Suppression of DNMT2/3 by proinflammatory cytokines inhibits CtBP1/2-dependent genes to promote the occurrence of atrophic nonunion.

Failure of bone healing after fracture often results in nonunion, but the underlying mechanism of nonunion pathogenesis is poorly understood. Herein, we provide evidence to clarify that the inflammatory microenvironment of atrophic nonunion (AN) mice suppresses the expression levels of DNA methyltransferases 2 (DNMT2) and 3A (DNMT3a), preventing the methylation of CpG islands on the promoters of C-terminal binding protein 1/2 (CtBP1/2) and resulting in their overexpression. Increased CtBP1/2 acts as transcriptional corepressors that, along with histone acetyltransferase p300 and Runt-related transcription factor 2 (Runx2), suppress the expression levels of six genes involved in bone healing: BGLAP (bone gamma-carboxyglutamate protein), ALPL (alkaline phosphatase), SPP1 (secreted phosphoprotein 1), COL1A1 (collagen 1a1), IBSP (integrin binding sialoprotein), and MMP13 (matrix metallopeptidase 13). We also observe a similar phenomenon in osteoblast cells treated with proinflammatory cytokines or treated with a DNMT inhibitor (5-azacytidine). Forced expression of DNMT2/3a or blockage of CtBP1/2 with their inhibitors can reverse the expression levels of BGLAP/ALPL/SPP1/COL1A1/IBSP/MMP13 in the presence of proinflammatory cytokines. Administration of CtBP1/2 inhibitors in fractured mice can prevent the incidence of AN. Thus, we demonstrate that the downregulation of bone healing genes dependent on proinflammatory cytokines/DNMT2/3a/CtBP1/2-p300-Runx2 axis signaling plays a critical role in the pathogenesis of AN. Disruption of this signaling may represent a new therapeutic strategy to prevent AN incidence after bone fracture.

Clinical and radiographic outcomes of revision with autogenous "structured" bone grafting combined with superior plate for recalcitrant atrophic nonunion of clavicular midshaft: a retrospective study.

PURPOSE: To assess the efficacy of autogenous "structured" bone grafting (ASBG), it was combined with superior plate (SP) revision operations for recalcitrant clavicular midshaft aseptic nonunion (CMAN). METHODS: This retrospective study included 12 patients who suffered from failure of autologous cancellous bone grafting (ACBG) and SP fixation because of CMAN. Visual analogue scale (VAS) data for pain and disabilities of arm, shoulder, and hand (DASH) scores of patients who underwent these procedures from January 2019 to December 2020, obtained before surgery and at the final follow-up time, were analysed. RESULTS: The average time between primitive fracture and this operative treatment was 29 months (15-38 months). The average duration of surgery was 153 minutes (range, 115-230 min), and the average blood loss was 560 ml (range, 350-860 ml). Complications occurred in two cases (16.67%): one was persistent pain at the donor site, and the other was a calf muscle vein thrombosis. No tissue infection was observed during follow-up. The mean follow-up time was 18 months (range, 12-30 months). All fractures progressed to osseous healing at a mean time of 14 weeks (range, 12-16 weeks). The mean pain VAS score significantly improved, from 4.8 ± 1.7 pre-operatively to 1.9 ± 1.1 at the final follow-up (P = 0.01). The mean DASH score improved significantly from 30.1 ± 11.2 pre-operatively to 7.8 ± 4. 2 at the final follow-up (P < 0.01). CONCLUSIONS: ASBG combined with SP revision surgery achieved excellent clinical outcomes in patients with recalcitrant CMAN.

Dose tranexamic acid reduce blood loss associated with simultaneous bilateral distal tibial tubercle-high tibial osteotomy?

