Objective To explore proprioceptive changes in patients with knee osteoarthritis(KOA)before and after total knee arthroplasty(TKA).Methods Thirty-four KOA patients were selected as the experimental group and divided into posterior-cruciate-retaining TKA(CR-TKA)and posterior-stabilized TKA(PS-TKA)groups according to the surgical method and followed up for three months after the surgery.Twenty healthy individuals were included as the control group.The proprioception(position sense,kinesthesia,and force sense)of healthy individuals and KOA patients before and after surgery was assessed using the Biodex system III isokinetic training system,self-designed force sense test equipment,and surface electromyography test system,and the data were processed and analyzed.Results Compared with healthy individuals,KOA patients had significantly worse position sense at 30°,45°,and 60°,kinesthesia,and semitendinosus force sense in the affected and unaffected knees(P<0.05).Three months after surgery,there were significant differences in the force sense of the affected biceps femoris and contralateral semitendinosus forces in the CR-TKA group compared with healthy individuals(P<0.05).There were no statistically significant differences in deviation for preoperative and 3-month preoperative position sense,kinesthetic sense,and force sense on the affected and contralateral knee joints between the CR-TKA and PS-TKA groups(P>0.05).Conclusions Knee proprioception in KOA patients was significantly impaired compared with that in healthy individuals.No significant improvement in proprioception was found three months after TKA in the CR-TKA and PS-TKA groups.There was no difference in proprioception among the different surgical methods.The results can provide data support for clinical diagnosis and treatment,as well as determine a direction for subsequent rehabilitation programs.

OBJECTIVE To study the pharmacokinetics of Esketamine hydrochloride nasal spray in rats and ciliary toxicity to maxillary mucosa of bullfrog. METHODS The plasma concentration of esketamine hydrochloride in rats was determined by LC-MS/ MS after intravenous injection of esketamine hydrochloride solution and nasal administration of esketamine hydrochloride； the pharmacokinetic parameters were calculated by using Phoenix WinNonlin 8.1.0 software. Using the maxillary mucosa of isolated bullfrog as a model， the morphological changes of maxillary mucosa were investigated， and the duration and recovery of ciliary oscillation were recorded after nasal administration of esketamine hydrochloride. RESULTS The peak of blood concentration occurred 2 min after nasal administration of esketamine hydrochloride； cmax was （814.58±418.80） ng/mL， AUC0－∞ was （203.75± 92.76） ng·h/mL， and the absolute bioavailability was 60.68%. After nasal administration of esketamine hydrochloride， it was observed that the cilia of bullfrog were arranged neatly， the edges were clear， the cilia tissue structure was complete and the cilia moved actively. The cilia movement time was （178.17±13.30） min for the first time， and after the cilia moved again， the ciliary movement time measured again was （24.50±9.19）min with a relative movement percentage of 53.56%. CONCLUSIONS Esketamine hydrochloride nasal spray has a rapid onset of action， high bioavailability， and low ciliary toxicity.