Overloaded axial stress activates the Wnt/ß-Catenin pathway in nucleus pulposus cells of adult degenerative scoliosis combined with intervertebral disc degeneration.

BACKGROUND: Intervertebral disc degeneration (IVDD) is the initiating factor of adult degenerative scoliosis (ADS), and ADS further accelerates IVDD, creating a vicious cycle. Nevertheless, the role of the Wnt/ß-Catenin pathway in ADS combined with IVDD (ADS-IVDD) remains a mystery. Accordingly, this study was proposed to investigate the effect of axial stress on the Wnt/ß-Catenin pathway in nucleus pulposus cells (NPCs) isolated from DS-IVDD patients. METHODS: Normal NPCs (N-NPC) were purchased and the NPCs of young (25-30 years; Y-NPC) and old (65-70 years; O-NPC) from ADS-IVDD patients were primary cultured. After treatment of NPC with overloaded axial pressure, CCK-8 and Annexin V-FITC kits were applied for detecting proliferation and apoptosis of N-NPC, Y-NPC and O-NPC, and western blotting was performed to assess the expression of Wnt 3a, ß-Catenin, NPC markers and apoptosis markers (Bax, Bcl2 and Caspase 3). RESULTS: N-NPC, Y-NPC and O-NPC were mainly oval, polygonal and spindle-shaped with pseudopods, and the cell morphology tended to be flattened with age. N-NPC, Y-NPC and O-NPC were capable of synthesizing proteoglycans and expressing the NPC markers (Collagen II and Aggrecan). Notably, the expression of Wnt 3a, ß-Catenin, Collagen II and Aggrecan was reduced in N-NPC, Y-NPC and O-NPC in that order. After overload axial stress treatment, cell viability of N-NPC and Y-NPC was significantly reduced, and the percentage of apoptosis and expression of Wnt 3a and ß-Catenin were significantly increased. CONCLUSIONS: Overloaded axial pressure activates the Wnt/ß-Catenin pathway to suppress proliferation and facilitate apoptosis of NPC in ADS-IVDD patients.

Radiographic Assessment of Relationship Between Medial Cuneiform Obliquity and Hallux Valgus.

The research results are inconsistent that assessing whether the increased obliquity of the distal articular surface of the medial cuneiform leads to an increase in hallux valgus angle. Thus, this study investigated the relationship between distal medial cuneiform obliquity and hallux valgus by measuring various angles in weightbearing anteroposterior radiographs of the foot. In total, 679 feet of 538 patients with the radiographs were included in the study. We measured radiographic parameters including hallux valgus angle, first to second intermetatarsal angle, metatarsus adductus angle, first metatarsus cuneiform angle, distal medial cuneiform angle, and first proximal metatarsal articular angle. The surface morphology (flat or curved) of the first tarsometatarsal joint was also recorded. Our results analysis revealed a weak negative correlation between distal medial cuneiform angle and both hallux valgus angle and first to second intermetatarsal angle, contrary to our assumption. So we believe that distal medial cuneiform angle was relatively constant and it cannot be used as a characteristic angle for quantifying hallux valgus. First metatarsus cuneiform angle was a characteristic indicator of hallux valgus and was positively correlated with its severity (p < .000), indicating that it can be used to measure the size of hallux valgus. It can also be used as a reference factor for the first metatarsal osteotomy in clinical bunion orthopedics. First tarsometatarsal joint morphology was unrelated to hallux valgus, whereas metatarsus adductus angle, and first proximal metatarsal articular angle should be considered in hallux valgus.

A modified surgical method for the treatment of ONFH: quadratus femoris muscle pedicle bone grafting with preservation of the posterior superior retinacular artery.

