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Biomedical subjects

G S Lausten

Publications and source records attributed to G S Lausten.

At least 19 recordsLinked to original sources
PubMed1999

Diagnosis of scaphoid fracture and dedicated extremity MRI.

We evaluated the value of dedicated extremity magnetic resonance imaging (E-MRI) in patients with clinical suspicion of a scaphoid fracture and normal initial radiographs. 52 patients underwent E-MRI within a mean of 4 (2-10) days after trauma. Follow-up radiographs were performed at average 11 (8-14) weeks after trauma, and these images were used as the "gold standard". A T1-weighted turbo gradient echo 3D and a tau short inversion recovery STIR were performed, both in coronal planes. The imaging time was less than 10 min. The images were evaluated independently by two radiologists. E-MRI detected occult fractures of the scaphoid in 9 patients, and of the distal radius in a further 6 patients. All these fractures were confirmed at follow-up radiographs. Furthermore, E-MRI revealed a fracture of the capitate bone in 1 patient, and of the triquetrum in 2 patients, and in 8 patients, bone bruise in 1 or more of the carpal bones. However, these fractures and bone lesions could not be confirmed by the follow-up radiographs. The agreement between the two examiners was high (kappa = 0.8) for E-MRI detection of fractures. E-MRI seems to be better than radiographs in the early diagnosis of occult fractures of the scaphoid bone and the wrist.

Adolescent↗
PubMed1998

Multiplanar reconstruction in MR imaging of the knee. Comparison with standard sagittal and coronal images.

PURPOSE: To compare standard MR sagittal and coronal imaging of the knee with the MR technique of finer sagittal imaging and subsequent reconstruction in any plane. MATERIAL AND METHODS: Forty-seven patients took part in the study. Two radiologists each made two independent interpretations in every case, based on images of: a) 4-mm sagittal and coronal slices; and b) 1.2-mm sagittal slices with subsequent reconstruction. RESULTS: We found no significant difference in diagnostic efficacy between the two MR techniques. The reconstruction in any desired plane involved a potential reduction of 10 min in examination time but an increase of approximately 20 min in postprocessing time. CONCLUSION: The use of multiplanar reconstruction offered no additional diagnostic value and no saving of time.

Adult↗
PubMed1998

Necrosis of the femoral head after kidney transplantation.

We reviewed the medical records of 750 patients (445 men, 305 women), who had received a kidney transplant during the period 1968-1995, for any sign of necrosis of the femoral head. For post-operative immunosuppression, 374 patients had received high-dose corticosteroids (average 12.5 g during the first year post-operatively), while 376 patients had received low-dose corticosteroids (average 6.5 g during the first year post-operatively) and cyclosporin A. Survival curves according to Kaplan and Meier (J Am Stat Ass 1958: 53: 457-481) were constructed. In the high-dose steroid group, 42/374 patients (11.2%) developed femoral head necrosis, at an average of 26.2 months post-transplantation. In the low-dose steroid group, only 19/376 (5.1%) patients developed this complication, at an average of 20.5 months post-transplantation. This difference in numbers of femoral head necroses was highly significant (p < 0.005). We conclude that steroid doses should be minimized whenever feasible in post-transplant immunosuppression therapy.

Adolescent↗
PubMed1997

[Relevance of the 112-emergency calls among the clientele of the emergency department of the Herlev hospital admitting office].

It is a common view, shared by Emergency Department staff and ambulance crews, that a large number of patients unnecessarily use Emergency Service ambulances instead of transporting themselves to the hospital by other, more appropriate means. In this retrospective study, 528 consecutive Emergency Service calls to the Herlev Hospital Casualty/Emergency Department during a six week period were reviewed for relevance. Attention was solely aimed at the relevance of the use of Emergency Service ambulances in each case, but not on patient or health care providers' perception of urgency. All calls resulting in admission to hospital were pre-defined as being relevant. Seventeen point six percent of all calls were deemed irrelevant. Thirty-three percent of all calls not resulting in admission were deemed irrelevant. The results confirm Emergency Department health care providers' and ambulance crews' view that Emergency Service ambulances are used inappropriately by the public.

Ambulances↗
PubMed1997

MRI preferable to diagnostic arthroscopy in knee joint injuries. A double-blind comparison of 47 patients.

