Cardiac morbidity and the cause of death in elderly patients with prostate cancer and incidental cardiac uptake on bone scintigraphy

Cardiac transthyretin amyloidosis (ATTR) is a possible incidental finding on bone scintigraphy imaged due to prostate cancer. We investigated its significance in 1426 elderly prostate cancer patients (>70 years) who underwent bone scintigraphy in three nuclear medicine departments in Finland. Patients with Perugini grade two or three uptakes were considered positive for cardiac uptake. Heart failure diagnoses and pacemaker implantations were collected from the hospital's records. Mortality data were gathered from the Finnish national statistical service (Statistics Finland). The Median follow-up time was 4 years (interquartile range: 2-5 years). Cardiac uptake was detected in 37 individuals (2.6%), and it was associated with an elevated risk of both overall and cardiovascular death in univariable analysis. However, cardiac uptake did not predict overall mortality in the multivariable analysis when adjusted to age, bone metastases or the diagnosis of heart failure (p > 0.05). The risk of heart failure was higher in patients with cardiac uptake (47% vs. 15%, p < 0.001), while the risk of pacemaker implantations was not elevated (5% vs. 5%, p = 0.89). In conclusion, cardiac uptake on bone scintigraphy imaged due to prostate cancer is associated with an elevated risk of heart failure and both overall and cardiovascular death. However, cardiac uptake was not independently associated with overall mortality when adjusted to age, bone metastasis or heart failure. Therefore, they are essential to consider when incidental cardiac uptake is detected on bone scintigraphy. The need for pacemaker implantation was not elevated in patients with cardiac uptake.

Prognostic significance of incidental suspected transthyretin amyloidosis on routine bone scintigraphy

BACKGROUND

Transthyretin amyloidosis (ATTR) is an occasional incidental finding on bone scintigraphy. We studied its prognostic impact in elderly patients.

METHODS

The study population consisted of 2000 patients aged over 70 years who underwent bone scintigraphies with clinical indications in three nuclear medicine departments (Kymenlaakso, Jorvi and Meilahti hospitals) in Finland. All studies were performed using 99mTechnetium labeled hydroxymethylene diphosphonate (HMDP). ATTR was suspected in patients with ≥grade 2 Perugini grade uptake (grade 0-3). Heart-to-contralateral ratio (H/CL) of ≥ 1.30 was considered positive for ATTR. The overall and cardiovascular mortality were obtained from the Finnish National Statistical Service.

RESULTS

There were a total of 1014 deaths (51%) and 177 cardiovascular deaths (9%) during median follow-up of 4 ± 2 years. ATTR was suspected in 69 patients (3.6%) of which 54 (2.7%) had grade 2 and 15 (.8%) had grade 3 uptake and in 47 patients (2.4%) by H/CL ratio. In multivariate analyses age, bone metastasis, H/CL ratio and grade 3 uptake were independent predictors of overall and cardiovascular mortality. Grade 2 uptake was a predictor of cardiovascular mortality.

CONCLUSIONS

A suspected ATTR as an incidental finding on bone scintigraphy predicts elevated overall and cardiovascular mortality in elderly patients.

Convolutional neural networks for detection of transthyretin amyloidosis in 2D scintigraphy images

BACKGROUND

Transthyretin amyloidosis (ATTR) is a progressive disease which can be diagnosed non-invasively using bone avid [^99mTc]-labeled radiotracers. Thus, ATTR is also an occasional incidental finding on bone scintigraphy. In this study, we trained convolutional neural networks (CNN) to automatically detect and classify ATTR from scintigraphy images. The study population consisted of 1334 patients who underwent [^99mTc]-labeled hydroxymethylene diphosphonate (HMDP) scintigraphy and were visually graded using Perugini grades (grades 0-3). A total of 47 patients had visual grade ≥ 2 which was considered positive for ATTR. Two custom-made CNN architectures were trained to discriminate between the four Perugini grades of cardiac uptake. The classification performance was compared to four state-of-the-art CNN models.

RESULTS

Our CNN models performed better than, or equally well as, the state-of-the-art models in detection and classification of cardiac uptake. Both models achieved area under the curve (AUC) ≥ 0.85 in the four-class Perugini grade classification. Accuracy was good in detection of negative vs. positive ATTR patients (grade < 2 vs grade ≥ 2, AUC > 0.88) and high-grade cardiac uptake vs. other patients (grade < 3 vs. grade 3, AUC = 0.94). Maximum activation maps demonstrated that the automated deep learning models were focused on detecting the myocardium and not extracardiac features.

CONCLUSION

Automated convolutional neural networks can accurately detect and classify different grades of cardiac uptake on bone scintigraphy. The CNN models are focused on clinically relevant image features. Automated screening of bone scintigraphy images using CNN could improve the early diagnosis of ATTR.

