineral content of the wrist was also measured with single photon absorptiometry (SPA) in 88 of the individuals. Weight, height, and vertebral height, as well as body fat, lean body mass, menarcheal age, menopausal age, and hand grip strength were determined. Measurements were compared with reference bone mineral content values from the United States, Japan, and France--also hip fracture incidence was compared. All bone mineral values decreased with age. A good correlation was found between the DEXA technique of total body bone mineral and the forearm SPA values. The bone mineral content was correlated with lean body mass and weight. The Malmö bone mineral content was on the same level as in the United States, but higher than in Japan and France. The comparatively high risk of fragility fractures in the Scandinavian countries compared with most other settings cannot be explained by low bone mass.

In 27 patients operated on for unilateral coxarthrosis with the Charnley hip, the muscular strength and mobility were measured. Half the cases had a trochanteric osteotomy and half an anterolateral transgluteal approach. The abduction strength was normal after trochanteric osteotomy and weaker than normal in the nonosteotomized hips.

Bone samples were taken from the trabecular part of the greater trochanter in 32 patients who had a fracture of the ipsilateral femoral neck, and from 24 patients who had coxarthrosis. 42 cadavers served as controls. The samples were sectioned, stained and examined histologically. The coxarthrosis cases differed only slightly from normal, whereas the fracture cases had increased osteoid volume and surface. Osteoclasts were also increased in number, as were active osteoblasts.

On the basis of an epidemiological study of the incidence of fracture of the upper end of the femur, undertaken in the city of Malmö for the period 1951-1960, the expected number of fractures in 1967 and 1968, and in 1974 and 1975, was calculated taking into account the changes in the size and the composition of the population. It was demonstrated that during the first period the previously described increasing trend continued so that more fractures were observed than could be expected from changes in the population only, whereas later on this trend became insignificant. The changes observed after 1968 could be explained by the increasing number of old residents in the city, and there was no obscure secular trend.