BACKGROUND: Osteonecrosis of the femoral head (ONFH) can lead to pain and loss of function of the hip joint, which places a great burden on patients and society. Surgery is the main treatment for osteonecrosis of the femoral head, and quadratus femoris muscle pedicle bone grafting has a definite therapeutic effect as one method of surgery for the treatment of ONFH. However, the posterior superior retinacular artery is often injured during quadratus femoris muscle pedicle bone graft surgery. There is evidence that this artery is extremely important to the femoral head, as injury to this artery will seriously affect the blood supply of the femoral head. Therefore, this situation restricts the clinical application of quadratus femoris muscle pedicle bone grafts. We aimed to explore a new surgical method of quadratus femoris muscle pedicle bone grafting that can preserve the integrity of the posterior superior retinacular artery. METHODS: We modified the traditional quadratus femoris muscle pedicle bone graft and preserved the integrity of the posterior superior retinacular artery. To explore the safety and feasibility of the operation, we simulated the operation on 6 fresh frozen cadavers (12 hips) and measured the related data. We also tried this modified surgical method in the clinic and collected detailed data from the patients. RESULTS: By simulating the modified quadratus femoris muscle pedicle bone graft on the hip joints of fresh frozen cadavers, we found that the posterior superior retinacular artery existed in all cadaver specimens and that the sources may be different (MFCA or IGA). In the modified operation, the joint capsule did not need to be cut during the operation; therefore, the integrity of the posterior superior retinacular artery was preserved. The quadratus femoris muscle was exposed via the posterior approach of the hip joint, and then the quadratus femoris muscle pedicle bone flap was chiseled. After the pedicle of the quadratus femoris muscle was loosened properly, the migration distance of the quadratus femoris muscle pedicle bone flap reached 5.89 ± 0.45 (χ ± s) cm. The bone flap was trimmed properly and placed on one side. Next, we drilled a bone tunnel from the external intertrochanteric aspect of the capsule of the hip joint, and the bone tunnel broke through the sclerosing zone and proceeded straight to the necrotic area of the femoral head. Next, the necrotic bone was removed with a ring saw and arc bone knife, autogenous bone or allogeneic bone was filled into the bone groove according to the situation, and the cancellous bone in the bone groove was tamped by percussion. Then, the bone flap was inserted into the bone groove, and appropriate pressurization was performed. The depth of the bone groove was determined by the location of ONFH. We found that the furthest distance between the bone groove and the femoral head was 4.76 ± 0.07 (χ ± s) cm and that the length of the bone flap was (4.91 ± 0.23) (χ ± s) cm. This means that when the depth of the bone groove reached the area of ONFH, the quadratus femoris muscle pedicle bone flap had a sufficient length and migration distance to be embedded in the area of ONFH and firmly fixed, and the quadratus femoris did not have much tension. The closest distance between the posterior superior retinacular artery and the bone groove was (1.11 ± 0.96) (χ ± s) cm. When the bone groove was created in this area, the edge of the bone groove had a safe distance of at least 1 cm from the posterior superior retinacular artery of the femoral head. We attempted to implement this modified operation clinically. During the procedure, the quadratus femoris muscle pedicle bone flap was embedded into the drilled bone groove and fixed with a magnesium nail. There was no sliding of the bone flap after the operation, and the posterior superior retinacular artery was intact. We followed the patient for 3 months and found that the patient recovered well with no weight-bearing by the affected limb. The duration of the modified operation was shorter than that of the traditional quadratus femoris muscle pedicle bone graft, the amount of bleeding was significantly reduced, the postoperative pain was lessened, and no special discomfort was reported. Postoperative imaging examination showed that the collapse of the femoral head had been partially corrected and that the bone flap had gradually fused with the surrounding bone. CONCLUSIONS: Through this experimental study, we confirmed the feasibility of the modified method for quadratus femoris muscle pedicle bone grafting with preservation of the posterior superior retinacular artery. This modified operation not only retains the integrity of the posterior superior retinacular artery of the femoral head but also reduces the difficulty of the operation and shortens the surgical time, which is of great clinical significance.

Treatment of symptomatic hip dysplasia by posterolateral small incision assisted Bernese periacetabular osteotomy.

