Effect of endplate reduction on endplate healing morphology and intervertebral disc degeneration in patients with thoracolumbar vertebral fracture.

OBJECTIVE: To determine the effect of endplate reduction on the final healing morphology and degenerative changes in intervertebral discs. METHODS: Forty-eight patients with single-level thoracolumbar fractures with endplate injury were included. All patients underwent posterior reduction and pedicle screw fixation, and postoperative imaging was used to determine whether endplate reduction was successful. The healing morphology of the endplate was divided into three types: increased endplate curvature, irregular healing and traumatic Schmorl node. MRI was performed at baseline and at the last follow-up evaluation to observe changes in disc degeneration (disc height and nucleus pulposus signal) and Modic changes. RESULTS: The reduction rate in the central area was significantly lower than that in the peripheral area (P = 0.017). In patients with successful reduction, 90.9% (20/22) of the endplates healed with increased curvature. In patients with an unsuccessful endplate reduction, 63.4% (26/41) of the endplates healed irregularly, and 34.1% (14/41) of the endplates formed traumatic Schmorl nodes. Endplate reduction was closely related to the final healing morphology of the endplate (P < 0.001), which had a significant protective effect on the degeneration of the intervertebral disc. At the last follow-up evaluation, there was no statistically significant correlation between different endplate healing morphologies and new Modic changes. CONCLUSIONS: The reduction rate in the central area is significantly lower than that in the peripheral area. Although all of the intervertebral discs corresponding to fractured endplates had degenerated to different degrees, successful endplate fracture reduction can obviously delay the degeneration of intervertebral discs.

Strontium Ranelate Combined with Insulin Is as Beneficial as Insulin Alone in Treatment of Fracture Healing in Ovariectomized Diabetic Rats.

BACKGROUND Type 2 diabetes mellitus (T2DM) and estrogen deficiency both predispose fracture patients to increased risk of delayed union or nonunion. The present study investigated the effects of strontium ranelate (SR) on fracture healing in ovariectomized (OVX) diabetic rats. MATERIAL AND METHODS A mid-shaft fracture was established in female normal control (CF), diabetic (DF), and OVX diabetic (DOF) rats. Treated DOF rats received either insulin alone (DOFI) or combined with SR (DOFIS). All rats were euthanized at 2 or 3 weeks after fracture. Fracture healing was evaluated using radiological, histological, immunohistochemical, and micro-computed tomography analyses. RESULTS At 3 weeks after fracture, radiological and histological evaluations demonstrated delayed fracture healing in the DF group compared with the CF group, which was exacerbated by OVX, as indicated by the significantly lower X-ray score, BMD, BV/TV, and Md.Ar/Ps.Cl.Ar, and the markedly decreased OCN and Col I expression in the DOF group. All these changes were prevented by insulin alone or combined with SR treatment. In comparison with the DOFI group, DOFIS rats displayed markedly higher OCN expression at 2 weeks after fracture and Col I expression at 2 and 3 weeks after fracture. CONCLUSIONS These results demonstrated delayed fracture healing with preexisting estrogen deficiency and T2DM. While insulin alone and combined with SR were both effective in promoting bone fracture healing in this model, their combined treatment showed significant improvement in promoting osteogenic marker expression, but not of the radiological appearance, compared with insulin alone.

Effectiveness of the Endplate Reduction Technique Combined With Bone Grafting for the Treatment of Thoracolumbar Fractures by Using Posterior Short-Segment Fixation.

OBJECTIVE: This study aimed to examine the effect of the endplate reduction (EPR) technique combined with bone grafting for treating thoracolumbar burst fractures using posterior short-segmental fixation. METHODS: Patients with thoracolumbar fractures admitted between January 2018 and October 2021 were retrospectively analyzed, and those meeting the criteria were assigned to the EPR group and the intermediate screws (IS) group. The vertebral wedge angle (VWA), Cobb angle (CA), anterior vertebral body height (AVBH), middle vertebral body height (MVBH), upper endplate line (UEPL), upper intervertebral angle (UIVA), and upper intervertebral disc height (UIDH) indices were examined and compared preoperatively, first day postoperatively, as well as at 12 months postoperatively. RESULTS: The result indicated that the EPR group achieved better MVBH reduction (p < 0.001), UEPL reduction (p < 0.001), vertebral body fracture healing (p = 0.006), as well as implant breakage (p = 0.04) than the IS group; VWA (p < 0.001), CA (p = 0.005), AVBH (p < 0.001), MVBH (p < 0.001), UEPL (p < 0.001), and UIDH (p < 0.001) were lost after reduction less than those in the IS group. There was no significant difference in operative time (p = 0.315) and intraoperative bleeding (p = 0.274) between the 2 groups. CONCLUSION: The EPR group achieved better results in repositioning and maintaining MVBH and endplate morphology, with less correction loss after the reduction of the VWA, CA, AVBH, and endplate morphology. The EPR group exhibited a better healing pattern after vertebral fracture and disc degeneration was better relieved.

