[Transcriptomic characteristics analysis of bone from chronic osteomyelitis].

OBJECTIVE: To explore the molecular mechanism of chronic osteomyelitis and to clarify the role of MAPK signal pathway in the pathogenesis of chronic osteomyelitis, by collecting and analyzing the transcriptional information of bone tissue in patients with chronic osteomyelitis. METHODS: Four cases of traumatic osteomyelitis in limbs from June 2019 to June 2020 were selected, and the samples of necrotic osteonecrosis from chronic osteomyelitis (necrotic group), and normal bone tissue (control group) were collected. Transcriptome information was collected by Illumina Hiseq Xten high throughput sequencing platform, and the gene expression in bone tissue was calculated by FPKM. The differentially expressed genes were screened by comparing the transcripts of the Necrotic group and control group. Genes were enriched by GO and KEGG. MAP3K7 and NFATC1 were selected as differential targets in the verification experiments, by using rat osteomyelitis animal model and immunohistochemical analysis. RESULTS: A total of 5548 differentially expressed genes were obtained by high throughput sequencing by comparing the necrotic group and control group, including 2701 up-regulated and 2847 down-regulated genes. The genes enriched in MAPK pathway and osteoclast differentiation pathway were screened, the common genes expressed in both MAPK and osteoclast differentiation pathway were (inhibitor of nuclear factor κ subunit Beta, IκBKß), (mitogen-activated protein kinase 7, MAP3K7), (nuclear factor of activated t cells 1, NFATC1) and (nuclear factor Kappa B subunit 2, NFκB2). In rat osteomyelitis model, MAP3K7 and NFATC1 were highly expressed in bone marrow and injured bone tissue. CONCLUSION: Based on the transcriptome analysis, the MAPK signaling and osteoclast differentiation pathways were closely related to chronic osteomyelitis, and the key genes IκBKß, MAP3K7, NFATC1, NFκB2 might be new targets for clinical diagnosis and therapy of chronic osteomyelitis.

Fabrication of Large-Area Silicon Spherical Microlens Arrays by Thermal Reflow and ICP Etching.

In this paper, we proposed an efficient and high-precision process for fabricating large-area microlens arrays using thermal reflow combined with ICP etching. When the temperature rises above the glass transition temperature, the polymer cylinder will reflow into a smooth hemisphere due to the surface tension effect. The dimensional differences generated after reflow can be corrected using etching selectivity in the following ICP etching process, which transfers the microstructure on the photoresist to the substrate. The volume variation before and after reflow, as well as the effect of etching selectivity using process parameters, such as RF power and gas flow, were explored. Due to the surface tension effect and the simultaneous molding of all microlens units, machining a 3.84 × 3.84 mm2 silicon microlens array required only 3 min of reflow and 15 min of ICP etching with an extremely low average surface roughness Sa of 1.2 nm.

CircGNB1 drives osteoarthritis pathogenesis by inducing oxidative stress in chondrocytes.

BACKGROUND: Circular RNAs (circRNAs) have risen to prominence as important regulators of biological processes. This study investigated whether circGNB1 functions as a competitive endogenous RNA to regulate the pathological process of oxidative stress in age-related osteoarthritis (OA). METHODS: The relationship between circGNB1 expression and oxidative stress/OA severity was determined in cartilages from OA patients at different ages. The biological roles of circGNB1 in oxidative stress and OA progression, and its downstream targets were determined using gain- and loss-of-function experiments in various biochemical assays in human chondrocytes (HCs). The in vivo effects of circGNB1 overexpression and knockdown were also determined using a destabilization of the medial meniscus (DMM) mouse model. RESULTS: Increased circGNB1 expression was detected in HCs under oxidative and inflammatory stress and in the cartilage of older individuals. Mechanistically, circGNB1 sponged miR-152-3p and thus blocked its interaction with its downstream mRNA target, ring finger protein 219 (RNF219), which in turn stabilized caveolin-1 (CAV1) by preventing its ubiquitination at the K47 residue. CircGNB1 inhibited IL-10 signalling by antagonizing miR-152-3p-mediated RNF219 and CAV1 inhibition. Consequently, circGNB1 overexpression promoted OA progression by enhancing catabolic factor expression and oxidative stress and by suppressing anabolic genes in vitro and in vivo. Furthermore, circGNB1 knockdown alleviated the severity of OA, whereas circGNB1 overexpression had the opposite effect in a DMM mouse model of OA. CONCLUSION: CircGNB1 regulated oxidative stress and OA progression via the miR-152-3p/RNF219/CAV1 axis. Modulating circGNB1 could be an effective strategy for treating OA.

