Single Versus Double Tunnel Fixation in Medial Patellofemoral Ligament Reconstruction: A Meta-Analysis.

The purpose of this meta-analysis was to conduct a comparative analysis of clinical scores and complication rates among patients experiencing recurrent patellar dislocation who underwent medial patellofemoral ligament (MPFL) reconstruction using both single and double tunnel techniques. A comprehensive search was conducted across electronic databases including PubMed, the Cochrane Library, Web of Science, and Google Scholar to retrieve articles relevant to MPFL reconstruction utilising the tunnel technique. Subsequently, meta-analyses were undertaken to assess complication rates and changes in clinical scores before and after surgery. Following this, sensitivity analysis and meta-regression analysis were performed to scrutinise potential confounding variables. A total of thirty-two studies were included in the analysis, comprising twenty-seven non-comparative studies and five comparative studies. The findings revealed a similarity in postoperative complication rates between the single and double tunnel fixation techniques: [9.0% (95%CI, 4.0%-15.6%) versus 8.9% (95%CI, 4.7%-14.1%, p = 0.844)]. Likewise, no statistically significant differences were observed in Lysholm scores [34.1 (95%CI, 26.7-41.5) versus 33.8 (95%CI, 27.7-40.0, p = 0.956)], Kujala scores [29.4 (95%CI, 22.3-36.4) versus 27.3 (95%CI, 22.3-32.3, p = 0.637)], and Tegner score change [1.1 (95%CI, 0.8-1.4) versus 0.7 (95%CI, -0.2-1.6, p = 0.429)] before and after MPFL reconstruction, respectively, using these two techniques. In conclusion, the authors found that the clinical functional improvement and complication rates in MPFL reconstruction using the single tunnel fixation technique are comparable to those achieved with the double tunnel fixation approach. However, to further advance the understanding in this field, additional randomised controlled studies must be conducted to provide further insights. Key Words: MPFL reconstruction, Bone tunnel, Patellar dislocation, Meta-analysis.

Development and validation of models for predicting mortality in intertrochanteric fracture surgery patients with perioperative blood transfusion: a prospective multicenter cohort study.

BACKGROUND: The association between allogenic blood transfusions (ABT) and all-cause mortality in surgically treated hip fracture patients with perioperative transfusion (STHFPT) remained unknown. We aim to introduce transfusion-related factors, new variables to develop and validate models to predict mortality in these patients. METHODS: A prospective multicenter cohort study was conducted with STHFPT hospitalized during Jan. 2018 and Jun. 2021. The database was divided into training cohort and validation cohort in a ratio of 70% to 30% using the randomization method. All participants received a minimum of 2-year follow-up and all participants' overall and eight time-specific survival status were recorded. Prediction models were developed using multivariate logistic regression and Cox regression for variable selection. Model performance was measured by determining discrimination, calibration, overall model performance or precision, and utility. Sensitivity analyses were performed to test robustness of the results. RESULTS: A total of 7074 consecutive patients were prospectively screened and assessed for eligibility to participate. Finally, 2490 patients met our inclusion and exclusion criteria and 1743 (70%) patients were randomized to the training cohort and 747 (30%) to the validation cohort. The median duration of follow-up was 38.4 months (IQR 28.0-62.0). Our novel models highlight that preoperative transfusion is of significance for short-term mortality while mid-term outcomes are predominantly determined by severe complications, pulmonary complications, and advanced age. Our models showed high discriminative power, good calibration and precision for mortality prediction in both training and validation cohorts, especially in short-term mortality prediction. CONCLUSIONS: We introduce transfusion-related factors, new variables to develop and validate models to predict mortality with STHFPT. The models can be further tested and updated with the ultimate goal of assisting in optimizing individual transfusion strategy.

Do Age and Timing Influence the Outcomes of Single-stage Reconstruction of Multiple Ligament Knee Injuries? 5-10 Years Follow Up.

