Corylifol A suppresses osteoclastogenesis and alleviates ovariectomy-induced bone loss via attenuating ROS production and impairing mitochondrial function.

Osteoporosis is a systemic disease characterized by an imbalance in bone homeostasis, where osteoblasts fail to fully compensate for the bone resorption induced by osteoclasts. Corylifol A, a flavonoid extracted from Fructus psoraleae, has been identified as a potential treatment for this condition. Predictions from network pharmacology and molecular docking studies suggest that Corylifol A exhibits strong binding affinity with NFATc1, Nrf2, PI3K, and AKT1. Empirical evidence from in vivo experiments indicates that Corylifol A significantly mitigates systemic bone loss induced by ovariectomy by suppressing both the generation and activation of osteoclasts. In vitro studies further showed that Corylifol A inhibited the activation of PI3K-AKT and MAPK pathways and calcium channels induced by RANKL in a time gradient manner, and specifically inhibited the phosphorylation of PI3K, AKT, GSK3 ß, ERK, CaMKII, CaMKIV, and Calmodulin. It also diminishes ROS production through Nrf2 activation, leading to a decrease in the expression of key regulators such as NFATcl, C-Fos, Acp5, Mmp9, and CTSK that are involved in osteoclastogenesis. Notably, our RNA-seq analysis suggests that Corylifol A primarily impacts mitochondrial energy metabolism by suppressing oxidative phosphorylation. Collectively, these findings demonstrate that Corylifol A is a novel inhibitor of osteoclastogenesis, offering potential therapeutic applications for diseases associated with excessive bone resorption.

[Advances in surgical strategies for ossification of posterior longitudinal ligament involving the C 2 segment].

Objective: To evaluate the application of surgical strategies for the treatment of cervical ossification of the posterior longitudinal ligament (OPLL) involving the C 2 segment. Methods: The literature about the surgery for cervical OPLL involving C 2 segment was reviewed, and the indications, advantages, and disadvantages of surgery were summarized. Results: For cervical OPLL involving the C 2 segments, laminectomy is suitable for patients with OPLL involving multiple segments, often combined with screw fixation, and has the advantages of adequate decompression and restoration of cervical curvature, with the disadvantages of loss of cervical fixed segmental mobility. Canal-expansive laminoplasty is suitable for patients with positive K-line and has the advantages of simple operation and preservation of cervical segmental mobility, and the disadvantages include progression of ossification, axial symptoms, and fracture of the portal axis. Dome-like laminoplasty is suitable for patients without kyphosis/cervical instability and with negative R-line, and can reduce the occurrence of axial symptoms, with the disadvantage of limited decompression. The Shelter technique is suitable for patients with single/double segments and canal encroachment >50% and allows for direct decompression, but is technically demanding and involves risk of dural tear and nerve injury. Double-dome laminoplasty is suitable for patients without kyphosis/cervical instability. Its advantages are the reduction of damage to the cervical semispinal muscles and attachment points and maintenance of cervical curvature, but there is progress in postoperative ossification. Conclusion: OPLL involving the C 2 segment is a complex subtype of cervical OPLL, which is mainly treated through posterior surgery. However, the degree of spinal cord floatation is limited, and with the progress of ossification, the long-term effectiveness is poor. More research is needed to address the etiology of OPLL and to establish a systematic treatment strategy for cervical OPLL involving the C 2 segment.

Isoimperatorin attenuates bone loss by inhibiting the binding of RANKL to RANK.

Osteoporosis, an immune disease characterized by bone mass loss and microstructure destruction, is often seen in postmenopausal women. Isoimperatorin (ISO), a bioactive, natural furanocoumarin isolated from many traditional Chinese herbal medicines, has therapeutic effects against various diseases; however, its effect on bone homeostasis remains unclear. In this study, we investigated the effect of ISO on the differentiation and activation of osteoclast and its molecular mechanism in vitro, and evaluated the effect of ISO on bone metabolism by ovariectomized (OVX) rat model. In vitro experiments showed that ISO affected RANKL-induced MAPK, NFAT, NFATc1 trafficking and expression, osteoclast F-actin banding, osteoclast-characteristic gene expression, ROS inhibitory activity, and calcium oscillations, NF-κB signaling pathway. In vivo experiments showed that oral administration of ISO effectively reduced bone loss caused by ovariectomy and retained bone mass.Collectively, ISO inhibits RANK/RANKL binding, thereby reducing the activity of NFATc1, calcium, and ROS and inhibiting osteoclast generation. In addition, ISO protects bone mass by slowing osteoclast production and downregulating NFATc1 gene and protein expression in the bone tissue microenvironment and inhibits OVX-induced bone loss in vivo.

