Application of AI-assisted MRI for the identification of surgical target areas in pediatric hip and periarticular infections.

OBJECTIVE: To develop an AI-assisted MRI model to identify surgical target areas in pediatric hip and periarticular infections. METHODS: A retrospective study was conducted on the pediatric patients with hip and periarticular infections who underwent Magnetic Resonance Imaging(MRI)examinations from January 2010 to January 2023 in three hospitals in China. A total of 7970 axial Short Tau Inversion Recovery (STIR) images were selected, and the corresponding regions of osteomyelitis (label 1) and abscess (label 2) were labeled using the Labelme software. The images were randomly divided into training group, validation group, and test group at a ratio of 7:2:1. A Mask R-CNN model was constructed and optimized, and the performance of identifying label 1 and label 2 was evaluated using receiver operating characteristic (ROC) curves. Calculation of the average time it took for the model and specialists to process an image in the test group. Comparison of the accuracy of the model in the interpretation of MRI images with four orthopaedic surgeons, with statistical significance set at P < 0.05. RESULTS: A total of 275 patients were enrolled, comprising 197 males and 78 females, with an average age of 7.10 ± 3.59 years, ranging from 0.00 to 14.00 years. The area under curve (AUC), accuracy, sensitivity, specificity, precision, and F1 score for the model to identify label 1 were 0.810, 0.976, 0.995, 0.969, 0.922, and 0.957, respectively. The AUC, accuracy, sensitivity, specificity, precision, and F1 score for the model to identify label 2 were 0.890, 0.957, 0.969, 0.915, 0.976, and 0.972, respectively. The model demonstrated a significant speed advantage, taking only 0.2 s to process an image compared to average 10 s required by the specialists. The model identified osteomyelitis with an accuracy of 0.976 and abscess with an accuracy of 0.957, both statistically better than the four orthopaedic surgeons, P < 0.05. CONCLUSION: The Mask R-CNN model is reliable for identifying surgical target areas in pediatric hip and periarticular infections, offering a more convenient and rapid option. It can assist unexperienced physicians in pre-treatment assessments, reducing the risk of missed and misdiagnosis.

Mapping the causal associations of cytokines with sarcopenia and aging traits: Evidence from bidirectional Mendelian randomization.

BACKGROUND: Cytokines and growth factors may serve as a bridge in studying the causal relationships between inflammaging and sarcopenia due to their roles in inflammaging. In this study, we aim to explore the causal association of cytokines with sarcopenia and aging traits and further identify the significant inflammation factors. METHODS: Bidirectional Mendelian randomization (MR) analysis was used to identify the causality. Forty-one kinds of circulation cytokines and growth factors were set as exposures, and the data were from a summary genome-wide association study (GWAS) containing three cohorts with 8293 healthy participants of European ancestry from 1983 to 2011. Hand grip strength, adjusted appendicular lean mass (AALM), usual walking pace, moderate-to-vigorous physical activity (MVPA) levels, able to walk or cycle unaided for 10 min (AWCU10) and telomere length were selected as outcomes. Data for outcomes were obtained from meta-GWAS and the UK Biobank, and sample sizes ranged from 69 537 to 472 174. Low hand grip strength was defined by the European Working Group on Sarcopenia in Older People (EWGSOP) and Foundation for the National Institutes of Health (FNIH) cut-off points, respectively. Other outcome traits were defined and measured according to the UK Biobank and raw cohorts' criteria. We set two significance thresholds for single nucleotide polymorphisms (SNPs) associated with exposures to obtain adequate SNPs (5 × 10-6 and 5 × 10-8). Inverse-variance weighted, MR-Egger and weighted median were employed to estimate the causality. RESULTS: Twenty-seven factors were identified to relate to sarcopenia and aging traits causally, and most were associated with only one outcome trait. IL16 (interleukin-16), CTACK (cutaneous T-cell attracting chemokine), MIP1b (macrophage inflammatory protein 1b) and PDGFbb (platelet-derived growth factor BB) were proven to relate causally to at least one sarcopenia and aging trait in both analyses with two significance thresholds. IL16 was causally associated with hand grip strength (0.977 [0.956-0.998] for EWGSOP and 0.933 [0.874-0.996] for FNIH), AALM (0.991 [0.984, 0.998]), MVPA (0.997 [0.995-1.000]) and AWCU10 (1.008 [1.003-1.013]). CTACK was proven to relate causally to hand grip strength (1.013 [1.007-1.019] for EWGSOP and 1.090 [1.041-1.142] for FNIH), AWCU10 (0.990 [0.986-0.994]) and telomere length (0.998 [0.983-0.994]). The results indicated that MIP1b has a causal effect on hand grip strength (1.032 [1.001-1.063] for EWGSOP), AWCU10 (0.994 [0.988-1.000] and 0.993 [0.988-0.998]) and telomere length (1.006 [1.000-1.012]). PDGFbb may causally relate to AALM (1.016 [1.001-1.030]) and telomere length (1.011 [1.007-1.015]). Reserve MR analyses also proved their unidirectional causal effects. CONCLUSIONS: Twenty-seven factors were causally related to sarcopenia and aging traits, and the causal effects of IL16, CTACK, MIP1b and PDGFbb were proven in both analyses with two significance thresholds.

