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M Dahlborn

Publications and source records attributed to M Dahlborn.

At least 19 recordsLinked to original sources
PubMed1994

Decrease in vertebral bone density after hip arthroplasty. A quantitative computed tomography study in 18 arthrosis cases.

We investigated the bone mineral density (BMD) of the lumbar vertebrae L1-3 with quantitative computed tomography (QCT) in 18 patients who had been operated on with hip arthroplasty because of unilateral arthrosis. In an earlier prospective study, we did not find any bone mineral changes in the femur or tibia after hip arthroplasty in spite of a large increase of the thigh muscle mass as a sign of a remobilization after the operation. The median BMD had decreased 5.3-8.4 percent in all the measured vertebrae after 6 months postoperatively. Because of the patients' improved walking ability after the operation, this decrease in cancellous vertebral BMD is interpreted as a sign of a post-traumatic osteopenia.

Aged↗
PubMed1993

Trabecular patterns of the calcaneum as an index of osteoporosis. A comparison using gamma-absorptiometry.

Measurements of bone mineral content in the calcaneum were made by gamma-absorptiometry in 77 patients with ankle fractures treated by operation, and compared with the calcaneal osteoporosis index. The index was calculated from plain lateral radiographs of the calcaneum. The bone mineral measurements showed a wide range, but there was only a narrow range of the index with exclusively high values. There was a weak correlation between the calcaneal index and the bone mineral content in the injured ankles, but no or only a very poor correlation in the uninjured ankles. We also found no correlation between the decline in index and loss of mineral content in the injured ankles.

Absorptiometry, Photon↗
PubMed1993

Bone and muscle mass after hip rearthroplasty. Controlled CT study of 12 patients.

The cortical bone mineral density (BMD), bone volume, bone mass and muscle volume of the thigh and the cancellous BMD of the distal femur and proximal tibia were quantified by computed tomography (QCT) in 12 patients after hip rearthroplasty due to prosthetic loosening following arthroplasty for arthrosis. Both legs were scanned and the operated side was compared with the healthy side. A control group, 12 patients, had had unilateral hip arthroplasty without subsequent rearthroplasty. There was a 19 percent decrease in bone mass and 13 percent decrease in muscle volume in the middle femur, compared to the contralateral side, in the patients who had undergone rearthroplasty, and a reduction of 9 percent for the same variables in the control group. There was also a more marked osteopenia in the reoperated extremity in the distal femur and proximal tibia compared to the unoperated side.

Aged↗
PubMed1993

Bone and muscle mass after hip arthroplasty. A quantitative computed tomography study in 20 arthrosis cases.

We performed a prospective, quantitative computed tomography (QCT) study of bone mineral density (BMD), cortical bone volume, bone mass and muscle volume in 20 patients who were operated on with cemented total hip arthroplasty because of unilateral arthrosis. Both extremities were measured preoperatively, 3 and 6 months after the operation by a single-energy computer tomograph equipped for bone mineral densitometry. Preoperatively, we found a 25 percent decrease in muscle volume of the thigh on the arthrosis side compared to the contralateral side, but only a 6 percent decrease in bone mass, mainly of the cortical bone volume in the middle femur. In the cancellous bone of distal femur and proximal tibia there was a reduction in BMD of 11 and 14 percent, respectively, compared to the contralateral side. After 6 months, we found no changes in cortical bone mass, either on the operated femur or on the contralateral, control femur. The BMD of cancellous bone in distal femur and proximal tibia had not changed. However, the thigh muscle on the operated side showed a strong recovery; 6 months after the operation there was a 19 percent gain on the operated side.

Aged↗
PubMed1990

Value of intercondylar notch plasty. CT studies and peroperative measurements of 127 knees.

The intercondylar notch diameter was measured in six knees on CT scans before and after anterior cruciate ligament reconstruction. During the operation, direct measurements of the anterior notch diameter was also performed before and after notch plasty. There was good agreement between CT and peroperative measurements, showing that the enlargement of the intercondylar notch can be measured on the CT scan. Twenty-one patients previously reconstructed because of old anterior cruciate ligament injuries were reexamined after a median of 4 years, and their notch diameters were measured by CT or at reoperation. The notch remained open in stable knees, but was narrowed in unstable knees. The notch diameter before notch plasty was assessed with a calliper at operation on 45 patients with acute and 60 patients with old injuries. Both groups had a mean intercondylar diameter of 16 mm. The conclusion that the notch plasty stays open in stable knees emphasizes the importance of this step in the reconstruction procedure.

Adult↗
PubMed1990

Fixation of 220 femoral neck fractures. A prospective comparison of the Rydell nail and the LIH hook pins.

