Infraclavicular topography of the brachial plexus fascicles in different upper limb positions / Topografía infraclavicular de los fascículos del plexo braquial en diferentes posiciones del miembro superior

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.

Study of the osteoconductive capacity of hydroxyapatite implanted into the femur of ovariectomized rats.

Osteoporosis is a global public health that affects postmenopausal women due to the deficiency of estrogen, a hormone that plays an important role in the microarchitecture of bone tissue. Osteoporosis predisposes to pathological bone fracture that can be repaired by conventional methods. However, depending on the severity and quantity of bone loss, the use of autogenous grafts or biomaterials such as hydroxyapatite might be necessary. The latter has received increasing attention in the medical field because of its good biological properties such as osteoconductivity and biocompatibility with bone tissue. The objective of this study was to evaluate using histologic and radiographic analyses, the osteogenic capacity of hydroxyapatite implanted into the femur of rats with ovariectomy-induced osteoporosis. Eighteen rats were divided into three groups with six animals in each: group nonovariectomized, bilaterally ovariectomized not receiving estrogen replacement therapy, and bilaterally ovariectomized submitted to estrogen replacement therapy. Defects were created experimentally in the distal epiphysis of the femur with a surgical drill and filled with porous hydroxyapatite granules. The animals were sacrificed 8 weeks after surgery. The volume of newly formed bone in the implant area was quantified by morphometrical methods. The results were analyzed by ANOVA followed by the Tukey test (P < 0.05). The hydroxyapatite granules showed good radiopacity. Histological analysis revealed less quantity of newly formed bone in the ovariectomized group not submitted to hormone replacement therapy. In conclusion, bone neoformation can be expected even in bones compromised by estrogen deficiency, but the quantity and velocity of bone formation are lower.