High throughput identification of carbonyl compounds in natural organic matter by directional derivatization combined with ultra-high resolution mass spectrometry.

Carbonyl compounds are important components of natural organic matter (NOM) with high reactivity, so that play a pivotal role in the dynamic transformation of NOM. However, due to the lack of effective analytical methods, our understanding on the molecular composition of these carbonyl compounds is still limited. Here, we developed a high-throughput screening method to detect carbonyl molecules in complex NOM samples by combining chemical derivatization with electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR-MS). In six different types of dissolved organic matter (DOM) samples tested in this study, 20-30 % of detected molecules contained at least one carbonyl group, with relative abundance accounted for 45-70 %. These carbonyl molecules displayed lower unsaturation level, lower molecular weight, and higher oxidation degree compared to non-carbonyl molecules. More importantly, the measured abundances of carbonyl molecules were consistent with the results of 13C nuclear magnetic resonance (NMR) analysis. Based on this method, we found that carbonyl molecules can be produced at DOM-ferrihydrite interface, thus playing a role in shaping the molecular diversity of DOM. This method has broad application prospects in screening carbonyl compounds from complex mixtures, and the same strategy can be used to directional identification of molecules with other functional groups as well.

Soil's Hidden Power: The Stable Soil Organic Carbon Pool Controls the Burden of Persistent Organic Pollutants in Background Soils.

Persistent organic pollutants (POPs) tend to accumulate in cold regions by cold condensation and global distillation. Soil organic matter is the main storage compartment for POPs in terrestrial ecosystems due to deposition and repeated air-surface exchange processes. Here, physicochemical properties and environmental factors were investigated for their role in influencing POPs accumulation in soils of the Tibetan Plateau and Antarctic and Arctic regions. The results showed that the soil burden of most POPs was closely coupled to stable mineral-associated organic carbon (MAOC). Combining the proportion of MAOC and physicochemical properties can explain much of the soil distribution characteristics of the POPs. The background levels of POPs were estimated in conjunction with the global soil database. It led to the proposition that the stable soil carbon pools are key controlling factors affecting the ultimate global distribution of POPs, so that the dynamic cycling of soil carbon acts to counteract the cold-trapping effects. In the future, soil carbon pool composition should be fully considered in a multimedia environmental model of POPs, and the risk of secondary release of POPs in soils under conditions such as climate change can be further assessed with soil organic carbon models.

IOX1 epigenetically enhanced photothermal therapy of 3D-printing silicene scaffolds against osteosarcoma with favorable bone regeneration.

Osteosarcoma (OS) is the third most common malignancy in adolescence. Currently, the treatments of OS confront great obstacles of tumor recurrence and critical bone defects after surgery, severely affecting the survival rates and living qualities of patients. Hence, it is urged to develop distinct biomaterials with both efficient tumor therapeutic and osteogenic functions. Although photothermal therapy (PTT) has aroused expanding interest, characterizing negligible invasiveness and high spatiotemporal adjustment, few studies discussed its drawbacks, such as thermal injury to adjacent normal tissue and exceeded laser power density, implying that focusing on sensitizing OS to PTT instead of simply elevating the laser power density may be a fresh way to enhance the PTT efficacy and attenuate the side/adverse effects. Herein, we successfully constructed 3D-printing silicene bioactive glass scaffolds with preferable PTT efficacy at the second near-infrared (NIR-II) biowindow and outstanding osteogenic biofunctions owing to the release of bioactive elements during degradation. Impressively, a histone demethylase inhibitor, IOX1, was introduced before PTT to sensitize OS to thermal therapy and minimize the side/adverse effects. This work offered a distinctive paradigm for optimizing the PTT efficacy of osteogenic scaffolds against OS with epigenetic modulation agents.

Tranexamic acid in patients with post-traumatic elbow stiffness: protocol for a randomised, double-blind, placebo-controlled trial investigating the effectiveness of tranexamic acid at reducing the recurrence of heterotopic ossification after open elbow arthrolysis.

