Objective To investigate the effect of knee suspension during titanium plate fixation on postoperative posterior tibial slope (PTS) in knee osteoarthritis (KOA) with medial opening-wedge high tibial osteotomy (OWHTO). Methods The clinical data of 47 patients with KOA treated by OWHTO between January 2019 and December 2020 was retrospectively analyzed. In 24 cases, the knee joint was suspended when titanium plate was fixed (research group), and in 23 cases, the knee joint was naturally straightened when titanium plate was fixed (control group). There was no significant difference in gender, age, side, body mass index, disease duration, preoperative visual analogue scale (VAS) score, American Hospital for Special Surgery (HSS) score, Western Ontario and McMaster University Osteoarthritis Index (WOMAC) score, Lysholm score, and preoperative PTS between the two groups (P>0.05). PTS were measured at 1 day after operation and last follow-up, and were compared with that before operation. Before operation and at last follow-up, VAS score was used to evaluate the knee pain, HSS score, WOMAC score, and Lysholm score were used to evaluate the knee function. Results The patients in both groups were followed up 13-24 months, with an average of 19.9 months. There was no complication such as incision infection, screw fracture, and deep venous thrombosis of lower limbs in two groups. At last follow-up, the VAS score, HSS score, WOMAC score, and Lysholm score in two groups were significantly improved when compared with those before operation (P<0.05), but there was no significant difference between the two groups in the each score difference of before and after operation (P>0.05). There was no significant difference in PTS at each time point before and after operation in the research group (P>0.05), but PTS in the control group significantly increased at 1 day after operation and last follow-up (P<0.05). PTS of the research group at 1 day after operation and last follow-up were significantly lower than those of the control group (P<0.05). ConclusionOWHTO can effectively relieve knee pain and improve knee function in KOA, and the increase of postoperative PTS can be effectively avoided by suspending knee joint.
The properties of mucus in a person with asthma can alter with disease process so that it may lead to the airway embolism. Fe2O3 nanoparticles can be used for drug delivery. Up till now, however, little is known about how the Fe2O3 nanoparticles influence the properties of airway mucus. In this study, Fe2O3 nanoparticles were dispersed with ultrasound, and the morphological properties were measured with scanning electron microscope, atomic force microscope and nanometer laser particle size and zeta potential analyzer. Then the dispersed Fe2O3 nanoparticles were added to the simulated asthma airway mucus with different final concentration (0.03, 0.3, and 0.4 mg/mL). The measurements of flow curve, yield stress, large amplitude oscillatory shear (LAOS) and shock scanning were carried out with a rotational rheometer. Experimental results showed that the Fe2O3 nanoparticles reduced the zero shear viscosity of simulated asthma airway mucus. With increase of shear rate, the wind speed of mucus was reduced. The yield stress of simulated asthma airway mucus was 19.0 Pa, but the yield stresses of experimental group (0.03, 0.3 and 0.4 mg/mL) were 17.0, 0.99, and 0.7 Pa, respectively. The results showed that the viscoelastic modulus of asthma airway mucus treated with Fe2O3 nanoparticles were changed obviously as measured with large amplitude scanning and frequency scanning. By adopting the method of optical phase microscopy, we found that different structures of simulated airway mucus were absorbed. The results showed Fe2O3 nanoparticles distroyed mucus structure. The experimental results proved that Fe2O3 nanoparticles could change the rheological characteristics of simulated asthma airway mucus. This experimental result would lay a foundation for the further development of airway mucus sticky agent based on the function of Fe2O3 nanoparticles.