Comparison of pedicle screw fixation with or without cement augmentation for treating single-segment isthmic spondylolisthesis in the osteoporotic spine.

The present study examined the necessity of cement-augmented pedicle screw fixation in osteoporotic patients with single-segment isthmic spondylolisthesis.Fifty-nine cases were reviewed retrospectively. Thirty-three cases were in the polymethylmethacrylate-augmented pedicle screw (PMMA-PS) group, and the other 26 cases were in the conventional pedicle screw (CPS) group. Evaluation data included operation time, intraoperative blood loss, hospitalization cost, hospitalization days, rates of fusion, screw loosening, bone cement leakage, visual analogue scale (VAS) scores, Oswestry disability index (ODI), lumbar lordosis (LL), pelvic tilt (PT) and sacral slope (SS).The operation time and blood loss in the CPS group decreased significantly compared to those in the PMMA-PS group. The average hospitalization cost of the PMMA-PS group was significantly higher than that of the CPS group. There was no significant difference in the average hospital stay between the 2 groups. The initial and last follow-up postoperative VAS and ODI scores improved significantly in the two groups. There were no significant differences in VAS and ODI between the 2 groups at each time point. The last postoperative spine-pelvic parameters were significantly improved compared with those preoperatively. In the PMMA-PS group, the fusion rate was 100%. The fusion rate was 96.15% in the CPS group. No significant difference was found between the two groups for the fusion rate. Nine patients in the PMMA-PS group had bone cement leakage. There was no screw loosening in the PMMA-PS group. There were 2 cases of screw loosening in the CPS group. There were no significant differences in screw loosening, postoperative adjacent segment fractures, postoperative infection or postoperative revision between the 2 groups. The use of PMMA-PS on a regular basis is not recommended in posterior lumbar interbody fusion for the treatment of single-segment isthmic spondylolisthesis with osteoporosis.

Long-term efficacy and safety of bone cement-augmented pedicle screw fixation for stage III Kümmell disease.

This study aimed to evaluate the efficacy and safety of bone cement-augmented pedicle screw fixation for stage III Kümmell disease. Twenty-five patients with stage III Kümmell disease who received bone cement-augmented pedicle screw fixation at the First Affiliated Hospital of Guangzhou University of Chinese Medicine between June 2009 and December 2015 were enrolled. All patients were females with a history of osteoporosis. The vertebral Cobb angle (V-Cobb angle), the fixed segment Cobb Angle (S-Cobb angle), pelvic parameters, visual Analogue Scale (VAS) score, and Oswestry Disability Index (ODI) were assessed preoperatively, postoperatively and at the final follow-up. Complications, loosening rate, operation time, and intraoperative bleeding were recorded. The average lumbar vertebral density T-value was - 3.68 ± 0.71 SD, and the average age was 71.84 ± 5.39. The V-Cobb angle, S-Cobb angle, and Sagittal Vertical Axis (SVA) were significantly smaller postoperatively compared to the preoperative values. The VAS and ODI at 1 month after surgery were 3.60 ± 1.00 and 36.04 ± 6.12%, respectively, which were both significantly lower than before surgery (VAS: 8.56 ± 1.04, ODI: 77.80 ± 6.57%). Bone cement-augmented pedicle screw fixation is a safe and effective treatment for stage III Kümmell disease. It can effectively correct kyphosis, restore and maintain sagittal balance, and maintain spinal stability.

Carnosol suppresses RANKL-induced osteoclastogenesis and attenuates titanium particles-induced osteolysis.