BACKGROUND: Simultaneous bilateral distal tibial tubercle high tibial osteotomy (SBDTT-HTO) can result in increased blood loss. The aim of this study is to evaluate the actual hemostatic effect of different tranexamic acid (TXA) treatment regimen in SBDTT-HTO. METHODS: We conducted a retrospective case-control study including 54 patients who underwent SBDTT-HTO. The single-dose group (n = 18) received 1 g of intravenous TXA 15-30 min before surgery, the two-dose group (n = 18) received an additional 1 g of intravenous TXA 6 h after surgery, and the multiple-dose group (n = 18) received an additional 1 g intravenous TXA per-day until discharge. Blood loss, hemoglobin levels, occurrence of any adverse events,functional analysis, quality of life, and pain assessmentswere compared among the three groups. RESULTS: The total blood loss, hidden blood loss, drainage volumes, and haemoglobin level in the multiple-dose group all occupy a significant advantage.(p < 0.05). In addition, better quality of life were observed in patients belonging to the multiple-dose group then single-dose group.(p < 0.05). CONCLUSIONS: Based on our results, for patients undergoing SBDTT-HTO, sequential intravenous TXA administration can effectively and safely reduce blood loss,maintain postoperative Hb levels,and with the advantage of accelerating recovery.

Bone marrow particle enrichment analysis for the laboratory diagnosis of multiple myeloma: A case study.

BACKGROUND: Bone marrow smear and biopsy are the main methods for the diagnosis of multiple myeloma (MM), bone marrow infiltration, and metastasis in lymphoma and cancer. However, several factors, including the focal growth of tumor cells, inappropriate puncture sites, and hemodilution of bone marrow aspirates, lower the rate of target cell detection. To solve this problem, we developed a novel method-bone marrow particle enrichment analysis-and here, we describe this procedure and its use in the diagnosis of a rare case of MM. METHODS: An 88-year-old man with primary gastric gamma delta T-cell lymphoma (γδTCL) was found to have anemia. As the cause of anemia could not be determined, hemodilution was suspected, warranting the re-examination of the bone marrow aspirate. Re-puncture could not be performed because of the patient's age and unwillingness to undergo this procedure. Hence, we used a novel approach to enrich bone marrow particles and isolate marrow cells, and subsequently performed morphological and flow cytometric analysis. RESULTS: Examinations performed after bone marrow particle enrichment revealed the presence of myeloma cells, and the patient was diagnosed with primary gastric γδTCL accompanied by MM. CONCLUSIONS: Bone marrow particle enrichment analysis may be applied to overcome the problems caused by hemodilution of bone marrow aspirates and to improve the rate of tumor cell detection. The application of this method for the diagnosis of hematological disorders should be explored further.

Cartilage oligomeric matrix protein and hyaluronic acid are sensitive serum biomarkers for early cartilage lesions in the knee joint.

The purpose of this study was to evaluate the relationship between five previously established serum osteoarthritis biomarkers and the severity of cartilage lesions in the knee. Cartilage damage (classified according to the Outerbridge scoring system) and serum concentrations of cartilage oligomeric matrix protein (COMP), collagen type II C-telopeptide (CTX-II), matrix metalloproteinase-3 (MMP-3), collagen type III N-propeptide, (PIIINP), and hyaluronic acid (HA) were determined in 79 patients who underwent knee arthroscopy or total knee replacement. HA and COMP concentrations were significantly higher in the Outerbridge score 1 and 2 groups, respectively. These results suggest that serum COMP and HA concentrations can be used to predict early cartilage lesions in the knee.

In vivo investigation to the macrolide-glycosylating enzyme pair DesVII/DesVIII in Saccharopolyspora erythraea.

Glycosyltransferase DesVII and its auxiliary partner DesVIII from Streptomyces venezulae, homologs of EryCIII and EryCII in Saccharopolyspora erythraea, have previously been demonstrated to be flexible on their substrates in vitro. Herein, we investigated their in vivo function by interspecies complementation in the mutant strains of Sac. erythraea A226. As desVII and desVIII were concomitantly expressed in the ΔeryCIII mutant, the erythromycin A (Er-A) production was restored. Interestingly, co-expression of desVII and desVIII in the ΔeryBV mutant exhibited an increased Er-A yield by 15 % in comparison to A226. Hence, DesVII/DesVIII not only replaced EryCIII to upload D-desosamine to C5 position of 3-O-mycarosyl erythronolide B (MEB) but also in vivo attached L-mycarose, not D-desosamine to C3 position of erythronolide B (EB) with a higher activity than EryBV. Furthermore, expression of desVII in ΔeryCIII and ΔeryBV-CIII partially restored the Er-A production; however, no Er-A was detected while desVII was expressed in ΔeryBV. It was implicated that DesVII coupled with EryCII to form the DesVII/EryCII complex for attaching above two deoxysugars in the absence of EryCIII in Sac. erythraea. In addition, when desVII and desVIII were co-expressed in ΔeryBV-CII, Er-A was recovered with a lower yield than ΔeryBV-CIII. Our study presents an opportunity with Sac. erythraea as a cell factory for macrolide glycodiversification.