Prognostic Value of 99mTc-HMDP Scintigraphy in Elderly Patients With Chronic Heart Failure

BACKGROUND

This study evaluated the prevalence and prognostic significance of cardiac transthyretin amyloidosis (ATTR) diagnosed using ^99mTc- hydroxymethylene-diphosphonate (^99mTc-HMDP) scintigraphy in an elderly heart failure population.

METHODS

This retrospective study included 335 patients aged >70 years with heart failure and who underwent ^99mTc-HMDP scintigraphy due to non-cardiac reasons in three imaging centres in Finland (Kymenlaakso Central Hospital, Jorvi Central Hospital, and Meilahti University Hospital). A Perugini grade >2 and heart-to-contralateral ratio (H/CL) of ≥1.30 were considered positive for cardiac ATTR. The overall and cardiovascular mortality were obtained from the national statistical service (Statistics Finland).

RESULTS

There were 234 deaths, of which 70 were classified as being due to cardiovascular causes during a median follow-up of 1 (1-3) year. Transthyretin amyloidosis was diagnosed in 22 patients (6.6%) using visual analysis and 17 patients using the H/CL ratio (5.1%). Patients with ATTR were older (85±5 vs 80±5 yrs; p=0.002) and had higher N-terminal pro-brain natriuretic peptide (NT-ProBNP) levels (1,451 [813-3,799] vs 6,192 [2,030-8,833] ng/L; p=0.02). Age, bone metastases, and glomerular filtration rate were independent predictors of overall mortality in multivariable analysis. Age, glomerular filtration rate, ≥grade 2 visual cardiac uptake, and H/CL ratio were independent predictors of cardiovascular mortality.

CONCLUSIONS

Cardiac uptake suggestive of ATTR was found in 5% of elderly patients with chronic heart failure. The presence of cardiac uptake on bone scintigraphy did not convey independent prognostic value on overall mortality but was independently associated with cardiovascular mortality.

Prognostic value of 99mTc-HMDP scintigraphy in elderly patients with chronic heart failure

Background

Bone scintigraphy is an accurate modality for diagnosis of transthyretin amyloidosis (ATTR).

Purpose

We evaluated the prevalence and prognostic significance of cardiac ATTR in elderly heart failure population.

Methods

Our retrospective study included 335 patients aged over 70 years with diagnosed heart failure who underwent 99mTc-hydroxymethylenediphosphonate (99mTc-HMDP) scintigraphy due to non-cardiac indications. A Perugini grade &gt;2 and heart-to-contralateral ratio (H/CL) of &gt;1.30 was considered positive for ATTR.

Results

There were a total of 234 deaths of which 70 were classified as cardiovascular during a median follow-up of 3±2 years. ATTR was diagnosed in 17 patients using H/CL ratio (5.1%). Patients with ATTR were older (85±5 vs. 80±5 years, p=0.002) and had higher N-terminal pro-brain natriuretic peptide (Nt-ProBNP) levels (6692±5694 vs. 3285±5233 ng/l, p=0.02). Age, presence of bone metastasis and GFR were independent predictors of overall mortality. Age, GFR, ≥grade 2 visual cardiac uptake and H/CL ratio were independent predictors of cardiovascular mortality.

Conclusions

ATTR was found in 5% of elderly patients with heart failure. The presence of cardiac uptake on bone scintigraphy did not convey independent prognostic value on overall mortality but was associated with cardiovascular mortality.

Funding Acknowledgement

Type of funding sources: None.

Is the weekend effect true in acute stroke patients at tertiary stroke center?

BACKGROUND

There is contradicting evidence on the outcome of emergency patients treated during weekends versus weekdays. We studied if outcome of ischemic stroke patients receiving intravenous thrombolysis (IVT) differs according to the treatment time.

METHODS

Our retrospective study included consecutive patients receiving IVT within 4.5 h of stroke onset between June 1995 and December 2018 at the Helsinki University Hospital. The patients were compared based on the treatment initiation either during weekdays (Monday to Friday) or weekend (Saturday and Sunday). The primary outcome was 3-month mortality and secondary outcomes comprised 3-month modified Rankin Scale (mRS) and incidence of symptomatic intracerebral hemorrhage (sICH). Additional analyses studied the effect of IVT treatment according to non-office hours, time of day, and season.

RESULTS

Of the 3980 IVT-treated patients, 28.0% received treatment during weekends. Mortality was similar after weekend (10.0%) and weekday (10.6%) admissions in the multivariable regression analysis (OR 0.78; 95% CI 0.59-1.03). Neither 3-month mRS (OR 0.98; 95% CI 0.86-1.12), nor the occurrence of sICH (4.2% vs 4.6%; OR 0.87; 95% CI 0.60-1.26) differed between the groups. No outcome difference was observed between the office vs non-office hours or by the time of day. However, odds for worse outcome were higher during autumn (OR 1.19; 95% CI 1.04-1.35) and winter (OR 1.15; 95% CI 1.01-1.30).

