Short-term results and surgical technique of arthroscopic centralization as an augmentation for medial meniscus extrusion caused by medial meniscus posterior root tear.

INTRODUCTION: The purpose of this study was to perform medial meniscus (MM) centralization for medial meniscus extrusion (MME) associated with medial meniscus posterior root tear (MMPRT) and to examine the short-term results. The hypothesis is that arthroscopic centralization as an augmentation of MMPRT repair improves clinical outcomes and the extrusion distance of MM in short-term results. MATERIALS AND METHODS: Twenty-six patients (mean age 62.1 ± 6.0 years) who underwent arthroscopic centralization as an augmentation of MMPRT repair were included. Clinical evaluation was performed before and 2 years after surgery using Lysholm score and knee injury and osteoarthritis outcome score (KOOS). Image evaluation used MRI and plain X-ray images. The extrusion distance and MME ratio were compared on MRI images before and 2 years after surgery. The degree of osteoarthritis (OA) was evaluated using Kellgren-Lawrence classification. The degree of OA and hip-knee-ankle (HKA) angle were compared by plane X-ray images before and 2 years after surgery. RESULTS: In clinical results, both Lysholm score and KOOS improved significantly after surgery. In image evaluation, the extrusion distance decreased significantly from 4.8 ± 0.7 mm before surgery to 2.7 ± 0.3 mm 2 years after surgery (p < 0.05). The MME ratio was significantly improved from 40.2 ± 7.0% before surgery to 22.6 ± 3.6% after surgery (p < 0.05). There was no significant difference in HKA angle at 2 years after surgery (p = 0.13). CONCLUSIONS: The arthroscopic centralization for medial meniscal extrusion associated with MMPRT significantly improved clinical outcomes and the extrusion distance of MM. It is also one of the surgical techniques that can suppress medial meniscus extrusion. LEVEL OF EVIDENCE: IV, therapeutic case series.

Outcome of arthroscopy-assisted treatment for distal clavicle fractures.

HYPOTHESIS: The purpose of the present study was described as the arthroscopically assisted procedure that uses a synthetic conoid ligament reconstruction using Zip Tight (Zimmer biomet, Warsaw, USA) and fracture-site fixation with K-wire. Our hypothesis was that this technique provided a satisfactory functional outcome with minimum complication. METHODS: 45 patients underwent operation to treat fractures of the distal clavicle between January 2014 and May 2017. The inclusion criteria were as follows: (1) there is an episode of trauma and it is the first fracture (2) distal clavicle fracture of Neer type IIb with dislocation in image findings. The exclusion criteria were as follows: (1) Neer type I, IIa and III of distal clavicle fracture (2) existing injury of rotator cuff, biceps tendon and labral during the arthroscopic procedure. Based on these criteria, 23 patients were included in this study. Clinical outcome assessments were performed using 1-year postoperative Quick DASH score, Constant-Murley score, ASES score. Radiological outcome consisted of antero-posterior and axillary radiographs. RESULTS: Mean clinical outcomes were as follows: Quick DASH score was 3.8 ± 2.8, ASES score was 92.3 ± 3.2 and Constant-Murley score was 94.1 ± 3.0. It was a highly satisfactory result in all of the score at 1-year follow-up. All patients had achieved radiographic union at a minimum 1-year follow-up. There were no cases of nonunion or osteolysis. CONCLUSIONS: This study demonstrated that the arthroscopy-assisted treatment using Zip Tight and K-wire provided a satisfactory functional outcome with minimum complication with Neer type IIb fractures of the distal clavicle. LEVEL OF EVIDENCE: IV, Case series, Treatment study.

The quadrant method measuring four points is as a reliable and accurate as the quadrant method in the evaluation after anatomical double-bundle ACL reconstruction.