OBJECTIVES: Multiple ligament knee injuries (MLKIs) are disruptive injuries, however, there are controversies in the results of acute and delayed reconstruction. Also, clinical outcomes between patients older or younger than 40 have not been compared in MLKIs. This study was designed to investigate the influence of age and timing of reconstruction on the outcomes of single-stage reconstruction of MLKIs. METHODS: The patients who underwent reconstruction of multiple injured ligaments because of MLKIs between May 2013 and July 2019 were added to the cohort. The postoperative complications, knee range of motion (ROM), Lysholm score, International Knee Documentation Committee (IKDC) 2000 score, Tegner activity level, patient satisfaction, and SF-36 score were compared between young (≤ 40 years old, n = 41) and old patients (n = 61); acute (≤ 3 weeks after injury, n = 75) and delayed reconstruction (n = 27), using Mann-Whitney U test or χ2 test. RESULTS: A total of 102 MLKI patients managed by single-stage multi-ligament reconstruction were retrospectively reviewed. Patients were followed up after surgery for a mean of 7.3 years (5.2-10.7 years). At the last follow-up, no significant difference was found in knee ROM, functional scores, and patient-reported outcomes between patients older or younger than 40; acute and delayed reconstruction (p > 0.05). The rate of complications in the delayed reconstruction group was higher than that of the acute reconstruction group (22.2% vs 5.3%, p < 0.05). The IKDC objective scores reached grade A in 63.7%-80.4% of patients, and grade B in 11.8%-23.5% patients. CONCLUSION: The single-stage reconstruction of MLKIs can obtain comparative long-term functional and objective outcomes regardless of patients older or younger than 40; acute and delayed reconstruction, however, delayed reconstruction is related to a high rate of postoperative complications.

Efficacy of surgical intervention over conservative management in intertrochanteric fractures among nonagenarians and centenarians: a prospective cohort study.

BACKGROUND: Optimal treatment strategy for nonagenarians and centenarians with hip fractures (NCHF) remained unknown. The authors aimed to compare the outcomes of surgical and conservative management in NCHF. METHODS: A prospective cohort study was conducted based on CPMHF database with NCHF patients hospitalized during 2014-2020. Comorbidities were evaluated by mECM score and restricted cubic spline was utilized to visually assess the dose-effect relationship between the mECM and outcomes. Propensity score matching was performed to balance baseline characteristics between nonsurgical and surgical groups. Multivariate logistic regression, Cox proportional hazard analysis, and survival analysis were employed for unfavorable outcomes (UFO) evaluation. Competing risk of death were analyzed based on Fine and Gray's hazard model and then constructed nomogram models for predicting survival rates. Subgroup analyses were used to determine potential population heterogeneity and sensitivity analyses were performed to test robustness of the results. RESULTS: The authors found increasing trends for UFO with the increase in the mECM score, and that high mECM score (HMS, ≥3) was independently associated with a 2.42-fold (95% CI: 2.07-3.54; P =0.024) increased risk of UFO, which remained significant after considering the competing role of death and were more pronounced in nonsurgical treatment, women, no insurance, and patients with spouse (all P for interaction <0.05). Surgical intervention was identified to be significant protective factors for UFO (RR, 0.59; 95% CI: 0.46-0.75; P <0.001) and severe complications (RR, 0.63; 95% CI: 0.41-0.96; P =0.033) after propensity score matching, as well as survival (HR, 0.40, 95% CI: 0.28-0.58; P <0.001), which remained significant after considering the competing role of death and in all sensitivity analyses and were more pronounced in HMS participants ( P for interaction=0.006). Subgroup analyses revealed surgical patients with HMS had a significantly higher UFO rate (excluding death, P <0.001) while nonsurgical patients with HMS had higher mortality rate as compared to the others ( P =0.005). CONCLUSION: Surgical treatment for NCHF yields better outcomes compared to conservative treatment.

A novel mechanism of Vildagliptin in regulating bone metabolism and mitigating osteoporosis.