Effect of inflammatory response on joint function after hip fracture in elderly patients: A clinical study.

BACKGROUND: Excellent hip joint function facilitates limb recovery and improves the quality of survival. This study aimed to investigate the potential risk factors affecting postoperative joint functional activity and outcomes in elderly hip fractures patients and to provide evidence for patient rehabilitation and clinical management. AIM: To explore the relationship between inflammatory factors and hip function and the interaction between inflammation and health after hip fracture in elderly patients. METHODS: The elderly patients who had hip fracture surgery at our hospital between January 1, 2021, and December 31, 2022 were chosen for this retrospective clinical investigation. Patients with excellent and fair postoperative hip function had their clinical information and characteristics gathered and compared. Age, gender, fracture site, surgical technique, laboratory indices, and other variables that could have an impact on postoperative joint function were all included in a univariate study. To further identify independent risk factors affecting postoperative joint function in hip fractures, risk factors that showed statistical significance in the univariate analysis were then included in a multiple logistic regression analysis. In addition to this, we also compared other outcome variables such as visual analogue scale and length of hospital stay between the two groups. RESULTS: A total of 119 elderly patients with hip fractures were included in this study, of whom 37 were male and 82 were female. The results of univariate logistic regression analysis after excluding the interaction of various factors showed that there was a statistically significant difference in interleukin (IL)-6, IL-8, IL-10, C-reactive protein (CRP), and complement C1q (C1q) between the fair and excellent joint function groups (P < 0.05). The results of multiple logistic regression analysis showed that IL-6 > 20 pg/mL [(Odds ratio (OR) 3.070, 95%CI: 1.243-7.579], IL-8 > 21.4 pg/ mL (OR 3.827, 95%CI: 1.498-9.773), CRP > 10 mg/L (OR 2.142, 95%CI: 1.020-4.498) and C1q > 233 mg/L (OR 2.339, 95%CI: 1.094-5.004) were independent risk factors for poor joint function after hip fracture surgery (all P < 0.05). CONCLUSION: After hip fractures in older patients, inflammatory variables are risk factors for fair joint function; therefore, early intervention to address these markers is essential to enhance joint function and avoid consequences.

Biomaterials for bone defect repair: Types, mechanisms and effects.

Bone defects or bone discontinuities caused by trauma, infection, tumours and other diseases have led to an increasing demand for bone grafts and biomaterials. Autologous bone grafts, bone grafts with vascular tips, anastomosed vascular bone grafts and autologous bone marrow components are all commonly used in clinical practice, while oversized bone defects require the use of bone tissue engineering-related biomaterials to repair bone defects and promote bone regeneration. Currently, inorganic components such as polysaccharides and bioceramics, as well as a variety of bioactive proteins, metal ions and stem cells can be loaded into hydrogels or 3D printed scaffold materials to achieve better therapeutic results. In this review, we provide an overview of the types of materials, applications, potential mechanisms and current developments in the repair of bone defects.