PURPOSE: The quadrant method was described by Bernard et al. and it has been widely used for postoperative evaluation of anterior cruciate ligament (ACL) reconstruction. The purpose of this research is to further develop the quadrant method measuring four points, which we named four-point quadrant method, and to compare with the quadrant method. METHODS: Three-dimensional computed tomography (3D-CT) analyses were performed in 25 patients who underwent double-bundle ACL reconstruction using the outside-in technique. The four points in this study's quadrant method were defined as point1-highest, point2-deepest, point3-lowest, and point4-shallowest, in femoral tunnel position. Value of depth and height in each point was measured. Antero-medial (AM) tunnel is (depth1, height2) and postero-lateral (PL) tunnel is (depth3, height4) in this four-point quadrant method. The 3D-CT images were evaluated independently by 2 orthopaedic surgeons. A second measurement was performed by both observers after a 4-week interval. Intra- and inter-observer reliability was calculated by means of intra-class correlation coefficient (ICC). Also, the accuracy of the method was evaluated against the quadrant method. RESULTS: Intra-observer reliability was almost perfect for both AM and PL tunnel (ICC > 0.81). Inter-observer reliability of AM tunnel was substantial (ICC > 0.61) and that of PL tunnel was almost perfect (ICC > 0.81). The AM tunnel position was 0.13% deep, 0.58% high and PL tunnel position was 0.01% shallow, 0.13% low compared to quadrant method. CONCLUSIONS: The four-point quadrant method was found to have high intra- and inter-observer reliability and accuracy. This method can evaluate the tunnel position regardless of the shape and morphology of the bone tunnel aperture for use of comparison and can provide measurement that can be compared with various reconstruction methods. The four-point quadrant method of this study is considered to have clinical relevance in that it is a detailed and accurate tool for evaluating femoral tunnel position after ACL reconstruction. LEVEL OF EVIDENCE: Case series, Level IV.

Latent changes in the pharyngeal stage of swallowing in non-aspirating older adults.

PURPOSE: The characteristic changes in the swallowing mechanism with aging are collectively termed presbyphagia. Although several studies have investigated presbyphagia in older adults, few have assessed oldest-old adults. We aimed to characterize the latent changes of swallowing function in oldest-old adults and to consider risk ages for presbyphagia. METHODS: We analyzed the records of 85 individuals (44 males and 41 females, aged 25-101 years) who underwent videofluoroscopic swallowing studies. The included participants had penetration and aspiration scores of ≤ 2 and no history of aspiration, pneumonia, or diseases that affect swallowing. They were divided into four age groups: 25-64 years (non-older), 65-74 years (young-old), 75-84 years (middle-old), and ≥ 85 years (oldest-old). We analyzed and compared the pharyngeal delay time (PDT), duration of tongue base and posterior pharyngeal wall contact, duration and dimension of upper esophageal sphincter opening (UES-O), and maximal hyoid bone displacement between the age groups. RESULTS: Among the older groups, the oldest-old showed significantly longer PDT than younger-old adults, and the UES-O tended to be wider in the former. However, no other remarkable differences were found between the oldest-old and other old groups. Statistical comparisons between the < 75 and ≥ 75-year age groups revealed significant age-related changes in the PDT and duration and dimension of UES-O. CONCLUSION: On videofluoroscopic evaluation, physiological changes with aging affected few parameters of swallowing in our cohort. These findings indicate that in non-aspirating oldest-old adults, any deterioration may be adjusted for by compensatory changes to maintain swallowing function.

A 2-year follow-up of isolated Medial Patellofemoral Ligament Reconstruction by using soft suture anchor and adjustable cortical fixation system.