INTRODUCTION: Exaggerated inflammatory response is one of the main mechanisms underlying heterotopic ossification (HO). It has been suggested that the antifibrinolytic drug tranexamic acid (TXA) can exert a significant anti-inflammatory effect during orthopaedic surgery. However, no prospective studies have yet investigated the effects of TXA on HO recurrence in patients following open elbow arthrolysis (OEA). METHODS AND ANALYSIS: Here, we present a protocol for a single-centre, randomised, double-blind, placebo-controlled trial to investigate the effectiveness of TXA on HO recurrence after OEA in a single hospital. A minimum sample size of 138 eligible and consenting participants randomised into treatment and control groups in a 1:1 manner will be included. Patients will receive 2 g of intravenous TXA (experimental group) or placebo (normal saline, control group) administered before skin incision. The primary outcome is HO recurrence rate within 12 months after surgery. The secondary outcomes are the serum immune-inflammatory cytokines including erythrocyte sedimentation rate, C reactive protein, interleukin (IL)-6, IL-1ß, IL-13 at the first and third day postoperatively, and elbow range of motion and functional score at 1.5, 6, 9 and 12 months after surgery. After completion of the trial, the results will be reported in accordance with the extensions of the Consolidated Standards of Reporting Trials Statement for trials. The results of this study should determine whether TXA can reduce the rates of HO occurrence after OEA. ETHICS AND DISSEMINATION: Ethical approval has been granted by the Medical Ethics Committee of the Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (reference number 2022-123-(1)). The results of this study will be disseminated through presentations at academic conferences and publication in peer-reviewed journals. TRIAL REGISTRATION NUMBER: ChiCTR2300068106.

Application of modified aldehyde compounds in self-etching bonding of dentin.

OBJECTIVE: The aim of this study was to evaluate the ability of 4-formylphenyl acrylate (FA) to enhance the bond strength and stabilize the resin-dentin bonding interface of universal adhesives in self-etching mode over time. METHODS: Different concentrations of FA (1%, 3%, 5%, 7%, 9%) were prepared as primer. The optimal group was selected according to degree of conversion of 2 universal adhesives (Single Bond Universal (SBU)/All-Bond Universal (ABU)), and grouped according to the pre-treatment time (30s, 1min, 2min). The micro-tensile strength before and after 10,000 times thermocycling aging was used to evaluate the bonding performance. RESULTS: The 1min application of FA (5%) increased the conversion rate of the adhesive. The expressions of microtensile bond strength and nanoleakage in the FA treatment group did not decrease significantly compared with their immediate values even after 10,000 thermocycling of aging. In situ zymography results showed that the hydrolytic activity of endogenous proteins decreased significantly in FA-1min group. CONCLUSIONS: Treatment by FA primer can effectively enhance the bond stability at the bonding interface. CLINICAL RELEVANCE: FA can be used as a functional monomer in self-etching bonding system to dentin, which not only had high biocompatibility, but also can show good collagen cross-linking ability within clinically acceptable application time.

Dual-engineered cartilage-targeting extracellular vesicles derived from mesenchymal stem cells enhance osteoarthritis treatment via miR-223/NLRP3/pyroptosis axis: Toward a precision therapy.

Osteoarthritis (OA) is the most common disabling joint disease with no effective disease modifying drugs. Extracellular vesicles released by several types of mesenchymal stem cells could promote cartilage repair and ameliorate OA pathology in animal models, representing a novel therapeutic strategy. In this study, we demonstrated that extracellular vesicles derived from human umbilical cord mesenchymal stem cells (hUC-EVs) could maintain chondrocyte homeostasis and alleviate OA, and further revealed a novel molecular mechanism of this therapeutic effect. miR-223, which could directly bind with the 3'UTR of NLRP3 mRNA, was found to be a key miRNA for hUC-EVs to exert beneficial effects on inflammation inhibiting and cartilage protecting. For enhancing the effect on mitigating osteoarthritis, exogenous miR-223 was loaded into hUC-EVs by electroporation, and a collagen II-targeting peptide (WYRGRL) was modified onto the surface of hUC-EVs by genetic engineering to achieve a more targeted and efficient RNA delivery to the cartilage. The dual-engineered EVs showed a maximal effect on inhibiting the NLRP3 inflammasome activation and chondrocyte pyroptosis, and offered excellent results for the treatment of OA. This study provides a novel theoretical basis and a promising therapeutic strategy for the application of engineered extracellular vesicles in OA treatment.