SACE_3986, a TetR family transcriptional regulator, negatively controls erythromycin biosynthesis in Saccharopolyspora erythraea.

Erythromycin, a medically important antibiotic, is produced by Saccharopolyspora erythraea. Unusually, the erythromycin biosynthetic gene cluster lacks a regulatory gene, and the regulation of its biosynthesis remains largely unknown. In this study, through gene deletion, complementation and overexpression experiments, we identified a novel TetR family transcriptional regulator SACE_3986 negatively regulating erythromycin biosynthesis in S. erythraea A226. When SACE_3986 was further inactivated in an industrial strain WB, erythromycin A yield of the mutant was increased by 54.2 % in average compared with that of its parent strain, displaying the universality of SACE_3986 as a repressor for erythromycin production in S. erythraea. qRT-PCR analysis indicated that SACE_3986 repressed the transcription of its adjacent gene SACE_3985 (which encodes a short-chain dehydrogenase/reductase), erythromycin biosynthetic gene eryAI and the resistance gene ermE. As determined by EMSA analysis, purified SACE_3986 protein specifically bound to the intergenic region between SACE_3985 and SACE_3986, whereas it did not bind to the promoter regions of eryAI and ermE. Furthermore, overexpression of SACE_3985 in A226 led to enhanced erythromycin A yield by at least 32.6 %. These findings indicate that SACE_3986 is a negative regulator of erythromycin biosynthesis, and the adjacent gene SACE_3985 is one of its target genes. The present study provides a basis to increase erythromycin production by engineering of SACE_3986 and SACE_3985 in S. erythraea.

Indian hedgehog in synovial fluid is a novel marker for early cartilage lesions in human knee joint.

To determine whether there is a correlation between the concentration of Indian hedgehog (Ihh) in synovial fluid (SF) and the severity of cartilage damage in the human knee joints, the knee cartilages from patients were classified using the Outer-bridge scoring system and graded using the Modified Mankin score. Expression of Ihh in cartilage and SF samples were analyzed with immunohistochemistry (IHC), western blot, and enzyme-linked immunosorbent assay (ELISA). Furthermore, we detected and compared Ihh protein levels in rat and mice cartilages between normal control and surgery-induced osteoarthritis (OA) group by IHC and fluorescence molecular tomography in vivo respectively. Ihh expression was increased 5.2-fold in OA cartilage, 3.1-fold in relative normal OA cartilage, and 1.71-fold in OA SF compared to normal control samples. The concentrations of Ihh in cartilage and SF samples was significantly increased in early-stage OA samples when compared to normal samples (r = 0.556; p < 0.001); however, there were no significant differences between normal samples and late-stage OA samples. Up-regulation of Ihh protein was also an early event in the surgery-induced OA models. Increased Ihh is associated with the severity of OA cartilage damage. Elevated Ihh content in human knee joint synovial fluid correlates with early cartilage lesions.

Histoplasmosis: An epidemiological and clinical update in China, review and a case report.

Histoplasmosis is a systemic mycosis caused by the dimorphic fungus in the genus Histoplasma. Histoplasmosis is overlooked in China. This study aims to provide an epidemiological and clinical update on histoplasmosis in China by literature review. We reviewed cases of histoplasmosis reported in recent 11 years and described a case of histoplasmosis-triggered hemophagocytic lymphohistiocytosis (HLH) in an immunocompetent patient. A total of 225 cases of histoplasmosis diagnosed in China between 2012 and 2022 were involved in this study, compared with 300 cases reviewed from 1990 to 2011, an increasing number of cases of histoplasmosis have been diagnosed in the last 11 years. The majority of cases of histoplasmosis were autochthonous cases, mainly from provinces Sichuan (56/225, 24.9%), Hunan (50/225, 22.2%), Guangdong (31/225, 13.8%), and Yunnan (24/225, 10.7%). Higher incidence (52.5%, 53/99) of histoplasmosis occurred in immunocompetent patients which is similar to those from the previous 21 years, and the prevalence of the disease did not vary highly over time. Of note, the number of histoplasmosis cases is increasing, and the geographic distribution is shifting southwards over time. Improved awareness is critically important for informing clinical practice in China.