Causal Roles of Lifestyle, Psychosocial Characteristics, and Sleep Status in Sarcopenia: A Mendelian Randomization Study.

BACKGROUND: Many studies reported that lifestyle, psychosocial characteristics, and sleep status related to sarcopenia, although few studies provided evidence of causal relationships between them. METHODS: The data used in our study were from UK Biobank, FinnGen Release 8, and large genome-wide association study meta-analyses. Two-sample Mendelian randomization was conducted to identify the causal associations of 21 traits of lifestyle, psychosocial characteristics, and sleep status with 6 traits of sarcopenia. Benjamini-Hochberg correction was performed to reduce the bias caused by multiple tests. Risk factor analyses were performed to explore the potential mechanism behind the exposures. RESULTS: Mendelian randomization analyses after adjustment proved the causal roles of coffee intake, education years, smoking, leisure screen time, and moderate-to-vigorous intensity physical activity during leisure time in sarcopenia was proven although providing no significant evidence for causal roles for carbohydrates intake, protein intake, alcohol, and sleep status in sarcopenia. CONCLUSIONS: Our results strongly support that coffee intake, education years, smoking, leisure screen time, and moderate-to-vigorous intensity physical activity during leisure time played significantly causal roles in sarcopenia, which may provide new intervention strategies for preventing the development of sarcopenia.

Recent advances in immunomodulatory hydrogels biomaterials for bone tissue regeneration.

There is a high incidence of fractures in clinical practice and therapy. The repairment of critical size defects in the skeletal system remains a huge challenge for surgeons and researchers, which can be overcame by the application of bone tissue-engineered biomaterials. An increasing number of investigations have revealed that the immune system plays a vital role in the repair of bone defects, especially macrophages, which can modulate the integration of biomaterials and bone regeneration in multiple ways. Therefore, it has become increasingly important in regenerative medicine to regulate macrophage polarization to prevent inflammation caused by biomaterial implantation. Recent studies have stressed the importance of hydrogel-based modifications and the incorporation of various cellular and molecular signals for regulating immune responses to promote bone tissue regeneration and integrate biomaterials. In this review, we first elaborate briefly on the described the general physiological mechanism and process of bone tissue regeneration. Then, we summarized the immunomodulatory role macrophages play in bone repair. In addition, the role of hydrogel-based immune modification targeting macrophage modulation in accelerating and enhancing bone tissue regeneration was also discussed. Finally, we highlighted future directions and research strategies related to hydrogel optimization for the regulation of the immune response during bone regeneration and healing.

Safe range of femoral neck system insertion and the risk of perforation.

BACKGROUND: Internal fixation of the femoral neck carries a risk of perforation due to the presence of the isthmus of the femoral neck. At present, there are few studies on the safe and risk zones of the femoral neck system (FNS) implantation. This study aimed to recommend the safe range of injection of FNS in the lateral wall of the proximal femur, parallel to the axis of the femoral neck, during FNS treatment of femoral neck fracture (FNF). METHODS: Femoral computed tomography (CT) data of 80 patients (male: 40; female: 40) who met the inclusion criteria were collected. Mimics 21.0 software was used to complete the modeling. 3-Matic 13.0 software was used to establish the axis of the femoral neck and its vertical plane, perform the cutting of the femoral neck, and project it on the vertical plane of the femoral neck axis. After matching a rectangle for each projection map, all sample sizes (80 cases) were standardized and superimposed to obtain gradient maps of the safe zone (SZ) and dangerous zone (RZ), thereby securing edge key points and safe FNS insertion range. RESULTS: In the 80 samples, the mean diameter of the smallest femoral neck section was 33.87 ± 2.32 mm for men and 29.36 ± 1.92 mm for women. All 80 femoral necks had safe and risky areas. The SZ/S × 100% was 77.59 (± 2.22%), and the RS/S × 100% was 22.39% (± 2.22%). The risk area was composed of four parts: (1), (2), (3), and (4), respectively, corresponding to 3.45 ± 1.74%, 5.51 ± 2.63%, 6.22 ± 1.41%, and 7.22 ± 1.39%. Four marginal key points, perforation risk, and safe ranges (SR) of FNS were analyzed on the lateral wall of the femoral neck. CONCLUSIONS: The SR of FNS placement was recommended by digital simulation. In addition, Regions (3) and (4) posed a higher risk of penetrating the cortex. Using the gradient map of RZ for preoperative evaluation is recommended to avoid iatrogenic perforation.

