Quanyin Du

A new TGF-β3 controlled-released chitosan scaffold for tissue engineering synovial sheath

The post-operative outcome of flexor tendon healing remains limited by flexor tendon adhesion that reduces joint range of motion. Despite improvement in different methods, peritendinous adhesion formation continues to present a formidable challenge. Recent studies showed that transforming growth factor-β3 (TGF-β3) may be the key factor to reducing adhesion formation in skin or tendon. In this study, we designed a novel type of tissue engineering synovial sheath containing TGF-β3, to prevent flexor tendon adhesion. First, to achieve a stable release of TGF-β3, chitosan microspheres, prepared by crosslinking-emulsion, were used for the delivery of TGF-β3. Second, a three-dimensional chitosan scaffold was prepared by lyophilization, and TGF-β3 microspheres were carefully introduced into the scaffold. Then, synovial cells were cultured and then seeded into the TGF-β3 loaded scaffold to produce TGF-β3 controlled-released tissue engineering synovial sheath. Tests clearly demonstrated that the scaffold has good structure and compatibility with cells. These results expand the feasibility of combinative strategies of controlled protein release and tissue-engineered synovial sheath formation. Application of this scaffold to tendon repair sites may help to prevent adhesion of tendon healing.

Comparison of a new minimum contact locking plate and the limited contact dynamic compression plate in an osteoporotic fracture model

The purpose of this study was to investigate the biomechanical properties of a new minimum contact locking plate (MC-LP) compared with the limited contact dynamic compression plate (LC-DCP). Eighteen pairs of fresh human osteoporotic cadaver radii were equally divided into three groups. Each specimen was tested in each of the following force applications: anteroposterior (AP) four point bending, mediolateral (ML) four point bending, and torsion. A 10-mm gap osteotomy model was used to simulate a comminuted diaphyseal radial fracture. For each pair, one radius received a limited contact dynamic compression plate (LC-DCP) and the contralateral radius was fixed with a minimum contact locking plate (MC-LP). Specimens were tested in nondestructive four point bending and torsion on an electronic universal material testing system. The results indicate that the MC-LP system is significantly more stable than the LC-DCP system when tested in four point bending and torsion in an osteoporotic comminuted radial diaphyseal fracture model.RésuméLe but de cette étude est d’étudier les propriétés biomécaniques d’une nouvelle minimum plaque de verrouillage de contact (MC-LP) en comparant avec la plaque dynamique de compression de contact limité (LC-DCP). Dix-huit paires de rayons d’osteoporose humains frais de cadavres sont divisées en trois groupes égaux. Chaque spécimen est respectivement examiné sous les charges suivantes : quatre points courbés antéropostérieurs (AP), quatre points courbés médiolatéraux(ML), et torsion. Un modèle de jeu de fracture de 10mm est construit pour chaque spécimen, afin de simuler un modèle de fracture pulvérisée. Pour chaque paire, l’un des rayons est fixé par la plaque dynamique de compression de contact limité (LC-DCP), l’autre est fixé par une minimum plaque de verrouillage de contact (MC-LP). Une épreuve de qutre points courbés et de torsion non-déstructive des spécimens s’est fait dans un système d’essai de matériaux universels électroniques. Les résultats indiquent que dans le modèle de fracture de rayon pulvérisé d’ostéoporose, le système de MC-LP est plus stable que celui de LC-DCP.

Effect of transforming growth factor-β3 on the expression of Smad3 and Smad7 in tenocytes

Tendon adhesion is a common problem in the healing of injured tendons. The molecular mechanisms of the TGF-β/Smad signaling pathway have been determined, and the role of TGF-β has been well characterized in wound healing. However, the intracellular mechanism or downstream signals by which TGF-β3 modulates its effects on tendon healing have not been well elucidated. The aim of this study was to determine the effect of TGF‑β3 on the TGF-β/Smad signaling pathway in tenocytes. Quantitative polymerase chain reaction and western blot analysis were used to analyze the effect of TGF‑β3 on the regulation of the expression of Smad proteins in tenocytes. The results demonstrated that TGF‑β3 has no significant effect on the proliferation of tendon cells. The addition of TGF‑β3 to tenocytes can significantly downregulate the expression of Smad3 and upregulate the expression of Smad7 at the gene and protein levels. The results demonstrate that TGF‑β3 may regulate Smad3 and Smad7 proteins through the TGF-β/Smad signaling pathway to minimize extrinsic scarring. Thus, it may provide a novel approach to decrease tendon adhesion and promote tendon healing.

