No abstract

Revision total hip arthroplasty (THA) with massive bone loss has been a real challenge for orthopaedic surgeons. Here we describe an approach using mineralized collagen (MC) graft to reconstruct acetabulum and femur with massive bone defects. We identified 89 patients suffering acetabular or femoral bone defects after primary THA, who required revision THA for this study. During the surgery, MC was applied to reconstruct both the acetabular and femoral defects. Harris hip score was used to evaluate hip function while radiographs were taken to estimate bone formation in the defect regions. The average follow-up period was 33.6 ± 2.4 months. None of the components needed re-revised. Mean Harris hip scores were 42.5 ± 3.5 before operation, 75.2 ± 4.0 at 10th month and 95.0 ± 3.6 at the final follow-up. There were no instances of deep infection, severe venous thrombosis or nerve palsy. The present study demonstrated that MC graft can serve as a promising option for revision THA with massive bone deficiency. Meanwhile, extended follow-up is needed to further prove its long-term performance.

For the continuous high-precision navigation and positioning needs of rotorcraft UAVs based on industry applications, based on low-cost GNSS single-frequency positioning modules and MEMS inertial navigation, the design high-precision GNSS / INS integrated navigation module. At the same time using computer vision algorithms. Aiming at the requirement of high precision, the original data acquisition scheme that fully guarantees the accuracy of MEMS inertial navigation is designed. No one against the rotor for the high-frequency vibration problem of the mobile platform, the effect of IMU white noise parameters on the performance of MEMS inertial navigation and integrated navigation was analysed. The test results show that the IMU white noise parameters can effectively improve the combined navigation performance under high-frequency vibration conditions; the positioning accuracy of the module can reach centimetre level and be continuous and stable.