Osteolysis is a common medical condition characterized by excessive activity of osteoclasts and bone resorption, leading to severe poor quality of life. It is essential to identify the medications that can effectively suppress the excessive differentiation and function of osteoclasts to prevent and reduce the osteolytic conditions. It has been reported that Carnosol (Car), isolated from rosemary and salvia, has anti-inflammatory, antioxidative, and anticancer effects, but its activity on osteolysis has not been determined. In this study, we found that Car has a strong inhibitory effect on the receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation dose-dependently without any observable cytotoxicity. Moreover, Car can inhibit the RANKL-induced osteoclastogenesis and resorptive function via suppressing NFATc1, which is a result of affecting MAPK, NF-κB and Ca2+ signaling pathways. Moreover, the particle-induced osteolysis mouse model confirmed that Car could be effective for the treatment of bone loss in vivo. Taken together, by suppressing the formation and function of RANKL-induced osteoclast, Car, may be a therapeutic supplementary in the prevention or the treatment of osteolysis.

Effect and potential risks of using multilevel cement-augmented pedicle screw fixation in osteoporotic spine with lumbar degenerative disease.

BACKGROUND: The increase of augmented level and bone cement dose are accompanied by the rising incidence of cement leakage (CL) of cement-augmented pedicle screw instrumentation (CAPSI). But the effect and potential risks of the application of CAPSI to osteoporotic lumbar degenerative disease (LDD) have not been studied in the case of multilevel fixation. This study aimed to investigate the effectiveness and potential complications of using multilevel CAPSI for patients with osteoporotic LDD. METHODS: A total of 93 patients with multilevel LDD were divided into the CAPSI group (46 subjects) and the conventional pedicle screw (CPS) group (47 subjects), including 75 cases for three levels and 18 cases for four levels. Relevant data were compared between two groups, including baseline data, clinical results, and complications. RESULTS: In the CAPSI group, a total of 336 augmented screws was placed bilaterally. The CL was observed in 116 screws (34.52%). Three cemented screws (0.89%) were found loosened during the follow-up and the overall fusion rate was 93.47%. For perioperative complications, two patients (4.35%) experienced pulmonary cement embolism (PCE), one patient augmented vertebral fracture, and three patients (6.52%) wound infection. And in the CPS group, thirty-three screws (8.46%) suffered loosening in cranial and caudal vertebra with a fusion rate of 91.49%. The operation time and hospital stay of CAPSI group were longer than the CPS group, but CAPSI group has a lower screw loosening percentage (P<0. 05). And in terms of blood loss, perioperative complications, fusion rate, and VAS and ODI scores at the follow-up times, there were no significant differences between the two groups. CONCLUSIONS: Patients with osteoporotic LDD underwent multilevel CPS fixation have a higher rate of screw loosening in the cranial and caudal vertebra. The application of cemented pedicle screws for multilevel LDD can achieve better stability and less screw loosening, but it also accompanied by longer operating time, higher incidence of CL, PCE and wound infections. Selective cement augmentation of cranial and caudal pedicle screws may be a worthy strategy to decrease the complications.

Stability Evaluation of Oblique Lumbar Interbody Fusion Constructs with Various Fixation Options: A Finite Element Analysis Based on Three-Dimensional Scanning Models.

BACKGROUND: Little is known about the biomechanical performance of various fixation constructs after oblique lumbar interbody fusion (OLIF). This study aimed to explore the stability of various fixation options for OLIF by using finite element analysis based on three-dimensional scanning models. METHODS: Six validated finite element models of the L3-L5 segment were reconstructed via computed tomography images, including (1) intact model, (2) stand-alone model with no instrument, (3) lateral rod-screw model, (4) lateral rod-screw plus contralateral translaminar facet screw (LRS-CTLFS) model, (5) unilateral pedicle screw model, and (6) bilateral pedicle screw (BPS) model. Models of the OLIF cage and pedicle screw were created with three-dimensional scanning to improve the accuracy of finite element analysis. Range of motion, stress of the cage, and stress of fixation were evaluated in the different models. RESULTS: Range of motion increased from least to greatest as follows: BPS, LRS-CTLFS, unilateral pedicle screw, lateral rod-screw, stand-alone. Differences in range of motion between BPS and LRS-CTLFS were not significant for all loading cases. Compared with the other 3 models, the stress of the cage was found to be lower in BPS and LRS-CTLFS under all loading conditions, especially in BPS. Stress exerted on the fixation was the greatest in LRS-CTLFS, and the stress experienced by the translaminar facet screw was concentrated in part of the facet joint. CONCLUSIONS: The BPS model provided the best biomechanical stability for OLIF; the stand-alone model could not provide sufficient stability. The LRS-CTLFS procedure increases the approximate stability and reduces stress at the cage-endplate interface; however, it causes an increase in screw stress.

