Posterior-Stabilized Antibiotic Cement Articulating Spacer With Endoskeleton-Reinforced Cam Reduces Rate of Post-Cam Mechanical Complications in Prosthetic Knee Infection: A Preliminary Study.

BACKGROUND: Posterior-stabilized antibiotic cement articulating spacers (PS spacers) reduce spacer mechanical complications in prosthetic knee infections (PKIs); however, joint dislocation after femoral cam fracture has been reported. We hypothesized that the rate of post-cam mechanical complications is lower in PS spacers with an endoskeleton-reinforced cam. METHOD: A retrospective study of PKIs using PS spacers with or without a Kirschner wire-reinforced cam (K-PS or nK-PS spacers, respectively) was conducted between 2015 and 2019. The rates of post-cam mechanical complications and reoperation, as well as risk factors for post or cam failure, were analyzed. RESULTS: The cohort included 118 nK-PS and 49 K-PS spacers. All patients were followed up for 2 years. The rate of joint subluxation/dislocation after femoral cam fracture was lower in K-PS (0%) than in nK-PS spacers (17.8%; P = .002). The reoperation rate for spacer mechanical complications was lower in K-PS (0%) than in nK-PS spacers (11.9%; P = .008). The identified risk factors for femoral cam fractures were body mass index ≥25 kg/m2, femoral spacer size ≤2, and surgical volume ≤12 resection arthroplasties per year. CONCLUSION: This preliminary study highlights that K-PS spacers have a lower rate of post-cam mechanical complications than nK-PS spacers. We recommend the use of PS spacers with endoskeleton-reinforced cam when treating PKIs performed by surgeons with lower surgical volumes, especially in patients with higher body mass index and smaller femoral spacer sizes.

Enterovirus A71 Infection Activates Human Immune Responses and Induces Pathological Changes in Humanized Mice.

Since the discovery of enterovirus A71 (EV-A71) half a century ago, it has been recognized as the cause of large-scale outbreaks of hand-foot-and-mouth disease worldwide, particularly in the Asia-Pacific region, causing great concern for public health and economic burdens. Detailed mechanisms on the modulation of immune responses after EV-A71 infection have not been fully known, and the lack of appropriate models hinders the development of promising vaccines and drugs. In the present study, NOD-scid IL2Rγ-/- (NSG) mice with a human immune system (humanized mice) at the age of 4 weeks were found to be susceptible to a human isolate of EV-A71 infection. After infection, humanized mice displayed limb weakness, which is similar to the clinical features found in some of the EV-A71-infected patients. Histopathological examination indicated the presence of vacuolation, gliosis, or meningomyelitis in brain stem and spinal cord, which were accompanied by high viral loads detected in these organs. The numbers of activated human CD4+ and CD8+ T cells were upregulated after EV-A71 infection, and EV-A71-specific human T cell responses were found. Furthermore, the secretion of several proinflammatory cytokines, such as human gamma interferon (IFN-γ), interleukin-8 (IL-8), and IL-17A, was elevated in the EV-A71-infected humanized mice. Taken together, our results suggested that the humanized mouse model permits insights into the human immune responses and the pathogenesis of EV-A71 infection, which may provide a platform for the evaluation of anti-EV-A71 drug candidates in the future.IMPORTANCE Despite causing self-limited hand-food-and-mouth disease in younger children, EV-A71 is consistently associated with severe forms of neurological complications and pulmonary edema. Nevertheless, only limited vaccines and drugs have been developed over the years, which is possibly due to a lack of models that can more accurately recapitulate human specificity, since human is the only natural host for wild-type EV-A71 infection. Our humanized mouse model not only mimics histological symptoms in patients but also allows us to investigate the function of the human immune system during infection. It was found that human T cell responses were activated, accompanied by an increase in the production of proinflammatory cytokines in EV-A71-infected humanized mice, which might contribute to the exacerbation of disease pathogenesis. Collectively, this model allows us to delineate the modulation of human immune responses during EV-A71 infection and may provide a platform to evaluate anti-EV-A71 drug candidates in the future.

Diagnosis of painful cemented vertebrae from failed vertebroplasty: modified dynamic radiographs play an important role.

PURPOSE: The diagnosis of painful cemented vertebrae resulting from failed PV is not clearly defined in literature. This report evaluates the effectiveness of modified dynamic radiographs in diagnosing painful cemented vertebrae resulting from failed PV. METHODS: From January 2011 to June 2015, 345 patients with a total of 399 VCFs underwent PV at our institution. Among the 345 patients, 27 patients underwent repeated PV at the cemented vertebrae because of persisting or recurrent pain after vertebroplasty. The prevertebroplasty examinations included routine radiographs, modified dynamic radiographs, and MRI. Kyphotic angles and the anterior vertebral body height (AVBH) were measured. The image findings in routine radiographs, modified dynamic radiographs, and MRI were compared. Finally, a visual analog scale was used to measure the outcome. RESULTS: The patients ranged in age from 67 to 90 years. MRI revealed a moderate amount of fluid (definite diagnosis of refracture) in the cemented vertebrae in seven patients, bone edema without fluid in nine patients, and bone edema with minimal fluid in ten patients. The rate of diagnosis of painful cemented vertebrae according to MRI was 27% (7/26). The difference in the kyphotic angle between sitting and supine cross-table lateral radiographs was -9.36° ± 5.20° (P < 0.001). The difference in AVBH was 8.08 ± 3.21 mm (P < 0.001). All 27 patients were confirmed to have dynamic mobility according to the modified dynamic radiographs. CONCLUSIONS: When the diagnosis of painful cemented vertebrae is questionable, modified dynamic radiographs can help diagnose painful cemented vertebrae resulting from failed PV.