Single-cell RNA-seq analysis reveals that immune cells induce human nucleus pulposus ossification and degeneration.

Background and aims: Determining the transcriptomes and molecular mechanism underlying human degenerative nucleus pulposus (NP) is of critical importance for treating intervertebral disc degeneration (IDD). Here, we aimed to elucidate the detailed molecular mechanism of NP ossification and IDD using single-cell RNA sequencing. Methods: Single-cell RNA-seq and bioinformatic analysis were performed to identify NP cell populations with gene signatures, biological processes and pathways, and subpopulation analysis, RNA velocity analysis, and cell-to-cell communication analysis were performed in four IDD patients. We also verified the effects of immune cells on NP ossification using cultured NP cells and a well-established rat IDD model. Results: We identified five cell populations with gene expression profiles in degenerative NP at single-cell resolution. GO database analysis showed that degenerative NP-associated genes were mainly enriched in extracellular matrix organization, immune response, and ossification. Gene set enrichment analysis showed that rheumatoid arthritis signaling, antigen processing and presentation signaling were activated in the blood cell cluster. We revealed that stromal cells, which are progenitor cells, differentiated toward an ossification phenotype and delineated interactions between immune cells (macrophages and T cells) and stromal cells. Immune factors such as TNF-α, CD74 and CCL-3 promoted the differentiation of stromal cells toward an ossification phenotype in vitro. Blocking TNF-α with a specific inhibitor successfully reversed NP ossification and modified NP morphology in vivo. Conclusion: Our study revealed an increase in macrophages and T cells in degenerative NP, which induced stromal cell differentiation toward an ossification phenotype, and contributed to the identification of a novel therapeutic target to delay IDD.

PCDH7 as the key gene related to the co-occurrence of sarcopenia and osteoporosis.

Sarcopenia and osteoporosis, two degenerative diseases in older patients, have become severe health problems in aging societies. Muscles and bones, the most important components of the motor system, are derived from mesodermal and ectodermal mesenchymal stem cells. The adjacent anatomical relationship between them provides the basic conditions for mechanical and chemical signals, which may contribute to the co-occurrence of sarcopenia and osteoporosis. Identifying the potential common crosstalk genes between them may provide new insights for preventing and treating their development. In this study, DEG analysis, WGCNA, and machine learning algorithms were used to identify the key crosstalk genes of sarcopenia and osteoporosis; this was then validated using independent datasets and clinical samples. Finally, four crosstalk genes (ARHGEF10, PCDH7, CST6, and ROBO3) were identified, and mRNA expression and protein levels of PCDH7 in clinical samples from patients with sarcopenia, with osteoporosis, and with both sarcopenia and osteoporosis were found to be significantly higher than those from patients without sarcopenia or osteoporosis. PCDH7 seems to be a key gene related to the development of both sarcopenia and osteoporosis.

Sericin/Nano-Hydroxyapatite Hydrogels Based on Graphene Oxide for Effective Bone Regeneration via Immunomodulation and Osteoinduction.

