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Biomedical subjects

A Høiseth

Publications and source records attributed to A Høiseth.

At least 37 records · Page 2Linked to original sources
PubMed1991

Effect of high-dose corticosteroids on the incidence of deep vein thrombosis after total hip replacement.

Fifty patients receiving uncemented total hip prostheses were examined by venography of the legs on the 2nd postoperative day. The patients were randomly divided into two groups, a non-steroid group (n = 26) and a steroid group (n = 24). Both groups received dextran thrombo-prophylaxis. The patients in the steroid group were treated with high-dose corticosteroids. The incidence of deep vein thrombosis (DVT) was 38% (19/50). No patients had clinical signs or symptoms of DVT. All thrombi were located distally in the leg. DVT was bilateral in nine patients, in the operated leg in three, and in the non-operated leg in seven. The administration of high-dose corticosteroids did not influence the incidence or pattern of DVT. All patients were followed up clinically and plethysmographically up to 12 months after surgery. Distally located asymptomatic DVT were not given specific treatment. The postoperative course was uneventful except for one patient in each group who developed clinically, apparent DVT more than 3 weeks after operation, although the initial venographic studies were normal.

Aged↗
PubMed1991

Radiographic prediction of early failure in femoral neck fracture.

We studied the primary radiographs of 56 patients treated with osteosynthesis for a displaced femoral neck fracture. The radiographic findings were subjected to a multiple regression analysis together with the results 3 months postoperatively. A primary fracture displacement of more than 20 mm on the AP film and a defect of the calcar due to fracture comminution were associated with a failed osteosynthesis.

Aged↗
PubMed1991

Bone mass distribution in the lower leg. A quantitative computed tomographic study of 36 individuals.

We measured bone density and volume at different levels of the normal lower leg by computed tomography. The fibular mass at each transverse level was 18-20 percent of the total bone mass. Tibial masses at all the levels correlated with distal femoral and proximal tibial masses. Summing the fibular and tibial masses augmented the correlations. The mass values varied substantially at different levels of the lower leg, being highest in the midshaft. We hypothesize that the lower extremity is a biomechanical continuum where the distribution of the bone mass corresponds to the functional demands, indicating that the fibula is not "dispensable."

Adult↗
PubMed1991

Assessment of bone mineral content in the internal bone volume.

A method for assessing values related to bone density and mass is described. Mean attenuation and pixel area are measured in pixels selected on the basis of CT units. The method is to a large extent computerized and not dependent on manual positioning or outlining of a region of interest. Because it is not dependent on a comparatively large volume of homogeneous bone it can be used to make assessments even in very heterogeneous bones including cortical bone. The method is adaptable for measurement in all parts of the skeleton and values related to both bone density (DRV) and bone mass (MRV) are derived. The measurements in the femoral condyles were shown to have a precision of approximately 0.25 to 0.30 Z-score units (standard deviation of the measurements expressed in Z-score units). The agreement between chemically analyzed calcium density (weight of calcium per volume) and DRV was little less than 0.50 Z-scores and 0.30 Z-scores for the chemically determined calcium mass and the MRV. The agreement with mechanical bone strength was 0.78 Z-scores for DRV and 0.64 for the MRV. Altering scan parameters or measuring approaches gave systematic differences in measurements. There were, however, good linear correlations between the measurements which show that these different measuring approaches essentially gave identical measurements.

Bone Density↗
PubMed1990

[Are statistical analyses appropriate when evaluating measurements?].

The article reviews the basic principles pertaining to the evaluation of measurements. It discusses the adequacy of the statistical analyses of significance, correlation and regression in the evaluation of measurements. It is concluded that these statistical methods are unsuitable in this connection and that the methods may even be a cause of inadequate conclusions. Alternatives are presented.

Biometry↗
PubMed1990

Patellofemoral relationships in normal subjects determined by computed tomography.

The normal relationships of the patellofemoral joint with the knee in extension were measured with computed tomography (CT) in 43 normal adults. The upper and lower halves of the joint were examined. The range in measurement of the sulcus angle was 115 degrees - 172 degrees, of the congruence angle 43 degrees - 27 degrees, and of the lateral patellofemoral angle 26 degrees - 11 degrees. No significant differences were found between men and women or between the right and left sides. There were some differences between the measurements of the upper and lower halves of the joint. These data may serve as a basis for the evaluation of patients with abnormalities of the patellofemoral joint.

