Total hip arthroplasty for sequelae of childhood hip disorders:Current review of management to achieve hip centre restoration

Adults requiring total hip arthroplasty(THA)for childhood disorder sequelae present with shortening,limp,pain,and altered gait.THA,which can be particularly challenging due to altered anatomy,requires careful planning,assessment,and computed tomography evaluation.Preoperative templating is essential to establish the appropriate acetabular and femoral size.Information regarding neck length and offset is needed to ensure the proper options are available at THA.Hip centre restoration must be planned preoperatively and achieved intraoperatively with appropriate exposure,identification,and stable fixation with optimum-size components.Identifying the actual acetabular floor is essential as changes include altered anatomy,distortion of the margins and version changes.Proximal femur changes include anatomical variation,decreased canal diameter,cortical thickness,changes in anteversion,and metaphyseal and diaphyseal mismatch.Preoperative assessment should consist of limb assessment for variations due to prior surgical procedures.Evaluation of the shortening pattern with the relationship of the lesser trochanter to the teardrop would help identify and plan for subtrochanteric shortening osteotomy,especially in high-riding hips.The surgical approach must ensure adequate exposure and soft tissue release to achieve restoration of the anatomical hip centre.The femoral components may require modularity to enable restoration of anteversion and optimum fixation.

Preparation of Porous Polylactide Microspheres and Their Application in Tissue Engineering

In this study, porous polylactide（PLA） microspheres with different structures were prepared through the multiple emulsion solvent evaporation method. By changing organic solvents（ethyl acetate and chloroform） and adding effervescent salt NH4 HCO3 in the inner water phase, microspheres with porous capsular, matrix, microcapsular and multivesicular structures were prepared. The protein encapsulation and release, and the cell growth behavior of porous microspheres were further explored. Under the same inner water phase, microspheres prepared with chloroform had higher protein encapsulation efficiency and less protein release rate as compared with those prepared with ethyl acetate. Cell experiments showed that the relatively rough surface of microspheres prepared with chloroform was more favorable for the cell growth in comparison with the smooth surface of microspheres prepared with ethyl acetate. This study shows a simple and effective method to control the protein release and cell growth behaviors of polymer microspheres by tuning their porous structure.