ObjectiveTo study the effect and mechanism of lipopolysaccharide (LPS) on osteoclasts formation and its bone resorption function.MethodsBone marrow-derived macrophages (BMMs) were extracted from the marrow of femur and tibia of 4-week-old male C57BL/6 mice. Flow cytometry was used to detect BMMs. The effect of different concentrations of LPS (0, 100, 200, 500, 1 000, 2 000 ng/mL) on BMMs activity was examined by cell counting kit 8 (CCK-8) activity test. In order to investigate the effect of LPS on osteoclastogenesis, BMMs were divided into macrophage colony-stimulating factor (M-CSF) group, M-CSF+receptor activator of nuclear factor κB ligand (RANKL) group, M-CSF+RANKL+50 ng/mL LPS group, M-CSF+RANKL+100 ng/mL LPS group. After the completion of culture, tartrate resistant acid phosphatase (TRAP) staining was used to observe the formation of osteoclasts. In order to investigate the effect of LPS on the expression of Connexin43, BMMs were divided into the control group (M-CSF+RANKL) and the LPS group (M-CSF+RANKL+100 ng/mL LPS); and the control group (M-CSF+RANKL), 50 ng/mL LPS group (M-CSF+RANKL+50 ng/mL LPS), and 100 ng/mL LPS group (M-CSF+RANKL+100 ng/mL LPS). The expressions of Connexin43 mRNA and protein were detected by Western blot and real-time fluorescent quantitative PCR, respectively. In order to investigate the effect of LPS on osteoclast bone resorption, BMMs were divided into M-CSF group, M-CSF+RANKL group, M-CSF+RANKL+50 ng/mL LPS group, and M-CSF+RANKL+100 ng/mL LPS group. Bone absorption test was used to detect the ratio of bone resorption area.ResultsThe flow cytometry test confirmed that the cultured cells were BMMs, and CCK-8 activity test proved that the 100 ng/mL LPS could promote the proliferation of BMMs, showing significant differences when compared with the 0, 200, 500, 1 000, and 2 000 ng/mL LPS (P<0.05). TRAP staining showed no osteoclast formation in M-CSF group. Compared with M-CSF+RANKL group, the osteoclasts in M-CSF+RANKL+50 ng/mL LPS group and M-CSF+RANKL+100 ng/mL LPS group were larger with more nuclei, while the osteoclasts in M-CSF+RANKL+100 ng/mL LPS group were more obvious, and the differences in the ratio of osteoclast area between groups were statistically significant (P<0.05). Western blot result showed that the relative expression of Connexin43 protein in LPS group was significantly higher than that in control group (P<0.05). Real-time fluorescent quantitative PCR showed that the relative expression of Connexin43 mRNA in control group, 50 ng/mL LPS group, and 100 ng/mL LPS group increased gradually, and the differences between groups were statistically significant (P<0.05). Bone resorption test showed that osteoclast bone resorption did not form in M-CSF group, but the ratio of bone resorption area increased gradually in M-CSF+RANKL group, M-CSF+RANKL+50 ng/mL LPS group, and M-CSF+RANKL+100 ng/mL LPS group, and the differences between groups were statistically significant (P<0.05).ConclusionLPS at concentration of 100 ng/mL can promote the expression of Connexin43, resulting in increased osteoclastogenesis and enhanced osteoclastic bone resorption.