Risk Factor Analysis of the Incidence of Subsequent Adjacent Vertebral Fracture After Lumbar Spinal Fusion Surgery with Instrumentation.

OBJECTIVE: This study aimed to evaluate the risk factors for adjacent vertebral compression fractures after lumbar spinal fusion with instrumentation. METHODS: A total of 669 patients who received lumbar instrumented spinal fusion between January 2012 and December 2015 were divided into 2 groups according to whether the adjacent vertebral body was fractured. The covariates recorded were age, sex, bone mineral density, and the number of fixed segments. The anatomic variables were pelvic incidence angle (PI), preoperative lumbar lordosis angle (Pre-LL), postoperative lumbar lordosis angle (Post-LL), Pre-LL minus Post-LL (Loss of LL), postoperative pelvic tilt (Post-PT), postoperative sacral slope, Pre-PI-LL mismatch (Pre-PI minus Pre-LL), and Post-PI-LL mismatch (Post-PI minus Post-LL). A 1-way analysis of variance (ANOVA) was performed with the aforementioned parameters, and binary logistic regression analysis was used to determine the relative risk factors. RESULTS: The 669 patients were followed-up for a mean of 2.7 ± 1.1 years (range, 2-4 years). Twenty-seven patients demonstrated fractures in the adjacent vertebral body after surgery. Analysis by 1-way ANOVA demonstrated that age, PI, Pre-LL, Post-LL, Loss of LL, Post-PI-LL mismatch, Post-PT, and osteoporosis were potential risk factors (all parameters, P < 0.001). Furthermore, binary logistic regression analysis showed that a large Loss of LL, osteoporosis, and old age were also risk factors for adjacent vertebral compression fractures. CONCLUSIONS: A greater Loss of LL, osteoporosis, and advanced age may be risk factors for fractures in the adjacent vertebral body of the fixed segment after lumbar fusion fixation.

Novel Surgical Strategy for Treating Osteoporotic Vertebral Fractures with Cord Compression.

OBJECTIVES: Treatment for osteoporotic vertebral fracture (OVF) with cord compression is challenging and it usually requires surgical interventions to decompress nerves and restore spinal sequences. To describe a novel surgical strategy for treating OVFs with cord compression. METHODS: This is a single-center retrospective analysis. The inclusion criteria were Frankel grade C-E, single level T10 -L2 . Between January 2008 and December 2016, a total of 56 OVF patients (47 females and nine males, with an average age of 72 years (66-88 years), comprising of eight grade C, 23 grade D, and 25 grade E patients) were enrolled. The treatment algorithm included preoperative evaluation by MRI, extension CT, and radiography to classify the OVFs as type 1.1 (reducible, stable; n = 13), type1.2 (reducible, unstable; n = 16), type 2 (irreducible; n = 19) or type 2M (modifier; n = 8). Vertebroplasty (VP)/kyphoplasty (KP) was applied in type 1.1. VP/KP with posterior fixation and posterolateral fusion was applied in type 1.2. And additional laminectomy/osteotomy was used in type 2, except in a modifier group (2M) where same procedure as applied for type 1.2 was used. VAS, ODI, Cobb angle, Frankel functional grade, and complications were recorded. RESULTS: Thirteen cases were classified as type 1.1, 16 cases as type 1.2, 19 cases as type 2, and eight cases as type 2M. The follow-up period was 38.9 months (range, 24-108 months). All patients were followed-up in at least 24 months, in which time four patients died, two patients were lost at the last follow-up, and 50 patients completed the full study. The total VAS and ODI improved from 8 (7, 9) and 75.5% (67.2%, 80.0%) preoperatively to 2 (1, 3) and 31% (24.0%, 37.0%) on conclusion, respectively (P < 0.01). The local kyphotic angle was corrected from 22.3° (17.1°, 33. 8°) preoperatively to 10.4° (6.4°, 15.3°) on conclusion (P < 0.01). Twenty-three patients had achieved neurological recovery on conclusion (42E, 8D, P < 0.01). Asymptotic cement leakage was observed in 17/56 cases (30.4%), 6/56 in the affected vertebra (10.7%), and 24/330 in the screw trajectory (7.3%). At 2 years postoperatively, 11 new VFs had occurred in nine patients (16.1%), including VFs in nine adjacent segments that all occurred within 1 year after surgery. No cement migration or implant failure was noted. CONCLUSION: The novel surgical strategy for treating OVFs with cord compression consists of the most tailored and least invasive treatment for each patient. The positive mid- and long-term clinical and radiological outcomes observed could represent a step forward in devising the proposed algorithm.