BACKGROUND: For periacetabular osteotomy, traditional approaches usually have a long learning curve. We aimed to evaluate the postoperative results and complications of periacetabular osteotomy under a new double-incision approach. METHODS: The records of 58 consecutive patients (65 hips) who underwent periacetabular osteotomy using the new approach were retrospectively reviewed and evaluated. There were 52 women and 6 men with a mean age of 28.1 years at the time of surgery. RESULTS: The average follow-up period was 35.2 months, during which no patients were converted to total hip arthroplasty. Complications included 6 hips (9.2%) with nerve dysesthesias and 1 hip (1.5%) with delayed wound healing. The mean operative time and intraoperative blood loss were 88.6 min and 402.8 ml, respectively. The mean modified Harris hip score had improved from 72.2 points preoperatively to 91.3 points at the last follow-up. Fifty-five patients (62 hips, 95.4%) were satisfied to their outcomes, and good preoperative functional score was associated with a satisfactory outcome. Furthermore, the average lateral center-edge angle, anterior center-edge angle and acetabular index angle were corrected well after surgery. CONCLUSION: Periacetabular osteotomy using modified Smith-Petersen or Bikini approach with posterolateral assisted small incision can be performed safely and with satisfactory results. In addition, this technique shortens the learning curve, and reduces the operating complexity, especially for beginner.

Nutrition deficiency promotes apoptosis of cartilage endplate stem cells in a caspase-independent manner partially through upregulating BNIP3.

Nutrition deficiency is reported to induce apoptosis of chondrocytes and degeneration of cartilage endplate (CEP) in rabbit. Cartilage endplate stem cells (CESCs) are important for the integrity of structure and function of CEP. Bcl-2/adenovirus E1B 19-kDa-interacting protein 3 (BNIP3) has been reported to regulate apoptosis, autophagy, and cytoprotection. In this study, we aimed to determine whether nutrition deficiency induces apoptosis of CESCs, and whether or not the BNIP3-related pathway is activated in CESCs during nutrition deficiency. CESCs isolated from degenerated human CEP were cultured under normal or nutrition-deficient condition. Then, apoptosis was analyzed by flow cytometry. The expression and intracellular localization of BNIP3 were detected by quantitative real-time polymerase chain reaction, western blot analysis, and immunofluorescence assay, respectively. Mitochondrial membrane potential (MMP) and caspase-3 activity were measured by JC-1 staining and caspase-3 activity assay. Our results showed that nutrition deficiency promotes apoptosis and BNIP3 expression in CESCs. Notably, knockdown of BNIP3 could partially decrease nutrition deficiency-induced apoptosis of CESCs. In addition, nutrition deficiency could also induce upregulation of BNIP3, resulting in mitochondrial translocation of BNIP3 and loss of MMP in CESCs in a time-dependent manner. However, nutrition deficiency showed no effects on caspase-3 activity in CESCs. In summary, nutrition deficiency may promote CESC apoptosis partially through upregulating BNIP3, which might lead to activation of the BNIP3-related pathway and apoptosis of CESCs in a caspase-independent manner.

Bioinformatics-Based Analysis of Key Genes in Steroid-Induced Osteonecrosis of the Femoral Head That Are Associated with Copper Metabolism.

Osteonecrosis of the femoral head (ONFH) is a common disabling disease. Copper has positive effects on cells that regulate bone metabolism. However, the relationship between copper metabolism (CM) and steroid-induced ONFH (SONFH) remains unclear. The GSE123568 dataset was downloaded from the Gene Expression Omnibus. The differentially expressed CM-related SONFH genes (DE-CMR-SONFHGs) were identified via differential analysis and weighted gene coexpression network analysis (WGCNA). Receiver operating characteristic (ROC) analysis was performed for the predictive accuracy of key genes. Targeting drugs and the copper death-related genes (CDRGs) relevant to key genes were investigated. The bioinformatics results were confirmed via quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot (WB) analysis. Two out of 106 DE-CMR-SONFHGs were identified as key genes (PNP and SLC2A1), which had diagnostic value in distinguishing SONFH from control samples and were related to various immune cell infiltrations. Eleven PMP-targeting drugs and five SLC2A1-targeting drugs were identified. The qRT-PCR, as well as WB, results confirmed the downregulation PNP and SLC2A1 and high expression of the CDRGs DLD, PDHB, and MTF1, which are closely related to these two key genes. In conclusion, PNP and SLC2A1 were identified as key genes related to SONFH and may provide insights for SONFH treatment.