Osteoporosis has become a global social problem with the tendency toward the aging population. The challenge in managing osteoporosis is to develop new anti-osteoporosis drugs that target bone anabolism. The purpose of this study was to uncover the novel mechanism of Vildagliptin on bone metabolism. We revealed that Vildagliptin significantly promoted osteogenic differentiation of precursor osteoblasts and bone marrow mesenchymal stem cells (BMSCs). At the same time, it significantly enhanced the polarization of RAW264.7 macrophages to the M2 type and the secretion of osteogenic factors BMP2 and TGF-ß1. This was confirmed by the increased osteogenic differentiation observed in the osteoblast-RAW264.7 co-culture system. Moreover, Vildagliptin significantly enhanced the transformation of BMSCs into the osteogenic morphology in the osteoblast-BMSC co-culture system. Finally, Vildagliptin also inhibited osteoclastic differentiation of RAW 264.7 cells. The potential mechanism underlying these effects involved targeting the GAS6/AXL/ERK5 pathway. In the in vivo study, Vildagliptin significantly alleviated postmenopausal osteoporosis in ovariectomized mice. These findings represent the first comprehensive revelation of the regulatory effect of Vildagliptin on bone metabolism. Specifically, Vildagliptin demonstrates the ability to promote bone anabolism and inhibit bone resorption by simultaneously targeting osteoblasts, BMSCs, and osteoclasts. The bone-protective effects of Vildagliptin were further confirmed in a postmenopausal osteoporosis model. The clinical significance of this study lies in laying a theoretical foundation for bone protection therapy in type-2 diabetes patients with compromised bone conditions or postmenopausal osteoporosis.

Artificial Intelligence Aids Detection of Rotator Cuff Pathology: A Systematic Review.

PURPOSE: To determine the model performance of artificial intelligence (AI) in detecting rotator cuff pathology using different imaging modalities and to compare capability with physicians in clinical scenarios. METHODS: The review followed the PRISMA guidelines and was registered on PROSPERO. The criteria were as follows: 1) studies on the application of AI in detecting rotator cuff pathology using medical images, and 2) studies on smart devices for assisting in diagnosis were excluded. The following data were extracted and recorded: statistical characteristics, input features, AI algorithms used, sample sizes of training and testing sets, and model performance. The data extracted from the included studies were narratively reviewed. RESULTS: A total of 14 articles, comprising 23,119 patients, met the inclusion and exclusion criteria. The pooled mean age of the patients was 56.7 years, and the female rate was 56.1%. The area under the curve (AUC) of the algorithmic model to detect rotator cuff pathology from ultrasound images, MRI images, and radiographic series ranged from 0.789 to 0.950, 0.844 to 0.943, and 0.820 to 0.830, respectively. Notably, 1 of the studies reported that AI models based on ultrasound images demonstrated a diagnostic performance similar to that of radiologists. Another comparative study demonstrated that AI models using MRI images exhibited greater accuracy and specificity compared to orthopedic surgeons in the diagnosis of rotator cuff pathology, albeit not in sensitivity. CONCLUSIONS: The detection of rotator cuff pathology has been significantly aided by the exceptional performance of AI models. In particular, these models are equally adept as musculoskeletal radiologists in using ultrasound to diagnose rotator cuff pathology. Furthermore, AI models exhibit statistically superior levels of accuracy and specificity when using MRI to diagnose rotator cuff pathology, albeit with no marked difference in sensitivity, in comparison to orthopaedic surgeons. LEVEL OF EVIDENCE: Level III, systematic review of Level III studies.

A novel lncRNA GM15416 regulates osteoblast apoptosis and differentiation through the c-Fos/Fas axis and mitigates osteoporosis.