Reparative effects of chronic intermittent hypobaric hypoxia pre­treatment on intervertebral disc degeneration in rats.

Previous studies have indicated that chronic intermittent hypobaric hypoxia (CIHH) preconditioning can inhibit TNF­α and other related inflammatory cytokines and exerts protective effect on intervertebral disc degeneration disease (IDD) in rats; however, the mechanism is still unclear. The present study aimed to explore the repair mechanisms of CIHH on IDD in rats. In the experiment, 48 adult Sprague­Dawley rats were selected and randomly divided into an experimental group (CIHH­IDD), a degenerative group (IDD) and a control group (CON). The CIHH­IDD group of rats (n=16) were treated with CIHH (simulated 3000 m altitude, 5 h per day, 28 days; PO2=108.8 mmHg) before disc degeneration surgery. The IDD group of rats (n=16) underwent tail­vertebral intervertebral disc surgery to establish a model of intervertebral disc degeneration. The CON group of rats (n=16) did not receive any treatments. After surgery, the disc height index was calculated using X­ray analysis of rat tail vertebrae, the degeneration process was observed and repair was evaluated by chemically staining degenerative intervertebral disc tissue slices. The expression levels of basic fibroblast growth factor (bFGF), TGFß1, Collagen I and Collagen II were measured in the intervertebral disc tissue using western blotting; while the expression levels of bFGF, TGFß1 and hypoxia­inducible factor 1­α (HIF­1α) were measured in rat serum using ELISA. The results demonstrated that: i) The degree of intervertebral disc height degeneration in CIHH­IDD rats was significantly lower compared with that in IDD rats (P<0.05); ii) the expression levels of bFGF, TGFß1 and HIF­1α were higher in CIHH­IDD rat serum compared with those in IDD rat serum (P<0.05); iii) optical microscopy revealed that the degree of disc degeneration was relatively mild in CIHH­IDD rats; and iv) the protein expression levels of bFGF, TGFß1 and collagen II were increased in CIHH­IDD rat intervertebral disc tissues compared with those of IDD rats, while the overexpression of collagen I protein was inhibited. Overall, after CIHH pre­treatment, the expression levels of bFGF and TGFß1 were up­regulated, which play notable roles in repairing degenerative intervertebral discs in rats.

A finite element analysis of the supportive effect of a new type of rotary support plate on lateral tibial plateau fractures.

Background: Tibial plateau fractures (TPFs) are a challenging type of fracture in orthopedic traumatology. We previously designed a plate (Patent Number: CN201520195596.5) for posterolateral TPF combined with posterior lateral collapse.. In this study, finite element analysis was used to compare the biomechanical characteristics of two internal fixation methods for posterolateral TPF. We investigated the support effect of the new steel plate on lateral TPFs combined with posterior TPFs. Methods: Two models of complex TPF were established. Model A was fixed with the new type of plate, and model B was fixed without the plate. Three axial loads of 500, 1,000, and 1,500 N were applied using FEA on the two fracture models (A and B) to analyze the data. Results: In model A, the maximum displacement at 500, 1,000, and 1,500 N was 0.085797, 0.17043, and 0.25465 mm, respectively; the maximum stress of the bone block was 11.285, 20.648, and 29.227 MPa, respectively; and the maximum strain of the bone block was 0.0012474, 0.007435, and 0.0035769 mm, respectively. The maximum displacement of the internal fixation was 0.096932, 0.18682, and 0.27655 mm, respectively; the maximum stress was 69.54, 112.1, and 155.71 MPa, respectively; and the maximum strain was 0.00066228, 0.0010676, and 0.0014829 mm, respectively. In model B, the maximum displacement of fractures at 500, 1,000, and 1,500 N was 0.15675, 0.29868, and 0.44017 mm, respectively; the maximum stress of the bone block was 6.5519, 12.575, and 18.842 MPa, respectively; and the maximum strain of the bone block was 0.0032554, 0.0074357, and 0.012146 mm, respectively. The maximum displacement of the screw was 0.14177, 0.27109, and 0.39849 mm, respectively; the maximum stress was 48.916, 92.251, and 135.27 MPa, respectively; and the maximum strain was 0.00046608, 0.00087893, and 0.0012887 mm, respectively. Conclusions: The fixation method using this type of plates and screws can replace other methods using two plates to fix complex TPF.

Accurate Placement of Cannulated Screws in Femoral Neck Fractures: Screw and Guide Wire Combined Technique.