Background: Immune responses and osteogenesis differentiation induced by implants are crucial for bone tissue regeneration. Consideration of only one of those properties is not sufficient. To investigate the synergistic actions, we designed alginate/graphene oxide/sericin/nanohydroxyapatite (Alg/GO/Ser/nHAP) nanocomposite hydrogels with both osteoimmunomodulatory and osteoinductive activities. This study aimed to explore the effect of hydrogel with osteoimmunomodulatory properties on promoting osteogenesis of bone marrow stem cells (BMSCs). Methods: Alg/GO/Ser/nHAP nanocomposite hydrogel was fabricated and was characterized by SEM, FTIR, XRD, stress-strain, rheology, swelling and degradation. After the impact of sericin on M2 macrophage polarization was identified, the BMSCs viability and adhesion were evaluated by CCK8 assay, live/dead staining, cytoskeleton staining. The cell osteogenic differentiation was observed by ALP/ARS staining, immunofluorescence staining, RT-PCR, and Western blotting, respectively. Rat cranial defect model was used to assess osteoimmunomodulatory effects of scaffolds in vivo by micro­computed tomographic, histological, and immunohistochemical analyses after 8 weeks of healing. Results: In vitro experiments revealed that the hydrogel presented desirable mechanical strength, stability, porosity, and biocompatibility. Significantly, sericin and nHAP appeared to exert synergistic effects on bone regeneration. Sericin was observed to inhibit the immune response by inducing macrophage M2-type polarization to create a positive osteoimmune microenvironment, contributing to improving osseointegration at the bone-implant interface to promote osteogenesis. However, the osteogenic differentiation in rat BMSCs was further enhanced by combining nHAP and sericin in the nanocomposite hydrogel. Eventually, the hydrogel was implanted into the rat cranial defect model, assisting in the reduction of local inflammation and efficient bone regeneration. Conclusion: The nanocomposite hydrogel stimulated bone formation by the synergistic effects of immunomodulation of macrophage polarization by sericin and direct osteogenic induction by nHAP, demonstrating that such a scaffold that modulates the osteoimmune microenvironment to promote osteogenesis is a promising approach for the development of bone tissue engineering implants in the future.

A Novel Zwitterionic Hydrogel Incorporated with Graphene Oxide for Bone Tissue Engineering: Synthesis, Characterization, and Promotion of Osteogenic Differentiation of Bone Mesenchymal Stem Cells.

Zwitterionic materials are widely applied in the biomedical field due to their excellent antimicrobial, non-cytotoxicity, and antifouling properties but have never been applied in bone tissue engineering. In this study, we synthesized a novel zwitterionic hydrogel incorporated with graphene oxide (GO) using maleic anhydride (MA) as a cross-linking agent by grafted L-cysteine (L-Cys) as the zwitterionic material on maleilated chitosan via click chemistry. The composition and each reaction procedure of the novel zwitterionic hydrogel were characterized via X-ray diffraction (XRD) and Fourier transformed infrared spectroscopy (FT-IR), while the morphology was imaged by scanning electron microscope (SEM). In vitro cell studies, CCK-8 and live/dead assay, alkaline phosphatase activity, W-B, and qRT-CR tests showed zwitterionic hydrogel incorporated with GO remarkably enhanced the osteogenic differentiation of bone mesenchymal stem cells (BMSCs); it is dose-dependent, and 2 mg/mL GO is the optimum concentration. In vivo tests also indicated the same results. Hence, these results suggested the novel zwitterionic hydrogel exhibited porous characteristics similar to natural bone tissue. In conclusion, the zwitterionic scaffold has highly biocompatible and mechanical properties. When GO was incorporated in this zwitterionic scaffold, the zwitterionic scaffold slows down the release rate and reduces the cytotoxicity of GO. Zwitterions and GO synergistically promote the proliferation and osteogenic differentiation of rBMSCs in vivo and in vitro. The optimal concentration is 2 mg/mL GO.

The prognostic value of retinol binding protein in geriatric hip fractures after surgeries: A propensity score matching and 1-year follow-up study.