Osteoporosis (OP) is a common systemic bone disorder, and the programmed cell death of osteoblasts is closely linked to the development of osteoporosis. Previous studies have shown that c-fos can cause osteoblast apoptosis. Furthermore, it has been demonstrated that long non-coding RNA (lncRNA) plays a pervasive role in regulating the biology of osteoblasts. Nevertheless, the precise role and mechanism of long non-coding RNA (lncRNA) in relation to c-Fos at the transcriptional level in osteoblast cell death remain uncertain. Compared with normal osteoblasts, serum deprivation resulted in significant upregulation of the transcription factor c-Fos and apoptosis-related Fas proteins in osteoblasts. In addition, the expression of lncRNA GM15416 related to c-Fos was significantly increased. The results showed that overexpression of c-Fos leads to an increase in downstream Fas protein, which subsequently leads to osteoblast apoptosis and hinders osteogenesis. On the contrary, a decrease in lncRNA GM15416 expression leads to a decrease in c-Fos/Fas expression, which hinders osteoblast apoptosis and promotes osteogenesis. Our results suggest that lncRNA GM15416 exerts inhibitory effects on osteoblast apoptosis and acts as a preventive factor against osteoporosis. As a result, GM15416 emerges as an important lncRNA associated with osteoporosis and holds potential as a future therapeutic target.

Chronological and Carbohydrate-Dependent Transformation of Fatty Acids in the Larvae of Black Soldier Fly Following Food Waste Treatment.

Although black soldier fly larvae (BSFL) can convert food waste into insectile fatty acids (FAs), the chronological and diet-dependent transformation of larval FAs has yet to be determined. This study focused on the dynamics of larval FA profiles following food waste treatment and characterized factors that may drive FA composition and bioaccumulation. Larval FA matters peaked on Day 11 as 7.7 ± 0.7% of food waste dry matter, maintained stably from Day 11-19, and decreased slightly from Day 19-21. The BSFL primarily utilized waste carbohydrates for FA bioconversion (Day 0-11) and shifted to waste FAs (Day 7-17) when the carbohydrates were close to depletion. The optimal time window for larvae harvest was Days 17-19, which fulfilled both targets of waste oil removal and larval FA transformation. Larval FAs were dominated by C12:0, followed by C18:2, C18:1, and C16:0. The waste-reducing carbohydrate primarily accounted for larval FA bioaccumulation (r = -0.947, p < 0.001). The increase in diet carbohydrate ratio resulted in the elevation of larval C12:0 yield, which indicated that larval C12:0-FA was primarily biosynthesized from carbohydrates and further transformed from ≥C16 FAs. This study elucidates the bioaccumulation process of larval FAs for food waste treatment and highlights the importance of waste carbohydrates for both the composition and transformation of larval FAs.

A New Technique of Achilles Tendon Rupture Repaired by Double Transverse Mini-incision to Avoid Sural Nerve Injury: A Consecutive Retrospective Study.

OBJECTIVE: Percutaneous suture is a classic technique used in Achilles tendon repair. However, the complication rates surrounding the sural nerve remain relatively high. Modified percutaneous repair technology can effectively avoid these complications; however, the surgical procedure is complicated. Hence, the present study was conducted to describe a redesigned repair technique for the Achilles tendon able to avoid sural nerve injury and reduce the complexity of the procedure. METHODS: Data of patients with acute primary Achilles tendon rupture at our hospital from January 2019 to May 2020 were included. Subjects with expectations for surgical scarring underwent a minimally invasive-combined percutaneous puncture technique. The surgical time, requirement for conversion to other technologies, and length of postoperative hospitalization were investigated to assess efficacy. The American Orthopedic Foot & Ankle Society (AOFAS) score and the Arner-Lindholm scale (A-L scale) were used to assess postoperative clinical outcomes (> 24 months). During the 2-year follow-up, MRI was performed to observe the healing of the Achilles tendon. In addition, subjective satisfaction with surgical scar healing was recorded. RESULTS: Twenty consecutive subjects with an average follow-up of 28.3 ± 4.5 months (range, 24-41) met the inclusion criteria. None of the 20 enrolled patients required a converted surgical approach. The mean surgical time was 26.9 ± 6.47 min (range, 20-44). None of the patients experienced dysesthesia or anesthesia around the sural nerve. No signs of postoperative infections were observed. MRI data showed that the wounds of the Achilles tendon healed completely in all the subjects. The AOFAS score increased from 55.6 ± 11.07 (range, 28-71) preoperatively to 97.8 ± 3.34 (range, 87-100) at the last follow-up. The A-L scale showed that 90% of the subjects (n = 18) presented as excellent and 10% of the subjects (n = 2) presented as good, with an excellent/good rate of 100%. Moreover, subjects' satisfaction for surgical scars was 9.1 ± 0.78 (upper limit, 10). CONCLUSIONS: The results indicate that this technique can achieve good postoperative function, a small surgical incision, and high scar satisfaction. In addition, this technique should be widely used in suturing Achilles tendon ruptures.