Inductively Coupled Plasma Dry Etching of Silicon Deep Trenches with Extremely Vertical Smooth Sidewalls Used in Micro-Optical Gyroscopes.

Micro-optical gyroscopes (MOGs) place a range of components of the fiber-optic gyroscope (FOG) onto a silicon substrate, enabling miniaturization, low cost, and batch processing. MOGs require high-precision waveguide trenches fabricated on silicon instead of the ultra-long interference ring of conventional F OGs. In our study, the Bosch process, pseudo-Bosch process, and cryogenic etching process were investigated to fabricate silicon deep trenches with vertical and smooth sidewalls. Different process parameters and mask layer materials were explored for their effect on etching. The effect of charges in the Al mask layer was found to cause undercut below the mask, which can be suppressed by selecting proper mask materials such as SiO2. Finally, ultra-long spiral trenches with a depth of 18.1 µm, a verticality of 89.23°, and an average roughness of trench sidewalls less than 3 nm were obtained using a cryogenic process at -100 °C.

Fabrication of High Precision Silicon Spherical Microlens Arrays by Hot Embossing Process.

In this paper, a high-precision, low-cost, batch processing nanoimprint method is proposed to process a spherical microlens array (MLA). The nanoimprint mold with high surface precision and low surface roughness was fabricated by single-point diamond turning. The anti-sticking treatment of the mold was carried out by perfluorooctyl phosphoric acid (PFOPA) liquid deposition. Through the orthogonal experiment of hot embossing with the treated mold and subsequent inductively coupled plasma (ICP) etching, the microstructure of MLA was transferred to the silicon substrate, with a root mean square error of 17.7 nm and a roughness of 12.1 nm Sa. The average fitted radius of the microlens array units is 406.145 µm, which is 1.54% different from the design radius.

Oxidative stress-induced circKIF18A downregulation impairs MCM7-mediated anti-senescence in intervertebral disc degeneration.

Low back pain, triggered by intervertebral disc degeneration (IVDD), is one of the most common causes of disability and financial expenditure worldwide. However, except for surgical interventions, effective medical treatment to prevent the progression of IVDD is lacking. This study aimed to investigate the effects of circKIF18A, a novel circRNA, on IVDD progression and to explore its underlying mechanism in IVDD. In this study, we found that oxidative stress was positively correlated with nucleus pulposus cell (NPC) senescence in IVDD and that circKIF18A was downregulated in IVDD and attenuated senescent phenotypes such as cell cycle arrest and extracellular matrix degradation in NPCs. Mechanistically, circKIF18A competitively suppressed ubiquitin-mediated proteasomal degradation of MCM7, and the protective effects of circKIF18A on NPCs were partially mediated by MCM7 under oxidative stress. Intradiscal injection of adenoviral circKIF18A ameliorated IVDD in a rat model. This study revealed that circKIF18A regulates NPC degeneration by stabilizing MCM7 and identified a novel signaling pathway, the circKIF18A-MCM7 axis, for anti-senescence molecular therapy in IVDD.

Fabrication of Antireflection Micro/Nanostructures on the Surface of Aluminum Alloy by Femtosecond Laser.

Designed micro-nano structures on the surface of aluminum alloy provide excellent light trapping properties that can be used extensively in thermal photovoltaics, sensors, etc. However, the fabrication of high-performance antireflective micro-nano structures on aluminum alloy is challenging because aluminum has shallow intrinsic losses and weak absorption. A two-step strategy is proposed for fabricating broadband antireflection structures by superimposing nanostructures onto microscale structures. By optimizing the processing parameters of femtosecond laser, the average reflectances of 2.6% within the visible spectral region (400-800 nm) and 5.14% within the Vis-NIR spectral region (400-2500 nm) are obtained.

Surgical treatment of recurrent acute lymphoblastic leukemia with humeral osteomyelitis as the first symptom: a case report and literature review.