Biomechanical evaluation of a modified intramedullary nail for the treatment of unstable femoral trochanteric fractures.

Background: The Proximal Femoral Nail Antirotation (PFNA) device is the most commonly used implant to fix unstable femoral trochanteric fractures (UFTFs), but it has a relatively high incidence of complications. Due to this factor, the modified intramedullary nail (MIN) was created to treat patients with UFTFs. The aim was to exhibit the MIN and make a comparison with PFNA and InterTAN using biomechanical methods. Methods: An adult UFTF model was developed using Mimics software. The PFNA, InterTAN nail, and MIN models were drawn referring to the corresponding parameters and installed in the fracture models. Vertical, anteroposterior (AP) bending, and torsion loads of the femoral head were set in advance and loaded onto the fracture models. The value of maximal displacement and von Mises stress was evaluated via finite element analysis (FEA). Results: The MIN model had smaller values for maximal displacement than that of the PFNA model, and the increase in displacement was less pronounced for the MIN compared to PFNA under increasing vertical loads. For the indicator of von Mises stress, the MIN model showed lower stress compared with the PFNA model in vertical loads ranging from 300 N to 2100 N. Except for the maximal stress at implants under AP bending loads, the MIN demonstrated the most superior biomechanical properties under AP bending and torsional loads. Conclusion: The MIN offered obvious advantages in terms of mechanical stability and stress distribution among the three studied implants, providing a promising implant option for patients with UFTFs.

The treatment of a femoral shaft fracture in patients with a previous post-traumatic femoral deformity using a Clamshell osteotomy.

The aim of this study was to assess the safety and clinical outcome of patients with a femoral shaft fracture and a previous complex post-traumatic femoral malunion who were treated with a clamshell osteotomy and fixation with an intramedullary nail (IMN). The study involved a retrospective analysis of 23 patients. All had a previous, operatively managed, femoral shaft fracture with malunion due to hardware failure. They were treated with a clamshell osteotomy between May 2015 and March 2020. The mean age was 42.6 years (26 to 62) and 15 (65.2%) were male. The mean follow-up was 2.3 years (1 to 5). Details from their medical records were analyzed. Clinical outcomes were assessed using the quality of correction of the deformity, functional recovery, the healing time of the fracture, and complications. The mean length of time between the initial injury and surgery was 4.5 years (3 to 10). The mean operating time was 2.8 hours (2.05 to 4.4)), and the mean blood loss was 850 ml (650 to 1,020). Complications occurred in five patients (21.7%): two with wound necrosis, and three with deep vein thrombosis. The mean coronal deformity was significantly corrected from 17.78° (SD 4.62°) preoperatively to 1.35° (SD 1.72°) postoperatively (p < 0.001), and the mean sagittal deformity was significantly corrected from 20.65° (SD 5.88°) preoperatively to 1.61° (SD 1.95°; p < 0.001) postoperatively. The mean leg length discrepancy was significantly corrected from 3.57 cm (SD 1.27) preoperatively to 1.13 cm (SD 0.76) postoperatively (p < 0.001). All fractures healed at a mean of seven months (4 to 12) postoperatively. The mean Lower Extremity Functional Scale score improved significantly from 45.4 (SD 9.1) preoperatively to 66.2 (SD 5.5) postoperatively (p < 0.001). Partial cortical nonunion in the deformed segment occurred in eight patients (34.8%) and healed at a mean of 2.4 years (2 to 3) postoperatively. A clamshell osteotomy combined with IMN fixation in the treatment of patients with a femoral shaft fracture and a previous post-traumatic femoral malunion achieved excellent outcomes. Partial cortical nonunions in the deformed segment also healed satisfactorily.

