Despite massive research efforts, the molecular etiology of bovine polledness and the developmental pathways involved in horn ontogenesis are still poorly understood. In a recent article, we provided evidence for the existence of at least two different alleles at the Polled locus and identified candidate mutations for each of them. None of these mutations was located in known coding or regulatory regions, thus adding to the complexity of understanding the molecular basis of polledness. We confirm previous results here and exhaustively identify the causative mutation for the Celtic allele (PC) and four candidate mutations for the Friesian allele (PF). We describe a previously unreported eyelash-and-eyelid phenotype associated with regular polledness, and present unique histological and gene expression data on bovine horn bud differentiation in fetuses affected by three different horn defect syndromes, as well as in wild-type controls. We propose the ectopic expression of a lincRNA in PC/p horn buds as a probable cause of horn bud agenesis. In addition, we provide evidence for an involvement of OLIG2, FOXL2 and RXFP2 in horn bud differentiation, and draw a first link between bovine, ovine and caprine Polled loci. Our results represent a first and important step in understanding the genetic pathways and key process involved in horn bud differentiation in Bovidae.

The carrying angle of the elbow is usually assessed in full elbow extension, with a protractor goniometer, or derived from X-ray images. Substantial differences in carrying angle values have been reported, possibly explained by methodological differences. Carrying angles tend to show higher values in women than in men. The aim of this study was to confirm the previously described progressive decrease of the carrying angle as a function of increasing elbow flexion. After assessment of the carrying angle with a protractor goniometer and an electromagnetic tracking system (Flock of Birds) in extension, flexion-extension movements with the forearm held in supination were recorded by means of the latter system. Three recordings were averaged in both the left and the right elbows of 20 volunteers without a history of elbow pathology (10 males and 10 females; mean age 25 years). In extension, a mean (+/- SD) carrying angle of 11.6 +/- 3.2 degrees was found in the male and 16.7 +/- 2.6 degrees in the female subjects. The carrying angles progressively decreased with flexion, at the end changing into a mean (+/- SD) varus angle of 1.8 +/- 2.9 degrees in men and 1.6 +/- 2.3 degrees in women. Significant differences in carrying angles between the sexes were recorded in moving from 0 to 30 degrees of flexion (p < 0.03 for the left and p < 0.01 for the right elbows), but disappeared beyond 30 degrees . No statistically significant differences were found between the results of left and right elbows. Although statistically significant differences (p < 0.05 to p < 0.001) were found along the course of flexion and extension, these differences were small (<0.6 degrees ). The mean carrying angles at 0, 30, 60, 90 and 120 degrees of flexion revealed larger standard deviations in the male group than in the female group.

Sonography may aid in diagnosing a rupture of the EPL tendon and in the preoperative assessment of gap size and position of the retracted tendon ends. A characteristic tubular hypoechoic area may be seen crossing over the extensor carpi radialis tendons.

Ankle sprains are frequently followed by chronic lateral instability, often with talar hypermobility. This might be due to subtalar instability. Among intrinsic risk factors, anatomical variants are generally overlooked. In the subtalar region, anatomical variation is particularly frequent. On the talus as well as on the calcaneus, the anterior articular facets may be missing or fused with the medial facets, giving rise to three subtalar joint configurations: a three-joint configuration, a fused configuration with a relatively large anteromedial joint, and a two-joint configuration without anterior joint. Osteometry was performed on these joint facets (134 calcanei, 122 tali), demonstrating significant differences in the surface of these configurations and the existence of a supplementary supporting surface with grossly transverse orientation in the three-joint configuration. There are also several variants of stabilizing ligaments within the sinus tarsi. Some of these configurations might expose to increased risk of associated subtalar lesions, resulting in subtalar instability. A systematic look for these variants is recommended in order to evaluate the associated risk factors, eventually resulting in a better understanding, prevention and cure of sequellae.

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