Adult↗
PubMed1990

Deep vein thrombosis after total hip replacement. A venographic study.

The incidence of deep vein thrombosis (DVT) in 62 consecutive patients under dextran thromboprophylaxis after total hip replacement, was examined by venography of the legs on the second postoperative day. The venography was repeated on day 9 after the operation in 43 patients to study the development of thrombi. Twenty-one patients were found to have venographically deep vein thrombosis on the second postoperative day, but had no clinical signs of DVT. All thrombi were located distally in the leg and equally distributed between the operated and the non-operated leg. Distally located asymptomatic DVT were not given specific treatment. Thrombolysis between postoperative day 2 and day 9 seemed to dominate over thrombus formation and propagation. Even large thrombi in the legs may dissolve during the first postoperative week. Thus, the timing is essential for the screening of DVT.

Aged↗
PubMed1990

Femoral cortical/cancellous bone related to age.

The femoral cancellous/cortical relationship with age has been determined in 53 dissected femoral specimens. By means of computed tomography (CT) values related to bone density and mass were assessed in the femoral head, neck, trochanter, shaft, and condyles. In the neck and trochanter separate measures were made in cortical and cancellous bone. The results were analyzed by means of correlation and regression analyses. There were significant negative linear correlations between the CT measures and age for all measures except for the isolated cancellous measures in the femoral neck and trochanter. Our results indicate that in the femoral neck and trochanter the cortical bone mass constitutes a substantial amount of the total bone mass. We conclude that, since bone strength to a large part is a function of the total bone mass, loss of cortical bone may be more important than loss of cancellous bone.

Aged↗
PubMed1990

Plethysmographic screening for deep venous thrombosis following total hip replacement.

A series of 97 lower limbs examined with venography and plethysmography after total hip replacement surgery is presented. No patients had clinical signs of deep venous thrombosis (DVT). Venography revealed distal DVT in 26 limbs. Plethysmography was negative in 25 of these cases. A low sensitivity for plethysmographic detection of calf thrombi is described in previous publications. In this study, however, we found a complete lack of correlation between positive plethysmography and venography in limbs with distal, symptomfree thrombosis.

Aged↗
PubMed1990

Axial and appendicular bone mineral content determined by computed tomography. Relationship to age and body size in males.

Bone density and mass related values were determined in femoral condyles and in the second lumbar vertebra in males of middle age. A poor agreement was found between measurements in the two locations. The measurements were compared with age and body size by means of correlation analysis and multiple regression analysis. There was a significant linear relationship between lumbar measures and age (beta coefficient -0.61 and -0.75) while the relationship with age for the femoral measures was less (beta -0.36 and -0.45). For all measurements there was a poor correlation with body size (weight, length and surface area). Bone mineral content measurements in the lumbar and appendicular skeleton have different clinical implications. When selecting a method for estimating the bone mineral content careful attention must be paid to what type of information is wanted and whether the method is adequate for that particular purpose.

Aging↗
PubMed1989

Basic concepts of femoral neck anteversion: comparison of two definitions.

Femoral neck anteversion is determined by the neck, shaft and knee axes. It is commonly assumed that the neck axis is a straight line connecting the centre of the femoral head, the centre of the femoral neck and the axis of the femoral shaft. However, the line through the centre of the femoral head and neck crosses anterior to the axis of the femoral shaft. A distinction has therefore to be made between two principal different definitions of anteversion, denoted ANTEV 1 and ANTEV 2 in this paper, depending on the precise definition of the neck axis. Previous studies have indicated substantial differences between these definitions. The present study, using precise measuring methods, shows that the definitions have a systematic but small spread of differences. The large individual variation previously found between the two definitions is therefore caused mainly by the measuring methods and to a lesser extent by real anatomical variations.

Adult↗
PubMed1989

Rotational strength of the femoral neck. Computed tomography in cadavers.