A novel and superior Lasso-plate technique in treatment for coronoid process fracture in the terrible triad of elbow.

The treatment of ulna coronal process fractures in the terrible triad of elbow, especially type I and II Regan-Morrey coronoid fractures, still have been controversial. The purpose of this retrospective study was to evaluate the novel Lasso-plate technique to have a more reliable fixation and a well clinical outcomes for type I and II Regan-Morrey coronoid fractures in a terrible triad of the elbow (TTE). Patients with simple TTE, closed fracture, aged > 18 years, duration of injury < 2 weeks, type I and II Regan-Morrey coronoid process fracture fixed by the Lasso-plate technique or ORIF were enrolled in the study. Total 144 patients with type I and II Regan-Morrey coronoid fracture in TTE were included in the Lasso-plate group or ORIF (open reduction and internal fixation) group in the Xi'an Honghui Hospital from January 2017 to December 2020. Eighty-six patients in Lasso-plate group underwent surgery using a novel Lasso-plate technique. And other 58 patients in ORIF group underwent surgery using ORIF. The data of two groups, including the X-ray films, Computed tomography (CT), the range of elbow motion, Mayo Elbow Performance Score (MEPS) and the surgical complications, were extracted from the hospital's patient records. All patients in both groups were followed up at least 12 months. The mean operation time (88.2 ± 12.3 min) in Lasso-plate group is shorter than that of ORIF group (109.1 ± 13.0 min). There was one patient with injury of deep branch of radial nerve and one patient with superficial surgical incision infection in Lasso-plate group. There were two patients with surgical incision infection in ORIF group. There were three heterotopic ossifications in Lasso-plate group and eight heterotopic ossifications in ORIF group. There were 5 elbow joints stiffness in Lasso-plate group and 12 in ORIF group. At 12 months follow up, the mean range of flexion-extension motion in Lasso-plate group was 122.9° ± 13.4° versus 113.2° ± 18.1° in ORIF group (p < 0.01), the mean 89.7 ± 5.6 MEPS in Lasso-plate group versus mean 83.7 ± 6.1 MEPSin ORIF group. The fixation of coronoid process fracture in TTE by the Lasso-plate technique, especially type I and II Regan-Morrey coronoid fracture, could be easier to master and operate, could provide the sufficient stability of elbow joint to enable early functional exercise, along with a better clinical outcome, a lower surgical complication. For the treatment of TTE, we recommend the fixation of type I and II Regan-Morrey coronoid fracture with the Lasso-plate technique, which would result in a better clinical outcome.

Biomechanical evaluation of two modified intramedullary fixation system for treating unstable femoral neck fractures: A finite element analysis.

Purpose: The existing implants for fixation of femoral neck fractures have poor biomechanical stability, so the failure rate is high. We designed two modified intramedullary implants for treating unstable femoral neck fractures (UFNFs). We tried to improve the biomechanical stability of fixation by shortening the moment and reducing stress concentration. Each modified intramedullary implant was compared with cannulated screws (CSs) through finite element analysis (FEA). Methods: Five different models were included: three cannulated screws (CSs, Model 1) in an inverted triangle configuration, the dynamic hip screw with an anti-rotation screw (DHS + AS, Model 2), the femoral neck system (FNS, Model 3), the modified intramedullary femoral neck system (IFNS, Model 4), and the modified intramedullary interlocking system (IIS, Model 5). Three-dimensional (3D) models of femur and implants were constructed by using 3D modelling software. Three load cases were simulated to assess the maximal displacement of models and fracture surface. The maximal stress at the bone and implants was also evaluated. Results: FEA data showed that Model 5 had the best performance in terms of maximum displacement while Model 1 had the worst performance for this index under axial load of 2100 N. With respect to Maximum stress, Model 4 had the best performance while Model 2 had the worst performance under axial load. The general trends under bending and torsion load were consistent with that under axial load. Our data demonstrated that the two modified intramedullary implants exhibited the best biomechanical stability, followed by FNS and DHS + AS, and then three cannulated screws in axial, bending, and torsion load cases. Conclusion: The two modified intramedullary designs showed the best biomechanical performance among the five implants included in this study. Therefore, this might provide some new options for trauma surgeons to deal with unstable femoral neck fractures.

