Influence of posteromedial corner injuries on clinical outcome and second-look arthroscopic findings after allograft transtibial anterior cruciate ligament reconstruction.

BACKGROUND: The purpose of this study was to evaluate the influence of posterior medial corner (PMC) injuries on clinical outcome and second-look arthroscopic findings after anterior cruciate ligament (ACL) reconstruction. METHODS: Seventy-eight consecutive patients underwent a second-look arthroscopic surgery after ACL reconstruction and magnetic resonance imaging (MRI) examination of the PMC. The patients were divided into a PMC intact group (n = 42) and a PMC injured group (n = 36). The stability and clinical outcomes were evaluated using the Lachman test, pivot-shift test, a KT-2000 arthrometer, and the Lysholm knee scoring scale. Graft tension and synovial coverage were evaluated in second-look arthroscopy. RESULTS: The clinical function showed no significant differences regarding PMC injury. Although the graft tendon tension revealed no significant differences (p = 0.141), the second-look arthroscopic findings indicated that the PMC intact group showed better synovial coverage compared to the PMC injured group (p = 0.012). CONCLUSION: Patients who injured the PMC had poor synovial coverage as assessed by second-look arthroscopic findings after transtibial ACL reconstruction, even though clinical outcomes and stability showed no significant differences.

Effect of Surgical-Site, Multimodal Drug Injection on Pain and Stress Biomarkers in Patients Undergoing Plate Fixation for Clavicular Fractures.

BACKGROUND: Surgical-site, multimodal drug injection has recently evolved to be a safe and useful method for multimodal pain management even in patients with musculoskeletal trauma. METHODS: Fifty consecutive patients who underwent plating for mid-shaft and distal clavicular fractures were included in the study. To evaluate whether surgical-site injections (SIs) have pain management benefits, the patients were divided into two groups (SI and no-SI groups). The injection was administered between the deep and superficial tissues prior to wound closure. The mixture of anesthetics consisted of epinephrine hydrochloride (HCL), morphine sulfate, ropivacaine HCL, and normal saline. The visual analogue scale (VAS) pain scores were measured at 6-hour intervals until postoperative hour (POH) 72; stress biomarkers (dehydroepiandrosterone sulfate [DHEA-S], insulin, and fibrinogen) were measured preoperatively and at POH 24, 48, and 72. In patients who wanted further pain control or had a VAS pain score of 7 points until POH 72, 75 mg of intravenous tramadol was administered, and the intravenous tramadol requirements were also recorded. Other medications were not used for pain management. RESULTS: The SI group showed significantly lower VAS pain scores until POH 24, except for POH 18. Tramadol requirement was significantly lower in the SI group until POH 24, except for POH 12 and 18. The mean DHEA-S level significantly decreased in the no-SI group (74.2 ± 47.0 µg/dL) at POH 72 compared to that in the SI group (110.1 ± 87.1 µg/dL; p = 0.046). There was no significant difference in the insulin and fibrinogen levels between the groups. The correlation values between all the biomarkers and VAS pain scores were not significantly different between the two groups (p > 0.05). CONCLUSIONS: After internal fixation of the clavicular fracture, the surgical-site, multimodal drug injection effectively relieved pain on the day of the surgery without any complications. Therefore, we believe that SI is a safe and effective method for pain management after internal fixation of a clavicular fracture.

Electrical and mechanical properties of poly(L-lactide)/carbon nanotubes/clay nanocomposites.

An organoclay containing epoxy groups, twice-functionalized organoclay (TFC), was synthesized by reacting (glycidoxypropyl)trimethoxy silane with Cloisite25A (C25A), which had already been modified with an amine compound. The introduction of epoxy groups to the clay surface and carboxylic group-functionalized multiwalled carbon nanotubes (MWCNTs) improved the interfacial adhesion between the poly(L-lactide) (PLLA) and nano-sized fillers when melt-compounded. The PLLA/MWCNTs/TFC nanocomposites showed superior tensile properties to those of PLLA and PLLA/CNTs. The dispersion of MWCNTs in the PLLA matrix decreased the electrical resistivity of the composite substantially due to the higher MWCNT loading. However, the introduction of TFC to the PLLA/MWCNTs nanocomposites resulted in a slight increase in volume resistivity. This increase was attributed to the individual MWCNTs being blocked by the TFC. The clays in the PLLA/MWCNTs/TFC nanocomposites prevented direct contact between the neighboring MWCNTs, which increased the electrical resistivity of the nanocomposites.