Mangiferin promotes osteogenic differentiation and alleviates osteoporosis in the ovariectomized mouse via the AXL/ERK5 pathway.

Mangiferin is a xanthone glucoside extracted from multiple plants, which has been shown to inhibit bone resorption and alleviate osteoporosis. However, the effect of purified Mangiferin on osteoporosis and its specific mechanisms is unknown. This study aimed to explore whether Mangiferin can promote osteogenic differentiation and alleviate osteoporosis in ovariectomized (OVX) mice and explore the potential mechanisms. Different concentrations and durations of Mangiferin were applied to MC3T3-E1 cells. The optimal concentration and duration of Mangiferin were determined by evaluating the cell viability via cell count kit-8 (CCK-8). The gene and protein expressions of AXL, ERK5, and osteogenic differentiation markers, including BMP2, Collagen1, OPN, Osterix, and Runx2, were detected using western blotting, qRT-PCR, immunofluorescence, and flow cytometry. Mangiferin was administered to OVX mice, and the severity of osteoporosis was evaluated by H and E staining, immunohistochemistry (IHC), microscopic computed-tomography (micro-CT) scanning, western blotting, and immunofluorescence of bone tissue. We found that Mangiferin promoted osteogenic differentiation in a dose-dependent manner at concentrations less than 30 µM. The 30 µM Mangiferin significantly upregulated the expression of AXL, ERK5, and osteogenic differentiation, including the ALP activity, percentage of alizarin red, and the levels of osteogenic differentiation markers. However, these expression levels decreased when AXL was knocked down in MC3T3-E1 cells and it could not be rescued by Mangiferin. Mangiferin relieved osteoporosis in OVX mice without causing severe organ damage. This study concluded that Mangiferin promoted osteogenic differentiation of MC3T3-E1 cells and alleviated osteoporosis in OVX mice. The potential mechanism was via the AXL/ERK5 pathway.

Does the Cementless, Hydroxyapatite on Porous, Long-stem Prosthesis Perform Well in Revision Total Hip Arthroplasty? A Multicenter Observation.

OBJECTIVE: To determine the multicenter outcomes of the cementless, hydroxyapatite on the porous, long-stem prosthesis for revision total hip arthroplasty (THA) at multiple centres. STUDY DESIGN: Observational study. PLACE AND DURATION OF STUDY: Lanzhou University Second Hospital, Gansu Province People's Hospital, New City District of Jiuquan People's Hospital, from March 2014 to December 2019. METHODOLOGY: The database in three centres was retrospectively reviewed hip arthroplasty during the study period. Patients who underwent revision THA using the cementless, hydroxyapatite on porous, long-stem femoral prostheses were included. Perioperative complications, functional outcomes including the Merle d'Aubign ́e-Postel hip questionnaire (MAP), Harris Hip Score (HHS), Oxford Hip Score (OHS), Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index, life independence, and patient satisfaction were analyzed, the radiographic evaluation was also performed. RESULTS: Fifty revision THA (50 hips) were included for analysis, the median interval between primary and index revision procedure was 5.1 (0.3-30) years, and the rate of perioperative complications was 18%. Patients were followed up for a mean of 3.1±1.5 (1.1-6.5) years. At the latest follow-up, the functional outcomes significantly increased compared to preoperative data (p<0.001). Thirty-nine patients (92.9%) were life-independent, and 36 patients (85.7%) were satisfied with the surgery. Subsidence was observed in 5 patients, osteolysis occurred in 3 patients, and no revision was required. CONCLUSION: The cementless, hydroxyapatite on porous, long-stem prosthesis was a good choice for revision THA with a poor bone condition in the proximal femur, unstable PFF, and recurrent dislocations after THA, no severe complications were found. KEY WORDS: Arthroplasty, Hip, Reoperation, Hip prosthesis.