Multifunctional Extracellular Matrix Hydrogel with Self-Healing Properties and Promoting Angiogenesis as an Immunoregulation Platform for Diabetic Wound Healing.

Treating chronic wounds is a global challenge. In diabetes mellitus cases, long-time and excess inflammatory responses at the injury site may delay the healing of intractable wounds. Macrophage polarization (M1/M2 types) can be closely associated with inflammatory factor generation during wound healing. Quercetin (QCT) is an efficient agent against oxidation and fibrosis that promotes wound healing. It can also inhibit inflammatory responses by regulating M1-to-M2 macrophage polarization. However, its limited solubility, low bioavailability, and hydrophobicity are the main issues restricting its applicability in wound healing. The small intestinal submucosa (SIS) has also been widely studied for treating acute/chronic wounds. It is also being extensively researched as a suitable carrier for tissue regeneration. As an extracellular matrix, SIS can support angiogenesis, cell migration, and proliferation, offering growth factors involved in tissue formation signaling and assisting wound healing. We developed a series of promising biosafe novel diabetic wound repair hydrogel wound dressings with several effects, including self-healing properties, water absorption, and immunomodulatory effects. A full-thickness wound diabetic rat model was constructed for in vivo assessment of QCT@SIS hydrogel, in which hydrogels achieved a markedly increased wound repair rate. Their effect was determined by the promotion of the wound healing process, the thickness of granulation tissue, vascularization, and macrophage polarization during wound healing. At the same time, we injected the hydrogel subcutaneously into healthy rats to perform histological analyses of sections of the heart, spleen, liver, kidney, and lung. We then tested the biochemical index levels in serum to determine the biological safety of the QCT@SIS hydrogel. In this study, the developed SIS showed convergence of biological, mechanical, and wound-healing capabilities. Here, we focused on constructing a self-healing, water-absorbable, immunomodulatory, and biocompatible hydrogel as a synergistic treatment paradigm for diabetic wounds by gelling the SIS and loading QCT for slow drug release.

Changes of Soil Dissolved Organic Matter and Its Relationship with Microbial Community along the Hailuogou Glacier Forefield Chronosequence.

Glacier-retreated areas are ideal areas to study soil biogeochemical processes during vegetation succession, because of the limited effect of other environmental and climatic factors. In this study, the changes of soil dissolved organic matter (DOM) and its relationship with microbial communities along the Hailuogou Glacier forefield chronosequence were investigated. Both microbial diversity and DOM molecular chemodiversity recovered rapidly at the initial stage, indicating the pioneering role of microorganisms in soil formation and development. The chemical stability of soil organic matter enhanced with vegetation succession due to the retaining of compounds with high oxidation state and aromaticity. The molecular composition of DOM affected microbial communities, while microorganisms tended to utilize labile components to form refractory components. This complex relationship network between microorganisms and DOM components played an important role in the development of soil organic matter as well as the formation of stable soil carbon pool in glacier-retreated areas.

Biomimetic Mineralized Hydrophilic Polyurethane Primers for Inducing Dentin Tubule Fillings.

This experiment aimed to synthesize a biomimetic mineralized hydrophilic polyurethane dentin primer containing DDDEEKC peptide (DDDEEKC-PU) to fill dentin tubules and induce mineralization. The degree of conversion (DC) was tested. Dentin samples were acid-etched and treated with DDDEEKC-PU. They were immersed in stimulated human fluid (SBF) for 7, 14 and 28 days. Dentin permeability, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and Vickers hardness were measured. After 28 days, regenerated minerals were deposited on resin tags which were confirmed to be hydroxyapatite (HAp). The minerals reduced the dentin permeability and improved the microhardness. DDDEEKC-PU was able to fill dental tubules immediately and induce mineralization simultaneously.