Synthesis and properties of multiwalled carbon nanotubes incorporated organic silk fibroin cryogels.

A new monolithic organic cryogel was synthesized from a silk fibroin/multiwalled carbon nanotube (MWCNT) hydrogel by the freeze-drying method in order to maintain the silk fibroin network. The silk fibroin/MWCNT hydrogel was prepared by the regeneration of silk fibroin using an aqueous silk fibroin solution in which MWCNTs were dispersed by in-situ methods. It was observed that the formation of the silk fibroin/MWCNT hydrogel was accelerated by increasing the MWCNT concentration. Fourier transform infrared spectrum analysis, X-ray diffraction, nitrogen adsorption-desorption, and electron microscopy analysis techniques were used to characterize the silk fibroin/MWCNT cryogel. The MWCNTs were embedded in the silk fibroin based cryogel with disordered porous structures. In addition, the MWCNTs induced a change in the crystal structure of the silk fibroin and also increased the proportions of micropores and mesopores in the supermacroporous cryogels when they were introduced in the appropriate amounts.

pH-sensitive multiwalled carbon nanotube dispersion with silk fibroins.

Multiwalled carbon nanotubes (MWCNTs) are considered to be ideal multifunctional materials for biorelated applications, but there is still some controversy regarding their toxicity. In addition, the poor dispersibility of MWCNTs in either water or organic solvents has limited their practical applications. Therefore, obtaining a good dispersion is one of the key issues in their applications. In this study, MWCNTs were dispersed in an aqueous solution using silk fibroin without chemical modification. An optical analyzer, Turbiscan, was used to confirm the stability of the MWCNT aqueous dispersion. Transmission electron microscopy showed individual MWCNTs coated with silk fibroin molecules. Silk fibroin in the sol state can interact with nanotubes through hydrophobic interactions. Therefore, silk fibroin molecules coat the nanotubes, which allow their dispersion in water. Under basic conditions (pH 12.0), an aqueous dispersion of MWCNTs with silk fibroin was stable without sedimentation or gelation. However, the MWCNT/silk fibroin dispersion was unstable under acidic conditions (pH 4.0). In addition, the MWCNT dispersion showed reversible changes with variations in pH. Under acidic conditions, the MWCNTs settled due to conformation changes in the silk fibroin. However, the stability of the MWCNTs had recovered fully under basic conditions. It is believed that silk fibroin has sol-like behavior under basic conditions and gel-like behavior under acidic conditions. Ultraviolet circular dichroism was used to determine the conformation of the silk fibroin molecules with pH. Overall, the pH-sensitive properties of the carbon nanotubes dispersed with silk fibroin can lead to a new class of novel biomaterials for cancer detection and treatment.

Preparation and characterization of silicone rubber/functionalized carbon nanotubes composites via in situ polymerization.

The dispersion of the nanometer-sized multiwalled carbon nanotubes (MWCNTs) in a silicone matrix leads to a marked improvement in the properties of the silicone based composite. In this study, silicone rubber/MWCNTs nanocomposite was successfully prepared by functionalizing MWCNTs with silane compound. This allowed a homogeneous dispersion of functionalized MWCNTs in the silicone matrix. The morphology of functionalized MWCNTs was observed using transmission electron microscopy and scanning electron microscopy with energy dispersive spectrometer. The silicone rubber/functionalized MWCNTs (1 wt%) composites showed that the tensile strength and modulus of the composites improved dramatically by about 50% and 28%, respectively, compared with silicone rubber.