To contrast the methodology of measuring cup placement precision utilizing Mimics and Matlab programming, based on clinical CT images of primary THA cases with computer assisted navigated surgery (CANS) and with the traditional manual method (MANS). The method was applied and analyzed to measure cup anteversion, cup abduction of 50 clinical cases with CANS and MANSThe results show that, cup placement precision differences exits between primary THA cases with CANS and MANS; more cases with CANS are within the safe zone contrasting MANS, and there was less variation and less placement error in CANS cases. CANS can improve cup placement precision and reduce the chance of dislocation efficiently.
Arthroplasty, Replacement, Hip ; instrumentation ; methods ; Humans ; Surgery, Computer-Assisted ; methods

Different porous structures were studied through finite element analysis and then optimal porous structure was selected for the orthopedic applications.The optimal Voronoi structure was designed and fabricated using 3D printing.The mechanical properties and osseointegration ability were both investigated.The mechanical tests showed that the tensile strength,compressive strength and bending strength of Voronoi structures were obviously higher than that of the human bone,and the modulus of Voronoi structures were similar to human bone.In addition,the animal experimental results exhibited that obvious bone ingrowth was found from Month 1 to Month 6.This study provides some theoretical references for the orthopedic application of porous structures.