Jianlin Zuo

Novel Mesoporous Hydroxyapatite/Chitosan Composite for Bone Repair

The objective of the present investigation was to evaluate the osteogenic properties of mesoporous Hydroxyapatite/Chitosan (HA/CS) composite in vitro and in vivo. HA/CS composite was successfully prepared and synthesized using a freeze-drying method, and then characterized by Scanning Electron Microscope (SEM). Results show that the mesoporous HA/CS composite presents high surface area and porosity. The effects of mesoporous HA/CS on early adhesion, proliferation and differentiation of osteoblast cells in vitro were measured. MTT cytotoxicity test and cell adhesion test show that the composite has good biocompatibility and promotes cell viability and proliferation. In vitro tests show that osteoblast-like cells on the composite surfaces are able to adhere, proliferate, and migrate through the pores. These cells maintained similar expression levels of osteoblastic-associated markers namely Collagen type I (COL-I), Bone Morphogenetic Protein 2(BMP-2). Histologic analysis and radiological analysis in vivo also prove that mesoporous HA/CS composite can be used to repair bone defect as a new kind of bone grafting materials.

Cross-sectional Anatomy of Ilium for Guiding Acetabular Component Placement Using High Hip Center Technique in Asian Population.

Background:Many clinical studies have been published involving the use of a high hip center (HHC), achieved good follow-up. However, there is a little anatomic guidance in the literature regarding the amount of bone stock available for initial implant coverage in this area of the ilium. The purpose of this study was to evaluate the thickness and width of the human ilium and related acetabular cup coverage for guiding acetabular component placement in HHC. Methods:A total of 120 normal hips in 60 cases of adult patients from lower extremities computer tomographic angiography Digital Imaging and Communications in Medicine data were chosen for the study. After importing the data to the mimics software, we chose the cross sections every 5-mm increments from the rotational center of the hip to the cephalic of the ilium according the body sagittal axis, then we measured the thickness and width of the ilium for each cross section in axial plane, calculated the cup coverage at each chosen section. Results:At the acetabular dome, the mean thickness and width of the ilium were 49.71 ± 4.88 mm and 38.92 ± 3.67 mm, respectively, whereas at 1 cm above the dome, decreased to 41.35 ± 5.13 and 31.13 ± 3.37 respectively, and 2 cm above the dome, decreased to 31.25 ± 4.04 and 26.65 ± 3.43, respectively. Acetabular cup averaged coverage for 40-, 50-, and 60-mm hemispheric shells, was 100%, 89%, and 44% at the acetabular dome, 100%, 43.7%, and 27.5% for 1 cm above the dome, and 37.5%, 21.9%, and 14.2% for 2 cm above the dome. Conclusions:HHC reconstructions within 1 cm above the acetabular dome will be an acceptable and smaller diameter prosthesis would be better.

The Effective Injection Zone at the Popliteal Crease for Tibial and Common Peroneal Nerve Blocks and its Relation with the Origin Point of the Medial and Lateral Sural Cutaneous Nerves

El bloqueo nervioso popliteo puede ser utilizado para proporcionar anestesia y analgesia prolongada del miembro inferior y para aliviar el dolor postoperatorio severo y duradero. El objetivo fue determinar la localizacion anatomica de los nervios tibial (NT) y fibular comun (NFC) en el pliegue popliteo para un bloqueo nervioso efectivo. Se utilizaron 50 miembros inferiores frescos pertenecientes a 27 cadaveres adultos chinos (16 hombres y 11 mujeres, rango de edad entre 35-87 anos). Se utilizaron 22 cadaveres para identificar la localizacion de los nervios y los 5 restantes para determinar la profundidad de los nervios en una seccion transversal. El NT se encontro en el 50% de los casos desde el punto mas lateral del pliegue popliteo a 1,4 cm de la superficie. En el 20% de 50 muestras, el nervio cutaneo sural medial se ramifico por debajo o en el pliegue popliteo, mientras que el NFC se encontro en el 26% de los casos desde el punto mas lateral del pliegue popliteo a 0,7 cm de la superficie. Ademas, en el 6% de las muestras, el nervio cutaneo sural lateral se ramifico por debajo o en el pliegue popliteo. Nuestros resultados sugieren que el NT y NFC emergen del nervio ciatico a distancias variables del pliegue popliteo. Creemos que los resultados sobre la ubicacion de NT y NFC en el pliegue popliteo ofrecen una buena guia para el adecuado bloqueo nervioso.