CONCLUSION

We did not discover any weekend effect for IVT-treated stroke patients. This confirms that with standardized procedures, an equal quality of care can be provided to patients requiring urgent treatment irrespective of time.

Screening for postoperative pulmonary embolism on the basis of clinical symptomatology, routine electrocardiography and plain chest radiography

The incidence of pulmonary embolism (PE) and the usefulness of various screening methods for its detection were studied in 108 patients undergoing elective hip surgery. Twenty patients had PE as shown by perfusion-ventilation lung scintigraphy. Six of them had symptoms of embolism. Clinical symptoms of PE, highly suggestive electrocardiographic (ECG) signs and signs in chest radiographs showed high specificity but low sensitivity with regard to PE. If the non-specific ECG signs and the symptoms and signs of deep vein thrombosis in the calves had also been taken into account, it would have been possible to identify 95% of the patients with PE. The use of all these screening tests revealed a suspicion of PE in two thirds of the patients. The simplest way to screen for postoperative PE seems to be to use a combination of the symptoms and signs of both PE and deep vein thrombosis, and to identify any tachycardia. This method gave a sensitivity of 85%.

Weight changes and the risk of knee osteoarthritis requiring arthroplasty

OBJECTIVE

To examine the effect of weight changes between 20 and 50 years of age on the risk of severe knee osteoarthritis (OA) requiring arthroplasty.

SUBJECTS AND METHODS

Cases were 55-75 year old men and women (n = 220) having had knee arthroplasty for primary osteoarthritis at the Kuopio University Hospital in 1992-93. Controls (n = 415) were randomly selected from the population of Kuopio Province. Weight at the age of 20, 30, 40, and 50 years was collected retrospectively with a postal questionnaire.

RESULTS

After adjustment for age, sex, history of physical workload, recreational physical activity, and previous knee injury, weight gain resulting to a shift from normal body mass index (BMI < or =25 kg/m(2)) to overweight (BMI >25 kg/m(2)) was associated with a higher relative risk of knee OA requiring arthroplasty than persistent overweight from 20-50 years of age, compared with those with normal relative weight during the corresponding age period. The odds ratios (OR) were 3.07 (95% confidence interval 1.87 to 5.05) for those with normal weight at the age of 20 years and overweight at two or three of the ages 30, 40 or 50 years, 3.15 (1.85 to 5.36) for those with overweight from the age of 30 years, and 2.37 (1.21 to 4.62) for those with overweight from the age of 20 years, respectively.

CONCLUSION

In adult life, a shift from normal to overweight may carry a higher risk for knee OA requiring arthroplasty than does constant overweight.

Bone mineral density after the removal of intramedullary nails: a cross-sectional and longitudinal study

We measured bone mineral density (BMD) using dual X-ray absorptiometry (DXA) at several sites in both fractured and nonfractured limbs in eight patients with femoral shaft fracture and six with tibial shaft fracture at the time of the intramedullary (IM) nail removal. Seven patients were followed up for an average of 13 months. The BMD at the proximal part of the femur and tibia was from 3% to 11% lower in the fractured side as compared to the nonfractured side. The greatest bone loss (13%-21%) was found in the operated distal tibia of the patients with tibial shaft fractures. At the fracture site of the femur, BMD was 10.5% ( P < 0.05) higher, possibly owing to fracture callus formation, whereas tibial shaft BMD was not increased. However, a calculated apparent volumetric BMDvol at the fracture site was 15%-16% decreased. Although BMDs of the fractured side almost reached the baseline level of the nonfractured side (96.9%-102.1%) by the final follow-up (>12 months), the absolute deficit was still 3%-9%. Surprisingly, significant BMD increases (5%-6%) were also detected in all proximal femoral measurement sites of the contralateral limb, which indirectly suggests that the uninjured limb may also suffer from bone loss after lower-extremity trauma. We conclude that clinically important bone loss exists in the proximal femur and proximal and distal tibia of the fractured limb at the time of IM nail removal. Although areal BMD was higher at the femoral fracture site, the lower apparent volumetric BMDvol suggests decreased mineralization and reduced strength of the fracture site. Although the present results do not suggest special recommendations for restricted weight bearing after the removal of IM nails, the relationship between decreased bone density and increased risk of fractures should be borne in mind.