Biomechanics and finite element analysis of a novel plate designed for posterolateral tibial plateau fractures via the anterolateral approach.

Surgical management of posterolateral tibial plateau (PLTP) fractures is challenging. One reason for this challenge is the lack of suitable internal fixation devices. Our aim was to introduce a novel plate via the anterolateral approach for managing PLTP fractures. The biomechanical testing and finite element analysis (FEA) were performed. PLTP fracture models were created using synthetic tibias (n = 10 within each group). These models were randomly assigned to three groups (groups A-C) and fixed with the lateral locking plate, the posterior buttress plate, and the novel plate, respectively. The vertical displacement of the posterolateral fragments was evaluated using biomechanical testing and FEA under axial loads of 250 N, 500 N, and 750 N. We also evaluated the stress distribution and maximum stress of each fracture model using FEA. Biomechanically, under the same loads of 250 N, 500 N, or 750 N, the vertical displacement was significantly different among the three fixation groups (p ≤ 0.001). FEA data indicated that the maximum displacement from group A to C was 3.58 mm, 3.23 mm, and 2.78 mm at 750 N, respectively. The maximum stress from group A to C was 220.88 MPa, 194.63 MPa, and 156.77 MPa in implants, and 62.02 MPa, 77.71 MPa, and 54.15 MPa in bones at 750 N, respectively. The general trends at 250 N and 500 N were consistent with those at 750 N. Based on our biomechanical and FEA results, the novel plate could be a good option for treating PLTP fractures. The novel plate showed stable and reliable features, indicating its suitability for further clinical application.

Self-assembling peptides with hBMP7 biological activity promote the differentiation of ADSCs into nucleus pulposus-like cells.

Functionalized self-assembling peptides, which display functional growth-factor bioactivity, can be designed by connecting the C-terminus of a pure self-assembling peptide with a short functional motif. In this study, we designed a novel functionalized peptide (RADA16-SNVI) in which an SNVI motif with hBMP-7 activity was conjugated onto the C-terminus of the RADA16 peptide via solid-phase synthesis. A mix of RADA16-SNVI and RADA16 solutions was used to create a functionalized peptide nanofiber scaffold (SNVI-RADA16). The hydrogels were analyzed by atomic force microscopy, circular dichroism, and scanning electron microscopy. The results showed that the SNVI-RADA16 solution effectively formed hydrogel. Next, we seeded the SNVI-RADA16 scaffold with adipose-derived stem cells (ADSCs) and investigated whether it displayed biological properties of nucleus pulposus tissue. SNVI-RADA16 displayed good biocompatibility with the ADSCs and induced their expression. Cells in SNVI-RADA16 gel had a greater secretion of the extracellular matrix marker collagen type II and aggrecan compared to ADSCs grown in monolayer and control gel (p < 0.05). The ratio of the aggrecan to collagen in cells in SNVI-RADA16 gel is approximately 29:1 after culture for 21 days. ADSCs in SNVI-RADA16 gels expressed the hypoxia-inducible factor 1α(HIF-1α) mRNA by real-time PCR. However, HIF-1 mRNA is absence in control gel and monolayer. The results suggested that the functionalized self-assembled peptide promotes the differentiation of ADSCs into nucleus pulposus-like cells. Thus, the designed SNVI-RADA16 self-assembling peptide hydrogel scaffolds may be suitable for application in nucleus pulposus tissue regeneration.

Flow Cytometric Analysis of Bone Marrow Particle Cells for Measuring Minimal Residual Disease in Multiple Myeloma.