220 patients with femoral neck fractures were randomly treated with either a Rydell nail (n 110) or two LIH hook pins (n 110). The age, sex, and displacement patterns were similar in both group. All the patients were operated on by orthopedic specialists and followed clinically and radiographically for 2 years or until death. The mortality at 2 years was similar (28 percent) in both groups. Among 154 survivors, early redisplacement or nonunion was recorded in 19 percent of the Rydell-nailed fractures and 32 percent of the LIH-pinned fractures. In nondisplaced fractures, complications occurred in 8/30 Rydell cases compared with 3/16 in the LIH group. In displaced fractures, complications occurred in 21/48 Rydell cases compared with 28/60 in the LIH group.

Adult↗
PubMed1989

Radionuclide hysterosalpingography for measurement of human oviductal function.

A clinical method is described and claimed to evaluate the active transportation capacity of the luminal epithelium lining the human uterus and fallopian tube. After intracervical application of technetium-labelled human albumin spheres at 1-2 days before ovulation this radioactivity could be followed by gamma-camera when moved in ad ovarian direction. This method is called radionuclide hysterosalpingography (RN-HSG). The results were compared to the findings at normal hysterosalpingography (HSG). By use of this method it was possible to verify active passage in cases of tubal spasm at HSG, lack of transport in cases of normal patent oviducts at HSG as well as presence or absence of active transport through sactosalpinges with or without fimbrial passages to the abdominal cavity as seen at normal HSG. Congruent findings between HSG and RN-HSG was observed in 49%. The studied oviducts were found to be patent with normal HSG but lacked transportation capacity when studied by RN-HSG in 41%. The clinical use of this method is discussed in view of the selection of patients for different forms of in vitro fertilization and egg transfer (IVF-ET).

Adult↗
PubMed1987

Sequential scintimetry in prediction of healing rate after femoral neck fracture.

Thirty-one femoral neck fractures which united without complications (nonunion or late segmental collapse) were included in a prospective sequential scintimetric study. Roentgenologically, three subgroups with different healing rates could be distinguished: rapid union, normal union, and delayed union. All fractures showed a rapid increase in relative femoral head radionuclide uptake after the 1-week scintimetry, followed by a gradual decline after 6 weeks-3 months. However, both the initial rise in activity and the time for maximal uptake tended to differ between the three groups. For rapid union and normal union the peak activity was registered at 6 weeks and for delayed union at 3 months. It is concluded that sequential scintimetric assessment of femoral head uptake can identify different healing rates and that this difference can be partly explained by a transient impairment of vascular supply to the femoral head in fractures with delayed healing.

Adult↗
PubMed1987

Sequential scintimetry after femoral neck fracture. Methodologic aspects and prediction of healing complications.

Forty-five patients with recent cervical hip fractures were included in a prospective, clinical, radiographic and sequential scintimetric study. Striking changes in radionuclide uptake over the entire hip region on the fracture side were found during the first 5 postoperative months. Fractures that healed without complications showed the highest relative femoral head uptake at 1 week and a peak value at 6 weeks, followed by a gradual decline at the subsequent examinations. Fractures with complications (redisplacement, nonunion, or late segmental collapse) showed a lower initial uptake and a more gradual increase and only a slight tendency towards increased uptake after 3 months. The accuracy in predicting nonunion with scintimetric examination alone is high both at 1 and at 6 weeks, and the accuracy is almost equally high with combined scintimetric, radiographic, and clinical assessment 3-5 months postoperatively.

Aged↗
PubMed1986

Radionuclide scintigraphy of femoral head specimens removed at arthroplasty for failed femoral neck fractures.

In order to determine the value of scintimetry as a tool for quantitative measurement of femoral head vascularity, the results of postoperative scintigraphic and histologic examination of surgically removed femoral head specimens were compared with those of preoperative radionuclide scintigraphy in 19 failed femoral neck fractures. Following intravenous administration of 600 MBq of Tc-99m MDP before hip replacement, the activity distribution in femoral head sections was recorded with a gamma camera and the area of isotope uptake calculated. A correlation was found between the results of preoperative noninvasive radionuclide scintigraphy and the assessment of isotope uptake in the removed femoral head specimens (r = 0.83, p less than .001) and was confirmed by the results of histologic examination. There is a risk, however, of overestimating the ratio of isotope uptake between the femoral head on the fracture side relative to the contralateral side with respect to quantitative assessment of femoral head vascularity, due to the general increase in isotope owing to accumulation in the injured hip region. The calculations, however, reflect the levels of radionuclide uptake and the varying degrees of femoral head vascularity.

Aged↗
PubMed1984

Gamma camera detection of 99mTC-plasmin in the diagnosis of deep-vein thrombosis.