Augmented pedicle trajectory applied on the osteoporotic spine with lumbar degenerative disease: mid-term outcome.

PURPOSE: To compare the safety and efficiency of cement-augmented pedicle screw with traditional pedicle screw technique applied on the patients in the osteoporotic spine with lumbar degenerative diseases. METHODS: Fifty-six patients followed up at least 2 years were enrolled in our institute with retrospectively reviewed from January 2009 to June 2014, diagnosed as lumbar spondylolisthesis, or lumbar stenosis, with T score ≤- 2.5 SD of BMD, and received less than three-segment PLIF or TLIF. All patients were divided into 2 groups: 28 (2 males, 26 females) in polymethylmethacrylate-augmented pedicle screw group (PSA) group, the other 28 (3 males, 25 females) in traditional pedicle screw group (TPS). Surgical data including the operation time, intra-operative blood loss, hospitalization day and surgical complications were recorded, as well as the radiological parameters measured from the postoperative X-rays and CT scans containing the rates of fusion, screw loosening, and cage subsidence incidence. In addition, the visual analog scores (VAS) and Oswestry Disability Index (ODI) were evaluated preoperatively and postoperatively. RESULTS: The average follow-up period was 34.32 months (ranging from 24 months to 51 months). Compared with PSA group, operation time and average hospital stay in the TPS group decreased significantly (P < 0.05). While no statistical difference for blood loss between 2 groups (P > 0.05). At 2 years postoperation, from CT-scans, 2/172 screws loosening and 1/56 segment non-union occurred in PSA group, with significantly lower incidence than those in TPS group (8/152 screws loosening and 6/50 segments non-union occurred, P < 0.05). Regarding the cage subsidence, 24 segments found height loss (5.30 ± 1.92 mm) in PSA group without difference compared with that of 19 segments (4.78 ± 1.37 mm) in TPS group (P > 0.05). Besides, the number and the location of cages and the leakage of the cement were found out little related with the subsidence in the PSA group (P > 0.05). After surgeries, VAS and ODI at 1 month, 6 months, 12 months, and last follow-up improved significantly in two groups (P < 0.05). There were no significant differences in VAS and ODI preoperatively and postoperatively between 2 groups (P > 0.05). In addition, eight patients with asymptomatic trajectory PMMA leakages were detected. CONCLUSION: Cement-augmented pedicle screw technique is effective and safe in the osteoporotic spine with lumbar degenerative diseases, with better fusion rates and less screw loosening incidence. There is no difference in the fusion rate and loosening rate between the two groups in the single segment patients; however, there are better fusion rate and lower pedicle screw loosening rate of the PSA group in the double or multiple group patients.

The cement leakage in cement-augmented pedicle screw instrumentation in degenerative lumbosacral diseases: a retrospective analysis of 202 cases and 950 augmented pedicle screws.