Identification of two novel lipid metabolism-related long non-coding RNAs (SNHG17 and LINC00837) as potential signatures for osteosarcoma prognosis and precise treatment.

OBJECTIVE: Dysregulated lipid metabolism enhances the development and advancement of many cancers, including osteosarcoma (OS); however, the underlying mechanisms are still largely unknown. Therefore, this investigation aimed to elucidate novel potential lipid metabolism-related long non-coding RNAs (lncRNAs) that regulate OS development and provide novel signatures for its prognosis and precise treatment. MATERIALS AND METHODS: The GEO datasets (GSE12865 and GSE16091) were downloaded and analyzed using R software packages. Immunohistochemistry (IHC) was used to evaluate protein levels in OS tissues while real-time qPCR was used to measure lncRNA levels, and MTT assays were used to assess OS cell viability. RESULTS: Two lipid metabolism-associated lncRNAs (LM-lncRNAs), small nucleolar RNA host gene 17 (SNHG17) and LINC00837, were identified as efficient and independent prognostic indicators for OS. In addition, further experiments confirmed that SNHG17 and LINC00837 were significantly elevated in OS tissues and cells than para-cancerous counterparts. Knockdown of SNHG17 and LINC00837 synergistically suppressed the viability of OS cells, whereas overexpression of the two lncRNAs promoted OS cell proliferation. Moreover, bioinformatics analysis was conducted to construct six novel SNHG17-microRNA-mRNA competing endogenous RNA (ceRNA) networks, and three lipid metabolism-associated genes (MIF, VDAC2, and CSNK2A2) were found to be abnormally upregulated in OS tissues, suggesting that they were potential effector genes of SNHG17. CONCLUSION: In summary, SNHG17 and LINC00837 were found to promote OS cell malignancy, suggesting their use as ideal biomarkers for OS prognosis and treatment.

Prevalence and drug resistance of Escherichia coli among patients with orthopaedic surgical site infections in China: A systematic review and meta-analysis.

To summarize current prevalence and drug resistance rate of Escherichia coli (E. coli) among orthopaedic surgical site infections (SSIs) in China from English and Chinese language sources. Online databases were searched to collect related researches. A meta-analysis was performed to analyse prevalence and 95 % confidence interval (CI) of E. coli among patients with orthopedic surgical site infections. Meta-regression analysis was used to investigate the difference in the prevalence and antimicrobial resistance of E. coli among different subgroups. A total of 52 studies were enrolled into our meta-analysis, with a total of 31,285 strains isolated. The overall E. coli prevalence was 13.4 % (95 % CI 11.6-15.5). Study design (R2 = 8.98) and sample size (R2 = 10.95) might be potential sources of heterogeneity and there were no significant differences in risk of bias (R2 = 0.28), study time (R2 < 0.01), region (R2 = 2.46) and hospital level (R2 = 1.42). E. coli resistance were reported in 43 of the 52 papers. Antimicrobial resistance of E. coli to Ampicillin [87.9 % (95 % CI 83.7-91.1)] before 2015 was higher than that after 2015 [80.3 % (95 % CI 75.0-84.7)] (R2 = 30.93, P = 0.033). While, resistance rate to Cefepime and Amikacin was significantly higher before 2015 (R2 = 17.25 and 6.54, P = 0.043 and 0.048), i.e., 46.4 % (36.3-56.9), 19.9 % (13.8-27.7) and 29.1 % (19.4-41.2), 8.6 % (4.4-16.2) in 2015 and after. It is necessary to carry out long-term monitoring to understand the actual prevalence and antimicrobial resistance of E. coli to develop appropriate health care mechanisms.

[Clinical study of a new biodegradable magnesium internal fixation screw in treatment of osteonecrosis of the femoral head].