Cannulated screw fixation is widely used in the treatment of femoral neck fractures. During surgery, we often face the situation that a guide wire needs to be adjusted because of poor positioning in the femoral neck. It is difficult to adjust the direction of the guide wire in the neck of the femur due to its elasticity. This study developed a practical technique to adjust the guide wire to the correct position. When the direction of insertion of the guide wire has deviated, first, measure the length of the guide wire. Second, select the appropriate cannulated screw based on the measurement, and screw the cannulated screw in along the direction of the guide wire to Ward's triangle. Then return the guide wire to the front of the cannulated screw. At this time, the cannulated screw can be used as a built-in guide, and a screwdriver can be used to fine-tune the position of the screw to the optimal direction under the X-ray guidance. Finally, the cannulated screw is screwed in in this direction until it passes through the Ward triangle area, and the guide wire is inserted. This technique can help doctors insert a guide wire more quickly and accurately, reducing intraoperative injury and the operation time.

Treatment of posterolateral tibial plateau fractures with a rotational support plate and special pressurizer: technical note and retrospective case series.

BACKGROUND: In tibial plateau fractures, the posterolateral segment of the tibia plateau is frequently affected and challenging to treat. Although there are many surgical approaches and fixation methods for the treatment of these fractures, all of these methods have limitations. We designed a new rotational support plate (RSP) and a special pressurizer that can fix the fracture directly via the anterolateral approach. This method is advantageous because it leads to little trauma, involves a simple operation, and has a reliable fixation effect. This study details the technique of treating these fractures with the RSP and special pressurizer and provides the outcomes. METHODS: From May 2016 to January 2019, the data of 12 patients with posterolateral tibial plateau fractures treated with the RSP and special pressurizer in our hospital were retrospectively analyzed. Postoperative rehabilitation was advised, knee X-rays were taken at follow-ups, and fracture healing, complications, and knee range of motion were assessed. The Hospital for Special Surgery (HSS) knee score and Knee Injury and Osteoarthritis Outcome Score (KOOS) were used to evaluate knee function at the last follow-up. RESULTS: The average follow-up time of all patients was 16.5 months (range, 12-25 months). The average bony union time was 3.2 months (range, 3-4.5 months). At the last follow-up, the average knee range of motion was 138° (range, 107-145°). The average HSS score was 91 (range, 64-98). The average KOOS Symptoms score was 90 (range, 75-96). The average KOOS Pain score was 91 (range, 72-97). The average KOOS ADL score was 91 (range, 74-97). The average KOOS sport/recreation score was 83 (range, 70-90). The average KOOS QOL score was 88 (range, 69-93). Skin necrosis, incision infections, and fixation failure did not occur during the follow-up period. CONCLUSIONS: With our newly designed RSP and special pressurizer, posterolateral tibial plateau fractures can be easily and effectively reduced and fixed through the anterolateral approach, which serves as a novel treatment for posterolateral tibial plateau fractures.

Upregulation of Sirt1 by tyrosol suppresses apoptosis and inflammation and modulates extracellular matrix remodeling in interleukin-1ß-stimulated human nucleus pulposus cells through activation of PI3K/Akt pathway.

Intervertebral disc degeneration (IDD) is the major pathogenesis of lower back pain. Tyrosol is a polyphenolic compound that exhibits anti-oxidant, anti-apoptotic, and anti-inflammatory effects. Herein, we explored the effects and mechanisms of tyrosol on IDD progression in interleukin (IL)-1ß-stimulated human nucleus pulposus cells (HNPCs). Cell viability and apoptosis were detected by CCK-8 and flow cytometry analysis, respectively. The production of tumor necrosis factor-α (TNF-α), IL-6, nitric oxide (NO), and prostaglandin E2 (PGE2) was examined to evaluate inflammation. The mRNA expression of matrix metalloproteinases (MMPs) (MMP-3/9/13), collagen type II, SRY-related high mobility group box 9 (SOX-9), and aggrecan was measured by qRT-PCR. Protein levels of silent information regulator 2 homolog 1 (Sirt1), phosphorylated protein kinase B (p-Akt), Akt, collagen type II, SOX-9, and aggrecan were determined by western blot. Results showed that tyrosol attenuated IL-1ß-induced viability reduction, apoptosis, and caspase-3/7 activity in HNPCs. The increase in the production of TNF-α, IL-6, NO, and PGE2 in IL-1ß-treated HNPCs was abolished by tyrosol treatment. Tyrosol treatment reversed IL-1ß-induced upregulation of MMP-3, MMP-9, and MMP-13, and downregulation of collagen II, SOX-9, and aggrecan in HNPCs. Additionally, tyrosol treatment activated the phosphatidylinositol 3-kinase (PI3K)/Akt pathway in IL-1ß-stimulated HNPCs. Sirt1 was upregulated by tyrosol, and Sirt1 silencing inhibited Akt phosphorylation in HNPCs. Sirt1 knockdown attenuated the effects of tyrosol on IL-1ß-induced apoptosis, inflammation, and ECM remodeling in HNPCs. In summary, upregulation of Sirt1 by tyrosol suppressed apoptosis and inflammation and regulated ECM remodeling in IL-1ß-stimulated HNPCs through activation of PI3K/Akt pathway.