Osteomyelitis is a complication of acute lymphoblastic leukemia (ALL); however, its incidence rate is low. Recurrent ALL for which osteomyelitis is the first manifestation is rarer still. The repair and reconstruction of segmental bone defects caused by infection is a clinical problem. This article reports a rare case study of a 22-year-old male patient with recurrent ALL for which right humeral osteomyelitis was the first symptom including chills at first, recurrent fever and chills then, purulence from poster lateral right upper arm finally. Before treatment, the patient concealed his previous history of ALL. Debridement was performed, and the Masquelet technique and free fibula transplantation were used to reconstruct the humerus. ALL recurred with extensive bone invasion throughout the body 10 weeks after the humeral reconstruction. Despite the success of bone marrow transplantation, the patient died of complications. A limited follow-up period reveled that while leukemia extensively affected the bones of the patient's body, the reconstruction of the humerus was successful, and bone healing was good. This case study suggests that atypical or unexplained osteoarticular infection may be the precursor to some systemic diseases, and that Masquelet technology combined with free fibula transplantation is one of the best choices to treat segmental bone defects.

An 83-year-old-male with bronchopleural fistula and empyema successfully treated with multidisciplinary management of thoracostomy, endoscopic, and surgical treatment: a case report.

Bronchopleural fistula (BPF) with empyema is a severe complication in patients undergoing lobectomy or pneumonectomy and is associated with high morbidity and mortality rates. Although a wide variety of treatment options exist, refractory cases with larger fistulas are still difficult to cure, especially in elderly patients. Here, we report a case of an 83-year-old man with stage I squamous cell lung carcinoma who underwent minimally invasive right lower lobectomy. After an initially uneventful postoperative course, he was readmitted to our hospital due to the progression of severe cough with fever after lung resection. Chest computed tomography (CT) showed an empyema cavity containing pleural effusion and a drainage tube in the right lower thorax. Bronchoscopy confirmed the presence of a fistula between the right lower bronchial stump and the pleural cavity. On the basis of his clinical symptoms and these imaging findings, the patient was diagnosed with BPF with empyema after lobectomy. He was successfully treated with multidisciplinary management including adequate pleural drainage by open-window thoracostomy, closure of the BPF by endoscopic therapy using an Amplatzer device, and complete obliteration of the empyema cavity with pedicled muscle flap. Multidisciplinary management combining thoracostomy, endoscopic therapy, and pedicled muscle flap transfer is a safe and effective treatment for elderly patients with larger fistulas and empyema.

Transcriptome sequencing profiling identifies miRNA-331-3p as an osteoblast-specific miRNA in infected bone nonunion.

Bone nonunion caused by bacterial infection accounts for bone fractures, bone trauma and bone transplantation surgeries. Severe consequences include delayed unions and amputation and result in functional limitations, work disability, and poor quality of life. However, the mechanism of bone nonunion remains unknown. In this study, we aimed to screen the miRNA biomarkers of bacterial bone infection and investigated whether miRNAs regulate the osteoblasts and thus contribute to bone nonunion. We established a miRNA-mRNA network based on high-throughput RNA sequencing to compare the model rabbits infected with Staphylococcus aureus with the control rabbits. After validation experiments, miRNA-331-3p and fibroblast growth factor 23 (FGF23) were found to be inversely correlated with the pathways of osteoblast mineralization and pathology of infected bone nonunion. In in vitro experiments, miRNA-331-3p was downregulated and FGF23 was upregulated in lipopolysaccharide (LPS)-induced mouse calvarial osteoblasts. Further studies of the mechanism showed that mutated of putative miRNA-331-3p can bind to FGF23 3'-untranslated region sites. MiRNA-331-3p acted as an osteoblast mineralization promoter by directly targeting FGF23. Downregulation of miRNA-331-3p led to inhibition of osteoblast mineralization by regulating the DKK1/ß-catenin mediated signaling. Thus, we established an improved animal model and identified new bone-related biomarkers in the infected bone nonunion. The miRNA-331-3p biomarker was demonstrated to regulate osteoblast mineralization by targeting FGF23. The novel mechanism can be used as potential diagnostic biomarkers and therapeutic targets in the infected bone nonunion and other inflammatory bone disorders.

Effective treatment of bronchopleural fistula with empyema by pedicled latissimus dorsi muscle flap transfer: Two case report.

