ObjectiveTo study the effect of different degrees of distal tibial varus and valgus deformities on the tibiotalar joint contact, and to understand the role of fibular osteotomy. MethodsEight cadaveric lower legs were used for biomechanical study. Nine conditions were included: normal ankle joint (group A), 10° varus (group B), 5° varus (group C), 5° valgus (group D), 10° valgus (group E) with fibular preserved, and 10° varus (group F), 5° varus (group G), 5° valgus (group H), and 10° valgus (group I) after fibular osteotomy. The joint contact area, contact pressure, and peak pressure were tested; and the translation of contact force center was observed. ResultsThe joint contact area, contact pressure, and peak pressure had no significant difference between group A and groups B to E (P>0.05). After fibular osteotomy, the contact area decreased significantly in groups F and I when compared with group A (P < 0.05); the contact pressure increased significantly in groups F, H, and I when compared with group A (P < 0.05); the peak pressure increased significantly in groups F and I when compared with group A (P < 0.05). There were two main anterior-lateral and anterior-medial contact centers in normal tibiotalar joint, respectively; and the force center was in anterior-lateral part, just near the center of tibiotalar joint. While the fibula was preserved, the force center transferred laterally with increased varus angles; and the force center transferred medially with increased valgus angles. However, the force center transferred oppositely to the medial part with increased varus angles, and laterally with increased valgus angles after fibular osteotomy. ConclusionFibular osteotomy facilitates the tibiotalar contact pressure translation, and is helpful for ankle joint realignment in suitable cases.
ObjectiveTo establish a comprehensive, appropriate quality control system on the Sysmex-XN series automatic blood cell analyzer to improve the reliability of blood cell count results. MethodsRoutine quality control was carried out every day, using high, normal and low levels of fresh whole blood controls offered by Sysmex. The results from the Sysmex online quality control was got timely. We monitored the variation of mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC) with the moving average method real-timely, and quality control was performed for fresh whole blood samples of patients once every two hours. ResultsEverything was under control, and the moving average was within the permitted range. ConclusionThe reliability of laboratory blood cell count results can be effectively improved by using this quality control system effectively and comprehensively on the Sysmex-XN automatic blood cell analyzer.