Percutaneous bone grafting in the treatment of the delayed union and non-union of tibial fractures

The classic method of open bone grafting in the treatment of un-united tibial fractures has been associated with some complications. A novel, minimally invasive, percutaneous technique of bone grafting is described. Forty-one consecutive patients with delayed union or non-union of a tibial fracture was treated with percutaneous bone grafting from 1993 to 1999. The mean age of the patients was 41 (15-86) years. Twenty-seven patients had grade I-III open fractures. The fractures had initially been treated in a cast (n=26), external fixator (n=14) or intramedullary nail (n=1). Two patients had an earlier unsuccessful Phemister-Charnley-type bone-grafting procedure for delayed union. The mean interval from injury to percutaneous bone grafting was 21 (13-66) weeks. Thirty-seven of the 41 un-united fractures healed in 13 (10-48) weeks after the percutaneous bone grafting. The mean hospital stay was 1 day. No infections, bleeding or neural complications existed. Percutaneous bone grafting appeared to be as effective as open techniques, and possessed considerable advantages. It is safe, time saving and economical, it involves minimal trauma at the fracture site and it avoids major donor site problems.

Physical exercise and risk of severe knee osteoarthritis requiring arthroplasty

OBJECTIVES

To examine the association between physical exercise and the risk of severe knee osteoarthritis requiring arthroplasty.

SUBJECTS AND METHODS

A case-control study was carried out in which the cases were men (n=55) and women aged 55-75 yr (n=226) receiving knee arthroplasty for primary osteoarthritis at the Kuopio University Hospital. Controls (n=524) were selected randomly from the population of Kuopio province. Lifetime physical exercise was assessed retrospectively. Cumulative exercise hours were calculated and divided into two classes by mean (low/high).

RESULTS

The risk of knee osteoarthritis requiring arthroplasty decreased with increasing cumulative hours of recreational physical exercise. After adjustment for age, body mass index, physical work stress, knee injury and smoking, the odds ratios (with 95% confidence intervals) of knee arthroplasty were 0.91 (0.31-2.63) in men with a low number of cumulative exercise hours and 0.35 (0.12-0.95) in those with a high number of cumulative exercise hours, with a history of no regular physical exercise as the reference. For the women, the corresponding odds ratios were 0.56 (0.3-0.93) and 0.56 (0.32-0.98).

CONCLUSION

Moderate recreational physical exercise is associated with a decrease in the risk of knee osteoarthritis.

Bone loss around failed femoral implant measured by dual-energy X-ray absorptiometry

Periprosthetic bone mineral density (BMD) and its changes after primary total hip arthroplasty (THA) have been studied extensively, but quantitative data on BMD around loosened prostheses are still lacking. In this study, using dual-energy X-ray absorptiometry (DXA), we determined periprosthetic BMD in 19 patients with failed primary THA. There was a decrease in BMD (8. 8%-25.5%) in every Gruen zone as compared with the patient's non-operated (control) side. Although the bone loss was most significant in the proximal femur, as in primary THA, the pattern of bone loss around the failed THA differred from the typical remodeling seen after successful THA. We suggest that quantitation of bone mass around the failed femoral stem is possible. Remarkable generalized bone loss around the stem is associated with a loosened prosthesis.

Measurement of bone density around total knee arthroplasty using fan-beam dual energy X-ray absorptiometry

The clinical survival of joint arthroplasties is clearly associated with the quality of surrounding bone environment. Bone mineral density (BMD) is an important measure of bone strength and quality. Periprosthetic BMD can be measured by using dual-energy X-ray absorptiometry (DXA) with special software algorithms. We studied short-term reproducibility of the periprosthetic BMD measurements after total knee arthroplasty (TKA) in 30 patients with primary osteoarthrosis. The operated knees and the contralateral control knees were measured twice and the results were expressed as a coefficient of variation (CV%). The average precision error was 3.1% in femoral regions of interest (ROI) and 2.9% in tibial ROIs after TKA. In the prosthesis-free control knees, CV% were similar; 3.2% and 2.5%, respectively. The best precision was found in the femoral diaphyses above the implant (1.3%), whereas the least reproducible BMD was determined in the patellar region of the TKA knees (6.9%). Our results confirm that DXA measures precisely small bone mineral changes around TKA and makes it possible to follow bone remodeling DXA and may provide a feasible method for monitoring TKA in the future.

Computed tomography findings 4 years after surgical management of lumbar spinal stenosis. No correlation with clinical outcome

STUDY DESIGN

A prospective, cross-sectional study of the correlation between postoperative computed tomography findings and patients' clinical outcomes approximately 4 years after laminectomy for lumbar spinal stenosis.

OBJECTIVES

To evaluate clinical and radiologic characteristics and their relation to each other.