Piezo1-mediated fluid shear stress promotes OPG and inhibits RANKL via NOTCH3 in MLO-Y4 osteocytes.

Piezo1, a mechanosensitive ion channel, participates in a variety of biological processes in maintaining bone homeostasis. As the most abundant cells in bones of the mammals, osteocytes play an essential role in bone formation, remodeling, and bone mass maintenance. Here, by exposing MLO-Y4 osteocytes to the fluid shear stress (FSS) microenvironment, we explored the effect of Piezo1-mediated FSS on the expression of the molecules critical to the process of bone formation and resorption, Receptor Activator of Nuclear Factor-Kappa-B Ligand (RANKL) and Osteoprotegerin (OPG). It was found that 9 dyne/cm2 loading for 30 minutes showed an upregulation trend on Piezo1 when MLO-Y4 osteocytes were exposed to an FSS microenvironment. FSS promotes the expression of OPG and inhibits the expression of RANKL. The blocker of Piezo1, GsMTx4, downregulates the effect of FSS on the expression of these two molecules. In addition, NOTCH3 was involved in this process. Thus, the results demonstrated that Piezo1-mediated FSS promotes the expression of OPG and inhibits the expression of RANKL via NOTCH3 in MLO-Y4 osteocytes.

An increased posterior tibial slope is associated with a higher risk of graft failure following ACL reconstruction: a systematic review.

PURPOSE: The posterior tibial slope (PTS) is considered a risk factor for anterior cruciate ligament (ACL) injury. However, the influence of PTS on graft failure following ACL reconstruction remains relatively unknown. Therefore, this systematic review was conducted to investigate whether PTS could be a potential risk factor for graft failure after ACL reconstruction. METHODS: PubMed, EMBASE, Cochrane Library, Web of Science, China National Knowledge Infrastructure Database, and Wanfang Database were comprehensively searched from inception to March 31, 2021. Observational studies reporting the associations of medial tibial plateau slope (MTPS) or lateral tibial plateau slope (LTPS) with graft failure after ACL reconstruction were evaluated. RESULTS: Twenty studies involving 12 case-control studies, 4 retrospective studies and 4 cross-sectional studies including 5326 patients met the final inclusion criteria. The high heterogeneity and the characteristics of nonrandomized controlled trials limited data synthesis. Fifteen of the 20 included studies detected a significant association between increased PTS and ACL graft failure, while 5 studies concluded that increased PTS was not associated with ACL graft failure. Ten studies suggested that MTPS is associated with ACL graft failure, and six studies suggested that LTPS is associated with ACL graft failure. The mean MTPS values for nonfailure group ranged from 3.5° ± 2.5° to 14.4° ± 2.8°. For the graft failure group, MTPS ranged from 4.71° ± 2.41° to 17.2° ± 2.2°. The mean LTPS values for nonfailure group ranged from 2.9° ± 2.1° to 11.9° ± 3.0°. For the graft failure group, LTPS ranged from 5.5° ± 3.0° to 13.3° ± 3.0°. The reported PTS values that caused ACL graft failure was greater than 7.4° to 17°. CONCLUSION: Based on the current clinical evidence, increased PTS is associated with a higher risk of ACL graft failure after ACL reconstruction. Despite various methods of measuring PTS have high reliability, there is still vast disagreement in the actual value of PTS. LEVEL OF EVIDENCE: IV.

Fluid shear stress-induced down-regulation of microRNA-140-5p promotes osteoblast proliferation by targeting VEGFA via the ERK5 pathway.

