Spine system changes in soldiers after load carriage training in a plateau environment: a prediction model research.

BACKGROUND: Low back pain is the most common spinal disorder among soldiers, and load carriage training (LCT) is considered the main cause. We aimed to investigate changes in the spine system of soldiers after LCT at high altitudes and the change trend of the lumbar spine and surrounding soft tissues under different load conditions. METHODS: Magnetic resonance imaging scans of the lumbar spines of nine soldiers from plateau troops were collected and processed. We used ImageJ and Surgimap software to analyze changes in the lumbar paraspinal muscles, intervertebral discs (IVDs), intervertebral foramina, and curvature. Furthermore, the multiple linear regression equation for spine injury owing to LCT at high altitudes was established as the mathematical prediction model using SPSS Statistics version 23.0 software. RESULTS: In the paraspinal muscles, the cross-sectional area (CSA) increased significantly from 9126.4 ± 691.6 mm2 to 9862.7 ± 456.4 mm2, and the functional CSA (FCSA) increased significantly from 8089.6 ± 707.7 mm2 to 8747.9 ± 426.2 mm2 after LCT (P < 0.05); however, the FCSA/CSA was not significantly different. Regarding IVD, the total lumbar spine showed a decreasing trend after LCT with a significant difference (P < 0.05). Regarding the lumbar intervertebral foramen, the percentage of the effective intervertebral foraminal area of L3/4 significantly decreased from 91.6 ± 2.0 to 88.1% ± 2.9% (P < 0.05). For curvature, the lumbosacral angle after LCT (32.4° ± 6.8°) was significantly higher (P < 0.05) than that before LCT (26.6° ± 5.3°), while the lumbar lordosis angle increased significantly from 24.0° ± 7.1° to 30.6° ± 7.4° (P < 0.05). The linear regression equation of the change rate, △FCSA% = - 0.718 + 23.085 × load weight, was successfully established as a prediction model of spinal injury after LCT at high altitudes. CONCLUSION: The spinal system encountered increased muscle volume, muscle congestion, tissue edema, IVD compression, decreased effective intervertebral foramen area, and increased lumbar curvature after LCT, which revealed important pathophysiological mechanisms of lumbar spinal disorders in soldiers following short-term and high-load weight training. The injury prediction model of the spinal system confirmed that a load weight < 60% of soldiers' weight cannot cause acute pathological injury after short-term LCT, providing a reference supporting the formulation of the load weight standard for LCT.

Intra-Articular Injection of Tranexamic Acid on Perioperative Blood Loss During Unicompartmental Knee Arthroplasty.

BACKGROUND Tranexamic acid (TXA) is safe and effective in total knee arthroplasty (TKA) for the prevention of bleeding. However, the role of TXA during unicompartmental knee arthroplasty (UKA) remains unclear. This study aimed to compare operative blood loss in patients undergoing UKA treated with an intra-articular injection of TXA with controls undergoing UKA without TXA. MATERIAL AND METHODS The prospective study included 101 patients who underwent UKA between January 2014 to March 2018. All patients completed a preoperative routine examination and were randomized to the study group (n=54) and the control group (n-47). The study group was given an articular injection of TXA (1.5 g in 50 ml normal saline) after the fascia was closed; the control group was injected with the same volume of normal saline. Blood volumes were measured from the drainage tube of the two groups during 48 hours. Total blood loss, postoperative drainage, hidden blood loss, blood transfusion rates, postoperative hemoglobin values, indicators of coagulation function, and the rates of wound complications were recorded. RESULTS Total blood loss in the study group was 745.6±105.1 ml, total drainage volume was 353.9±79.5 ml, and the hidden blood loss was 391.7±80.5 ml, which were all significantly lower when compared with the control group (P<0.05). None of the patients in the two groups suffered complications of surgery. CONCLUSIONS Intra-articular injection of TXA significantly reduced the total blood loss in patients who underwent UKA and did not increase the rate of complications.

Adiponectin receptor 1 mediates the difference in adiponectin- induced prostaglandin E2 production in rheumatoid arthritis and osteoarthritis synovial fibroblasts.

BACKGROUND: The synovial fluid concentrations of adiponectin are significantly higher in patients with rheumatoid arthritis (RA) than in patients with osteoarthritis (OA). Accumulating evidence suggests that adiponectin may be an inducer of inflammation in arthritis, but the mechanism remains unclear. The objectives of this study were to compare the expression levels of adiponectin receptors in rheumatoid arthritis synovial fibroblasts (RASF) and osteoarthritis synovial fibroblasts (OASF), evaluate the roles of adiponectin receptors in adiponectin-induced prostaglandin E(2) (PGE(2)) production, and then investigate the effects of a nonsteroidal anti-inflammatory drug (NSAID) and a cyclooxygenase (COX)-2-selective inhibitor on adiponectin-induced PGE(2) release. METHODS: The expressions of adiponectin receptor 1 (AdipoR1) and AdipoR2 mRNA and protein in synovial fibroblasts from seven patients with RA and eight patients with OA undergoing total knee replacement were evaluated by real-time polymerase chain reaction, immunofluorescence microscopy and Western blotting analysis. Adiponectin-induced PGE(2) production was detected by enzyme-linked immunosorbent assay. RNA interference against the AdipoR1 and AdipoR2 genes was performed to investigate the effects of the adiponectin receptors on adiponectin-induced PGE(2) production in both RASF and OASF. RESULTS: AdipoR1 and AdipoR2 mRNA and protein were expressed by both RASF and OASF. Compared with OASF, RASF exhibited higher levels of AdipoR1, but there was no significant difference for AdipoR2. Adiponectin induced the production of PGE(2) by the synovial fibroblasts in a concentration-dependent manner, and this was more obvious in RASF. RNA interference showed that the difference may be mediated by the diverse distribution of AdipoR1. The adiponectin-induced PGE(2) production was efficiently relieved by the NSAID and COX-2-selective inhibitor. CONCLUSION: The present findings suggest that AdipoR1 may mediate the difference in adiponectin-induced PGE(2) production in RASF and OASF.