Damage Control Orthopedics Management as Vital Procedure in Elderly Patients with Femoral Neck Fractures Complicated with Chronic Renal Failure: A Retrospective Cohort Study.

Background Chronic renal failure (CRF) predisposes to hip fractures in elderly patients, with high subsequent mortality. Selection and timing of the surgical procedure of such patients is a serious challenge. Many clinicians believe in earlier surgery as preferable and providing better outcomes. Damage control orthopedics (DCO) aids to adjust and optimize the overall condition of patients. Methods In 32 patients with femoral neck fractures complicated with CRF, we evaluated how the timing of the surgery determines the mortality rates if the DCO approach is applied. Preoperative ASA grading, POSSUM score, P-POSSUM score and DCO were carried out. Based on the assessment, timing of the surgery was ascertained. Results Of a total of 32 patients, twenty-nine patients were accepted for either early (< 48 hours; n = 18) or delayed (3–10 days; n = 10) surgery. Hip arthroplasty (total hip arthroplasty and hemiarthroplasty) was the principal surgery option. All patients survived operation and were followed up postoperatively with the average time of 30 days. Postoperative complications tended to occur at higher rates in the early vs. delayed surgery group (7/18 vs. 5/10). During follow up, a total of 3 patients died in both groups (2/18 in the early surgery and 1/10 in the delayed surgery group), mostly from multi-organ failures and acute respiratory distress syndrome. There was no significant difference in complication rates and Harris hip score between both groups. Conclusion In patients with femoral neck fracture complicated with CRF, delaying the surgery for several days does not increase the incidence of postoperative adverse events.

Damage-control orthopedics versus early total care in the treatment of borderline high-energy pelvic fractures.

The purpose of this study was to compare the effectiveness of damage-control orthopedics (DCO) vs early total care (ETC) in the treatment of borderline high-energy pelvic fractures. Seventy-two patients with borderline high-energy pelvic fractures were retrospectively reviewed; 39 received DCO and 33 received ETC. Demographic data and initial injury severities were comparable between groups, except for Abbreviated Injury Scale (AIS) head scores and Glasgow Coma Scale (GCS) scores. Regarding postoperative complications, the incidence rates of acute lung injury and acute respiratory distress syndrome and the mean Acute Physiology and Chronic Health Evaluation II (APACHE II) score were significantly lower in the DCO group compared with the ETC group. Similar results were also observed in subgroups stratified by age (younger than 40 years and 40 years and older). Regarding patients with Tile B fractures, there was no significant difference between groups in incidence rates of overall postoperative complications. However, in patients with Tile C fractures, especially in those 40 years and older, the DCO group had a lower incidence rate of ALI and had lower APACHE II scores than did the ETC group. This studys findings indicate that DCO is the most suitable therapeutic option for patients with Tile C fractures, especially for those 40 years and older, whereas ETC is preferred for patients with Tile B fractures, provided that it is possible to avoid a second operation as well as any delays in patient mobilization.

Anti-thrombosis effect of LRRFIP1 shRNA lentivirus in a mouse model of deep vein thrombosis.