A novel resin cement to improve bonding interface durability.

Bonding failure is one of the main causes of failure of dental restorations. The bonding strength, aging resistance, and polymerization shrinkage of cement can affect the stability of the bonding interface and lead to marginal microleakage. To reduce the bonding failure rate of restorations, a novel polyurethane (PU) cement was designed to improve the mechanical properties, hydrophobicity, degree of conversion (DC), polymerization shrinkage, bond strength and aging resistance of cement by introducing isophorone diisocyanate (IPDI) and hydroxyethyl methacrylate (HEMA) and adjusting the polyester : polyether ratio to increase the degree of cross-linking. Experimental results verified that the novel PU could increase the mechanical properties and thermal stability of the cement, reduce polymerization shrinkage during the curing reaction, improve the bonding performance and DC, endow the cement with hydrophobic properties, and improve its ability to resist aging in the salivary environment to maintain the long-term stability of interfacial bonding under the influence of comprehensive factors. The results of this study provide a new direction and insights to reduce microleakage and improve the success rate of restorations.

Procyanidins and Their Therapeutic Potential against Oral Diseases.

Procyanidins, as a kind of dietary flavonoid, have excellent pharmacological properties, such as antioxidant, antibacterial, anti-inflammatory and anti-tumor properties, and so they can be used to treat various diseases, including Alzheimer's disease, diabetes, rheumatoid arthritis, tumors, and obesity. Given the low bioavailability of procyanidins, great efforts have been made in drug delivery systems to address their limited use. Nowadays, the heavy burden of oral diseases such as dental caries, periodontitis, endodontic infections, etc., and their consequences on the patients' quality of life indicate a strong need for developing effective therapies. Recent years, plenty of efforts are being made to develop more effective treatments. Therefore, this review summarized the latest researches on versatile effects and enhanced bioavailability of procyanidins resulting from innovative drug delivery systems, particularly focused on its potential against oral diseases.

Factors affecting the evolution of Chinese elderly depression: a cross-sectional study.

BACKGROUND: In the past decades, China's rapid economic growth has been accompanied by rapid changes in lifestyle and an increasing prevalence of mental disorders. This study explored the changes and factors associated with depression among the elderly population of China from 2011 to 2018. METHOD: Data were obtained from the China Health and Retirement Longitudinal Study. The total sample size consists of 21,484 individuals aged ≥60 years, and the sample sizes in 2011, 2013, 2015 and 2018 were 5081, 4853, 5207, 6343, respectively. Depressive symptoms were measured by the 10-item Short-Form developed by the Center for Epidemiological Studies Depression. RESULT: We found that the tendency in depression rate of the Chinese elderly from 2011 (36.8%) to 2018 (44.5%). The results showed poor health (OR = 3.553), ADL damage (OR = 2.010), multiple chronic diseases (OR = 1.287), and western (OR = 1.777) are risk factors for depression. CONCLUSION: The rate of depression of the elderly people in China has risen dramatically. Therefore, additional steps to prevent, treat and care for the affected population are needed, Mental health prevention and treatment strategies should be incorporated into China's public health policies in a timely manner to mitigate the serious economic burden caused by the increase of depression.

Macrophage Polarization Modulated by NF-κB in Polylactide Membranes-Treated Peritendinous Adhesion.