SUMMARY OF BACKGROUND DATA

The goal of surgical management for lumbar spinal stenosis is to decompress the stenotic area determined in radiologic examinations to relieve pressure on the neurovascular structures. However, the success of this decompression very rarely has been confirmed by postoperative radiologic imaging or compared with clinical outcome.

METHODS

Postoperative computed tomography was performed on 191 patients. The findings were classified as "no stenosis," "central stenosis," "lateral stenosis," or "central-lateral stenosis." Postoperative instability of the lumbar spine was investigated by functional radiography. Clinical status was assessed by clinical examination. Subjective disability was assessing using the Oswestry questionnaire, and severity of pain using the visual analog scale. Walking capacity was evaluated by the tread-mill test.

RESULTS

Radiologic studies revealed postoperative stenosis in 123 patients (64%). Small differences between the computed tomography groups were shown for the Oswestry score, but not for walking distance. Clinical signs, severity of pain, and radiologic instability were very similar for all computed tomography groups.

CONCLUSIONS

Postoperative radiologic stenosis was very common in patients operated on for lumbar spinal stenosis, but this did not correlate with clinical outcome. The clinician must be cautious when reconciling clinical symptoms and signs with postoperative computed tomography findings in patients operated on for lumbar spinal stenosis.

Long-term clinical and magnetic resonance imaging follow-up assessment of patients with lumbar spinal stenosis after laminectomy

STUDY DESIGN

A cross-sectional retrospective study to observe the correlation between postoperation findings shown on magnetic resonance imaging and clinical observations of 56 patients 10 years after laminectomy for lumbar spinal stenosis.

OBJECTIVE

To evaluate the relation between postoperation findings on magnetic resonance imaging and surgical outcome in patients surgically treated for lumbar spinal stenosis.

SUMMARY OF BACKGROUND DATA

Surgical management of lumbar spinal stenosis is based on the compression seen in radiologic imaging of neurovascular structures in the vertebral canal, but the success of surgical decompression and its correlation with clinical observations very seldom have been monitored by postoperation radiologic imaging.

METHODS

In this study, 56 patients surgically treated for lumbar spinal stenosis were re-examined clinically by use of the Oswestry disability questionnaire. Their walking capacity was evaluated by the treadmill test. Severity of pain before and after the treadmill test was investigated using a visual analog scale. Patients' perception of improvement measured as the change in their condition during the preceding 5 years was elicited by a questionnaire. On the basis of the stenotic findings on magnetic resonance imaging, the patients were classified into no stenosis (NoSten, n = 15) and stenosis (Sten, n = 41) groups, and a summative degenerative scale also was constructed with the findings categorized as follows: disc degeneration, disc herniation, facet joint arthrosis, and degenerative spondylolisthesis.

RESULTS

Whereas the patients' perception of improvement correlated very strongly with the Oswestry score and walking capacity, there was no statistical difference between the NoSten and Sten groups in the Oswestry score, walking capacity, perception of improvement, or severity of pain. The effect of the summative degenerative scale on the patients' walking capacity was 13 times greater than the effect of the minimum area of the dural sac.

CONCLUSIONS

Patients' perception of improvement had a much stronger correlation with long-term surgical outcome than structural findings seen on postoperation magnetic resonance imaging. Moreover, degenerative findings had a greater effect on patients' walking capacity than stenotic findings.

The degree of decompressive relief and its relation to clinical outcome in patients undergoing surgery for lumbar spinal stenosis

STUDY DESIGN

A cross-sectional, clinical study to evaluate surgical decompression of the stenotic area monitored by computed tomographic scan and its relation to clinical variables in patients operated on for lumbar spinal stenosis.

OBJECTIVE

To study in patients with lumbar spinal stenosis the influence of the degree of compressive relief on the patients' clinical outcome.

SUMMARY OF BACKGROUND DATA

The goal of surgical treatment in lumbar spinal stenosis is to decompress the stenotic area. Although the decompression should be adequate, there are no clear guidelines to determine the extent of necessary decompression. In fact, there is clinical evidence that there is a discrepancy between the surgical outcome in the patient with lumbar spinal stenosis and postoperative radiologic findings.

METHODS

In 92 patients with lumbar spinal stenosis who had had no prior back surgery, preoperative and postoperative computed tomographic scans were obtained to determine the degree of decompression. The postoperative scan findings were classified according to the degree of decompression into a no-stenosis group (n = 35), an adjacent-stenosis group (n = 27), and a residual-stenosis group (n = 30). The postoperative instability of the lumbar spine was investigated by functional radiography. The subjective disability of the patients was assessed using the Oswestry score and the severity of pain using the visual analog scale. Walking capacity was evaluated by a treadmill test. The patients' estimations of the results of surgery were classified into groups of satisfied patients and dissatisfied patients.