PURPOSE: Numerous surgical techniques and fixation methods have been described in medial patellofemoral ligament (MPFL) reconstruction such as choice of graft, graft fixation method of patella/femur and initial tension. We describe short term clinical results of MPFL reconstruction by using soft suture anchor and adjustable cortical fixation system. METHODS: Twenty-four patients who underwent isolated MPFL reconstruction by using soft suture anchor and adjustable cortical fixation system were included in this study. All patients were followed up for at least 2 years, and pre-operative and 2 years post-operative Kujala score, IKDC score and Knee Injury and Osteoarthritis Outcome Score were used to assess clinical outcome. Radiographic evaluation included the Q angle, congruence angle and patellar tilt angle. Pre- and post-operative changes were evaluated by Mann-Whitney U test. RESULTS: There were no complications including re-dislocation, patella fracture, infection, and joint contracture. The apprehension test was positive in 4.2% post-operatively. A statistically significant improvement in clinical scores and radiographic evaluation were evident after surgery. CONCLUSIONS: Isolated MPFL Reconstruction using soft suture anchor and adjustable cortical fixation system led good restoration of patellar stability and significant improvement of knee function in short-term results. This surgical technique can reduce complications such as patella fractures, and can be done safely. CLINICAL RELEVANCE: This technique may be a treatment option with little associated complications in the treatment for patellar instability. LEVEL OF EVIDENCE: Case series, Level IV.

Fabrication of Fluorite-Type Fluoride Ba0.5Bi0.5F2.5 Thin Films by Fluorination of Perovskite BaBiO3 Precursors with Poly(vinylidene fluoride).

Metal fluorides are gathering significant interest for use in many applications, such as optical glasses, chemical sensors, and solid electrolytes using fluoride ion batteries, due to their high transparency over a wide wavelength range (ultraviolet to infrared) and fast fluoride ion conductivity. Here, we present a topotactic route for synthesizing thin films of fluorite-type Ba0.5Bi0.5F2.5 (BBF), a promising fluoride ion conductor, from perovskite-type BaBiO3 (BBO) precursor films by fluorination using poly(vinylidene fluoride). The fluorination reaction fully converted BBO to BBF without stopping at the oxyfluoride stage. The BBF films obtained at relatively low reaction temperatures (150-200 °C) showed Ba/Bi cation ordering in the [001] direction, indicating that the cation framework of perovskite BBO was maintained during the fluorination reaction. Meanwhile, increasing the fluorination temperature led to mixtures of cations, resulting in random distribution of Ba and Bi. This demonstrates that the degree of cation ordering in BBF can be controlled by adjusting the fluorination temperature.

Injectable and biodegradable temperature-responsive mixed polymer systems providing variable gel-forming pH regions.

Aqueous solutions of biodegradable polymers exhibiting sol-to-gel transitions in response to external stimuli such as temperature and pH are expected to be used as injectable polymers (IPs) for biomedical applications. In this study, we prepared novel biodegradable temperature-responsive IP systems providing variable gel-forming pH regions. We synthesized PCGA-b-PEG-b-PCGA (tri-PCG) and attached carboxylic acid or primary amine groups on both termini, tri-PCG-COOH and tri-PCG-NH2, and investigated the temperature-responsive sol-to-gel transition behavior of the mixtures of these two copolymers at various pHs. We found that the gel-forming pH region of the mixed system could be easily controlled by simply changing the mixing ratios of these polymers.

Extemporaneously preparative biodegradable injectable polymer systems exhibiting temperature-responsive irreversible gelation.

On clinical application of biodegradable injectable polymer (IP) systems, quick extemporaneous preparation of IP formulations and longer duration time gel state after injection into the body are the important targets to be developed. Previously, we had reported temperature-responsive covalent gelation systems via bio-orthogonal thiol-ene reaction by 'mixing strategy' of amphiphilic biodegradable tri-block copolymer (tri-PCG) attaching acryloyl groups on both termini (tri-PCG-Acryl) with reactive polythiol. In other previous works, we found 'freeze-dry with PEG/dispersion' method as quick extemporaneous preparation method of biodegradable IP formulations. In this study, we applied this quick preparative method to the temperature-triggered covalent gelation system. The instant formulation (D-sample) could be prepared by 'freeze-dry with PEG/dispersion' just mixing of tri-PCG-Acryl micelle dispersion and tri-PCG/DPMP micelle dispersion with PEG, that can be prepared in 30 s from the dried samples. The obtained D-sample showed irreversible gelation and long duration time of gel state, which was basically the same as the formulations prepared by the usual heating dissolution method (S-sample). Interestingly, the D-sample could maintain its sol state for a longer time (24 h) after preparing the formulation at r.t. compared with the S-sample, which became a gel in 3 h after preparing. The IP system showed good biocompatibility and long duration time of the gel state after subcutaneous implantation. These characteristics of D-samples, quick extemporaneous preparation and high stability in the sol state before injection, would be very convenient in a clinical setting.