Foreign body reactions (FBR) to implants seriously impair tissue-implant integration and postoperative adhesion. The macrophage, owing to its phenotypic plasticity, is a major regulator in the formation of the inflammatory microenvironment; NF-κB signaling also plays a vital role in the process. It is hypothesized that NF-κB phosphorylation exerts a proinflammatory regulator in FBR to polylactide membranes (PLA-M) and adhesion. First, in vitro and in vivo experiments show that PLA-M induces NF-κB phosphorylation in macrophages, leading to M1 polarization and release of inflammatory factors. The inflammatory microenvironment formed due to PLA-M accelerates myofibroblast differentiation and release of collagen III and MMP2, jointly resulting in peritendinous adhesion. Therefore, JSH-23 (a selective NF-κB inhibitor)-loaded PLA membrane (JSH-23/PLA-M) is fabricated by blend electrospinning to regulate the associated M1 polarization for peritendinous anti-adhesion. JSH-23/PLA-M specifically inhibits NF-κB phosphorylation in macrophages and exhibits anti-inflammatory and anti-adhesion properties. The findings demonstrate that NF-κB phosphorylation has a critical role in PLA-induced M1 polarization and aggravating FBR to PLA-M. Additionally, JSH-23/PLA-M precisely targets modulation of NF-κB phosphorylation in FBR to break the vicious cycle in peritendinous adhesion therapy.

Effect of collagen cross-linkers on dentin bond strength: A systematic review and network meta-analysis.

Objective: This study aimed to evaluate the role of collagen cross-linkers in the bonding performance of the resin-dentin interface through a systematic review and a network meta-analysis. Sources: The literature search was conducted in several databases like PubMed, EMBASE, Cochrane, Scopus and Web of Science from their inception till 30 April 2022. Study selection: The inclusion criteria consisted of in vitro studies evaluating the micro-tensile and micro-shear bond strengths of different cross-linkers acting on dentin. Bayesian network meta-analysis was conducted using RStudio. Data: Out of the 294 studies evaluated in the full-text analysis, 40 were included in the systematic review and meta-analysis. Most studies have used cross-linkers as primer (65.1%), followed by incorporating them into in adhesives and acid etching agents. The application methods of the adhesive system were classified as "etch-and-rinse (ER) adhesives" (77%) and "self-etching (SE) adhesives". Moreover, there were six types of cross-linkers in this presented review, of which the most numerous were polyphenols. Conclusion: Different application methods of cross-linkers, the long-term results showed that were only effective when used for longer durations, the immediate results were not statistically different. According to immediate and long-term results, etch-and-rinse (ER) adhesives showed a greater bonding performance than the control groups (p ≤ 0.05), whereas self-etching (SE) adhesives showed similar bond strength values (p ≥ 0.05). The result of network meta-analysis (NMA) showed that Dope like compound showed higher long-term bonding performance than other cross-linkers. Clinical significance: Long-term clinical studies may be needed to determine the effect of the cross-linkers on the bonding properties.

A novel dental adhesive containing Ag/polydopamine-modified HA fillers with both antibacterial and mineralization properties.

OBJECTIVES: To evaluate the antibacterial and mineralization properties of a dental adhesive containing Ag/polydopamine-modified HA (HA, hydroxyapatite) fillers. METHODS: First, an HA-polydopamine-Ag-polydopamine (HA-PDA-Ag-PDA) filler was prepared and characterized using SEM, TEM, XPS, XRD and FTIR. Then, the HA-PDA-Ag-PDA filler was mixed into an adhesive at different mass fractions (0 wt%, 0.5 wt%, 1 wt%, 2 wt%) to prepare a functional adhesive. Antibacterial and mineralization tests were carried out, and the cytotoxicity of the functional adhesive against L929 fibroblasts was also examined. RESULTS: The SEM, TEM, XPS, XRD and FTIR characterizations confirmed the successful preparation of the HA-PDA-Ag filler. The 1 wt% and 2 wt% functional adhesives showed the strongest bacterial inhibition effect among all the samples (p < 0.05). Obvious apatite crystals were observed in the SEM micrograph of the surface of the functional adhesive sample after immersion in artificial saliva for predetermined times (1 d, 7 d, 14 d and 28 d). There was no significant difference between the experimental group and the control group in terms of cell proliferation activity (p > 0.05). CONCLUSIONS: The 1 wt% and 2 wt% functional adhesives demonstrated good antibacterial and mineralization properties, as well as good biocompatibility. CLINICAL SIGNIFICANCE: Functional adhesives containing Ag/polydopamine-modified HA fillers with antibacterial and mineralization capabilities might have excellent potential to enhance the stability and durability of hybrid layers and prolong the service life of dental restorations. Our study on bifunctional adhesives has paved the way for future clinical applications to increase restoration longevity.