RESULTS

The mean Oswestry score in all 92 patients was 27.1, and mean walking capacity was 630 m. In the satisfied patients, the Oswestry score was 18.8 and in the dissatisfied patients, 34.9 (P < 0.0000). Walking capacity was 690 m and 594 m, respectively. There were 30 patients with postoperative spinal instability, but it had no influence on surgical outcome. There were no differences in the Oswestry score, walking capacity, and patients' satisfaction among the postoperative CT groups. In the linear regression analysis, the satisfied patient corresponded significantly with the Oswestry score.

CONCLUSIONS

The satisfaction of the patients with the results of surgery was more important in surgical outcome than the degree of decompression detected on computed tomographic scan.

Bone density at the proximal femur after total hip arthroplasty

Recent developments in dual xray absorptiometry have made it possible to quantify bone mineral density changes adjacent to total hip arthroplasty. Even small changes in local bone mass that are not visible with conventional radiographs can be detected using dual xray absorptiometry. Commonly there is a loss of 10% to 45% of the periprosthetic bone mass during the first years after total hip arthroplasty. Recent studies have suggested that this bone loss is not necessarily progressive and some degree of restoration of bone density around implants may occur. Current data suggest that there is active bone remodeling in the proximal femur in response to prosthetic implantation. Such response differs between different stem designs and type of fixation.

Periprosthetic bone loss and regional bone turnover in uncemented total hip arthroplasty: a prospective study using high resolution single photon emission tomography and dual-energy X-ray absorptiometry

Single photon emission computed tomography (SPECT) at 6 and 12 months and dual-energy X-ray absorptiometry (DXA) at 0, 6, and 12 months were performed prospectively in 15 patients who had undergone uncemented total hip arthroplasty (THA) without any complications. Periprosthetic bone mineral density (BMD) decreased significantly in all regions of interests (ROIs) during 1 year of follow-up. The greatest annual decrease was found in the lesser trochanter region (22.1%). From 6-12 months, SPECT activity in the operated side decreased significantly (10-24%) in all ROIs, with the exception of the medial cortex ROI. In contrast, increases (8-36%) were found in the contralateral side. At 12 months, the operated versus control difference was still 10% in the lesser trochanter ROI, but as much as about 70% in the greater trochanter and tip ROIs. The decrease in BMD was significantly related to an increase in SPECT activity in the lesser trochanter region (r = -0.589, p < 0.05). In conclusion, increased periprosthetic SPECT activity seems to be associated with increased bone loss. We suggest that increased SPECT activity and subsequent bone loss reflect altered stress distribution and bone remodeling in the femur after prosthesis implantation.

Evaluation of periprosthetic bone using dual-energy x-ray absorptiometry: precision of the method and effect of operation on bone mineral density

To assess the perioperative bone loss of femur during total hip arthroplasty (THA), periprosthetic bone mineral density (BMD) of the seven regions of interests (Gruen zones) was determined with dual-energy x-ray absorptiometry (DXA) preoperatively in both proximal femurs and postoperatively in the involved side in 53 patients with degenerative hip osteoarthrosis. The mean (standard deviation, SD) precision error (coefficient of variation percent, CV%) in various regions of interest (ROIs) based on two consecutive measurements (n = 16) were 2.3 (0.8)%, 2.5 (1.5)%, and 2.8 (1.6)% for uncemented stems, cemented stems, and control sides, respectively. Furthermore, the mean variability caused by the rotation of femur was 3.5 (1.4)%. The most significant perioperative bone loss (13.5-19.2%) was found in the calcar area (zone 7) after noncemented THA. Zone 4, representing the bone below the prosthesis, also showed BMD decreases. These decreases suggest perioperative bone loss owing to rasping and reaming the calcar and bone canal. However, after cemented THA, highly significant BMD increases were found in all the lateral zones. The calcar area was the only site where significant perioperative bone loss was detected (12.8%). In conclusion, DXA is a precise method for quantifying bone mass and density changes in the follow-up of THA. However, when interpreting the results, the preoperative BMD, differences between the femurs and the effect of operation on bone mass should be taken into account. We suggest that the best reference for BMD follow-up is the periprosthetic BMD of the involved side measured soon after the THA.

Intra-articular hyaluronan injections in the treatment of osteoarthritis of the knee: a randomised, double blind, placebo controlled multicentre trial. Hyaluronan Multicentre Trial Group

OBJECTIVE

To assess the effects of intra-articular injections of hyaluronan on symptoms of knee osteoarthritis (OA).