99mTc-Plasmin scintigraphy of suspected vein thrombosis registered by a gamma camera was compared with phlebography. The results indicate that the plasmin test can be an alternative method to phlebography. The plasmin test registered by a gamma camera has a high sensitivity but relatively low specificity; this agrees with the results of previous investigations regarding registration with a single detector.

Adult↗
PubMed1984

Ventilation and perfusion of each lung during differential ventilation with selective PEEP.

Lung perfusion was studied in 10 patients (mean age 58 yr) in the lateral position during enflurane anesthesia. They were ventilated through a double-lumen endotracheal catheter: 1) by one ventilator with free distribution of ventilation between the lungs, with no (zero) end-respiratory pressure (ZEEP); 2) as above but with a general positive end-expiratory pressure (PEEP) of 9 cmH2O; or 3) by two ventilators with equal distribution of ventilation between the lungs and with a selective PEEP of 8 cmH2O to the dependent lung only. Total ventilation was on average 8 l/min (BTPS) throughout the study. During the first method, 34% of ventilation was distributed to the dependent and 66% to the nondependent lung. Cardiac output (thermodilution) was 4.5 l/min, 57% being distributed to the dependent lung as assessed by iv boli of Xenon 133. During the second method, ventilation was assumed to be distributed equally between the lungs. Cardiac output was decreased to 3.8 l/min, and the dependent lung received 81% of lung blood flow. During the third method, cardiac output was significantly greater than during the second method (4.1 l/min), 51% passing to the dependent lung. Peak and end-inspiratory airway pressures were 5-18 cm H2O lower during selective than during general PEEP. Arterial oxygen tension was significantly greater during the third method than during either of the other ventilator settings and the alveolar-arterial oxygen tension difference was almost halved compared with the first method. It is concluded that differential ventilation with selective PEEP improves ventilation-perfusion matching and thus oxygenation.

Adult↗
PubMed1984

Radionuclide scintimetry for diagnosis of complications following femoral neck fracture.

A scintimetric study using Tc-99m MDP was made of 54 patients with delayed union, nonunion, or late segmental collapse of the femoral head, 4-92 months after femoral neck fracture. In radiographically verified collapse, the radionuclide uptake ratio between the femoral head on the fractured and on the intact side (HHR) was significantly higher than in fractures resulting in delayed union or nonunion. On the basis of scintimetric and radiographic findings, the patients with healing disturbances could be divided into three groups, characterized by the following features: Satisfactory post-reduction position of the fracture without subsequent redisplacement and a high HHR, which as a rule turned out to be delayed union; The same radiographic pattern but with a lower HHR, which in most cases resulted in nonunion; Inadequate reduction or early redisplacement of the fracture with a high HHR, which resulted in nonunion. The fractional precision in discriminating between different types of disturbed fracture healing by means of skeletal scintimetry was 0.86 in this study. This non-invasive and technically simple method would therefore be a valuable complement to radiography in the assessment of healing, more than 4 months after fracture of the femoral neck.

Adult↗
PubMed1984

Comparison of skeletal and bone marrow radionuclide scintimetry of femoral neck fracture.

Twenty-six patients with late complications following femoral neck fracture were examined with both skeletal and bone marrow radionuclide scintimetry. There was no correlation between the methods with respect to the quantitative assessment of femoral head vascularity based on different uptake ratios comparing the fractured and the intact side. Skeletal scintimetry always had good image quality and permitted reliable differentiation between nonunion of the fracture and late segmental collapse, in contrast to bone marrow scintimetry which gave poor image quality. Skeletal scintimetry thus seems superior to bone marrow scintimetry for assessment and differential diagnosis of late complications following femoral neck fracture. It is emphasized that the physiological mechanisms for radionuclide uptake must be taken into account when comparing scintimetric studies using different tracers.

Aged↗
PubMed1980

Blood flow into vascular catheters of different size and number of sideholes. Model experiments with flush fluid injections.

Using an experimental model of the arterial circulation system, inflow of blood into polyethylene catheters following injection of contrast medium and isotonic saline solution was evaluated. The experiments included an analysis of the influence of density and viscosity of the flush solutions as well as the effect of catheters of different sizes with and without sideholes.

Arteries↗
PubMed1980

Blood inflow and coagulation in vascular catheters. Comparison of the effect of polysaccharide solutions, saline and contrast medium.

Inflow of blood into intraarterial catheters in dogs following single and continuous injections of saline, contrast medium and polysaccharide fluids were analysed with special reference to the influence of their density and viscosity. Clot formation was also analysed and the favourable properties of one variant of the polysaccharide fluids were demonstrated.

Animals↗