PURPOSE: To evaluate the incidence, type and risk factors of cement leakage (CL) with cement-augmented pedicle screw instrumentation (CAPSI) in degenerative lumbosacral disease. METHODS: Two hundred and two patients using a total of 950 cement-augmented screws were enrolled. CL was classified into three types: type S: leakage via segmental veins; type B: leakage via basivertebral veins; and type I: leakage via pedicle screw instrumentation to paravertebral soft tissue. The age, gender, operation stage (primary or later stage), body mass index, bone mineral density, the number and type of augmented screw, the position of the tip of screw (lateral or internal part of vertebral body), the position of screw (left or right side), the volume of bone cement, location of the augmented vertebra (lumbar or sacrum), the type of CL and complications were recorded. Binary logistic regression correlation was used to analyze risk factors of veins leakage (type S and type B). RESULTS: The CL was observed in 165 patients (81.68%) and 335 screws (35.26%), leakage types of S, B and I were seen in 255 (76.12%), 77 (22.99%), and 30 (8.96%) of screws, respectively. Besides, double or multiple routes of leakage were seen in 27 screws. Number of augmented screw was a risk factor for vein leakage (OR 0.58; 95% CI 0.44-0.77; P = 0.000). Furthermore, the doses of cement (OR 0.79; 95% CI 0.61-0.99; P = 0.038) and the position of screw (OR 0.39; 95% CI 0.29-0.53; P = 0.000) were identified as risk factors for type S, and the doses of bone cement (OR 0.37; 95% CI 0.25-0.54; P = 0.000) and the position of the tip of screw (OR 0.07; 95% CI 0.04-0.13; P = 0.000) were risk factors for type B. CONCLUSIONS: CAPSI bears a high risk of asymptomatic CL, with a higher rate of leakage into segmental veins and basivertebral veins. As is known, more augmented screws and larger doses of cement are risk factors for veins leakage (type S and type B), while the tip of screw approaching to the midline of the vertebral body is another risk factor to type B. Thus, the CL could be reduced by the amelioration of operative techniques and procedures. These slides can be retrieved under Electronic Supplementary Material.

The Effect and Safety of Polymethylmethacrylate-Augmented Sacral Pedicle Screws Applied in Osteoporotic Spine with Lumbosacral Degenerative Disease: A 2-Year Follow-up of 25 Patients.

BACKGROUND: A high rate of instrumentation failure is frequently seen in osteoporotic spines, especially at the sacral segment because of the great shear stress. Several techniques of sacral pedicle screw placement, such as bicortical and tricortical fixation, have been developed; however, the problems of loosening and pulling out of the screws are still a concern. Recently, the polymethylmethacrylate (PMMA)-augmented pedicle screws have been shown to strengthen the purchase in osteoporotic spine, but there are few reports on the effect of S1 pedicle screw with PMMA augmentation. METHODS: Seventy-five patients receiving cement-augmented pedicle screws at lumbosacral vertebra were enrolled and divided into 3 groups by different patterns of S1 pedicle screw placement: S1 pedicle screw with PMMA augmentation (group A, 25 patients), S1 bicortical pedicle screw fixation (group B, 25 patients), and S1 tricortical pedicle screw fixation (group C, 25 patients). The Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI) scores were assessed preoperatively and at the last follow-up. Besides, the complications, loosening rate, and fusion rate were recorded. RESULTS: The VAS and ODI scores at the last follow-up were significantly improved in the 3 groups compared with preoperative results. Better pain relief and functional improvement at the last follow-up was seen in group A compared with the other 2 groups; however, no significant difference was detected between groups B and C. Although the lowest screws loosening rates and the highest fusion rate were found in group A, no significant difference among these 3 groups. Furthermore, longer fusion segments and larger postoperative pelvic incidence-lumbar lordosis (PL-LL) were found as risks related to S1 screw loosening without cement augmentation. CONCLUSIONS: The S1 pedicle screws with PMMA augmentation achieved better stability with less screw loosening in the osteoporotic spine with lumbosacral degenerative diseases compared with bicortical/tricortical fixation at S1. This procedure is especially recommended for patients with long segment fixation and large postoperative PI-LL, but there is also a risk of bone cement leakage and a learning curve.

[Establish mouse osteoblast -osteoclast cell co-culture system in a Transwell chamber].