METHODS

Two hundred and forty patients with symptomatic, radiological knee OA were randomly assigned to treatment with weekly injections for five weeks with either 25 mg of high molecular weight hyaluronan or vehicle. Results were evaluated at weeks 1, 2, 3, 4, 5, 13, and 20 by visual analogue scales (pain, function, motion, activity), algofunctional index, and global evaluation by patient and investigator. Analysis was by "intention to treat', "per protocol', and area under the curve principles on unstratified patient groups and for patients stratified into four groups of equal size by age and baseline algofunctional index.

RESULTS

No serious side effects were reported. At 20 weeks both treatment groups were improved compared with baseline, with no difference between unstratified groups treated with placebo or hyaluronan. Comparison of treatment groups stratified by age and baseline algofunctional index revealed a significant difference in favour of hyaluronan over placebo (pain, activity, algofunctional index, global evaluations by patient and investigator) for patients older than 60 years and with a baseline algofunctional index greater than 10. There was no clinically relevant difference between the two treatments for the other three stratified subgroups of younger age or fewer symptoms. Similar results were obtained by area under the curve, intention to treat, and per protocol analysis.

CONCLUSIONS

Patients older than 60 years with knee osteoarthritis and with significant symptoms corresponding to an index of severity of knee disease of 10 or more, comprise the group most likely to benefit from treatment with intra-articular hyaluronan injections.

Density of lumbar muscles 4 years after decompressive spinal surgery

Results of decompressive surgery for lumbar spinal stenosis vary. We evaluated the density of lumbar muscles by computed tomography (CT) at the L2-L4 levels in patients 4 years after they had undergone surgery for lumbar spinal stenosis. Twenty of these patients had an excellent outcome clinically, and 16 patients had very poor outcome. The residual stenosis and density of lumbar muscles in Hounsfield units were measured on CT images. The clinical evaluation of outcome also included the Oswestry questionnaire and a walking test. The density of lumbar flexors was higher in the group with excellent results than in the group with poor results. The density of lumbar extensors showed a marked decrease in the operated area. These results suggest that the decrease of muscular density can be partially explained by disuse or inactivity. The decrease in the operated area probably reflects muscular atrophy caused by muscle denervation.

Prevention of fatal pulmonary embolism with warfarin after total hip replacement

We studied retrospectively the efficacy of low-dose warfarin for the prevention of fatal pulmonary embolism in 1140 patients (1280 hips) undergoing total hip replacement between 1972 and 1989. The first dose, 10-20 mg, was given the night before operation and the regime was continued for 2 weeks after the procedure. Anticoagulation was aimed at achieving a therapeutic level in 4 to 5 days. All the patients were followed for 3 months. Seven died during this period and autopsy showed that 2 (0.16%) died from pulmonary embolism, one at 3 days and the other 10 days after operation. Pulmonary embolism causing symptoms, but which was not fatal, occurred in 32 patients (2.5%). Symptomatic deep vein thrombosis was present in 45 patients (3.5%). There were 14 (1.1%) massive postoperative haematoma, and 7 needed operative treatment. Low-dose warfarin can be recommended as a safe and efficient method of achieving an acceptably low incidence of postoperative thrombo-embolic complications after total hip replacement.

Prophylaxis for the prevention of venous thromboembolism after total knee arthroplasty. A comparison between unfractionated and low-molecular-weight heparin

We compared the efficacy and safety of low-molecular-weight heparin with that of low-dose unfractionated heparin in the prevention of venous thromboembolism after total knee arthroplasty in a prospective, randomized, multicenter trial. One hundred and eighty-five patients were randomly assigned to two groups: ninety-two received low-molecular-weight heparin (forty milligrams of enoxaparin the evening before the operation and once a day subsequently) and ninety-three received unfractionated heparin (5000 international units the evening before the operation and three times a day thereafter). The prophylaxis was continued until bilateral ascending venography was performed six to nine days after the operation or, if venography was not done, until the eighth postoperative day. Venography revealed a prevalence of deep-vein thrombosis of 27 per cent (twenty-five of ninety-three patients) in the group that received unfractionated heparin and 23 per cent (twenty-one of ninety-two patients) in the group that received low-molecular-weight heparin. The difference was not significant (p = 0.6). Five patients (5 per cent) who received unfractionated heparin and 3 patients (3 per cent) who received low-molecular-weight heparin had a deep-vein thrombosis in the proximal veins. Two patients who received unfractionated heparin and one who received low-molecular-weight heparin had clinical symptoms suggestive of a pulmonary embolism. None of these three patients had a positive ventilation-perfusion scan. There were no deaths, major bleeding episodes, or wound hematomas necessitating operative intervention or discontinuation of the anticoagulation in the series.(ABSTRACT TRUNCATED AT 250 WORDS)

Asymptomatic deep venous thrombosis in the calf: accuracy and limitations of ultrasonography as a screening test after total knee arthroplasty

Patients who have recently undergone total knee arthroplasty are at high risk of developing deep venous thrombosis (DVT) in the calf. The clinical diagnosis of DVT is difficult in these patients owing to recent operation. A combination of compression ultrasonography (US) and colour flow imaging was used as a screening method of asymptomatic DVT in 51 patients who had undergone total knee replacement surgery. Both limbs were examined by US from the common femoral vein to the ankle approximately 7 days after operation and the results were compared with bilateral venography. 12 patients (24%) developed infrapopliteal DVT on the operated side, in two cases the thrombosis extended to the lower part of popliteal vein. One patient had bilateral thrombosis. US showed sensitivity of 77%, specificity of 96% and overall accuracy of 93%. US seems to be a useful screening method for DVT after knee replacement operation.

