Distal biceps tendon ruptures: more efficient diagnostics for a better outcome.

Distal biceps tendon ruptures are a rare pathology, but can have significant functional repercussions. Rapid, accurate diagnosis and treatment are essential for a favorable prognosis. During the diagnostic process of distal biceps tendon ruptures, several problems can emerge. An answer to the following clinical questions is given based on an extensive literature review. - Which clinical tests are the most sensitive/ specific for clinical examination? - Can ultrasound evaluation of the distal biceps tendon be optimized? - Is ultrasound an equivalent alternative to MRI in the diagnosis of distal biceps tendon injuries? An extensive literature search was conducted through Pubmed and Embase. The search strategy was developed systematically in the Medline data- base (PubMed interface), using medical subject headings as well as free text words. A standardized clinical examination of the distal biceps tendon consisting of the Hook test, the Passive Forearm Pronation Test and the Biceps Crease Interval test has a high accuracy for correct diagnosis of full-thickness ruptures. Furthermore, Cobra sign, Supinator view and Pronator view give an additional value to the standard ultrasound examination of the distal biceps tendon. Finally, ultrasound can be considered a trustworthy and cost-effective alternative to MRI in evaluation of distal biceps tendon ruptures.

Hand size representation in healthy children and young adults.

Whereas we experience our body as a coherent volumetric object, the brain appears to maintain highly fragmented representations of individual body parts. Little is known about how body representations of hand size and shape are built and evolve during infancy and young adulthood. This study aimed to investigate the effect of hand side, handedness, and age on the development of central hand size representation. The observational study with comparison groups was conducted with 90 typically developing Belgian school children and young adults (48 male and 42 female; age range = 5.0-23.0 years; 49 left-handed and 41 right-handed). Participants estimated their hand size and shape using two different tasks. In the localization task, participants were verbally cued to judge the locations of 10 anatomical landmarks of an occluded hand. An implicit hand size map was constructed and compared with actual hand dimensions. In the template selection task, the explicit hand shape was measured with a depictive method. Hand shape indexes were calculated and compared for the actual, implicit, and explicit conditions. Participants were divided into four age groups (5-8 years, 9-10 years, 11-16 years, and 17-23 years). Implicit hand maps featured underestimation of finger length and overestimation of hand width, which is already present in the youngest children. Linear mixed modeling revealed no influence of hand side on finger length underestimation; nonetheless, a significant main effect of age (p = .001) was exposed. Sinistrals aged 11 to 16 years showed significantly less underestimation (p = .03) than dextrals of the same age. As for the hand shape, the implicit condition differed significantly with the actual and explicit conditions (p < .001). Again, the implicit shape index was subjected to handedness and age effects, with significant differences being found between sinistrals and dextrals in the age groups of 9 and 10 years (p = .029) and 11 to 16 years (p < .001). In conclusion, the implicit metric component of the hand representation in children and young adults is misperceived, featuring shortened fingers and broadened hands since a very young age. Crucially, the finger length underestimation increases with age and shows a different developmental trajectory for sinistrals and dextrals. In contrast, the explicit hand shape is approximately veridical and seems immune from age and handedness effects. This study confirms the dual character of somatoperception and establishes a point of reference for children and young adults.

Positioning of longest axis of the radial head in neutral forearm rotation.

INTRODUCTION: The radial head has an ellipsoid shape so that a longest and a shortest axis can be defined. The aim of this study is to evaluate the position of the longest axis of the radial head (LARH) in relation to proximal radioulnar joint (PRUJ) and to the forearm in neutral position using 3D computed tomography (CT). MATERIALS AND METHODS: 3D CT reconstructions of the distal humerus, the radius and the ulna of 27 healthy volunteers (average age 27.65 ± 9.25; 24 males, 3 females) were created. First an evaluation of the elliptic form of the radial head and the location of its longest axis was performed. Next, three planes were defined: the PRUJ plane, the forearm plane and a neutral plane. Based on the angle between the forearm plane and the neutral plane, the rotation of the scanned forearm was measured. Taking this rotation into account, the position of the LARH compared to PRUJ plane and forearm plane in neutral position is recalculated. RESULTS: The shape of the radial head is determined to be non-circular based on this study population (p < .001). In neutral position, the angle between the LARH and the forearm plane is 5.28° (SD: 15.09) and between the LARH and the PRUJ is 33.46° (SD: 13.91). CONCLUSIONS: The position of the LARH is found to be approximately perpendicular to the forearm plane when the forearm is in neutral position and perpendicular to the PRUJ plane when the forearm is on average in 30° of pronation.