We compared the findings of low-field MRI of the knee with those of subsequent arthroscopy. In a double-blind set-up, 47 patients with knee joint injuries were enrolled. Two radiologists independently interpreted the MRI examinations and consensus was obtained in case of discrepancy. Arthroscopy was performed without knowledge of the MRI findings. The accuracy rates of MRI for evaluating the medial meniscus, lateral meniscus and anterior cruciate ligament were 77%, 91% and 96%, respectively, when arthroscopy was considered the "golden standard". When MRI was considered the standard, the figures for arthroscopy were 74%, 91% and 96%. MRI found the indication for treatment in 18 of 21 patients who were treated at the arthroscopy. In 17 patients, neither MRI nor arthroscopy detected any lesion. In the remaining 9 patients, MRI demonstrated a lesion, but no lesion was found at the subsequent arthroscopy. Our conclusion is that low-field MRI can be used as a first-line diagnostic examination in patients with suspected meniscus or cruciate ligament injuries and thus a substantial number of negative diagnostic arthroscopies can be avoided.

Adult↗
PubMed1997

Skeletal metastases of unknown origin: a retrospective analysis of 29 cases.

The objective of this study was to assess the diagnostic strategy in identifying occult primary carcinomas in metastatic bone disease. The records of 29 patients seen between 1983 and 1993 were reviewed retrospectively. The patients had been evaluated nonuniformly with a wide array of diagnostic procedures. The primary tumor was identified in 22 patients antemortem, and in 2 patients postmortem. In 5 patients a diagnosis of the primary tumor was never obtained. Eleven of the primary tumors were carcinomas of the lung, 3 were prostatic carcinomas, 2 were carcinomas of the breast and 2 were malignant lymphomas. In 4 patients respectively a carcinoma of the kidney, the pancreas, the ovary or the stomach was found. One patient had a carcinoid tumor of the small intestine, and one had a retroperitoneal rhabdomyosarcoma. The average survival time after clinical onset of skeletal metastases was 12 months. We propose a flow sheet to evaluate this category of patients including a medical history, thorough physical examination, routine laboratory tests, chest radiography, bone scintigram, ultrasonography or computed tomography of the abdomen and biopsy of the most accessible metastasis. These tests allowed premortem diagnosis of the primary tumor in 75% of the cases. Biopsy should be considered the last test to be performed.

Adult↗
PubMed1996

[Femoral head necrosis treated with total hip alloplasty].

One hundred and three patients with non-traumatic osteonecrosis of the femoral head had 144 primary total hip replacements performed. Average age was 47 (22-73) years. In 85 cases a cemented prosthesis, and in 45 cases an uncemented prosthesis was used, while 14 cases had a cemented femoral stem and an uncemented cup. At follow up, 25 patients had died, 13 patients had had a revision of the prosthesis, and two patients were lost to follow-up, leaving 63 patients (92 hips) for clinical and radiological evaluation. Kaplan-Meier plots for survival of the prosthesis were constructed, showing a total risk of failure of 8% at five years, increasing to 16% at seven years. In 89% of the patients without concomitant diseases, the clinical result was excellent or good. There was no difference in the clinical or radiological result in patients with cemented and uncemented prostheses. It is concluded, that the result after total hip replacement due to non-traumatic osteonecrosis of the femoral head is comparable to that of total hip replacement due to osteoarthrosis, and that an uncemented prosthesis can be expected to yield a result comparable to a cemented prosthesis.

Adult↗
PubMed1996

Local recurrences in giant cell tumour of bone. Long-term follow up of 31 cases.

We studied the value of histopathological grading in determining the prognosis of giant cell tumour (osteoclastoma) and the rate of local and distant recurrences in a consecutive series of 31 patients. We found that grading had no prognostic value. Eighteen patients were treated by intralesional curettage and 13 by wide excision. Ten patients (56%), who were all treated by curettage, had local recurrences, but none of the tumours with wide excision recurred (p < 0.05). Five (16%) had local recurrences as well as distant metastases, usually to the lungs. The recurrences developed later than an average of 12 years after primary treatment in 3 patients. Wide excision and life-long follow up should be considered in the management of these tumours.

Adolescent↗
PubMed1996

MR imaging before arthroscopy in knee joint disorders?