OBJECTIVE: To establish osteoblast-osteoclast cell co-culture system in a Transwell chamber, and detect cell viability of osteoblasts and osteoclasts in system. METHODS: Osteoblast MC3T3-E1 and mouse monocytes RAW264.7 were cultivated in vitro. RANKL-induced mouse RAW264.7 monocytes differentiated into mature osteoclasts, osteoblast-osteoclast cell co-culture system was established in Transwell chamber. Cell activity of osteoblasts and osteoclasts were detected by CCK-8 experimenting, Alizarin Red staining, TRAP staining. The expression of OPG, ALP, RANKL, TGF-b1 gene and RANKL protein in osteoblast MC3T3-E1 were detected by PCR, Western-Blot methods. Also, the expression of RANK, NF-κB in gene and protein level in osteoclast were measured through the same method respectively. RESULTS: The co-culture system of Mouse MC3T3-E1 cells and RAW264.7 cell were established in Transwell chamber. Co-culture system affected cell division activities of osteoblasts and osteoclasts. Differentiation of osteoblasts were increased, while differentiation of osteoclast division were slight decreased under microscope observation. OPG (0.65±0.08) and ALP (0.16±0.01) gene expression of co-culture system were less than single culture OPG(1.00±0.08) and ALP (1.01±0.16); TGF-b1(4.42±0.21) and RANKL(4.12±1.04) of osteoblasts in co-culture system were higher than TGF-b1(1.00±0.10) and RANKL(1.00±0.09) under single culture. However, gene expression of RANK(0.63±0.06) and NF-κB(0.64±0.08) in co-culture system were decreased than RANK(1.00±0.08) and NF-κB(1.00±0.09), in single culture, and had significant differences. Similarly, protein expression of OPG(0.43±0.05) and NF-κB(0.59±0.05) of co-culture system were less than OPG(0.84±0.06) and NF-κB(1.13±0.03) of single culture. While RANKL protein expression (0.54±0.03)of co-culture system was more than single culture RANKL(0.31±0.03), and had statistically differences, which was in agreement of the trend of gene expression change. CONCLUSIONS: Co-culture system of mouse MC3T3-E1 cells and RAW264.7 cell was viable in Transwell chamber, and the activity of osteoblasts is higher than osteoclasts in co-culture system.

Risk factor analysis for re-collapse of cemented vertebrae after percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP).

PURPOSE: Re-collapse of cemented vertebrae occasionally occurs after percutaneous augmentation. However, the potential risks still remain unclear. Several articles have reported some possible risk factors which were not consistent or comprehensive. This study aimed to make a retrospective review on patients with osteoporotic vertebral compression fracture (OVCF) after percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP) and to further analyse the risk factors for treated vertebral refracture. METHODS: All patients receiving the PKP/PVP with bilateral approach were retrospectively reviewed from January 2014 to January 2016, among whom 230 patients with single level augmentation (30 in refracture group and 200 in the non-refracture group) were enrolled according to inclusion criteria. The following covariates were reviewed: gender, age, height, weight, body mass index (BMI), bone mineral density (BMD), serum bone turnover markers, surgical parameters including approach, cement volume, anterior height, and Cobb angle restoration. Binary logistic regression analysis was used to determine the relative risk of re-collapse of cemented vertebrae. RESULTS: Regarding the patient data, weight, BMI, and BMD were of statistical significance in refracture group (P < 0.01), among which only low BMD was a risk factor to cemented vertebral re-collapse (P = 0.022, OR = 4.197). In respect of surgical variables, the better restoration of anterior height and Cobb angle was found in refracture group (P < 0.05), both of which might increase the refracture risk but not be risk factors (P = 0.065, OR = 0.891, and P = 0.937, OR = 0.996, respectively). Besides, less injected cement (3.30 ± 0.84 ml vs 4.46 ± 1.10 ml, P = 0.000, OR = 19.433) and PKP (P = 0.007, OR = 13.332) significantly boosted the potential risk of refracture (P < 0.001). CONCLUSION: Patients with low BMD, or undergoing PKP, or receiving a low volume of injected cement might have a high risk of re-collapse in surgical vertebrae.

Icariin influences adipogenic differentiation of stem cells affected by osteoblast-osteoclast co-culture and clinical research adipogenic.