BACKGROUND: We aimed to explore the predictive value of retinol binding protein (RBP) for outcomes of hip fractures. METHODS: Patients with hip fractures who underwent hip surgeries between December 2017 and February 2021 and met the inclusion criteria were analyzed. Propensity score matching was used to reduce the bias of co-factors and ROC curves based on matched populations were created to determine the optimal cutoff point of RBP. The outcomes between patients with low levels of RBP and high levels of RBP were compared. RESULTS: Four hundred eighty patients were enrolled in this study and 69 patients died within one year. After a 1:1 PSM, patients with more than 1-year survival had significantly higher RBP (p = 0.013) than those who died within one year, as well as patients divided by 6-months survival (p = 0.012). Logistics analysis showed that low RBP may be an independent risk factor for 3-month survival, 6-month survival, 1-year survival, and 3-month free walking ability. CONCLUSION: RBP may be associated with the survival and 3-month walking abilities of patients with hip fractures.

A sophisticated fracture classification system of the proximal femur trochanteric region (AO/OTA-31A) based on 3D-CT images.

Objective: Fracture classification evolves dynamically with new and enhanced imaging modalities. This paper aims to introduce a novel hypothesis of a sophisticated fracture classification system for the proximal femur trochanteric region (AO/OTA-31A) based on 3D-CT images and accommodate the clinical requirement of the worldwide outbreak of geriatric hip fractures with large amounts of surgical operations. Methods: In the current practice of widely preoperative 3D-CT application and cephalomedullary nailing, we attempt to propose a new comprehensive classification system to describe the fracture characteristics in a more detailed and sophisticated architecture, and pay the most important concern to the parameters that contribute to fracture stability reconstruction in osteosynthesis. Results: The new four-by-four comprehensive classification system, followed the structure of the AO/OTA system, incorporates many fracture characteristics as dividing indexes into multiple grade levels, such as fracture line direction, the number of fragments, the lesser trochanter fragment and its distal extension (>2 cm), the posterior coronal fragment and its anterior expansion (to the entry portal of head-neck implant at the lateral cortex), the lateral wall and anterior cortex fracture, and the anteromedial inferior corner comminution. From a panoramic perspective, there are four types and each type has four subtypes. A1 is simple two-part fractures (20%), A2 is characterized by lesser trochanter fragment and posterior coronal fractures (62.5%), A3 is reverse obliquity and transverse fractures with complete lateral wall broken (15.5%), and A4 is medial wall comminution which further lacks anteromedial cortex transmission of compression force (2%). For subtypes, A2.2 is with a banana-like posterior coronal fragment, A2.4 is with distal cortex extension >2 cm of the lesser trochanter and anterior expansion of the posterior coronal fragment(s) to the entry portal of head-neck implants, A3.4 is a primary pantrochanteric fracture, and A4.4 is a concomitant ipsilateral segmental fracture of the neck and trochanter region. Conclusion: Classification represents diversity under consistency. The four-by-four sophisticated classification system delineates fracture characteristics in more detail. It is applicable in the time of rapid outbreak of trochanteric fractures in the older population, the large amounts of surgical operations, and incorporates various rare and/or more complicated subtypes which is unclassifiable before.

[Proposal of a novel comprehensive classification for femoral intertrochanteric fractures].

