Many researches aim to develop different biomaterials that are compatible with natural tissues. In vitro and in vivo tests are used to evaluate this potential. Our aim was to report the importance of the critical defect’s location for in vivo assays, to evaluate this approach; in vivo studies were performed, using different compositions of biomaterials in two critical size defects: tibia and parietal bone. Polycaprolactone was used as the main polymeric matrix with and without addition of hydroxyapatite. In vivo studies on the standard critical size defect in tibia and parietal bone were performed using Wistars models: 3x2 and 5x1 dimensions, respectively. The animals were sacrificed after 32 days; neobone formation was assessed with the histological data. The in vivo data demonstrated differences between the tibia and parietal bone groups: the influence of the bone on the neobone’s formation was notable. All the tibia defect samples had greater neobone volume when compared to the parietal data. Indeed, these bones have distinct embryology, influence of mechanical forces and vascularization rate that are well known; moreover, these characteristics were demonstrated to be critical for neobone formation.

Brachial plexus neuropathies are common complaints among patients seen at orthopedic clinics. The causes range from traumatic to occupational factors and symptoms include paresthesia, paresis, and functional disability of the upper limb. Treatment can be surgical or conservative, but detailed knowledge of the brachial plexus is required in both cases to avoid iatrogenic injuries and to facilitate anesthetic block, preventing possible vascular punctures. Therefore, the objective of this study was to evaluate the topography of the infraclavicular brachial plexus fascicles in different upper limb positions adopted during some clinical procedures. A formalin-preserved, adult, male cadaver was used. The infraclavicular and axillary regions were dissected and the distance of the brachial plexus fascicles from adjacent bone structures was measured. No anatomical variation in the formation of the brachial plexus was observed. The metric relationships between the brachial plexus and adjacent bone prominences differed depending on the degree of shoulder abduction. Detailed knowledge of the infraclavicular topography of neurovascular structures helps with the diagnosis and especially with the choice of conservative or surgical treatment of brachial plexus neuropathies.

Las neuropatías del plexo braquial son quejas comunes entre los pacientes atendidos en las clínicas ortopédicas. Las causas van desde traumas a factores ocupacionales y los síntomas incluyen parestesias, paresia e incapacidad funcional del miembro superior. El tratamiento puede ser quirúrgico o conservador, pero se requiere un conocimiento detallado del plexo braquial en ambos casos para evitar lesiones iatrogénicas y para facilitar el bloqueo anestésico, evitando posibles lesiones vasculares. Por lo tanto, el objetivo de este estudio fue evaluar la topografía de los fascículos del plexo braquial infraclavicular en diferentes posiciones de los miembros superiores adoptadas durante algunos procedimientos clínicos. Se llevó a cabo la disección de las regiones infraclavicular y axilar de un cadáver adulto, de sexo masculino, conservado en formaldehído. Se midió la distancia de los fascículos del plexo braquial en relación a las estructuras óseas adyacentes. No se observó variación anatómica en la formación del plexo braquial. Las relaciones métricas entre el plexo braquial y las prominencias óseas adyacentes difieren en función del grado de abducción del hombro. El conocimiento detallado de la topografía infraclavicular de las estructuras neurovasculares ayuda con el diagnóstico y sobre todo con la elección del tratamiento conservador o quirúrgico de las neuropatías del plexo braquial.