Minimal residual disease (MRD) is one of the most relevant prognostic factors in patients with multiple myeloma (MM). However, the hemodilution of bone marrow (BM) aspirates, the most common preanalytical problem, is known to affect MRD detection. In the present study, we analyzed a preanalytical method for routine BM aspirates and a bone marrow particle cell (BMPL) enrichment assay and validated it as a reliable preanalytical method for flow cytometric MRD determination. A total of 120 BM samples were taken from 103 MM patients consecutively recruited; 77 BM samples had BMPL enrichment analysis and 99 BM samples were routinely analyzed. Then, the two different samples from patients with MM were sent for MRD detection using an eight-color flow cytometry. Our data showed that assessment of the BMPL enrichment samples attenuated the overestimation of MRD-negative assessed in the routine BM samples, which was mainly caused by hemodilution. In conclusion, the BMPL enrichment assay is a functional and practical preanalytical method for flow cytometric MRD analysis.

Kirschner Wire as a Reference Marker for the Positioning of a Syndesmotic Screw: A Radiological Study and Clinical Evaluation.

OBJECTIVE: No consensus has been reached regarding optimal implantation for a syndesmotic screw. Thus, we aimed to explore the feasibility of a reliable and static fibular incisura plane reference for ideal syndesmotic screw placement. METHODS: A retrospective review of computed tomography (CT) scans of 42 uninjured adult ankles with foot fractures were analyzed to measure the tibiofibular vertical distance (TFVD) at 2.5 cm proximal to the plafond from August 2016 to June 2017 in our hospital. The patients (20 females, 22 males) were divided into four groups according to their TFVD: 0-1, 1-2, 2-3, and 3-4 mm, and patients in each group were counted. We retrospectively assessed 41 patients (15 females, 26 males) who underwent syndesmotic screw fixation for ankle fractures from December 2015 to June 2020. We performed t-testing of two independent samples to determine the differences in the angle between the anatomic axis of the syndesmosis and screw axis (AAS) and ankle function using the American Orthopaedic Foot and Ankle Society (AOFAS) score at 3 and 6 months postoperatively between the conventional (20 patients) and K-wire marker (21 patients) groups. The correlation between the AAS and AOFAS score was analyzed. RESULTS: The TFVD measured 2.23 ± 1.01 mm at 2.5 cm proximal to the plafond, and occurred at 25% of the distance from 2 to 3 mm in 47.6% of the patients. This new technique decreased AAS deformation by 62%, from 13.01° ± 2.84° to 4.89° ± 2.43°, in the conventional group (p < 0.001). At 3 months postoperatively, the AOFAS scores of ankle function were similar in both groups, but it was significantly better in the new group than that of conventional group at the 6-month follow-up (p = 0.024). There was a moderate negative correlation between AAS and AOFAS score at 6 months postoperatively (R = -0.684). No obvious complications affecting ankle function were observed in either group postoperatively. CONCLUSIONS: Surgeons can accurately place a screw trajectory using the fibular incisura plane as a reliable intraoperative reference. A 1.6-mm K-wire placed in the syndesmosis at 2.5 cm proximal to the tibial plafond could act as a static marker of the syndesmotic plane.

An Approach to Intraoperatively Identify the Coronal Plane Deformities of the Distal Tibia When Treating Tibial Fractures with Intramedullary Nail Fixation: a Retrospective Study.

OBJECTIVE: To develop a new approach to intraoperatively identify the presence of coronal plane deformities (both valgus and varus) when treating tibial fractures with closed reduction and intramedullary nail fixation. METHODS: A retrospective analysis was conducted by enrolling 33 consecutive patients with tibial fractures who received closed reduction and intramedullary nail fixation from January 2018 to January 2019 at our trauma center. Out of the 33 patients, 23 were males and 10 were females and the average age was 41 years (ranging 22 to 69 years of age). Standard anteroposterior and lateral preoperative radiographs were routinely performed. After intraoperatively inserting the tibial intramedullary nail through the standard entry point, the parallel relationship between the distal horizontal interlocking screw and the tibiotalar joint surface on the anteroposterior fluoroscopy was used to determine the occurrence of valgus or varus deformities of the distal tibial fragment. Radiographic and clinical outcomes were analyzed using the average interval from injury to surgery, the lateral distal tibial angle (LDTA) of the unaffected and affected sides, complications and the Olerud-Molander ankle score. RESULTS: All 33 patients were postoperatively followed for 13 to 25 months (mean 18.7 months). The fractures achieved bone union at an average of 4.3 months (ranging from 3 to 6 months). The total complication rate was 60.6% (20 cases), including four cases that showed deep vein thrombosis, one case showing an infection and delayed union and 15 cases showing slight to moderate anterior knee pain. The postoperative LDTA of the unaffected side measured 87.3° to 89.6 ° (average 88.7° ± 0.8°), and the LDTA of the affected side was 87.5° to 90.4° (average 88.9° ± 1.1°). There was no significant difference between the unaffected and affected sides (t = -1.865, P = 0.068). The intraoperative measurement indicated six cases of valgus angulation and three cases of varus angulation deformities, and all deformities were corrected during surgery. According to the Olerud-Molander ankle score, clinical outcomes demonstrated 22 excellent cases, eight good cases, two fair cases, and one poor case 12 months after surgery. CONCLUSION: The parallel relationship between the distal horizontal interlocking screw and tibiotalar joint surface on intraoperative anteroposterior films were able to determine the onset of valgus or varus angulations of the distal tibial fragment in the fracture zone after the tibial intramedullary nail was inserted through the standard entry point.

