BackgroundConsistent reference data used for anatomic posterior cruciate ligament (PCL) reconstruction is not well defined. Quantitative guidelines defining the location of PCL attachment would aid in performing anatomic PCL reconstruction. The purpose was to characterize anatomic parameters of the PCL tibial attachment based on magnetic resonance imaging (MRI) in a large population of adult knees.MethodsThe PCL tibial attachment site was examined in 736 adult knees with an intact PCL using 3.0-T proton density–weighted sagittal MRI. The outcomes measured were the anterior-posterior diameter (APD) of the tibial plateau; angle between the tibial plateau and the posterior tibial ‘shelf’ (the slope where the PCL tibial attachment site was) (PTS); length of the PTS; proximal, central, and distal PCL attachment positions as well as the width of the PCL attachment site; and vertical dimension of the PCL attachment site inferior from the tibial plateau.ResultsThe average APD of the tibia plateau was 33.6 ± 3.5 mm, yielding significant differences between males (35.5 ± 3.0 mm) and females (31.6 ± 2.7 mm), P <.05, and there was a significantly decreasing trend with increasing age in males (P <.05). Mean angle between the tibial plateau and the PTS was 122.4° ± 8.1°, and subgroup analysis showed that the young group had a differently smaller angle (120.9° ± 7.5°) than the middle-aged (123.7° ± 8.2°) and the old (123.4° ± 7.7°) in males population, while there were no significant differences between sexes (P >.05). The proximal, central positions and width of the PCL attachment site were 13.4 ± 3.0 mm, 17.8 ± 3.0 mm and 9.6 ± 2.4 mm along the PTS, with significant differences between males and females (P <.05), and accounted for 60.0 % ± 9.1 %, 80.0 % ± 4.6 % and 43.3 % ± 9.7 % of the PTS respectively, with no significant differences between sexes and among age groups (all P >.05).ConclusionsThis study provides reference data of the tibial PCL attachment based on MRI in the sagittal orientation. In analysis of retrospective data from a large population of adult patients, the quantitative values can be used as references to define the inserted angle and depth of the drill guide, and the exact position and size of the tibial PCL tunnel for performing arthroscopic anatomic PCL reconstruction.

α‐Mangostin (α‐M) is a commonly used traditional medicine with various biological and pharmacological activities. Our study aimed to explore the effects and mechanism of α‐M in regulating apoptosis of rheumatoid arthritis fibroblast‐like synoviocytes (RA‐FLS). α‐M of 10 to 100 μM was used to treat RA‐FLS for 24 hours, followed by measuring cell viability and apoptosis. The involvement of reactive oxygen species (ROS) and mitogen‐activated protein kinases was detected. Treatment of α‐M promoted apoptosis and reduced viability of RA‐FLS in a dose‐dependent manner. The mitochondrial membrane potential in RA‐FLS was remarkably reduced by α‐M treatment, accompanied by the cytochrome c accumulation in the cytosol and increased activities of caspase‐3 and caspase‐9. Moreover, we found that α‐M treatment promoted ROS production and extracellular signal‐regulated kinase 1/2 (ERK1/2) phosphorylation. The proapoptotic activity of α‐M in RA‐FLS was markedly reversed by the co‐induction with the ERK1/2 inhibitor LY3214996 or ROS scavenger N‐acetyl‐l‐cysteine. In conclusion, our studies found that α‐M had remarkable proapoptotic activities in RA‐FLS, which is regulated by the induction of ROS accumulation and ERK1/2 phosphorylation. α‐M may thus have potential therapeutic effects for rheumatoid arthritis.

Waste medicinal plants are widely used in drug production. With the increasing demand for botanical drugs, there is an urgent need to identify new and effective drugs and improve the utilization of medicinal plant resources. Wuteng tablets (WTP) are extracted from the stem of Schisandra chinensis and have a good therapeutic effect on Alzheimer’s disease. In this study, a holistic identification strategy based on UHPLC–Q/TOF–MS was developed for the first time to investigate the metabolites and metabolic pathways involved in the in vitro metabolism and liver microsomal incubation and in the in vivo metabolic system of rats after WTP administration. After the oral administration of WTP, 21 metabolites were identified in the serum and 25 metabolites were identified in the urine, of which six were new metabolites; 33 metabolites were inferred from the microsomal metabolites in vitro. The metabolic pathways related to WTP mainly involve demethylation, hydroxylation, dehydroxylation and dehydrogenation. In this study, the metabolites and metabolic pathways of WTP were elucidated via UHPLC–Q/TOF–MS, which provided a basis for an in‐depth study of the pharmacodynamic and pharmacotoxicological effects of WTP.