RATIONALE: Bronchopleural fistula (BPF) is a dreaded complication after lobectomy or pneumonectomy and is associated with high morbidity and mortality. Successful management remains challenging when this condition is combined with empyema, and the initial treatment is usually conservative and endoscopic, but operative intervention may be required in refractory cases. PATIENT CONCERNS: Two patients diagnosed with BPF with empyema were selected to undergo surgery in our hospital because they could not be cured by conservative and endoscopic therapy for 1 or more years. One was a 70-year-old man who had a 1-year history of fever and cough after he received a minimally invasive right lower lobectomy for intermediate lung adenocarcinoma and chemotherapy 2 years ago; the other was a 73-year-old man who had a 2-year history of cough and fever after he underwent a minimally invasive right upper lobectomy for early lung adenocarcinoma 3 years earlier. DIAGNOSIS: Both patients were diagnosed with BPF with empyema. INTERVENTIONS: After receiving conservative and endoscopic therapies, both patients underwent pedicled latissimus dorsi muscle flap transfers for complete filling of the empyema cavity. OUTCOMES: The patients recovered very well, with no recurrence of BPF and empyema during postoperative follow-up. LESSONS: It is crucial to not only completely control infection and occlude BPFs, but also obliterate the empyema cavity. Thus, pedicled latissimus dorsi muscle flap transfer associated with conservative and endoscopic therapies for BPF with empyema is a useful treatment option, offering feasible and efficient management with promising results.

[Progress on complications of chronic osteomyelitis with bone defect treated by bone transportation].

Bone transportation technology (Ilizarov technique) effectively solves the clinical problem of chronic osteomyelitis with structural bone defect. The paper combined with own clinical experience and a large number of literatures, the results showed that this method had some complications related to severe bone healing, such as non union of the joint ends and poor mineralization of the extended gap. Maintenance of force line during operation, protection of osteotomy end tissues, appropriate transporting velocity and stress stimulation after operation, and application of "accordion technology" are the keys to reduce such complications. At present, there is still much controversy about the timing of removal of external fixator. Once the re fracture is caused by early removal, it must be treated actively as soon as possible. In addition, it is necessary to reduce the local thermal injury of nail canal during operation and strengthen the nursing of nail canal after operation in order to prevent nail canal infection. Reasonable analgesic regimen combined with active functional exercise is an important method to avoid the occurrence of adjacent joint dysfunction.

End-to-End Incomplete Time-Series Modeling From Linear Memory of Latent Variables.

Time series with missing values (incomplete time series) are ubiquitous in real life on account of noise or malfunctioning sensors. Time-series imputation (replacing missing data) remains a challenge due to the potential for nonlinear dependence on concurrent and previous values of the time series. In this paper, we propose a novel framework for modeling incomplete time series, called a linear memory vector recurrent neural network (LIME-RNN), a recurrent neural network (RNN) with a learned linear combination of previous history states. The technique bears some similarity to residual networks and graph-based temporal dependency imputation. In particular, we introduce a linear memory vector [called the residual sum vector (RSV)] that integrates over previous hidden states of the RNN, and is used to fill in missing values. A new loss function is developed to train our model with time series in the presence of missing values in an end-to-end way. Our framework can handle imputation of both missing-at-random and consecutive missing inputs. Moreover, when conducting time-series prediction with missing values, LIME-RNN allows imputation and prediction simultaneously. We demonstrate the efficacy of the model via extensive experimental evaluation on univariate and multivariate time series, achieving state-of-the-art performance on synthetic and real-world data. The statistical results show that our model is significantly better than most existing time-series univariate or multivariate imputation methods.

Absorption and utilisation of epimedin C and icariin from Epimedii herba, and the regulatory mechanism via the BMP2/ Runx2 signalling pathway.

Bone nonunion remains a challenge during the treatment of bone defect accompanied with infection. Epimedii herba is a widely used medicine in clinic to enhance bone healing. Epimedin C and icariin are the major flavonoid glycosides from Epimedii herba. Although the effects of these compounds have been reported, their different absorption and utilisation by osteoblasts remain unclear. In the present study, lipopolysaccharide (LPS)-induced osteoblast was adopted as the model cell to evaluate the effects of epimedin C and icariin. The intracellular and extracellular drug concentrations within 24 h were assayed by pipette tip solid-phase extraction and high-performance liquid chromatography, respectively. MTT, alkaline phosphatase (ALP) and calcified nodule staining were performed to identify and evaluate the effects of epimedin C and icariin on LPS-induced osteoblasts. The regulatory roles of epimedin C and icariin in the bone morphogenetic protein-2 (BMP-2)/Runt-related transcription factor 2 (Runx2) signalling pathway were investigated. The results revealed that epimedin C and icariin were not efficiently absorbed by LPS-induced osteoblasts. Nevertheless, they still had high utilisation efficiency after entering the cells. ALP activity, mineralisation and osteoblasts proliferation were enhanced by a high concentration of epimedin C and icariin. The suppressed expression of BMP-2 and Runx2 in LPS-induced osteoblasts was up-regulated significantly after treatment with epimedin C and icariin. These findings firstly illustrated the behavior of epimedin C and icariin from Epimedii herba on LPS-induced osteoblasts and the regulatory property on the expression of key genes and proteins of the BMP-2/Runx2 signalling pathway, which might be helpful for better understanding flavonoids' mechanism to enhance bone repair and improving their future application.