PURPOSE: To review the current literature examining the relative merits of arthroscopy and MR imaging of the knee. MATERIAL AND METHODS: All papers comparing MR imaging with arthroscopy published within the last 10 years according to Medline were collected and read. RESULTS: Technology has improved considerably during recent years allowing detailed non-invasive visualization of the knee. In particular, the development of cheaper whole-body and dedicated low-field MR units has opened up for non-invasive inspection of the knee at reasonable cost. Meniscal tears can be detected with accuracy rates of around 90% and rupture of the anterior cruciate ligament with accuracy rates of around 93% compared to arthroscopy. However, arthroscopy is not the ideal gold standard, since it has weak points, e.g. peripheral meniscal tears or osteochondritis without apparent damage to the cartilage. CONCLUSION: Based on the overwhelming literature it seems safe to conclude that MR examinations of the knee should be performed before arthroscopy is undertaken.

Arthroscopy↗
PubMed1995

[Pyomyositis].

A 49 year old man with a palpable femoral tumor was examined by ultrasonography, CT and MRI within five days. Ultrasonography and CT indicated a solid malignant tumor, whereas MRI showed high signal intensity throughout the medial vastus muscle on T2-weighted images and centrally localized areas with low signal intensity on T1-weighted images indicative of pyomyositis. This diagnosis was immediately confirmed at surgery. Prompt diagnosis of pyomyositis is of utmost importance since it can rapidly develop into a life-threatening condition. The present case demonstrates the superiority of MRI in this clinical entity, whereas ultrasonography and CT may be misleading in the early stage.

Diagnosis, Differential↗
PubMed1995

Microvascular obstruction in avascular necrosis. Immunohistochemistry of 14 femoral heads.

14 femoral heads with late stage avascular necrosis of different etiologies were histologically examined, with special attention to vascular structures. Decalcified slices were stained with hematoxylin-eosin, safranin-O, van Gieson stain, and Martius Scarlet Blue. Immunohistochemical techniques with antibodies against Factor VIII, and Ulex Europeus Lectin were used to visualize the endothelium of the blood vessels. 5 distinct zones of the necrotic femoral head could be identified. The necrotic zone contained areas with richly vascularized connective tissue. In the transitional zone, several areas with intravascular aggregations of newly formed and older fibrin clots were noticed, mainly on the venous side of the vascular system. Other small vessels were collapsed, with a few endothelial cells clumped together in the center of a concentric fibrous tissue. We suggest that obstruction to the venous outflow due to intravascular thrombosis as well as to perivascular fibrosis is important in the pathogenesis of non-traumatic avascular necrosis of the femoral head.

Adult↗
PubMed1993

[Bone scintigraphy in assessment of risk of complications after medial femoral neck fractures].

The value of visually evaluated bone scintigraphy in predicting postoperative non-union and avascular necrosis was examined in a prospective, consecutive series of patients with intracapsular fracture of the femoral neck. 49 patients had scintigraphy carried out preoperatively, and 37 postoperatively. In 18 scintigraphy was done preoperatively as well as postoperatively. The patients were followed clinically and radiographically for at least two years after operation. In the preoperative group 19 patients had been excluded at follow up and 13 patients in the postoperative group. The results indicate a high correlation between a reduced uptake of isotope in preoperative scintigraphy and development of late complications in these patients. It is concluded that visually evaluated preoperative planar scintigraphy is of value in selecting those patients with intracapsular femoral neck fractures, who are at risk of developing late complications.

Aged↗
PubMed1993

The relationship between inert gas wash-out and radioactive tracer microspheres in measurement of bone blood flow: effect of decreased arterial supply and venous congestion on bone blood flow in an animal model.

Several methods have been employed in the study of bone perfusion. We used a method of determining inert gas wash-out by mass spectrometry in the study of blood flow rates in pigs. The method was validated by comparison of the result obtained with inert gas wash-out to that with measurement by microspheres. Furthermore, the effect of decreased inlet flow and venous congestion on the bone perfusion data was tested. The undisturbed bone blood flow was not significantly different when measured with wash-out of inert gas (7 +/- 0.7 ml/min/100 g) or with microspheres (9 +/- 2.9 ml/min/100 g), and the methods were correlated. Perfusion was reduced significantly, to 20% of the original value, after arterial occlusion. The changes in wash-out curves and accumulation of radioactive tracer provided substantial evidence for impaired intraosseous circulation following venous obstruction also. In conclusion, the study showed that this method of determining inert gas wash-out is feasible for studies of local perfusion rates in bone. The flow rates obtained by wash-out correlated well with the results of microsphere studies. In this animal model, both methods detected a fivefold reduction in flow rate after clamping of the arterial inflow. Obstruction of the venous outflow also impaired blood flow and lowered the cellular supply.

