ABSTRACT
Objective: To evaluate the medial anterior flange overhang related to the femoral prosthesis size determined by femoral sizer in total knee arthroplasty. Methods: Sixty one cases of varus knee osteoarthritis (61 knees) were analyzed from January 2014 to January 2015, 14 males and 47 females, aged (66.8±6.8) year old. 3D models of distal femur were established by Mimics, total knee arthroplasty surgeries were simulated and the medial and lateral femoral condylar anteroposterior diameter were measured. According to the AP diameter of lateral femoral condyle (lateral condyle group) and femoral sizer (sizer group), different size of the PFC Sigma femoral prosthesis models were imported to mimics, and the coverage of medial anterior femoral flange were compared. Results: The AP diameter of lateral femoral condyle[(55.76±3.64) mm]was significantly less than the sizer group[(57.02±3.59) mm], P<0.05. The distal femur aspect ratio for male (1.2 %±0.1%) and female (1.2%±0.1%) has no statistically difference (P>0.05). Femoral prosthesis sizes, the uncoverage diameter of the anterior chamfer line, midpoint of the flange in the sizer group were significantly larger than the lateral condyle group (P<0.05). The femoral size, overhang ratio of anterior chamfer line and midpoint of the flange in male were significantly larger than females (P<0.05). Conclusion: The AP diameter determined by femoral sizer instrument had a tendency to larger prosthesis, and the risks of medial femoral anterior flange overhang increased. Medial anterior flange overhang in male was significantly less than female, but the difference had no correlation to the distal femur asepect ratio.
Subject(s)
Arthroplasty, Replacement, Knee , Femur , Aged , Epiphyses , Female , Humans , Knee , Knee Joint , Knee Prosthesis , Male , Osteoarthritis, KneeABSTRACT
Brief description was given about the construction and function of the LCG (liquid cooling garment) used for EVA (extravehicular activity). The heat convection was analyzed between ventilating gas and LCG, the heat and mass transfer process was analyzed too, then a heat and mass transfer mathematical model of LCG was developed. Thermal physiological experimental study with human body wearing LVCG (liquid cooling and ventilation garment) used for EVA was carried out to verify this mathematical model. This study provided a basis for the design of liquid-cooling and ventilation system for the space suit.