Objective: To investigate the safety and efficacy of a new biodegradable magnesium internal fixation screw for vascularized iliac bone flap grafting in treatment of osteonecrosis of the femoral head (ONFH). Methods: Patients with ONFH admitted between July 2020 and February 2021 were selected as the research objects, and 20 patients (20 hips) met the selection criteria and were included in the study. The patients were divided into two groups ( n=10) by central random method. The iliac bone flap was fixed with a new biodegradable magnesium internal fixation screw in the trial group, and the iliac bone flap was wedged directly in the control group. There was no significant difference ( P>0.05) in gender, age, and side, type, Association Research Circulation Osseous (ARCO) stage, and disease duration of ONFH between the two groups. The operation time and intraoperative blood loss of the two groups were recorded. Laboratory tests were performed at each time point before and after operation, including white blood cell (WBC), electrolytes (K, Ca, P, Mg), blood urea nitrogen (BUN), serum creatinine (Scr), glomerular filtration rate (eGFR), lymphocyte ratio (CD4/CD8), immunoglobulin G (IgG), IgM, alanine transaminase (ALT), aspartate aminotransferase (AST). After operation, Harris score was used to evaluate the hip joint function. CT of the hip joint and X-ray films in anteroposterior and frog positions of the pelvis were used to review the iliac bone flap position, fusion, and screw biodegradation in the trial group. Results: The vital signs of the two groups were stable, the incisions healed by first intention, and no adverse events occurred after operation. One patient in the control group refused to return to the hospital for follow-up at 3 months after operation, and 1 patient in the trial group refused to return to the hospital for follow-up at 1 year after operation. The rest of the patients completed the follow-up at 2 weeks, 3 months, 6 months, and 1 year after operation. Laboratory tests showed that there was no significant difference in WBC, electrolytes (K, Ca, P, Mg), BUN, Scr, eGFR, CD4/CD8, IgG, IgM, ALT, and AST between the two groups at each time point before and after operation ( P>0.05). The operation time and intraoperative blood loss of the trial group were significantly less than those of the control group ( P<0.05). The Harris scores of the two groups at 1 year significantly increased when compared with the values before operation and at 6 months after operation ( P<0.05). There was no significant difference in Harris score between the two groups at each time point ( P>0.05). Postoperative CT of hip joint and X-ray films of pelvis showed that the iliac bone flap reached osseous fusion with the fenestration of the head and neck junction of femoral head in the two groups at 1 year after operation, and no loosening or shedding of iliac bone flap was observed during follow-up. In the trial group, there were signs of dissolution and absorption of the new biodegradable magnesium internal fixation screws after operation, and the diameter of the screws gradually decreased ( P<0.05); no screw breakage or detachment occurred during follow-up. Conclusion: In the treatment of ONFH with vascularized iliac bone flap grafting, the new biodegradable magnesium internal fixation screws can fix the iliac bone flap firmly. Compared with the traditional iliac bone flap wedging directly, it has a shorter operation time, less intraoperative blood loss, and can obtain similar joint function.

[Digital subtraction angiography assisted musculoskeletal flap transplantation for the treatment of osteonecrosis of the femoral head].