INTRODUCTION Deep vein thrombosis (DVT) is one of the common complications of orthopedic surgery. Low molecular weight heparin (LMWH) is a usually used agent for DVT, but it would increase the risk of bleeding. LRRFIP1 has been shown to play an important role in the formation of thrombosis. Therefore, we investigated the effect of LRRFIP1 shRNA lentivirus on DVT in mice. MATERIALS AND METHODS Lentiviral Vectors carrying LRRFIP1 shRNA were constructed and transfected into cultured mouse bone marrow cells (BMCs). Male ICR mice were irradiated with a single dose of 9.5 Gy and then were injected with different agents through the tail vein. Stasis venous thrombosis was induced by inferior vena cava (IVC) ligation. Mice were sacrificed on the 1st, 3rd and 7th day post operation and the thrombi were removed, blotted the excess blood on it with filter paper and immediately weighed. P-selectin and d-Dimer were determined by enzyme-linked immunosorbent assay (ELISA). RESULTS LRRFIP1 shRNA significantly suppressed the expression of LRRFIP1 in the thrombi. In contrast, low molecular weight heparin (LMWH) and negative shRNA exhibited little effect on the expression of LRRFIP1. LRRFIP1 shRNA, LMWH and negative shRNA inhibited the thrombus formation in vivo significantly. The plasma P-selectin and d-Dimer levels were significantly increased after IVC ligation. LRRFIP1 shRNA significantly decreased the plasma P-selectin and d-Dimer levels. However, LMWH and negative shRNA showed little effects on the levels of plasma P-selectin and d-Dimer. CONCLUSION LRRFIP1 shRNA might represent a promising prevention strategy for DVT.

Stimulated phase-shift acoustic nanodroplets enhance vancomycin efficacy against methicillin-resistant Staphylococcus aureus biofilms

Purpose Bacterial biofilms on the surface of prostheses are becoming a rising concern in managing prosthetic joint infections. The inherent resistant features of biofilms render traditional antimicrobial therapy unproductive and revision surgery outcomes uncertain. This situation has prompted the exploration of novel antimicrobial strategies. The synergy of ultrasound microbubbles and vancomycin has been proposed as an efficient alternative for biofilm eradication. The purpose of this study was to evaluate the anti-biofilm effect of stimulated phase-shift acoustic nanodroplets (NDs) combined with vancomycin. Materials and methods We fabricated lipid phase-shift NDs with a core of liquid perfluoropentane. A new phase change mode for NDs incorporating an initial unfocused low-intensity pulsed ultrasound for 5 minutes and a subsequent incubation at 37°C into a 24-hour duration was developed. Methicillin-resistant Staphylococcus aureus (MRSA) biofilms were incubated with vancomycin and NDs under the hybrid stimulation. Biofilm morphology following treatment was determined using confocal laser scanning microscopy and scanning electron microscopy. Resazurin assay was used to quantify bactericidal efficacy against MRSA biofilm bacteria. Results NDs treated sequentially with ultrasound and heating at 37°C achieved gradual and substantial ND vaporization and cavitation in a successive process. NDs after stimulation were capable of generating stronger destruction on biofilm structure which was best characterized by residual circular arc margins and more dead bacteria. Furthermore, NDs combined with vancomycin contributed to significantly decreasing the metabolic activity of bacteria in MRSA biofilms (P<0.05). Conclusion Phase-shift acoustic NDs could exert a significant bactericidal effect against MRSA biofilms through a new stimulation mode. Acoustic NDs present advantages over microbubbles for biofilm damage. This anti-biofilm strategy could be used either alone or as an enhancer of traditional antibiotics in the control of prosthetic joint infections.

The infection of Mycoplasma hominis after total knee replacement: Case report and literature review

The Mycoplasma hominis infection is a rare postoperative complication after joint replacement. Based on our knowledge, there were only two cases reported by Korea all over the world currently. A case of postoperative Mycoplasma hominis infection after total knee replacement in our hospital was reported in this article. It was confirmed through mass spectrometer and Mycoplasma cultivation and treated by the first stage debridement, polyethylene insert replacement, and then drainage and irrigation combined with sensitive antibiotics after the operation. We observed that the C reactive protein (CRP) level correlates with the development of disease, while the erythrocyte sedimentation rate (ESR) remains at a high level, indicating the relevance between the Mycoplasma hominis infection caused by knee joint replacement and CRP. This study aims to report the case and review relevant literature.

Desmoplastic fibroma of the scapula: a case report and review of the literature

Desmoplastic fibroma of the scapula is a rare benign tumor in a rare site. We describe the management of a 61-year-old man with desmoplastic fibroma of the scapula. We think that a wide excision is one good treatment for this tumor. If there is a major functional deficit, the reconstructional operation may be designed for saving the function.