PURPOSE: Fluid shear stress (FSS) plays a critical role in osteoblast proliferation. However, the role of miRNA in osteoblast proliferation induced by FSS and the possible molecular mechanisms remain to be defined. The aim of the present study was to investigate whether miR-140-5p regulates osteoblast proliferation under FSS and its molecular mechanism. MATERIALS AND METHODS: miR-140-5p expression was measured by qRT-PCR. Western blot was used to measure the expressions of P-ERK1/2, ERK1/2, P-ERK5 and ERK5. The levels of VEGFA, PCNA, CDK4 and Cyclin D1 were identified through qRT-PCR and western blot, respectively. Cell proliferation was detected by CCK-8 assay and EdU labeling assay. Dual-luciferase reporter assay was used to validate the target of miR-140-5p. RESULTS: miR-140-5p was significantly down-regulated when MC3T3-E1 cells were exposed to FSS. We then confirmed that up-regulation of miR-140-5p inhibited and down-regulation of miR-140-5p promoted osteoblast proliferation. In addition, FSS promotes osteoblast proliferation via down-regulating miR-140-5p. Luciferase reporter assay demonstrated that VEGFA is a direct target of miR-140-5p. Furthermore, transfection of mimic-140-5p inhibited the up-regulation of VEGFA protein level induced by FSS, suggesting that FSS regulates VEGFA protein expression via miR-140-5p. Further investigations demonstrated that VEGFA could promote osteoblast proliferation. Lastly, we demonstrated that miR-140-5p regulates osteoblast proliferation and ERK5 activation through VEGFA. CONCLUSIONS: Our study demonstrates that FSS-induced the down-regulation of miR-140-5p promotes osteoblast proliferation through activing VEGFA/ERK5 signaling pathway. These findings may provide a novel mechanism of FSS-induced osteoblast proliferation and offer a new avenue to further investigate osteogenesis induced by mechanical loading.

Fluid shear stress regulates osteoblast proliferation and apoptosis via the lncRNA TUG1/miR-34a/FGFR1 axis.

LncRNAs and microRNAs play critical roles in osteoblast differentiation and bone formation. However, their exact roles in osteoblasts under fluid shear stress (FSS) and the possible mechanisms remain unclear. The aim of this study was to explore whether and how miR-34a regulates osteoblast proliferation and apoptosis under FSS. In this study, FSS down-regulated miR-34a levels of MC3T3-E1 cells. MiR-34a up-regulation attenuated FSS-induced promotion of proliferation and suppression of apoptosis. Luciferase reporter assay revealed that miR-34a directly targeted FGFR1. Moreover, miR-34a regulated osteoblast proliferation and apoptosis via FGFR1. Further, we validated that lncRNA TUG1 acted as a competing endogenous RNA (ceRNA) to interact with miR-34a and up-regulate FGFR1 protein expression. Furthermore, lncRNA TUG1 could promote proliferation and inhibit apoptosis. Taken together, our study revealed the key role of the lncRNA TUG1/miR-34a/FGFR1 axis in FSS-regulated osteoblast proliferation and apoptosis and may provide potential therapeutic targets for osteoporosis.

The role of fibrinogen in predicting reinfection after DAIR for periprosthetic joint infections.