Does the anesthetic method influence the postoperative breathing pattern and gas exchange in hip surgery? A comparison between general and spinal anesthesia

We studied the effects of elective hip surgery, performed under either spinal (SA, n = 10) or general anesthesia (GA, n = 10), on breathing pattern and gas exchange. Measurements were made with respiratory inductive plethysmograph and indirect calorimetry in two positions before and after surgery. The method of anesthesia had no effect on the severity of postoperative hypoxemia. Reduced arterial oxygenation (PaO2; P less than 0.001, SA from 12.5 +/- 2.37 kPa to 10.5 +/- 1.38 kPa, GA from 12.5 +/- 2.95 kPa to 10.5 +/- 1.75 kPa) despite increased alveolar ventilation (P less than 0.01; from 2.30 +/- 0.37 l/min to 2.39 +/- 0.43 l/min in SA, 2.27 +/- 0.56 l/min to 2.57 +/- 0.35 l/min in GA) and reduced arterial carbon dioxide partial pressure (PaCO2; SA from 5.20 +/- 0.22 kPa to 4.95 +/- 0.33 kPa, P less than 0.01, GA from 5.07 +/- 0.36 kPa to 4.72 +/- 0.41 kPa, P less than 0.05) indicated maldistribution of ventilation and perfusion. Changes in breathing pattern and gas exchange and differences between the groups were minimal. Minute ventilation, tidal volume and mean inspiratory flow remained unchanged in both groups. The contribution of rib cage to tidal volume increased postoperatively in the supine position (P less than 0.001; SA from 32.6% +/- 10.3 to 46.3% +/- 7.5, GA from 36.5 +/- 16.4 to 48.5% +/- 15.4). CO2 production, oxygen consumption and energy expenditure remained unchanged. The postoperative changes in breathing pattern are related to the operation, not to the type of anesthesia and do not explain the alterations in gas exchange.

Thromboprophylaxis in patients with hip fractures: a prospective, randomized, comparative study between Org 10172 and dextran 70

A prospective, randomized, assessor-blind trial has been undertaken to compare the thromboprophylactic effect and safety of the heparinoid Org 10172 (a mixture of low molecular-weight sulfated glycosaminoglycuronides) and dextran 70 in patients operated on for hip fracture. Prestudy biostatistical calculations led to the need for 260 patients. Three hundred eight patients were randomized and 19 were excluded after randomization, the majority because of postponed surgery. Analyses were made on the 289 patients on an intention-to-treat basis, as well as on the 247 patients given correct prophylaxis. Diagnosis of deep vein thrombosis was based on bilateral ascending phlebography on postoperative days 10 through 12. The frequency of deep vein thrombosis on an intention-to-treat basis was 10% in the Org 10172 group and 30% in the dextran 70 group and, on the basis of correct prophylaxis, 12% and 31%, respectively, both differences being significant (p less than 0.001). Two-month mortality rates were equal in the groups. Three fatal pulmonary emboli were seen in the dextran group. Significantly more patients in the dextran group received postoperative transfusions; no other differences in various hemorrhagic parameters were seen. Thus it can be concluded that Org 10172 has a significantly better thromboprophylactic effect than does dextran in patients with hip fractures without significant side effects.

The use of fibrinogen uptake test in screening for deep vein thrombosis in patients with hip fracture

255 hip fracture patients were studied by 125I-fibrinogen uptake test and bilateral phlebography. We found the sensitivity of fibrinogen scanning to be 44% for the non-operated limb and 50% for the calves. The predictive value of a negative result was found to be 92% and 93% respectively. We conclude that the use of fibrinogen uptake test as single diagnosticum is not valid and can only be recommended in combination with phlebography when studying patient where the frequency of DVT is expected to be low.

Fracture dislocation of the lumbar spine without paraplegia. A case report

A 17-year-old boy sustained a complete fracture-dislocation of the lumbar spine. Immediately after the injury there was motor paralysis of the lower limbs; 17 hours post-injury, operative reduction and fixation were carried out. Nearly full neurological recovery was obtained.