[Ultrasonic and radiographic quantification of palmar angulation in metacarpal IV and V neck fractures]

Therapy of metacarpal neck fractures depending on radiographically measured palmar angulation is discussed controversially in the literature. Some authors describe normal hand function of malunited metacarpal neck fractures with a palmar angulation up to 70°; others define 30° as the uppermost limit to maintain normal hand function. However, the methods of measuring palmar angulation are not clearly defined. Here, we present a new method to measure palmar angulation using ultrasound. The aim of this prospective study is to compare the radiographic methods of measuring palmar angulation with the ultrasound method. PATIENTS/MATERIAL AND METHOD: 20 patients with a neck fracture of the metacarpals IV or V were treated either conservatively or operatively. 2 weeks after trauma or operation, an x-ray was performed. 2 examiners measured the palmar angulation on the oblique and lateral projections using 2 different methods (medullary canal and dorsal cortex methods). At the same time, the 2 examiners performed measurements of palmar angulation using ultrasound. The measurements obtained with the different methods as well as by the 2 examiners at 2 different terms were compared. Intra- and interobserver reliability of each method was calculated, and for the ultrasound method a test for accuracy of the measured angles was performed.

Tidal volume single breath washout of two tracer gases--a practical and promising lung function test

Background Small airway disease frequently occurs in chronic lung diseases and may cause ventilation inhomogeneity (VI), which can be assessed by washout tests of inert tracer gas. Using two tracer gases with unequal molar mass (MM) and diffusivity increases specificity for VI in different lung zones. Currently washout tests are underutilised due to the time and effort required for measurements. The aim of this study was to develop and validate a simple technique for a new tidal single breath washout test (SBW) of sulfur hexafluoride (SF6) and helium (He) using an ultrasonic flowmeter (USFM). Methods The tracer gas mixture contained 5% SF6 and 26.3% He, had similar total MM as air, and was applied for a single tidal breath in 13 healthy adults. The USFM measured MM, which was then plotted against expired volume. USFM and mass spectrometer signals were compared in six subjects performing three SBW. Repeatability and reproducibility of SBW, i.e., area under the MM curve (AUC), were determined in seven subjects performing three SBW 24 hours apart. Results USFM reliably measured MM during all SBW tests (n = 60). MM from USFM reflected SF6 and He washout patterns measured by mass spectrometer. USFM signals were highly associated with mass spectrometer signals, e.g., for MM, linear regression r-squared was 0.98. Intra-subject coefficient of variation of AUC was 6.8%, and coefficient of repeatability was 11.8%. Conclusion The USFM accurately measured relative changes in SF6 and He washout. SBW tests were repeatable and reproducible in healthy adults. We have developed a fast, reliable, and straightforward USFM based SBW method, which provides valid information on SF6 and He washout patterns during tidal breathing.