Quantitative study on the biomechanical mechanism of sacroiliac joint subluxation: A finite element study.

The biomechanical mechanism of sacroiliac joint pain caused by sacroiliac joint subluxation is still unclear. And the purpose of this study is to elucidate the mechanism. In the present study, a finite element model of female lumbar spine-pelvis-femur was established. To simulate the sacroiliac joint subluxation quantitatively, the left ilium was shifted ±1, ±2, and ±3 mm along each axis, respectively. The stress and strain of articular surfaces and ligaments between the sacroiliac joint subluxation model and the normal model were compared. When the left ilium shifted along the positive direction of the X/Y/Z axis, the stress on most articular surfaces of the sacroiliac joint increased, of which the stress on the iliac surface of the right sacroiliac joint increased most obviously. The stress and strain of the ligaments increased most obviously when the left ilium shifted along the Y-axis, of which the left sacrospinous ligament increased the most, followed by the right sacrospinous ligament and right long posterior sacroiliac ligament. While the left long posterior sacroiliac ligament decreased the most, followed by the left short posterior sacroiliac ligament. The present study suggests that when the sacroiliac joint subluxation happens, even a slight shift, different biomechanical changes of different ligaments around the sacroiliac joint will happen. This may lead to an abnormal proprioceptive sensation of the ligaments, resulting in stress imbalance of the sacroiliac joint, and finally resulting in sacroiliac joint pain.

Decoction of Heat-Clearing, Detoxifying and Blood Stasis Removing Relieves Acute Soft Tissue Injury via Modulating MiR-26b-5p/COX2 Axis to Inhibit Inflammation.

Traditional Chinese medicine (TCM), such as Huanglian-Jie-Du-Tang, a heat-clearing and detoxifying decoction is beneficial to alleviation of inflammation-related diseases. The objective of this study is to uncover the effect and mechanism of heat-clearing, detoxifying and blood stasis removing decoction (HDBD) on the treatment of acute soft tissue injury (STI) which is characterized with excessive inflammatory cascade at the onset. Male Sprague-Dawley (SD) rats with hammer beating served as the in vivo models of acute STI. Haematoxylin-eosin (HE) staining was used for histopathology assessment. The levels of inflammatory factors, including prostaglandin E2 (PGE2), tumor necrosis factor-αumTNF-α), interleukin (IL)-1t and IL-6 were measured by enzyme linked immunosorbent assay (ELISA). Human dermal microvascular endothelium cell line HMEC-1 and rat vascular endothelium cell line RAOEC were used to explore the mechanism in vitro. Luciferase gene reporter assay was applied to determine the relationship between miR-26b-5p and COX2. The results showed that HDBD intervention significantly reduced the temperature difference between the healthy side and affected side of rats with hammer beating, together with the decreased levels of COX2, PGE2, TNF-α, IL-6 and IL-1ß, and the increased level of miR-26b-5p. In mechanism, miR-26b-5p targeted COX2 and decreased its expression, leading to significant decreases in the levels of PGE2, TNF-α and IL-6 in RAOEC and HMEC-1 cells. In addition, miR-26b-5p inhibition impaired the effects of HDBD on the suppression of PGE2, TNF-α, IL-6 and IL-1ß in vitro. In conclusion, this study revealed that HDBD relieved acute STI via modulating miR-26b-5p/COX2 axis to inhibit inflammation.