Intravenous tranexamic acid reduce postoperative drainage and pain after open elbow arthrolysis: a randomized controlled trial.

BACKGROUND: Open elbow arthrolysis (OEA), which has become an established treatment for post-traumatic elbow stiffness (PTES), requires complete release of contracture tissue and wide excision of ectopic bone, which results in extensive bleeding. The aim of the present study is to evaluate the efficacy of intravenous tranexamic acid (TXA) on postoperative drainage, calculated blood loss, and early clinical outcomes in patients undergoing OEA. METHODS: A double-blind, randomized, placebo-controlled trial including 96 patients undergoing OEA was undertaken. Patients received intravenously either 100 mL saline (placebo group, n = 48), or 100 mL saline plus 1 g TXA (TXA group, n = 48) before skin incision. The primary outcome was the drainage volume on postoperative days (PODs) 1-3. Secondary outcomes included the calculated blood loss, elbow pain score measured by visual analog scale (VAS), elbow function valued by Mayo Elbow Performance Score (MEPS), and rate of complications after OEA. RESULTS: Mean total postoperative drainage volume (TXA group: 182 mL vs. placebo group: 214 mL, P = .003) and mean calculated total blood loss (TXA group: 582 mL vs. placebo group: 657 mL, P = .004) were significantly lower in the TXA group. No transfusions were necessary in either group. Mean VAS pain scores in elbow motion showed marked differences between both groups on POD 1 (TXA: 5 vs. placebo: 6, P = .003) and POD 2 (TXA: 4 vs. placebo: 5, P = .023) but not in other postoperative time points. No differences were detected in complications, such as pin-related infection, hematoma, new or exacerbation of ulnar nerve symptoms, and recurrent heterotopic ossification. At the 6-month follow-up, no statistical differences were found between the 2 groups with respect to the elbow functions including range of motion, VAS score, and MEPS. CONCLUSION: Intravenous administration of TXA significantly decreased the postoperative drainage volume and the total estimated blood loss and alleviated the elbow pain with motion during early postoperative days in patients undergoing OEA.

Construction and properties of the antibacterial epitaxial transition layer on a zirconia ceramic surface.

Secondary caries is one of the main causes of dental zirconia restoration failure in the clinic. Therefore, it is urgent to improve the antibacterial performance of zirconia ceramics to reduce the occurrence of secondary caries. In this study, a quaternary ammonium compound antibacterial polymer was innovatively synthesized by solution polymerization with a quaternary ammonium salt monomer as the antibacterial component. The antibacterial epitaxial transition layer was successfully prepared on the surface of zirconia ceramics by the hydroxyl group on HEMA reacting with the siloxane group in the KH570 hydrolysate, which makes the antibacterial polymer indirectly chemically combine with the silicate epitaxial transition layer. The antibacterial epitaxial transition layer exhibited excellent mechanical properties, satisfactory biocompatibility and significant antibacterial effects, and the maximum antibacterial rate is 99%. The antibacterial epitaxial transition layer plays an important role in preventing secondary caries and improving the success rate of clinical zirconia ceramic restorations.

Construction of a silicate-based epitaxial transition film on a zirconia ceramic surface to improve the bonding quality of zirconia restorations.