Objective To evaluate the effectiveness of arthroscopic Pushlock anchor fixation with iliac creast bone autograft in the treatment of recurrent anterior shoulder instability with critical bone defect. Methods The clinical data of 80 patients with recurrent anterior shoulder instability with critical bone defect treated by arthroscopic Pushlock anchor fixation with iliac creast bone autograft between January 2016 and January 2019 were retrospectively analyzed. The patients were all male; they were 18-45 years old at the surgery, with an average of 25 years old. The disease duration ranged from 3 months to 5 years, with an average of 2 years. The shoulder joint dislocated 3-50 times, with an average of 8 times. X-ray films, MRI, CT scans and three-dimensional reconstruction of the shoulder were performed before operation. The area of the anterior glenoid defect was 25%-45%, with an average of 27.3%. The shoulder mobility (forward flexion and external rotation in abduction at 90°), the Constant-Murley score, and the Rowe score were used to evaluate the shoulder function before operation and at last follow-up. ResultsPatients were followed up 1-3 years, with an average of 2 years. No shoulder dislocation occurred again during follow-up. All partial graft absorption occurred after operation, CT scan showed that the graft absorption ratio was less than 30% at 1 week and 3 months after operation. CT three-dimensional reconstruction at 1 year after operation showed that all grafts had healed to the glenoid. The anterior glenoid bone defect was less than 5% (from 0 to 5%, with an average of 3.2%). At last follow-up, the shoulder mobility (forward flexion and external rotation in abduction at 90°), the Constant-Murley score, and the Rowe score significantly improved when compared with preoperative ones (P<0.05). The shoulder mobility of external rotation in abduction at 90° of the affected side limited when compared with the healthy side [(6.7±5.1)°]. ConclusionArthroscopic Pushlock anchor fixation with iliac creast bone autograft has a good effectiveness in the treatment of recurrent anterior shoulder instability with critical bone defect. The method is relatively simple and the learning curve is short.
Objective To investigate the biomechanical characteristics of self-developed distraction reduction fixation system (DRFS) and to evaluate its cl inical effect on thoracolumbar vertebrate fracture. Methods Twelve fresh porcine spines were prepared for the biomechanical test. The stiffness of each intact specimen were recorded on forward bending (20°),backward bending (10°), lateral bending (30°) and axial rotation (20°), and then specimens of fracture dislocation were made by cuneiform osteotomy of L3 vertebral body and excision of posterior facet joints. Finally, DRFS internal fixation was performed on each specimen. The stiffness of specimens in fracture dislocation and after DRFS fixation were measured during the same movements mentioned above, respectively. The cl inical effect of DRFS on thoracolumbar vertebrate fracture in 31 patients (aged 17-46 years with an average of 32.1) from April 1998 to October 2002 was summarized. Fracture types were classified according to Denis classification: 2 patients suffered simple compressed fracture, 16 burst fracture, and 13 fracture dislocation, including 2 cases of T11, 11 cases of T12, 14 cases of L1 and 4 cases of L2. Frankel and X-ray examination were adopted to assess the results. Results The stiffness during forward bending, backward bending, lateral bending and axial rotation in the fracturedislocation state was markedly lower than that of the corresponding movements of the intact porcine spines (P lt; 0.05). After DRFS, the stiffness during various movements increased to the level that significantly higher than that in the fracture-dislocation state (P lt; 0.05), and the stiffness during backward bending was of significant difference (P lt; 0.05), but without significant difference during the rest three movements (P gt; 0.05) when compared to that in intact spines. Regarding cl inical observation, the operation time was 2.2-4.1 hours (2.7 hours on average) and blood loss was 250-600 mL (450 mL on average). The patients were followed up for 5-20 months (10.2 months on average). The heal ing time for fracture was 5-11months (8 months onaverage). The mean anterior and posterior heights of the injured vertebrate recovered from 46.2% ± 7.5% and 76.4% ± 2.4% preoperatively to 89.8% ± 4.6% and 94.1% ± 1.5% postoperatively (P lt; 0.05).The median point height also raised from 60.8% ± 6.4% to 90.7% ± 2.9% (P lt; 0.05). The Cobb’s angle decreased from (26.3 ± 5.9)° to (5.2 ± 1.8)° (P lt; 0.05), and all the sl ipped vertebrates were well repositioned. Spine function was assessed by Frankel classification as follows: 2 of 5 Class A preoperatively improved to Class B postoperatively, and the other 3 remained unchanged ; 4 of 6 from B to C, and the other 2 to D; 6 of 13 from C to D, and the other 7 to E; and 7 from D to E. Conclusion DRFS is capable of providing sufficient stabil ity, meeting the requirement of the spine physical activity without any obvious side effect. DRFS, as a handy, safe and effective technique in cl inical practice, is featured by satisfying functions of distraction, reposition and fixation.