Photoelectrochemical sensor for the detection of Escherichia coli O157:H7 based on TPA-NO2 and dual-functional polythiophene films.

The detection of Escherichia coli (E. coli) is of great significance for the environment and human health. Herein, a photoelectrochemical (PEC) detection strategy based on molecularly imprinted polymers (MIPs) was proposed for the sensitive detection of E. coli. 4,4',4″-Trinitrotriphenylamine (TPA-NO2) was prepared using a simple nitration reaction. Subsequently, MIP films were polymerized on the surface of TPA-NO2 using 1,3-dihydrothieno[3,2-d]pyrimidine-2,4-dione as the functional monomer with the dual functions of specific recognition and sensitization. The linear range was 10-108 CFU/mL and the limit of detection was 10 CFU/mL. It showed favorable recoveries in real sample tests of milk, orange juice and tomato. Additionally, the ability of functional monomers to bind excellently with E. coli was verified using molecular docking techniques. This research provided broader possibilities for constructing MIPs-PEC sensors and analyzing the interaction mechanism between E. coli and functional monomers.

A preliminary study of the novel antibiotic-loaded cement computer-aided design-articulating spacer for the treatment of periprosthetic knee infection.

BACKGROUND: In comparison to static spacers, articulating spacers have been shown to result in a similar infection eradication rate in two-stage revision of periprosthetic knee infections. However, the optimal construct for articulating spacers has not been identified yet. The aim of this study was to present a preliminary result of treatment for periprosthetic knee infection using a novel computer-aided design (CAD)-articulating spacer. METHODS: We retrospectively reviewed 32 consecutive cases of chronic periprosthetic knee infection occurring from January 2015 to December 2015. In these cases, we used an antibiotic-loaded, optimized CAD-articulating spacer based on the retrieved knee prosthesis. Evaluation included infection eradication rate, the Hospital of Special Surgery (HSS) knee score, range of motion (ROM), and spacer-related mechanical complications. All cases were regularly followed-up for 2 years minimum. RESULTS: Twenty-eight of 32 patients (87.5%) had infection eradication; 18 patients (56.3%) received reimplantation successfully. The mean interval between spacer insertion and reimplantation was 8.8 months (range 4.0-12.5 months). The mean HSS knee score and ROM significantly increased during each interval (p < 0.0001 for both). The mean HSS knee scores were 31.2 (range 20-48) at initial visit, 65.4 (range 60-78.8) at 1 month after spacer insertion, and 84.2 (range 78-90) at 3 months after reimplantation (p < 0.0001). The mean ROM were 72.0° (range 15-100°), 85.6° (range 35-110°), and 102.0° (range 80-122°), respectively (p = 0.002). Two (6.3%) spacer-related mechanical complications occurred. CONCLUSIONS: The CAD-articulating spacer in two-staged revision of periprosthetic knee infection significantly controlled infection, improved clinical outcomes, increased ROM, and decreased mechanical complications in the preliminary study. Further larger clinical studies are needed to confirm the findings presented here.

Kirschner wire-guided technique for inserting a second needle into inadequately filled vertebrae in vertebroplasty: a technical report.

BACKGROUND CONTEXT: Absence or inadequate filling of cement in the fractured vertebrae can cause unsatisfactory results in a vertebroplasty. Repeated needle insertion can reduce the incidence of recollapse at the cemented vertebrae. However, when inserting the second needle in the usual method, it takes the same time and radiation exposure as the first needle. PURPOSE: To report a Kirschner wire-guided technique for inserting a second needle into inadequately filled vertebrae in vertebroplasty that can make the procedure simple, effective, and, most importantly, reduce the radiation exposure. STUDY DESIGN: Description of a modified surgical technique with retrospective data analysis. PATIENT SAMPLE: From January 2012 to December 2012, 87 percutaneous vertebroplasties were performed in our department to treat painful osteoporotic compression fractures. Seven adult patients (five women, two men; mean age: 75.7 years) had inadequate cement filling in the treated vertebrae that required the insertion of a second needle. OUTCOME MEASURES: Back pain was measured using the visual analog scale (VAS). The post-vertebroplasty anterior vertebral height and local kyphotic angle were used as the radiologic parameters. Intraoperative procedure time and fluoroscopy shots and postoperative complication were also evaluated. METHODS: The stylus of the first needle was inserted into the trocar to push the cement out of the trocar. The stylus was removed, a small diameter K-wire was inserted into the trocar, and the trocar was then removed. A second (new) trocar was inserted into the vertebral body following the track of the K-wire. When the new trocar reached the posterior 1/4 of the vertebral body, the K-wire was removed, the stylus was inserted, and the new needle was advanced to the anterior third of the vertebra. Cement was then injected into the new area until the filling was adequate. RESULTS: The immediate post-vertebroplasty anterior vertebral height was 23.31±1.95 mm, changed to 22.20±3.72 mm at final follow-up. The VAS decreased from a mean of 8.4 before vertebroplasty to 1.6 at the final follow-up. The follow-up duration ranged from 6 to 15 months (mean 12.6 months). There was no case of recollapse of the cemented vertebrae and no procedure-related complications. The procedure time of historical controls was 153.5 seconds, which reduced to 47.9 seconds by using this technique. The fluoroscopy shots of historical controls were 9.7 shots, which reduced to 2 shots by using this technique. CONCLUSIONS: This report suggests that Kirschner wire-guided technique for inserting a second needle during vertebroplasty could make the procedure simple, effective, and, most importantly, reduce the procedure time and radiation exposure.