Development of an electronic navigation system for elimination of examiner-dependent factors in the ultrasound screening for developmental dysplasia of the hip in newborns.

To develop an electronic navigation system to increase reliability and comparability in the ultrasound screening of developmental dysplasia of the hip (DDH). The impact of the navigation system on transducer positioning and on sonographic measurements according to Graf was analyzed. Twenty hips in newborns were examined sonographically using a new navigation system capable of detecting the transducer and pelvis position in order to calculate the relative tilt in the frontal, axial, and sagittal-plane. In each newborn an ultrasound image was obtained conventionally according to Graf and a second image using the sonographic navigation system. Relative roll and pitch angles and sonographic measurements were analyzed using paired T-tests and Levene-tests. Relative tilt angles in the conventional group ranged from - 8.9° to 14.3° (frontal-plane) and - 23.8° to 14.2° (axial-plane). In the navigation-assisted group ranges from - 3.0° to 3.5° and - 2.8° to 4.5° were observed. Variances were significantly lower in the navigation-assisted group (p < 0.001 and p = 0.004 respectively). The navigation system allowed for a significant reduction of relative tilt angles between the transducer and the newborn pelvis, thus supporting an optimal transducer positioning. This is a promising approach to improve reproducibility and reliability in the ultrasound screening for DDH.

The influence of sex and trauma impact on the rupture site of the ulnar collateral ligament of the thumb.

PURPOSE AND HYPOTHESIS: Although sex- and gender-specific analyses have been gaining more attention during the last years they have rarely been performed in orthopaedic literature. The primary purpose of this study was to investigate whether for injuries of the UCL the specific location of the rupture is influenced by sex. A secondary study question addressed the sex-independent effect of trauma intensity on the rupture site of the UCL. METHODS: This study is a retrospective analysis of all patients with either a proximal or distal bony avulsion or with a mid-substance tear or ligament avulsion of the UCL treated surgically between 1992 and 2015 at two level-I trauma centres. Trauma mechanisms leading to the UCL injury were classified into the following categories: (1) blunt trauma (i.e., strains), (2) low-velocity injuries (e.g., fall from standing height, assaults), and (3) high-velocity injuries (e.g., sports injuries, motor vehicle accidents). After reviewing the surgical records, patients were divided into three groups, depending upon the ligament rupture site: (1) mid-substance tears, (2) proximal ligament or bony avulsions and (3) distal ligament or bony avulsions. Dependencies between the specific rupture site and the explanatory variables (sex, age, and trauma intensity) were evaluated using χ2 test and logistic regression analysis. RESULTS: In total, 1582 patients (1094 males, 488 females) met the inclusion criteria. Mean age was 41 years (range: 9-90 years). Taking into account the effects of sex on trauma intensity (p<0.001) and of trauma intensity on rupture site (p<0.001), mid-substance tears occurred more frequently in women, whereas men were more prone to distal ligament or bony avulsions (p<0.001). In other words, sex and rupture site correlated due to the effects of sex on trauma intensity and of trauma intensity on rupture site, but taking into account those effects there still was a significant effect of sex on rupture site. CONCLUSIONS: The results of this study demonstrate that with regression analysis both sex and trauma intensity allow to predict rupture site in UCL injuries.