The mean bone density of the femur at different levels was determined by means of quantitative computed tomography (QCT) in 50 pairs of normal cadaveric femora and related to the rotational strength of the femoral neck. All the femora fractured vertically and spirally in the neck. The bone-mass-related measures at different levels were calculated from QCT densities and volumes. Cancellous bone was defined with threshold limits ranging from 50-500 Hounsfield units (HU), and attenuation values exceeding 500 HU were assessed as cortical bone. The recorded QCT mass-related measures of cortical and cancellous bone separately and as total bone masses gave significant right/left correlations. Correlations were found between the ultimate torsional strength of the femoral neck and QCT recordings of bone mass at all the femoral levels. The best correlations were demonstrated between the rotational strength of the femoral neck and the total bone-mass-related measures in the femoral shaft and condylar area. Bone mass of the femur measured by computed tomography may become useful as an index of the mechanical strength of the femoral neck.

Aged↗
PubMed1989

Torsion of the leg determined by computed tomography.

Torsion of the leg was measured in 50 adults by computed tomography. The tangent to the dorsal aspect of the femoral condyles gave the proximal reference line. The distal reference line joined the centers of the medial and lateral malleoli. Tibial torsion was measured as the inclination between the dorsal tangent to the tibial condyles and the distal reference line, and torsion of the leg was measured as the inclination between the proximal and the distal reference lines. The anatomy of the dorsal aspects of the tibial condyles was more inconsistent than the anatomy of the dorsal aspects of the femoral condyles. In the females the external torsion of the leg was 38 +/- 9 degrees on the right side and 37 +/- 11 degrees on the left side. In the males the values were 41 +/- 6 degrees and 40 +/- 10 degrees, respectively.

Adolescent↗
PubMed1989

Quantification of bone mineral measured by single-energy computed tomography.

Twenty cadaver femoral condyles were examined with single-energy quantitated computed tomography (QCT), and the composition of the bone scanned was analyzed chemically. The calcium concentration correlated well with the QCT density (r = 0.89, P less than 0.001). The highest correlation was recorded between the total calcium content in the scanned slices and the bone mass-related measures recorded by QCT (r = 0.96, P less than 0.001). Single-energy computed tomography thus provides an accurate measure of total bone mineral content.

Aged↗
PubMed1989

Lack of correlation between femoral neck anteversion and acetabular orientation. Radiography and computed tomography in cadavers and in vivo.

Radiography and computed tomography measurements were made of femoral neck anteversion, femoral head cartilage distribution, and the orientation of the acetabulum. The measurements were made in elderly cadaver femurs and in patients. They failed to establish any correlation between the femoral neck anteversion and the orientation of the articulating surface of the femoral head, nor between the femoral neck anteversion and the angles of the acetabulum.

Acetabulum↗
PubMed1989

Bone-mass distribution in the femur. A cadaver study on the relations of structure and strength.

We measured the bone density and volume in the femoral head, cervicotrochanteric, midshaft, and condylar regions by quantitative computed tomography of the femora of 26 elderly cadavers. We also measured the shearing force at fracture of the femora in axial bending; 25 fractures occurred vertically in the neck and only one in the shaft. The bone mass-related measurements, calculated as the product of bone density times volume, increased steadily from the femoral neck down to the condyles. The bone densities of males and females did not differ, whereas the bone volumes were higher in males. Several correlations were found between the ultimate shearing force of the cervical trabecular/cortical bone and cortical and cancellous bone densities in different locations of the femur. The ultimate shearing force was correlated with the bone mass in all the locations.

Absorptiometry, Photon↗
PubMed1988

Calcium status and calcium-regulating hormones in alcoholics.

To elucidate effects of chronic ethanol consumption on clinical chemical parameters reflecting overall calcium homeostasis 34 hospitalized male alcoholics and 35 age-matched controls were studied during the winter season. Serum concentrations of 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 were reduced by 28% (p less than 0.01) and 24% (p less than 0.02) among the alcoholics as compared to the controls, respectively. Dietary intake of vitamin D3 did not differ significantly between the groups. The calcium level was below lower limit of reference in nine alcoholics (26%). Serum concentrations of parathyroid hormone and phosphorus were within normal ranges in both groups, and no differences were observed in levels of magnesium, vitamin D-binding protein, calcitonin, or alkaline phosphatase. In conclusion, it is possible that the activities of enzymes crucial in vitamin D3 metabolism may be altered in alcoholics.

Adult↗