OBJECTIVE: To build mouse osteoblast MC3T3-E1 and mouse osteoclast RAW264.7 co-culture system and to study the effect of icariin on the activity of osteoblasts and osteoclasts in the co-culture system. METHODS: In vitro acquisition and cultivation of mouse osteoblasts MC3T3-E1 and mouse RAW264.7 cells were conducted. Osteoblast and osteoclast activities of cells were detected by CCK-8 staining experiment, alizarin red staining and tartaric-resistant acid phosphatase (TRAP) staining. We used different concentrations of icariin to interfere in osteoblast-osteoclast co-culture system. The effects of icariin on various genes were detected by PCR and Western blot methods The correction between the expression of PPARγ and BMD was analyzed in patients with osteoporosis. RESULTS: Mouse osteoblast-osteoclast co-culture system was built, and the osteogenic differentiation effect was enhanced. Icariin can improve the MC3T3-E1 osteogenic differentiation activity, enhance the expression of OPG and RANKL gene protein, reduce the NF-κb gene and protein expression, increase of ALP, TGF-b1 and RANKL gene expression level and reduce RANK gene expression. Icariin can act on MC3T3-E1 cells-RAW264.7 cells co-culture system, and promote the osteogenic activity of MC3T3-E1 cells, inhibit the osteoclast activity of RAW264.7 cells and reduce the level of BMSCs adipogenic differentiation. The expression level of PPAR-γ gene was negatively correlated with the level of BMD. CONCLUSIONS: Mouse MC3T3-E1 cells and mouse RAW264.7 cells could be co-cultured in vitro, and icariin could improve the osteogenic activity of MC3T3 cells-RAW264.7 cells and decrease the osteoclast activity. Icariin could inhibit adipogenic differentiation of BMSCs in the osteoblast-osteoclast co-culture, promoting osteogenic differentiation and inhibiting osteoclast differentiation.

[Analysis of clinical characteristics of 20 patients with pyogenic spondylitis].

OBJECTIVE: To investigate the diagnostic value of clinical manifestation, laboratory examination and imaging changes for pyogenic spondylitis and to summarize the clinical characteristics of patients with pyogenic spondylitis. METHODS: The clinical data, of 20 patients with pyogenic spondylitis were diagnosed by histopathological examination from March 2012 to March 2015, were retrospectively analyzed. There were 9 males and 11 females, aged from 43 to 72 years old with an average of 58.9 years. Included 3 cases of cervical vertebrae, 7 cases of thoracic vertebrae, 10 cases of lumbar vertebrae. Patients of blood analysis, erythrocyte sedimentation rate(ESR), C reactive protein(CRP), X rays, CT and MRI were performed before treatment. Visual analogue scale (VAS) was used to evaluate the pain of patients suffering from vertebral pain. RESULTS: All the patients had suffered from vertebral pain before treatment. VAS was 9 points in 4 cases, 8 points in 6 cases, 7 points in 1 case, 3 points in 6 cases, and 2 points in 3 cases. Among them, 7 patients complicated with neurological symptoms, 11 with aggravating night pain, 10 with fever. WBC and Neutrophil count (NEU) of 5 cases were increased and other 15 cases were normal;CRP of 19 cases were increased and 1 case was normal;ESR of all 20 cases were increased. X rays showed the intervertebral space narrowing in all 20 cases, 13 cases complicated with destruction of vertebral body; CT showed the lesions of vertebral body in the 20 cases and complicated with destruction, sclerosis of sclerotin; MRI showed that the lesions of the vertebral body in the T1 image had uneven medium low signal, in the T2 image of the 16 cases had uneven high signal and 2 cases had uniform and high signal, 2 cases had main high signal compliated with mixed signal. Thirteen patients underwent surgical treatment and 7 patients received conservative treatment, and the patients left hospital while VAS had significantly improved after treatment. CONCLUSIONS: Pyogenic spondylitis is easy to be misdiagnosed or missed in clinic. It can be combined with the clinical manifestations, laboratory examination and imaging characteristics in order to make a definite diagnosis for purulent spondylitis in early.