The effect of a silicate-based epitaxial transition film on zirconia produced by a silicate solution during zirconia-resin bonding was investigated. The airborne-particle abraded zirconia was placed in different concentrations of silicate solutions and heated at 50 °C. The silicate transition film was characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), energy-dispersive X-ray spectroscopy (EDX), contact angle measurement and profilometry. The silicate-based epitaxial transition film was successfully constructed on the surface of zirconia, and the surface morphology and composition of zirconia changed. After coupling with KH570 hydrolysate, the shear bond strength (SBS) of zirconia-resin after either 24 h water storage or 5000 thermal cycles can be significantly improved by a silicate-based epitaxial transition film on the surface of zirconia, and all the samples had no cytotoxicity. This may provide a new strategy for improving the bonding quality of zirconia restorations.

Risk Factors for the Occurrence and Progression of Posttraumatic Elbow Stiffness: A Case-Control Study of 688 Cases.

Background: Elbow stiffness is a severe complication after trauma. Surgical or conservative treatments may be ineffective for restoring functional elbow motion. We aim to evaluate intrinsic and extrinsic factors for the occurrence and severity of elbow stiffness. Methods: This retrospective case-control study included mild/moderate stiffness, severe stiffness, and non-stiffness groups between January 2011 and December 2017 at a single orthopedic center. Multivariable logistic regression analysis and subgroup analysis were used to evaluate age, gender, body mass index, muscle strength, fracture type and site, injury mechanism, immobilization time, elbow dysfunction time, multiple surgeries, nerve symptoms, physical therapy, smoking and alcohol abuse, and dominant hand of stiff elbow as potential risk factors for the occurrence and severity of elbow stiffness. Results: There were 461 patients in the stiffness group and 227 patients in the non-stiffness group. The odds ratios (ORs) of the age, muscle strength, and injury mechanism were 0.960, 0.333, and 0.216 for the occurrence of elbow stiffness. In subgroup evaluation, increased cast immobilization time might be a risk factor for patients receiving conservative therapies (OR = 2.02; p = 0.014). In the evaluation on factors for progression of elbow stiffness, "multiple surgeries" might be a risk factor in surgical treatment by subgroup analysis (OR = 1.943; p = 0.026). Nevertheless, alcohol abuse might increase severity of elbow stiffness in conservatively treated patients (OR = 3.082; p = 0.025). Conclusion: Increased cast immobilization time in the conservative therapy might be a risk factor for stiffness occurrence. Multiple surgeries might be risk factors for stiffness progression. Alcohol abuse potentially increased stiffness severity after conservative treatment.

Severe traumatic valgus instability of the elbow: pathoanatomy and outcomes of primary operation.

BACKGROUND: The objective of the study was to depict the pathoanatomy of traumatic valgus instability of the elbow and to report clinical outcomes of primary operation. METHODS: Thirty-one patients presented with traumatic valgus instability of the elbow without dislocation. Thirty-one patients underwent surgical intervention of radial head fractures (28 open reduction and internal fixation and 3 radial head resection) and anatomical repair of the anterior bundle of medial collateral ligament (AMCL) with suture anchors. Twenty patients with disruption of the flexor-pronator tendon (FPT) and 14 patients with tears of the anterior capsule had primary repair of the FPT and anterior capsule simultaneously. Clinical outcomes were evaluated with the Mayo Elbow Performance Score (MEPS), modified hospital for special surgery assessment scale (HSS), and Disabilities of the Arm, Shoulder, and Hand (DASH) score. RESULTS: The median follow-up was 37.3 months (range, 15-53 months). Radial head fractures and complete avulsion of the medial collateral ligament (MCL) from its humeral footprint were confirmed in all patients intraoperatively. Intraoperative findings indicated disruption of the FPT in 20 patients and tears of the anterior capsule in 14 patients. Twenty-nine of 31 patients returned to previous activity and work levels within 6 months after surgery. The MEPS, modified HSS, and DASH score were 94 ± 4, 91 ± 5, and 8 ± 2 at the latest follow-up. CONCLUSIONS: Radial head fractures with avulsion of the MCL can lead to severe valgus instability of the elbow. Primary operation to repair these disrupted structures, especially repair of the AMCL, can effectively restore valgus stability.