Time series classification with Echo Memory Networks.

Echo state networks (ESNs) are randomly connected recurrent neural networks (RNNs) that can be used as a temporal kernel for modeling time series data, and have been successfully applied on time series prediction tasks. Recently, ESNs have been applied to time series classification (TSC) tasks. However, previous ESN-based classifiers involve either training the model by predicting the next item of a sequence, or predicting the class label at each time step. The former is essentially a predictive model adapted from time series prediction work, rather than a model designed specifically for the classification task. The latter approach only considers local patterns at each time step and then averages over the classifications. Hence, rather than selecting the most discriminating sections of the time series, this approach will incorporate non-discriminative information into the classification, reducing accuracy. In this paper, we propose a novel end-to-end framework called the Echo Memory Network (EMN) in which the time series dynamics and multi-scale discriminative features are efficiently learned from an unrolled echo memory using multi-scale convolution and max-over-time pooling. First, the time series data are projected into the high dimensional nonlinear space of the reservoir and the echo states are collected into the echo memory matrix, followed by a single multi-scale convolutional layer to extract multi-scale features from the echo memory matrix. Max-over-time pooling is used to maintain temporal invariance and select the most important local patterns. Finally, a fully-connected hidden layer feeds into a softmax layer for classification. This architecture is applied to both time series classification and human action recognition datasets. For the human action recognition datasets, we divide the action data into five different components of the human body, and propose two spatial information fusion strategies to integrate the spatial information over them. With one training-free recurrent layer and only one layer of convolution, the EMN is a very efficient end-to-end model, and ranks first in overall classification ability on 55 TSC benchmark datasets and four 3D skeleton-based human action recognition tasks.

Free vastus lateralis musculocutaneous flap transfer for radiation-induced chest wall fistula combined with osteomyelitis: Two case report.

RATIONALE: Chronic chest wall fistula is a refractory and agonizing disease that results from multiple predisposing etiologies, including radiation-induced damage. Successful management remains challenging when this condition is combined with osteomyelitis, and a limited number of reports have been published in the literature concerning this management. PATIENT CONCERNS: Two Chronic chest wall fistula patients were selected to undergo surgery in our hospital because they could not be cured by conventional therapy for several years. One is a 74-year-old female who has received a right radical mastectomy and had radiation therapy 23 years ago; the other is a 59-year-old male who underwent a excision of thyroid cancer and had chemoradiation therapy 20 years earlier. DIAGNOSIS: Both patients were diagnosed with radiation-induced chest wall fistula combined with osteomyelitis. INTERVENTIONS: After total resection of the diseased chest walls, both patients underwent free vastus lateralis musculocutaneous flap transfers, in which the vessels were microvascularly anastomosed to the transverse carotid artery and vein via a subcutaneous tunnel or a direct incision. Histologic evaluations of the specimens demonstrated inflammation and osteomyelitis. OUTCOMES: The patients recovered very well and currently have no recurrence of chest wall fistulae during the postoperative follow-up. LESSONS: It is crucial to not only completely resect chest wall fistulae and the surrounding diseased tissues but also reconstruct the chest wall. Thus, the use of the free vastus lateralis musculocutaneous flap transfer method for radiation-induced chest wall fistulae, combined with osteomyelitis, is a useful option for treatment and is also a feasible and efficient surgical procedure with promising results.

Treatment with Vancomycin Loaded Calcium Sulphate and Autogenous Bone in an Improved Rabbit Model of Bone Infection.