BACKGROUND: Fibrinogen (FIB) has been found to be a promising marker in diagnosing periprosthetic joint infection (PJI), however, the value of FIB in predicting reinfection of PJI is unknown. The purpose of this study was to evaluate the value of FIB in predicting reinfection after debridement, antibiotics, and implant retention (DAIR) for PJI. METHODS: We retrospectively analyzed the clinical data of patients who were diagnosed with PJI and underwent DAIR from 2013 to 2019. The levels of the FIB, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) were measured before DAIR. After DAIR, patients were followed and reinfections were identified. For both acute and chronic PJI, the predictive value of FIB was evaluated by calculating the sensitivity, specificity, and area under the curve (AUC) of the receiver operating characteristic curve (ROC), and was compared with traditional inflammatory markers including ESR and CRP. RESULTS: The expression of FIB differed between patients reinfected and those not reinfected in both acute and chronic PJI (p < 0.05). In patients who underwent DAIR for acute PJI, the sensitivity and specificity of FIB were 81.82 and 83.33%, respectively, which were significantly higher than that of CRP (sensitivity, 72.73%; specificity, 50%; p < 0.05), while the specificity was higher than that of ESR (specificity, 41.67%; p < 0.05). In patients who underwent DAIR for chronic PJI, the sensitivity and specificity of FIB were 80.00 and 66.66%, respectively, which were significantly higher than that of CRP (sensitivity, 53.33%; specificity, 66.66%; p < 0.05) and ESR (sensitivity was 66.00%; specificity, 16.66%; p < 0.05). The ROC curves showed that FIB demonstrated the highest AUC among the biomarkers in both acute and chronic PJI. CONCLUSION: FIB is a promising indicator in predicting reinfection after DAIR for both acute and chronic PJI, and it seems to perform better than ESR and CRP.

Low-molecular-weight heparin calcium attenuates the tourniquet-induced ischemia-reperfusion injury in rats.

Ischemia-reperfusion injury (IRI) is a common postoperative complication of the tourniquet used surgery; low-molecular-weight heparin calcium (LMWH) is frequently used postoperatively to prevent the formation of deep venous thrombosis. However, subcutaneous hemorrhage can usually be seen in patients who underwent lower limb surgery, especially in total knee arthroplasty, the influence of LMWH on IRI remains controversial. In this experiment, we designed an animal model to observe the influence of LMWH on the skeletal muscle injury induced by tourniquets. Sprague-Dawley (SD) rats underwent either 2 h of unilateral hindlimb ischemia or anesthesia alone, at different time points of reperfusion interval, animals received either 4mg/kg LMWH or normal saline subcutaneously twice a day. The levels of inflammatory markers in serum, the expression of apoptosis proteins, as well as histological examination of skeletal muscles, were detected at 48-h reperfusion. We found that the injury of skeletal muscle and the systemic inflammatory response was less severe in LMWH-treated animals, indicating that LMWH could attenuate the tourniquet-induced IRI. In conclusion, LMWH given postoperatively after limb surgery may be clinically beneficial.

Bibliometric Analysis of the Top-Cited Articles on Unicompartmental Knee Arthroplasty.

BACKGROUND: Unicompartmental knee arthroplasty (UKA) has been proven to be an effective surgical technique for unilateral compartment osteoarthritis. The purpose of this study is to identify and analyze the top 100 cited articles in the field of UKA research. METHODS: Publications on UKA from 1980 to 2020 in the Web of Science database were retrieved. The characteristics of the top 100 cited articles were analyzed, including information of publications and citations, level of evidence, and research interests. RESULTS: The number of publications and citations increased over time. The majority of the highly cited articles were from the Nuffield Orthopedic Centre (Oxford, England) and the Brigham and Women's Hospital (Boston, USA). Long-term outcome of UKA and comparison between UKA and TKA gathered most research interests. The most frequently occurring keywords were "survival" and "revision." Since 2012, "life quality" and "robotics" have been used. There was no level I evidence, and most studies provided level IV evidence. CONCLUSION: There was a rising trend in publications and citations in the field of UKA research, the majority of them were from a few centers, and were low-level evidence. Most studies focused on the long-term outcomes of UKA; in recent years, patient satisfaction and navigation surgery have become new research trends.

Reconstruction of forearm support with ulnar translocation after resection of chondrosarcoma in the proximal radius.

This is a report of the reconstructive surgery of a patient with chondrosarcoma in the proximal radius. After extensive resection of the proximal radius that contained the tumor, the skeleton of the forearm was reconstructed by ulnar translocation. This patient was followed for 2 years, no recurrence of the tumor was found and the function of the forearm was nearly normal. This case is reported and discussed and a literature review is presented.