Mano-videoendoscopic assessment in the evaluation of the pharyngeal contraction and upper esophageal sphincter function in dysphagic patients.

OBJECTIVE: Mano-videoendoscopy (MVE) is a manometry technique with endoscopic confirmation of the pressure catheter. This study aimed to investigate the possibility of replacing a videofluorographic swallowing study (VFSS) with MVE for the precise evaluation of the pharyngeal contraction and the upper esophageal sphincter (UES) function. METHODS: The data from 69 patients with dysphagia were retrospectively reviewed. All of the patients underwent both MVE and a VFSS for the evaluation of dysphagia. Manometry was performed with a transnasally inserted catheter (2.6-mm outer diameter and 4 pressure sensors) under endoscopic observation. The sensors were kept at the tongue base, upper pyriform sinus, apex of the pyriform sinus, and UES. We evaluated the pharyngeal contraction and UES function fluorographically and statistically compared the manometric parameters. RESULTS: The fluorographic pharyngeal contraction was diagnosed as good in 28 patients and poor in 41 patients. The UES opening was diagnosed as good in 44 patients and poor in 25 patients. The highest pressure values at the tongue base (sensor 1), upper pyriform sinus (sensor 2), and apex of the pyriform sinus (sensor 3) were significantly larger in the good contraction group than in the poor contraction group. A stepwise logistic regression test revealed that the peak pressure of sensor 2 (upper pyriform sinus) was a robust predictor of fluorographic pharyngeal contraction, and the cut-off level for good fluorographic pharyngeal contraction was >81.5mmHg (specificity, 0.929; sensitivity, 0.870; area under the curve, 0.923). The nadir pressure, pressure drop, and pressure rise in the UES were significantly correlated with the fluorographic UES opening. A stepwise logistic regression test revealed that the pressure drop-the gap between the resting pressure and the nadir of the UES pressure-was a robust predictor of fluorographic UES opening, and the cut-off level to anticipate good fluorographic opening was ≥33.5mmHg (specificity, 0.853; sensitivity, 0.759). CONCLUSION: MVE can supplement the information obtained regarding the pharyngeal contraction and UES function, and overcomes the drawbacks of a videoendoscopic swallowing study (VESS).

Peptide Drug Release Behavior from Biodegradable Temperature-Responsive Injectable Hydrogels Exhibiting Irreversible Gelation.

We investigated the release behavior of glucagon-like peptide-1 (GLP-1) from a biodegradable injectable polymer (IP) hydrogel. This hydrogel shows temperature-responsive irreversible gelation due to the covalent bond formation through a thiol-ene reaction. In vitro sustained release of GLP-1 from an irreversible IP formulation (F(P1/D+PA40)) was observed compared with a reversible (physical gelation) IP formulation (F(P1)). Moreover, pharmaceutically active levels of GLP-1 were maintained in blood after subcutaneous injection of the irreversible IP formulation into rats. This system should be useful for the minimally invasive sustained drug release of peptide drugs and other water-soluble bioactive reagents.

Biodegradable Injectable Polymer Systems Exhibiting Temperature-Responsive Irreversible Sol-to-Gel Transition by Covalent Bond Formation.