Bone infection results from bacterial invasion, which is extremely difficult to treat in clinical, orthopedic, and traumatic surgery. The bone infection may result in sustained inflammation, osteomyelitis, and eventual bone non-union. Establishment of a feasible, reproducible animal model is important to bone infection research and antibiotic treatment. As an in vivo model, the rabbit model is widely used in bone infection research. However, previous studies on rabbit bone infection models showed that the infection status was inconsistent, as the amount of bacteria was variable. This study presents an improved surgical method for inducing bone infection on a rabbit, by blocking the bacteria in the bone marrow. Then, multi-level evaluations can be carried out to verify the modelling method. In general, debriding necrotic tissue and implantation of vancomycin-loaded calcium sulphate (VCS) are predominant in antibiotic treatment. Although calcium sulphate in VCS benefits osteocyte crawling and new bone growth, massive bone defects occur after debriding. Autogenous bone (AB) is an appealing strategy to overcome bone defects for the treatment of massive bone defects after debriding necrotic bone. In this study, we used the tail bone as an autogenous bone implanted in the bone defect. Bone repair was measured using micro-computed-tomography (micro-CT) and histological analysis after animal sacrifice. As a result, in the VCS group, bone non-union was consistently obtained. In contrast, the bone defect areas in the VCS-AB group were decreased significantly. The present modeling method described a reproducible, feasible, stable method to prepare a bone infection model. The VCS-AB treatment resulted in lower bone non-union rates after antibiotic treatment. The improved bone infection model and the combination treatment of VCS and autogenous bone could be helpful in studying the underlying mechanisms in bone infection and bone regeneration pertinent to traumatology orthopedic applications.

[Surgical treatment of deep infection around the spine].

OBJECTIVE: To study the surgical method and clinical effect of deep infection around the spine. METHODS: The clinical data of 7 patients with deep infections around the spine treated from January 2015 to January 2018 were retrospectively analyzed. All patients were acute infection within 3 weeks after spinal surgery. There were 5 males and 2 females, aged from 29 to 67 years old with an average of 42 years old. Four of them had implants and the other three didn't. After infection was diagnosed, they accepted aggressive debridement with assistance of vacuum sealing drainage(VSD). The antibiotic artificial bones were put in wounds, combined with intravenous antibiotics. Blood-rich adjacent tissue flaps were used to reconstruct defect of wounds. The tissue flaps included 4 paraspinal muscle flaps, 1 thoracolumbar fascial flap, 1 latissimus dorsi flap and 1 paraspinal muscle combined with thoracolumbar fascial flap. RESULTS: All 7 patients were followed up from 6 to 24 months with an average of 13.28 months. During the follow-up period, among the 4 patients with instrument, except one patient of lumbar fusion removed internal fixation due to postoperative infection, the other 3 patients successfully kept the implants. One case of cervical fracture and dislocation was repaired by latissimus dorsi transposition. Its wound healed but hydrops accumulated under the flap. This patient was cured by puncture drainage and local pressure bandaging. The other 5 wounds' healing were first intention and no postoperative complications such as infection recurrence, hematoma, effusion or wound dehiscence occurred. CONCLUSIONS: Deep infection around the spine is a serious complication and should be treated aggressively once diagnosed. Thorough debridement with the help of negative pressure closed drainage, local application of antibiotic artificial bone combined with systemic intravenous antibiotics and repairing wounds with adjacent tissue flaps are effective procedures for the treatment of deep infection around the spine.

[Transfer of gastrocnemius muscle flap for postoperative infection with patellar internal fixation].

OBJECTIVE: To investigate clinical effect of gastrocnemius muscle flap for repairing postoperative infection of patellar internal fixation. METHODS: From January 2011 to January 2017, 15 patients with postoperative infection of patellar internal fixation were treated, including 9 males and 6 females ranged from 31 to 66 years old with an average age of (42.5±11.2) years old. The courses of disease ranged from 2 to 8 months with an average of (4.3±1.5) months. All wounds were repaired by gastrocnemius muscle flap after debridement. The coverage of muscle flap was performed by free skin graft and donor site was closed directly. Survival of muscle flap, healing of incision were observed. HUANG Yong-xin clinical criteria and KSS score criteria were used to evaluate knee joint function 9 after operation. RESULTS: All muscle flaps were survived without necrosis. Incision of 13 patients were healed at stageI, and 2 patients had wound dehiscence after operation and healed after symptomatic treatment. All patients were followed up from 9 months to 30 months with an average of(20.6±8.3) months. No recurrence of infection was observed, and texture of muscle flap, skin color, appearance were good. According to HUANG Yong-xin clinical criteria, 13 excellent and 2 moderate. The clinical score of KSS score was 83.3±7.8, and functional score of KSS score was 86.3±10.4. CONCLUSIONS: Gastrocnemius muscle flap is an effective method in repairing postoperative infection of patellar internal fixation with stable curative effect and low recurrence rate, which is worthy popularizing.