Clinical Application Effects of Different Preoperative Blood Management Schemes in Older Patients with Delayed Intertrochanteric Fracture Surgery.

Introduction: Research on preoperative blood management in older patients with delayed surgery for intertrochanteric fracture is scarce, especially regarding hematopoiesis and hemostasis. We assessed the effectiveness of optimized blood management programs in older patients undergoing delayed surgery for intertrochanteric fractures. Methods: This retrospective study included 456 patients who underwent delayed surgery for intertrochanteric fractures. According to the optimized blood management plan, the patients were divided into four groups: group A was the control group; group B received 1 g of tranexamic acid (TXA) intravenously at admission; group C underwent sequential TXA treatment after admission until 1 day before surgery (1 g/day); and group D received iron supplements (200 mg/day) in addition to the treatment administered to group C, with or without recombinant human erythropoietin (rHuEPO; 40,000 IU). The primary outcomes were preoperative hidden blood loss (HBL), preoperative allogeneic blood transfusion (ABT) rate, hemoglobin (Hb) change, and actual Hb drop. Results: The Hb reduction, calculated HBL, and hospitalization duration in groups C and D were significantly lower than those in groups A and B. The preoperative ABT rates in groups C and D were significantly lower than those in groups A and B, with no significant difference between groups C and D. Discussion: The results of this study suggested that iron supplementation (with or without rHuEPO) combined with the sequential IV TXA scheme did not show a better clinical effect than the sequential IV TXA scheme in the management of patients undergoing delayed surgery for intertrochanteric fractures. Therefore, further evaluation is needed before recommending iron supplements and rHuEPO in older patients.

Combined Medial Plate and Intramedullary Nailing for the Fixation of Extra-Articular Proximal Tibial Fractures: a Biomechanics Study.

Purpose: The extra-articular proximal tibial fractures continue to have high malunion rates despite development in intramedullary nailing (IMN) technology. Combined plate and IMN fixation can increase mechanical stability. The purpose of this study was to investigate combined plate and IMN for the treatment of extra-articular proximal tibial fracture using a biomechanical model. Methods: A 10-mm defective osteotomy was created in the fourth-generation composite tibia to simulate extra-articular proximal tibial fractures (AO/OTA 41A2). The fractures were stabilized with IMN alone (IMN group), IMN with supplementary medial plate (M-IMN group), and IMN with supplementary lateral plate (L-IMN group). The biomechanical properties of each specimen were tested under axial compression loading, bending stress, and cyclic loading. The maximum displacement of the fragments and implant-bone construct failure was recorded. Results: The maximum displacement of the M-IMN group was significantly less than either the L-IMN or IMN group in both axial compression loading and bending stress (p < 0.05 for both comparisons). All specimens in the three groups survived in 10,000 cyclic loading without hardware deformation. The maximum stiffness of failure was similar between the M-IMN and L-IMN groups, but the IMN group was statistically lower than either the L-IMN or the IMN group (p < 0.05). Conclusion: The results indicated that combined medial plate and IMN fixation could effectively increase the mechanical stability of proximal tibial fractures.