OBJECTIVE: To observe the effectiveness of digital subtraction angiography (DSA) assisted musculoskeletal flap transplantation in the treatment of osteonecrosis of the femoral head (ONFH). METHODS: The clinical data of 15 patients with 15 hips of ONFH admitted between January 2016 and December 2019 were retrospectively analyzed. All patients were male, aged 20-45 years, with an average age of 31.6 years. There were hormone type in 9 cases and alcohol type in 6 cases. The disease duration ranged from 15 days to 3 years, with an average of 8 months. The Association Research Circulation Osseous (ARCO) staging: 4 hips in stage Ⅱ, 11 hips in stage Ⅲ. The preoperative visual analogue scale (VAS) score was 6.2±0.2, and the Harris score of the hip joint was 57.3±1.3. Preoperative DSA examination of the femoral head was performed to determine the location of vascular lesions of the femoral head. According to the results of the angiography, the surgical selection of the musculoskeletal flap was guided. For the patients with both superior and inferior retinaculum vessels developed, simple core decompression was performed. For the patients with superior retinaculum vessels developed but inferior retinaculum vessels not developed, anterolateral tensor fasciae flap was used. For the patients whose superior retinaculum did not develop and the inferior retinaculum developed, posterolateral quadratus femoris flap was used. The fibular flap with anastomotic vessels was used in the patients whose superior and inferior retinaculum vessels were not developed. RESULTS: All 15 cases of 15 hips were followed up 6-24 months, with an average of 14 months. During the follow-up, the patient's ONFH did not worsen, the femoral head did not collapse, the joint space was normal, and the hip joint fextion and extension function was acceptable. At last follow-up, the VAS score was 1.9±0.2, and the hip Harris score was 92.1±0.8, both of which were significantly improved when compared with preoperative ones ( t=14.85, P=0.00; t=23.22, P=0.00). CONCLUSION: For patients with ONFH who need musculoskeletal flap transplantation, preoperative DSA of femoral head can determine the location of vascular lesions of femoral head, so as to guide the selection of musculoskeletal flap transplantation, which is of great significance for hip-conserving surgery.

BNIP3/Bcl-2-mediated apoptosis induced by cyclic tensile stretch in human cartilage endplate-derived stem cells.

The present study aimed to investigate the molecular mechanisms of cyclic stretch-induced apoptosis in human intervertebral disc cartilage endplate-derived stem cells (CESCs). CESCs were stretched by the Flexercell-4000™ Tension Plus system, the effect on cell viability was measured by a Cell Counting Kit-8 assay, while cell apoptosis was detected by flow cytometry. Western blot analysis was used to evaluate the expression of B-cell lymphoma 2 (Bcl-2)/adenovirus E1B 19 kDa interacting protein 3 (BNIP3), Bcl-2, Bcl-2 homologous antagonist killer (Bak), Bcl-2-associated X protein (Bax), Bcl extra large (Bcl-xl) and the activity of caspase-3, while Z-VAD-FMK was used to inhibit caspase-3. Compared with the control group, the cell viability decreased in a time-dependent manner after stretching. Furthermore, cell apoptosis and the activity of caspase-3 were increased in a time-dependent manner. The ratio of pro-death factor BNIP3 to anti-apoptotic protein Bcl-2 was significantly increased. When cells were stretched for 36 h, the apoptosis-associated proteins Bak and Bax were increased, while Bcl-xl was decreased. The viability and apoptotic ratio of stretched cells were significantly restored after caspase-3 was repressed. In conclusion, cyclic tensile stretch induced apoptosis of CESCs, which was probably due to upregulation of the expression of BNIP3.

Nutrient deprivation induces apoptosis of nucleus pulposus cells via activation of the BNIP3/AIF signalling pathway.

Nutrient deprivation (ND)­induced nucleus pulposus (NP) cell death serves an important role in intervertebral disc degeneration disease. However, the underlying mechanisms have yet to be thoroughly elucidated. The present study created a cell culture model under ND conditions to investigate the roles of the nutrient­sensitive protein B­cell lymphoma 2/adenovirus E1B 19 kDa­interacting protein (BNIP3) and the mitochondrial pro­death protein apoptosis­inducing factor (AIF) in the death pathway of NP cells. The present study demonstrated that cells subjected to ND for up to 72 h exhibited a time­dependent increase in cell death and decrease in mitochondrial membrane potential (Δψm), as compared with cells cultured under normal conditions. The results of western blotting demonstrated that BNIP3 expression was significantly upregulated in NP cells subjected to ND for 24 h, which coincided with AIF translocation to the cell nucleus and alterations in cell viability and Δψm. Furthermore, BNIP3 overexpression increased ND­induced NP cell death, whereas knockdown of BNIP3 or AIF abolished ND­induced NP cell death. In addition, BNIP3 overexpression increased AIF expression and BNIP3 knockdown decreased AIF expression in NP cells subjected to ND. In conclusion, ND induced NP cell death partially via activation of the BNIP3/AIF signalling pathway. These findings provide novel insights into the potential mechanisms underlying ND­induced death of NP cells during disc degeneration.