Transcutaneous reduction and external fixation of displaced fractures of the proximal humerus. A controlled clinical trial

A consecutive series of 31 displaced fractures of the proximal humerus were randomly selected for treatment either by closed manipulation or by transcutaneous reduction and external fixation. Follow-up assessed the quality of reduction and healing as well as the functional outcome. The external fixation method gave better reduction, safer healing and superior function.     

Local blood flow, pressure and resistance measured with a strain gauge plethysmograph in limbs with constricting burns before and following treatment with incisional decompression

The effect of decompression incisions on the local blood flow, pressure and resistance was examined with a strain gauge plethysmograph and venous occlusion in 7 patients. The measurements were performed immediately before and following incisional decompression. The treatment was instituted on well accepted clinical indications, and the results of the measurements were not available for the surgeons before the project was completed.

The strain gauge plethysmograph was found helpful as a supplement to the clinical evaluation of the indications for incisional decompression. In 24 of the 28 burned fingers or legs of the 7 patients, the blood flow was insufficient or low before incisional decompression, but rose significantly following the treatment, supporting its causal effect. The remaining 4—all burned fingers from 3 different patients—had a high blood flow initially and would probably not have been incised if the results had been available at that time. The surgeons considered all fingers on the same hand to be burned to the same degree. An estimate of the local vascular resistance in 19 limbs confirmed the conclusion based on the blood flows. The data obtained also confirmed the generally accepted hypothesis of the pathogenesis of hypoxic fibrosis and necrosis in constricting limb burns.     

Bone marrow circulation after osteotomy. Blood flow, pO2, pCO2, and pressure studied in dogs

We investigated the immediate effect of osteotomy of the femoral shaft in adult dogs on intramedullary pO2, pCO2, relative bone blood flow (RBF) and intraosseous pressure (IOP). Single osteotomy resulted in a pO2 decrease from 49 mm Hg to 30 mm Hg. Double osteotomy further reduced pO2 to 21 mm Hg. Following double osteotomy, pCO2 increased from 42 mm Hg to 55 mm Hg. IOP was decreased by single osteotomy from 29 mm Hg to 15 mm Hg, and to 4 mm Hg by the second osteotomy. Linear regression analysis showed a negative correlation between pCO2 and RBF. We concluded that osteotomy introduces immediate haemodynamic and metabolic changes in the bone marrow canal. A periosteal supply of the endosteal bone seems possible provided this system is intact.     

Subtraction CT angiography improves evaluation of significant coronary artery disease in patients with severe calcifications or stents—the C-Sub 320 multicenter trial

Objectives

Diagnostic accuracy of conventional coronary CT angiography (CCTA_conv) may be compromised by blooming artifacts from calcifications or stents. Blooming artifacts may be reduced by subtraction coronary CT angiography (CCTA_sub) in which non-contrast and contrast CT data sets are subtracted digitally. We tested whether CCTA_sub in patients with severe coronary calcification or stents reduces the number of false-positive stenosis evaluations compared with CCTA_conv.

Methods

In this study, 180 symptomatic patients scheduled for invasive coronary angiography (ICA) were prospectively enrolled and CT scanned (2013-2016) at three international centers. CCTA_conv, and CCTA_sub data sets were reconstructed. Target segments were defined as motion-free coronary segments with a suspected stenosis (> 50% of lumen) potentially due to blooming of either calcium or stents. Target segments were evaluated with respect to misregistration artifacts from the CCTA_sub reconstruction process, in which case evaluation was omitted. CCTA_sub and CCTA_conv were compared with ICA. Primary outcome measure was the frequency of false positives by CCTA_conv versus CCTA_sub to identify > 50% coronary stenosis by ICA on a per-segment level.

Results

After exclusion of 76 patients, 104 (14% females) with mean age 67 years and median Agatston score 852 were included. There were 136 target segments with misregistration and 121 target segments without. Accuracy calculations in target segments without misregistration showed a reduction of the false positives from 72% [95% confidence interval (CI): 63-80%] in CCTA_conv to 33% (CI:25-42%) in CCTA_sub, at the expense of 7% (CI:3-14%) false negatives in CCTA_sub.

Conclusions

In severely calcified coronary arteries or stents, CCTA_sub reduces the false-positive rate in well-aligned, calcified or stent segments suspected of significant stenosis on CCTA_conv. Nevertheless, misregistration artifacts are frequent in CCTA_sub.

Key Points

? A high calcium-score reduces the diagnostic accuracy in patients scanned with cardiac CT. ? These patients would normally need an invasive angiogram for diagnosis. ? In this prospective, multicenter study, subtraction CT, when evaluable, reduces false-positive stenosis evaluations. ? Subtraction coronary CT angiography may, when evaluable, reduce excessive downstream testing.

     

Modification of LKB 8600 for 1-Minute Determination of Creatine Kinase Activity in Serum

The degree of respiratory compensation to metabolic acid-base disturbances in a series of patients at the University Hospital, Lund was studied. As there was no statistical significance between the compensation lines for metabolic acidosis and for metabolic alkalosis, one single compensation line for metabolic disturbances could be drawn.     

Lens autofluorescence is not increased at high altitude

Purpose: To study the relation between ambient environmental ultraviolet radiation exposure and lens fluorescence. Methods: Non‐invasive lens fluorometry measurements were compared in healthy Bolivian and Danish subjects. Background ultraviolet radiation was 4.5 times higher in Bolivia than in Denmark. Results: No significant differences in lens fluorescence or transmittance were found between Bolivian and Danish volunteers. Conclusion: Age‐corrected lens fluorescence and transmittance were comparable for healthy participants living at high altitude near the equator and healthy volunteers living at sea level at 55° northern latitude. These results suggest that lens ageing, as assessed by lens autofluorometry, is independent of exposure to ultraviolet radiation.