Animals↗
PubMed1993

Laser Doppler flowmetry for estimation of bone blood flow: studies of reproducibility and correlation with microsphere technique.

The blood flow in the femoral condyles of six pigs was measured by the microsphere technique and by laser Doppler flowmetry (LDF) before and after clamping of the external iliac artery. A significant decrease in the bone blood flow was found with both microsphere and LDF measurements, and a high correlation was found between the two methods. After release of the arterial clamp, the LDF values rapidly returned to approximately the same values as before clamping. In a second part of the study, the LDF output signal was studied in the intertrochanteric area of eight patients. The reproducibility of two LDF measurements at the same location was within 15%. The temporal variability of the LDF signal during 10 min of recording showed only slight variations. It is concluded that LDF is relative in nature and that the mean LDF output signal is suitable for monitoring dynamic responses of the bone blood flow to various stimuli. Several consecutive measurements have to be performed if the blood flow at different locations of a specific bone are to be compared with each other.

Animals↗
PubMed1993

Metabolism of prednisone in kidney transplanted patients with necrosis of the femoral head.

Interindividual variation of the metabolism of prednisolone and of the susceptibility to glucocorticoids might be possible factors contributing to the development of osteonecrosis after renal allotransplantation. As this aspect has not been properly investigated previously, we compared, in the present study, the metabolism of total and free prednisolone in 6 renal allotransplanted patients who subsequently developed osteonecrosis of the femoral head and the metabolism of 6 matched controls, who did not develop osteonecrosis. There was no difference in age, bodyweight, total serum protein or albumin, or in liver or renal function. The baseline cortisol was 54 +/- 23 micrograms in patients with necrosis, and 102 +/- 53 micrograms/l in patients without necrosis (n.s.). Likewise there was no difference in the peak concentration of prednisolone (420 +/- 43 vs. 394 +/- 42 micrograms/l, n.s.), the bioavailability (0.57 +/- 0.09 vs. 0.61 +/- 0.05, n.s.) or in the apparent volume of distribution at steady state (Vdss, 0.37 +/- 0.09 vs. 0.37 +/- 0.04 l/kg, n.s.). The clearance of prednisolone in patients with osteonecrosis was 33% lower (0.79 +/- 0.11 vs. 1.18 +/- 0.13 ml/min./kg b.wt., P < 0.05) and t1/2 was correspondingly 33% longer (246 +/- 18 min. vs. 184 +/- 15 min., P < 0.05) than in patients without osteonecrosis. However, there was no difference in the apparent volume of distribution of free prednisolone (2.07 +/- 0.36 vs. 1.69 +/- 0.28 l/kg, n.s.), in the t1/2 (152 +/- 30 vs. 107 +/- 20 min., n.s.), or in the clearance (7.33 +/- 2.12 vs. 7.82 +/- 1.18 ml/min./kg) between the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMed1993

Blood perfusion uneven in femoral head osteonecrosis. Doppler flowmetry and intraosseous pressure in 12 cases.

We measured the microvascular regional perfusion in 12 hips with non-traumatic osteonecrosis of the femoral head, using laser Doppler flowmetry (LDF). Simultaneously, the intraosseous pressure (IOP) was measured in the femoral head. For comparison, the same 2 parameters were measured in 6 normal femoral heads during surgery of the contralateral hip. In osteonecrosis, the regional blood cell flux in the intertrochanteric area was 165 mV, at the rim of the lesion 430 mV, and in the necrotic lesion 35 mV. In the same areas, the IOP was 38 mmHg, 61 mmHg and 55 mmHg. In the normal hips, the LDF signal was 221 mV and 224 mV, and the IOP was 21 mmHg and 19 mmHg intertrochanterically and in the femoral head, respectively. We conclude that the microvascular blood perfusion is uneven in an osteonecrotic head.

Adult↗
PubMed1992

Prediction of late complications of femoral neck fractures by scintigraphy.

A prospective study was undertaken to determine the value of scintigraphy in predicting nonunion or necrosis of the femoral head following femoral neck fractures. Scintigraphy was carried out in 49 patients before operation and in 37 one week after operation; in 18 it was done before and after operation. The uptake of isotope was estimated visually as either normal or reduced compared to the opposite side. All the patients were followed up for at least 2 years. The results indicate that pre-operative bone scintigraphy is useful in elderly patients to predict nonunion and necrosis, and therefore is recommended to select those patients who will benefit from primary arthroplasty instead of fixation of the fracture.

Aged↗