Biodegradable injectable polymer (IP) systems exhibiting temperature-responsive sol-to-gel transitions between room temperature and body temperature have the potential for use in biomedical applications. However, gelation of such IP systems is a reversible process through physical cross-linking, and the hydrogels thus formed are likely to revert to the sol state under highly wet conditions after injection. In this study, a biodegradable IP system exhibiting temperature-responsive irreversible sol-to-gel transition by covalent bond formation was developed by simple mixing of polymers. A triblock copolymer of poly(caprolactone-co-glycolic acid) and poly(ethylene glycol) (tri-PCG) and tri-PCG with attached succinimide ester groups at both termini (tri-PCG-SA-OSu) were prepared and mixed together with a water-soluble polyamine (typically poly-l-lysine). The obtained IP formulation was in the sol state after mixing, but exhibited a rapid sol-to-gel transition within 30 s upon increasing the temperature to 37 °C. Once formed, the hydrogel did not revert to the sol state, even after cooling to 4 °C, because of the formation of covalent bonds upon transition. The obtained hydrogel soaked in phosphate buffered saline (PBS) exhibited a significantly longer duration time of the gel state. This IP system exhibiting a rapid and irreversible sol-to-gel transition is convenient for medical professionals and possesses great potential for use in biomedical devices for clinical applications such as drug delivery systems and antiadhesive materials.

Biodegradable injectable polymer systems exhibiting a longer and controllable duration time of the gel state.

Here, we report biodegradable temperature-triggered covalent gelation systems exhibiting a longer and controllable duration time of the gel state by a "mixing strategy" utilizing a thiol-ene reaction. We synthesized a tri-block copolymer of poly(caprolactone-co-glycolic acid) and PEG (tri-PCG) as a temperature-responsive injectable polymer (IP) and attached acryloyl groups on both termini (tri-PCG-Acryl). A tri-PCG micelle solution containing hydrophobic hexa-functional polythiol (Solution-A) and a tri-PCG-Acryl micelle solution (Solution-B) were mixed together. After mixing, the solution was still in the sol state at r.t., but exhibited an irreversible sol-to-gel transition in response to temperature. The duration time of the gel state while soaking in PBS could be altered from 1 day to 93 days by changing the mixing ratio of Solution-A/B. The physical strengths of the hydrogels were also controllable by changing the mixing ratio. The IP system showed good biocompatibility and a long duration time of the gel state after subcutaneous implantation.

Fluorescent azadipyrrinato zinc(II) complex: hybridisation with a dipyrrinato ligand.

We synthesised heteroleptic azadipyrrinato-dipyrrinato hybrid zinc(II) complex 1-Zn-2, by means of the stepwise coordination method. Homoleptic bis(azadipyrrinato)zinc(II) complex 1-Zn-1 was non-fluorescent, whereas 1-Zn-2 exhibited detectable fluorescence from azadipyrrinato ligand 1.

Electron transport in silver-semiconductor nanocomposite films exhibiting multicolor photochromism.

In the multicolor photochromism of TiO2 nanoporous films loaded with photocatalytically deposited Ag nanoparticles, visible light-induced electron transfer from Ag to oxygen molecules plays an essential role. Here we examined the effect of TiO2 on the electron transfer. We found that not only photocatalytically deposited Ag, but also electrodeposited Ag and commercially available Ag nanoparticles in a nanoporous TiO2 film exhibit the multicolor photochromism. The electrodeposited Ag exhibits the multicolor photochromism also in a nanoporous ZnO film, but not in nanoporous indium-tin oxide (ITO) and SiO2 matrices. Photoelectrochemical measurements for the Ag-TiO2 nanocomposite elucidated that some of the photo-excited electrons on Ag are transferred to oxygen molecules via TiO2 and non-excited Ag. Thus, an n-type semiconductor plays an important role in the charge separation between the excited electrons and Ag+. Non-excited Ag on TiO2 also plays an important role in the charge separation and/or catalysis of oxygen reduction. Replacement of the non-excited Ag with Pt accelerated the electron transport from the photo-excited Ag to oxygen molecules and the photochromic behavior.