Objective: To introduce a novel comprehensive classification for femoral intertrochanteric fractures, and to accommodate the clinical requirement for the world-wide outbreak of geriatric hip fractures and surgical operations. Methods: On the basis of reviewing the history of classification of femoral intertrochanteric fractures and analyzing the advantages and disadvantages of AO/Orthopaedic Trauma Association (AO/OTA) classification in different periods, combined with the current situation of extensive preoperative CT scan and three-dimensional reconstruction and widespread use of intramedullary nail fixation in China, the "Elderly Hip Fracture" Research Group of the Reparative and Reconstructive Surgery Committee of the Chinese Rehabilitation Medical Association proposed a novel comprehensive classification for femoral intertrochanteric fractures, focusing on the structure of fracture stability reconstruction during internal fixation. Results: The novel comprehensive classification of femoral intertrochanteric fractures incorporates multiple indicators of fracture classification, including the orientation of the fracture line, the degree of fracture fragmentation, the lesser trochanteric bone fragment and its distal extension length (>2 cm), the posterior coronal bone fragment and its anterior extension width (involving the lateral cortex of the head and neck implant entry point), transverse fracture of the lateral and anterior wall and its relationship with the implant entry point in the head and neck, and whether the cortex of the anteromedial inferior corner can be directly reduced to contact, etc. The femoral intertrochanteric fractures are divided into 4 types (type A1 is simple two-part fractures, type A2 is characterized by lesser trochanter fragment and posterior coronal fractures, type A3 is reverse obliquity and transverse fractures, type A4 is medial comminution which lacks anteromedial cortex transmission of compression force), each of which is subdivided into 4 subtypes and further subdivide into finer subgroups. In a review of 550 trochanteric hip fracture cases by three-dimensional CT, type A1 accounted for 20.0%, type A2 for 62.5%, type A3 for 15.5%, and type A4 for 2.0%, respectively. For subtypes, A2.2 is with a "banana-like" posterior coronal fragment, A2.4 is with distal cortex extension >2 cm of the lesser trochanter and anterior cortical expansion of the posterior coronal fragment to the entry portal of head-neck implants, A3.4 is a primary pantrochanteric fracture, and A4.4 is a concomitant ipsilateral segmental fracture of the neck and trochanter region. Conclusion: The novel comprehensive classification of femoral intertrochanteric fractures can describe the morphological characteristics of fractures in more detail, include more rare and complex types, provide more personalized subtype selection, and adapt to the clinical needs of both fractures and surgeries.

Prealbumin as a nutrition status indicator may be associated with outcomes of geriatric hip fractures: a propensity score matching and 1-year follow-up study.

AIM: Nutrition status may affect bone metabolism and regeneration in the elderly. However, few studies reported a sensitive nutrition indicator or evaluation tool for geriatric hip fractures. This study aimed to explore if prealbumin (PAB), a critical nutrition-related protein, is related to the prognosis of hip fractures. METHODS: Patients with hip fractures who met the inclusion criteria were included in our study. Geriatric nutritional risk index (GNRI) and prognostic nutritional index (PNI) were calculated. Propensity score matching (PSM) was used to reduce the influence of confounding factors and ROC curves were conducted to explore the optimal cutoff points of PAB and to compare the prognostic value between GNRI, PNI, and PAB. Then Cox and Logistics analyses were performed to identify the relation between PAB and outcomes of hip fractures. RESULTS: Out of the 546 patients enrolled in this study, 91 patients died within one year. After a 1:1 PSM, the patients with less than 1-year survival had significantly lower PAB (p < 0.001) than those who were still alive at one year. ROC curves showed that the PAB may sensitively predict 6-month survival (AUROC: 0.695), 1-year survival (AUROC: 0.696), and 1-year-free walking ability (AUROC: 0.642). Logistics analysis showed that low PAB may be an independent risk factor for survival and 1-year-free walking ability. CONCLUSION: Low levels of PAB may be associated with poor survival and walking abilities of older patients after surgery for hip fracture.

The paradoxical relation between serum uric acid and outcomes of hip fracture in older patients after surgery: A 1-year follow-up study.

BACKGROUND: The relation between serum uric acid and bone metabolism has been reported in many studies, but few studies have focused on serum uric acid and fracture rehabilitation. We aimed to explore the potential relationships between serum uric acid and outcomes of hip fractures. METHODS: A total of 742 patients with hip fractures who underwent surgeries between December 2017 and February 2021 and met the inclusion criteria were included. The data of male and female patients were analyzed separately. Cox models with different adjusted forms were performed to explore the potential risk factors, and restricted cubic splines were used to determine the nonlinear relationships between serum uric acid and outcomes and optimal cutoff points of serum uric acid. Then, the outcomes were analyzed in the groups divided by cutoff points mentioned above, as well as groups divided by the diagnosis of hyperuricemia or gout. RESULTS: Cox analysis showed that hyperuricemia or gout was associated with increased death risk, and a typical J-shaped curve was observed in the restricted cubic spline. For male patients, a serum uric acid of high level may relate to a high risk of 6-month (P = .008) and 1-year (P = .016) mortality, and a serum uric acid of low level may predict a poor 6-month free walking ability. For female patients, both a serum uric acid of high level and low level were associated with poor 1-year survival (all P < .05), and a serum uric acid of high level may relate to poor 6-month (P = .001) and 1-year (P = .001) free walking ability. CONCLUSION: Patients with hyperuricemia or gout or patients with high and low levels of serum uric acid may face poor outcomes of hip fractures.

