Relative forelimb–hindlimb investment is associated with flight style, foraging strategy, and nestling period, but not nest type

We investigated Dial’s 2003 hypothesis that birds that rely more heavily on flight as their primary mode of locomotion and thus invest more in their forelimbs than hindlimbs will experience selection for smaller body sizes, greater altriciality, and more complex nests. To test this hypothesis, we examined the skeletons of over 2,000 individuals from 313 species representing the majority of avian families and all major branches of the avian tree. We used the lengths of the sternal keel and long bones of the wing relative to the lengths of the leg long bones as an index of relative locomotor investment. We found that locomotor investment was predicted by flight style, foraging method, and length of nestling period, supporting Dial’s hypothesis. Soaring birds and birds with more acrobatic flight styles, birds whose foraging methods were heavily reliant upon flight, and birds whose young spent more time in the nest tended to invest more in their forelimbs relative to hindlimbs. Nest type and body size were not significant predictors of relative forelimb–hindlimb investment, however, suggesting that the relationships among flight style, locomotor investment, and life history are not as tightly intertwined as Dial originally hypothesized.

BMP3 Affects Cortical and Trabecular Long Bone Development in Mice

Bone morphogenetic proteins (BMPs) have a major role in tissue development. BMP3 is synthesized in osteocytes and mature osteoblasts and has an antagonistic effect on other BMPs in bone tissue. The main aim of this study was to fully characterize cortical bone and trabecular bone of long bones in both male and female Bmp3−/− mice. To investigate the effect of Bmp3 from birth to maturity, we compared Bmp3−/− mice with wild-type littermates at the following stages of postnatal development: 1 day (P0), 2 weeks (P14), 8 weeks and 16 weeks of age. Bmp3 deletion was confirmed using X-gal staining in P0 animals. Cartilage and bone tissue were examined in P14 animals using Alcian Blue/Alizarin Red staining. Detailed long bone analysis was performed in 8-week-old and 16-week-old animals using micro-CT. The Bmp3 reporter signal was localized in bone tissue, hair follicles, and lungs. Bone mineralization at 2 weeks of age was increased in long bones of Bmp3−/− mice. Bmp3 deletion was shown to affect the skeleton until adulthood, where increased cortical and trabecular bone parameters were found in young and adult mice of both sexes, while delayed mineralization of the epiphyseal growth plate was found in adult Bmp3−/− mice.

Open Surgical Hip Dislocation for an Acetabular Osteoid Osteoma - A Case Report

Osteoid osteoma is a benign tumor that accounts for roughly 10-12% of all benign bone forming tumors. This tumor generally occurs within the first three decades of life and occurs more commonly in males. This lesion is painful and is generally worse at night and has relief of symptoms with the use of NSAIDs. Osteoid osteoma is characterized by the production of osteoid surrounded by a rim of sclerotic bone. These lesions most commonly occur in long bones such as the proximal femur, however they can occur anywhere. Rarely, as with our patient, have these lesions been reported in the acetabulum.

The Regulation of Growth in Developing, Homeostatic, and Regenerating Tetrapod Limbs: A Minireview

The size and shape of the tetrapod limb play central roles in their functionality and the overall physiology of the organism. In this minireview we will discuss observations on mutant animal models and humans, which show that the growth and final size of the limb is most impacted by factors that regulate either limb bud patterning or the elongation of the long bones. We will also apply the lessons that have been learned from embryos to how growth could be regulated in regenerating limb structures and outline the challenges that are unique to regenerating animals.

Preliminary mechanical evaluation of two novel veterinary angle-stable-threaded interlocking nail systems

ABSTRACT: The interlocking nail represents an excellent option as a surgical approach to treat fractures in long bones in veterinary medicine. However, failures were reported mainly due to a slack present in the interface of the rod with the screws. The present study tested and mechanically compare axial compression loads of two novel models of stable angle interlocking nails with threaded holes. Among the two models, one was uniplanar and the other was multiplanar with orthogonally arranged distal holes. Twenty-one specimens made of polylactic acid were used for the implantation of interlocking nail´s rods, divided into three groups: conventional interlocking nail (G1), novel interlocking nail with a stable angle with holes arranged in a single plane (G2), and novel interlocking nail with a stable angle in two planes, with the penultimate hole at 90 degrees from the others (G3). Biomechanical tests were performed using axial, cyclic, and destructive compression load for comparison between them. All the specimens showed plastic deformation in the screws after destructive tests, in both proximal and distal sides, being highly intense in G1. G2 and G3 of the stable angle rods supported higher loads than G1 in all tests performed (P<0.05). The novel stems did not differ statistically from each other (P>0.05). The initial hypothesis that the novel models would provide increased stability was confirmed; however, no differences were demonstrated between them. The screw locking system on the rods allowed high resistance values in the tests performed, proving to be effective and potentially applicable in real clinical situations.

Masquelet technique in management of infective non-union of long bones- A prospective study

Introduction and Aim: Masquelet’s technique is a 2-staged procedure, for treatment of infected segmental bone defect. 1st stage involves radical debridement with antibiotic-induced cement spacer. During second stage, the spacer is removed and the autologous bone graft is applied into the biomembrane formed. In this study, we evaluate the Masquelet’s technique for the management of infective non-union of long bones. Materials and Methods: 15 patients with infective non-union of long bones- tibia, femur and a case of congenital pseudoarthrosis of tibia, were treated with Masquelet’s technique. They underwent 2 stages of procedures 6-8 weeks apart and was followed up for about 9 months and radiological and clinical outcomes were assessed. Results: Out of 15 patients with infective non-union, 8 patients attained union. Out of the 7 patients with failure of the technique, higher failure rates were attributed to Pseudomonas infection. Conclusion: Masquelet’s technique is a cost-effective method for treating infective segmental non-unions, not requiring special training or sophisticated instruments. This method shows good results with Gram positive infections. Although, the outcome with Pseudomonas aeruginosa infection, have not shown satisfactory results.