Is topical or intravenous tranexamic acid preferred in total hip arthroplasty? A randomized, controlled, noninferiority clinical trial.

PURPOSE: The present study aimed to confirm the efficacy and safety of topical and intravenous tranexamic acid (TXA) compared with that of topical placebo and to assess the noninferiority between the two application methods of TXA in patients undergoing unilateral primary total hip arthroplasty. METHODS: Our randomized controlled trial investigated 170 patients with 1:1:1 allocation to two doses of 10-mg/kg intravenous TXA, 3-g topical TXA, and topical placebo of 60-ml physiological saline groups. The primary outcome, total blood loss, was calculated with Nadler and Gross formula. The secondary outcomes included allogeneic blood transfusion requirement, drain blood loss, decreased hemoglobin level. Noninferiority would be established when the upper limit 95% CI is lower than 250 ml of the noninferiority margin for the mean difference of total blood loss between topical and intravenous TXA. Thromboembolic complication incidence was considered as a safety outcome. RESULTS: The total blood loss of patients administered intravenous (mean±standard deviation, 1125±514 ml) and topical TXA (1211±425 ml) was significantly reduced compared with that of those administered topical placebo (1464±556 ml) (p = 0.0012). Drain blood loss and hemoglobin level reduction in patients administered with TXA were also significantly lower than those in patients administered topical placebo. The mean difference of total blood loss between topical and intravenous TXA is 86 ml (95% CI, -88 to 260 ml). The complications were comparable between patients managed with TXA and patients with topical placebo. CONCLUSION: The noninferiority of topical TXA to intravenous TXA can not be concluded. Considering no significant difference was found in all efficacy outcomes between the two administration methods. Any of the two TXA administration methods can be adopted for blood loss prevention in total hip arthroplasty.

Magnetic resonance imaging parameter optimizations for diagnosis of periprosthetic infection and tumor recurrence in artificial joint replacement patients.

To evaluate the efficacy of magnetic resonance imaging (MRI) parameter optimizations for the diagnosis of periprosthetic infection and tumor recurrence in joint replacement patients. We compared the quality of images for 16 joint replacement patients that were recorded using the optimized MRI parameters with and without view angle tilting (VAT) correction at 1.5 T in coronal fast-spin-echo T2-weighted MRI. The optimized MRI data of 86 patients with pain after hip replacement and 67 patients who received tumor resection and joint replacement for bone cancer were retrospectively analyzed to identify MRI features that were useful for the diagnosis of periprosthetic infection and tumor recurrence. Increasing receiver bandwidth and decreasing slice thickness combined with VAT significantly reduced the area of metal-induced artifacts. Irregular soft tissue mass, soft tissue edema, bone destruction, and fistula were significant features of periprosthetic infection, with sensitivities of 47.4-100% and specificities of 73.1-100.0%, which were confirmed based on surgical and pathological findings. Soft tissue mass was a significant feature of tumor recurrence, with 100% sensitivity, 96.0% specificity, and 97.0% consistency. The optimized VAT MRI method demonstrated a high level of diagnostic accuracy for the detection of periprosthetic infection and tumor recurrence in joint replacement patients.

Water-assisted growth of graphene on carbon nanotubes by the chemical vapor deposition method.

Combining carbon nanotubes (CNTs) with graphene has been proved to be a feasible method for improving the performance of graphene for some practical applications. This paper reports a water-assisted route to grow graphene on CNTs from ferrocene and thiophene dissolved in ethanol by the chemical vapor deposition method in an argon flow. A double injection technique was used to separately inject ethanol solution and water for the preparation of graphene/CNTs. First, CNTs were prepared from ethanol solution and water. The injection of ethanol solution was suspended and water alone was injected into the reactor to etch the CNTs. Thereafter, ethanol solution was injected along with water, which is the key factor in obtaining graphene/CNTs. Transmission electron microscopy, scanning electron microscopy, X-ray diffraction, and Raman scattering analyses confirmed that the products were the hybrid materials of graphene/CNTs. X-ray photo-electron spectroscopy analysis showed the presence of oxygen rich functional groups on the surface of the graphene/CNTs. Given the activity of the graphene/CNT surface, CdS quantum dots adhered onto it uniformly through simple mechanical mixing.

Fabrication of a multifunctional carbon nanotube "cotton" yarn by the direct chemical vapor deposition spinning process.

A continuous cotton-like carbon nanotube fiber yarn, consisting of multiple threads of high purity double walled carbon nanotubes, was fabricated in a horizontal CVD gas flow reactor with water vapor densification by the direct chemical vapor deposition spinning process. The water vapor interaction leads to homogeneous shrinking of the CNT sock-like assembly in the gas flow. This allows well controlled continuous winding of the dense thread inside the reactor. The CNT yarn is quite thick (1-3 mm), has a highly porous structure (99%) while being mechanically strong and electrically conductive. The water vapor interaction leads to homogeneous oxidation of the CNTs, offering the yarn oxygen-functionalized surfaces. The unique structure and surface of the CNT yarn provide it multiple processing advantages and properties. It can be mechanically engineered into a dense yarn, infiltrated with polymers to form a composite and mixed with other yarns to form a blend, as demonstrated in this research. Therefore, this CNT yarn can be used as a "basic yarn" for various CNT based structural and functional applications.

Manipulation of individual double-walled carbon nanotubes packed in a casing shell.

Controlled placement of carbon nanotubes is important for carbon-based nanodevice assembly. However, it is difficult to manipulate individual nanotubes because of their extremely small dimensions. Ultra-fine tubes are often in the form of bundles and are hard to efficiently move on a surface due to the strong adhesion among themselves and between the tubes and the substrate. This paper presents a novel manipulation approach of individual double-walled carbon nanotubes encased in a thick amorphous carbon shell. With an atomic force microscope, we are able to freely displace the nanotubes within a casing shell, and unpack it from the shell on a silicon surface. The theoretical analysis demonstrates that the unpacking process is determined by the difference of the static friction between the shell and the substrate and the resistance force between the shell and the embedded nanotube.

Results of selective hip arthroplasty revision in isolated acetabular failure.

BACKGROUND: Controversy exists over whether to remove well-fixed components at the time of revision of a failed total hip arthroplasty (THA). The purpose of this study was to evaluate the results of selective acetabular revision after acetabular failure in which only the failed component was replaced. MATERIALS AND METHODS: Thirty-six isolated acetabular component revisions were performed and prospectively followed for a mean of 4.7 y (range, 2-9.3 y). The components had been in place for a mean of 10.8 y. All femoral components and some metal-backed acetabular shells were well fixed at the time of revision and left in place. Surgery involved cementation of an acetabular liner into a well-fixed acetabular shell in 16 cases, and acetabular revision in 20 cases. Morselized cancellous allograft was used to fill acetabular defects in 27 hips, and proximal femoral defects in 17 hips. Bulk allografts were used to reconstruct the proximal femur in two hips. RESULTS: The mean Harris hip score improved from 57.8 preoperatively to 89.1 at the final follow-up visit. The results were rated excellent in 24 patients, good in nine patients, and fair in three patients. The unrevised femoral components and acetabular shells remained well fixed, and final follow-up radiographs revealed no cases of osteolytic lesion progression around the femoral and acetabular components. CONCLUSIONS: Revision of only the failed acetabular component is recommended in cases of isolated acetabular failure, providing excellent results over the medium term, and allowing preservation of bone stock with lower surgical morbidity.