Cebpb Regulates Skeletal Stem Cell Osteogenic Differentiation and Fracture Healing via the WNT/ß-Catenin Pathway.

Fracture is the most common traumatic organ injury, and fracture nonunion is a critical clinical challenge. The research on the mechanisms of skeletal stem cell (SSC) differentiation and fracture healing may help develop new treatment strategies and improve the prognosis of patients at high risk of nonunion. Bioinformatic analysis of scRNA-seq data of mouse SSCs and mouse osteoprogenitors was applied to discover major transcription factors for the regulation of SSC differentiation. FACS was used to isolate SSCs prospectively. The expression of Cebpb, osteogenesis-related genes (Runx2, Sp7, and Bglap2), and markers for Notch, Hedgehog, MAPK, BMP2/SMAD, and WNT/ß-catenin signaling pathways (Hes1, Gli1, p-Erk1/2, p-Smad1/5/9, and ß-catenin) were detected in SSCs with qPCR or western blot, respectively. Alkaline phosphatase assay and alizarin red S staining were used to illustrate the osteogenic differentiation ability of SSCs in vitro. A WNT inhibitor, IWR-1, was further used to explore the mechanism of WNT signaling in the differentiation of SSCs. Micro-CT, mechanical testing, and immunohistochemistry of osteogenic and chondrogenic proteins (Sp7 and Col2α1) were used to demonstrate the capacity of Cebpb knockdown in promoting fracture healing in a monocortical defect model. We found that Cebpb was the crucial transcription factor regulating SSC differentiation. Inhibiting Cebpb in SSCs enhanced the expression of active ß-catenin to promote the expression of WNT target genes, thus facilitating the osteogenic differentiation of SSCs. Bone mass, mechanical properties, and osteogenic protein expression were also increased in the Cebpb inhibition group compared to the group without Cebpb inhibition. Collectively, our results proved that Cebpb knockdown promotes SSC osteogenic differentiation and fracture healing via the WNT/ß-catenin signaling pathway.

Superoxide Dismutase and Glutathione Reductase as Indicators of Oxidative Stress Levels May Relate to Geriatric Hip Fractures' Survival and Walking Ability: A Propensity Score Matching Study.

Background: Oxidative stress status may affect bone metabolism and regeneration. However, few studies reported whether oxidative stress could impact the outcomes of hip fractures. This study aimed to explore if superoxide dismutase and glutathione reductase, the critical antioxidant enzymes, correlated with the prognosis of hip fractures. Methods: Patients with hip fractures were extracted from our database, and those who met the inclusion criteria were analyzed. Propensity score matching was used to reduce the influence of confounding factors, and ROC curves based on matched populations were created to determine the optimal cutoff points of SOD and GR. Then, outcomes between SOD or GR and outcomes of hip fractures were compared. Results: Out of 301 patients enrolled in this study, 50 patients died within one year. After a 1:1 PSM, the patients with less than 1-year survival had significantly lower SOD (p = 0.026) and GR (p = 0.021) than those who were still alive at one year. Logistics analysis showed that low SOD and low GR may be independent risk factors for 6-month survival, 1-year survival, 6-month free walking ability, and 1-year free walking ability. Conclusion: SOD and GR may be the independent risk factors for survival and walking abilities of hip fractures.