Association between imaging parameter changes and triangular fibrocartilage complex injury after distal radius fractures.

BACKGROUND: Triangular fibrocartilage complex (TFCC) injury is a frequent soft tissue injury that has been observed to accompany distal radius fractures (DRFs) with concomitant changes in radiologic parameters. The aim of this study was to investigate the relevance of distal radial radiologic parameters associated with DRF and traumatic TFCC injury. METHODS: A total of 172 patients with distal radius fractures who underwent X-ray, CT, and MRI before undergoing volar locking plate or external splint fixation between October 2021 and December 2022 were included in this study. An analysis of various radiologic parameters and the classification of fracture type and TFCC injuries by CT and MRI was performed. All patients were divided into the TFCC uninjured group and the injured group. The incidence and relevant radiologic parameters were compared. RESULTS: This study included 76 males and 96 females with a mean age of 56.1 years. Among all patients, 33 (19.2%), 40 (23.2%), and 99 (57.6%) had DRF with A, B, and C fractures, respectively, according to the AO/OTA classification. In patients with fractures, the TFCC was found to be injured in 54.1% (93/172) of patients (type 1A in 21, 1B in 46, 1C in 39, and 1D in 35) but uninjured in 45.9% (79/172). There were significant differences between the TFCC injured and uninjured groups regarding the radius length (p = 0.044) and DRUJ distance (p = 0.040) of radiologic parameters that changed with DRF, although there were no differences between the two groups regarding gender, age, injured side, intra- and extra-articular, radius inclination and palmer tilt angle, or sagittal translation. Within the TFCC injured group, the radius length and DRUJ distance were 4.83 mm and 2.95 mm less or wider than 7.19 mm and 1.83 mm of the uninjured group. Moreover, shorter radius length was related to type lB TFCC injury (p = 0.041). Both radius length (AUC = 0.658) and DRUJ distance (AUC = 0.582) had no convincing predictive value for TFCC injury in DRF. CONCLUSION: 1B TFCC injury is most common in patients with DRF and concomitant TFCC injury. Both radius length and DRUJ distance have a significant statistical correlation with TFCC injury, and patients with TFCC injury tend to have a shortened radius and wider DRUJ distance, although they have no predictive value for TFCC injury in DRF. In addition, a shorter radius length was related to type lB TFCC injury.

GSDMD inhibitor protects chondrocyte from mechanical injury in human articular cartilage.

Traumatic arthritis is caused by mechanical injury and results in the degeneration of articular cartilage, but it is unclear whether it is related to the pyroptosis of chondrocyte (CHs). Thus, this study was designed to investigate the role of GSDMD, the executor of pyroptosis, in the human cartilage during mechanical injury. We collected the human hip joint and used a loading apparatus to produce compression on the cartilage disc. After one hour of 15 MPa or 25 MPa injury, the acute and chronic effects of the mechanical injury on the cartilage were tested. We stained the CHs in the cartilage with calcein and DAPI to calculate the live-cell rate. The chondrogenic phenotype was determined by analyzing the mRNA levels of type II collagen alpha 1 (Col2A1), type I collagen alpha 2 (Col2A1), and SOX9. Besides, the pyroptosis process was determined by the mRNA levels of caspase-1/5, GSDMD, IL-1ß, and IL-18. We also explored the preventive role and therapeutic role of GSDMD inhibitors in mechanical injury via culturing the cartilage before and after the compression, respectively. Mechanical compression injured the viability and function of CHs in cartilage partly based on the pyroptosis. The pretreatment of GSDMD inhibitor in cartilage before injury could maintain the live cells and Col2A1 expression and prevent pyroptosis after injury. Besides, supplying the cartilage with GSDMD inhibitor after injury also alleviated the cell death and dysfunction of CHs, and suppressed the pyroptosis. Using an inhibitor of GSDMD can play a preventive role and play a therapeutic role in the mechanical injury of cartilage.

Expression of MicroRNA-29a Regulated by Yes-Associated Protein Modulates the Neurite Outgrowth in N2a Cells.

Yes-associated protein (YAP) is proved to increase miR-29a in the present study, but the relevant molecular mechanism is not clear. Also, growing evidence indicates that the high-level miR-29a promotes the neurite outgrowth by decreasing PTEN (phosphatase and tensin homologue deleted on chromosome 10). Results show that the expression of miR-29a increases but the PTEN decreases during transfecting the N2a cells with the YAP plasmid. Meanwhile, the advancement of neurite outgrowth is presented via using multiple methods to detect the expression of GAP-43 and NF-200, which have a strong association with neurite outgrowth. The expression of miR-29a, GAP-43, and NF-200 shows an opposite tendency compared to the PTEN when YAP is downregulated. By treating N2a cells with miR-29a mimic and inhibitor, we also find the same conclusion. For in silico analysis of miR-29a, its promoter may have a binding site for YAP. Based on a luciferase reporter assay and a chromatin immunoprecipitation (ChIP) experiment, we demonstrate that YAP could increase the expression of miR-29a by targeting the promoter of miR-29a. In conclusion, the results identify that YAP promotes the neurite outgrowth via targeting the promoter of miR-29a, and it may be an effective therapeutic medicine for the neural disease.