In Vitro Bioactivity and Antibacterial Effects of a Silver-Containing Mesoporous Bioactive Glass Film on the Surface of Titanium Implants.

Peri-implantitis is defined as a bacterial infection-induced inflammation and suppuration of soft and hard tissues surrounding a dental implant. If bacteria further invade the alveolar bone, they can easily cause bone loss and even lead to the early failure of a dental implant surgery. In the present study, an 80SiO2-15CaO-5P2O5 mesoporous bioactive glass film system containing 1, 5, and 10 mol% of silver was prepared on titanium implant discs (MBG-Ag-coated Ti) using sol-gel and spin coating methods. The wettability and adhesion strength of the films were evaluated using contact angle measurements and adhesion strength tests, respectively. The phase composition, chemical bonding, morphology, and oxidation states of the films were analyzed via X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). In vitro bioactivity analysis of the films was performed by immersion in a simulated body fluid (SBF) for 24 h. Disk diffusion tests were performed on the early colonizing bacteria Aggregatibacter actinomycetemcomitans and Streptococcus mutans to evaluate the antibacterial ability of the films. A silver-containing mesoporous bioactive glass film with excellent biocompatibility and antibacterial properties was successfully prepared.

Treatment of Fabella syndrome with arthroscopic fabellectomy: a case series and literature review.

BACKGROUND: The fabella is a sesamoid bone in the posterolateral capsule of the human knee joint. In quadrupedal mammals, the fabella is believed to have a role similar to the patella in redirecting extension forces of the knee joint from one point to another. In bipeds, the fabella is not touching the back of the bent knee, and therefore the role in redirecting forces declines. Posterolateral knee pain can be associated with the irritation between the fabella and lateral femoral condyle, a phenomenon also known as fabella syndrome. In cases that are unresponsive to conservative management, surgical fabellectomy can be a successful treatment option. Among the surgical approaches, open resection is most commonly seen. There are also literature reporting arthroscopic-assisted open resection, but seldom mentioned the all-arthroscopic fabellectomy. CASE PRESENTATION: We present 3 patients with a long history (> 12 month) of posterolateral knee pain under suspicion of different pain origins. The diagnosis of fabella impingement was eventually made by ruling out of other causes. All the patients underwent all-arthroscopic fabellectomy for diagnosis and treatment. Investigations of the resected fabella suggested chronic impingement with apparent osteophyte formation and cartilage wearing of the articular side. All patients have been continually followed up at our outpatient department and reported to be pain free after the procedure. CONCLUSIONS: In the patients presenting posterolateral pain, fabella syndrome cannot be ignored due to its relative higher presence in Asian population. In our experience, the all-arthroscopic fabellectomy offers a smaller wound size, less post-operative pain, fewer days of hospitalization and quicker time to rehabilitation for the patients with chronic posterolateral knee pain caused by fabella syndrome.

Effects of an in-hospital nursing intervention on changing illness perceptions in patients with injury.

AIM: The aim of this study was to evaluate the effectiveness of a nursing intervention in changing the illness perceptions of injured patients. BACKGROUND: Illness perceptions have been found to be among the important patient outcomes after an injury. Research has suggested that a designed intervention might be an effective means of shaping injured patients' illness perceptions. DESIGN: An experimental study design was employed. METHODS: A total of 82 injured patients completed this study, with 42 in the experimental group and 40 in the control group. Data were collected from 2011-2013. A trained nurse practitioner delivered an in-hospital nursing intervention according to self-regulatory theory. The outcome measure was the change in illness perceptions of injury among the patients as measured by the Chinese Illness Perception Questionnaire Revised-Trauma (the Chinese IPQ-R-Trauma), which comprises eight subscales. The experimental and control groups were followed up via telephone survey 3 months after discharge. The generalized estimating equations were used to analyse the data. RESULTS: The results showed statistically significant differences on two subscales of the Chinese IPQ-R-Trauma, Identity and Controllability, before and after the intervention. Results for the remaining six subscales did not change significantly. The findings indicate that the intervention resulted in a decrease in injury-related physical symptoms and in increases in positive perceptions among patients about controlling their postinjury condition. CONCLUSIONS: This nursing intervention led to changes in patients' illness perceptions and potentially improved the patients' self-regulation after their injuries. Future research can be conducted to enhance the effectiveness of the intervention protocol.

Early recovery experience of patients with injury in Taiwan.

PURPOSE: To fill out the gaps in the existing research on the early recovery experiences of patients who have suffered moderate to severe injuries. DESIGN: Exploratory phenomenology was applied in this study. METHODS: Data were collected at a hospital in Taiwan from a purposive sample of 14 participants who were interviewed before hospital discharge. Semi-structured and audio-taped interviews were conducted. Colaizzi's methods were applied to analyze data. Four criteria were applied to establish the rigors of this study. FINDINGS: The patients expressed that during the early stages following their injury, several aspects of the traumatic event caused them concern. Six themes were delineated: "experience of acute pain after the injury," "inability to fulfill daily needs," "concerns with impacts caused by the injury," "perceiving that time is needed to recover," "applying multiple methods to restore one's health," and "perceiving fate as the cause of the accident." CONCLUSIONS: The findings identify that injuries bring several problems for patients. Some culture-related issues such as Chinese diets, Chinese medicine, and karmic causation have emerged. Clinicians should better understand patient care needs in the early stages of recovery after an injury. CLINICAL RELEVANCE: Findings from this study could lead to new interventions, and finally improve care outcomes for patients with injuries.

Development and verification of a novel bone collector with automatic size separating function for orthopedics surgery.

BACKGROUND: Autologous bone dust can be filled in bone defects to promote effective bone healing but typically it is lost when using suction during surgery. The aim of this study was to develop a novel bone collector that can be used to collect bone chips/dust of varying sizes without changing current surgical procedures. RESEARCH DESIGN AND METHODS: This collector was designed to connect to a surgical continuous suction system and comprised a plate filter with a 3 mm hole and featured a taper filter with a mesh size of 0.27 mm for the separation and collection of both coarse and fine bone chips/dust. The bone collector was manufactured using nylon 3D printing and plastic injection with biocompatible materials. RESULTS: The bone collector functional test revealed high bone chip collection efficiency (93%) with automatic size separation function. Low (3.42%) filtration errors showed that most of the water can be drained smoothly from the bone collector. In clinical usability testing, bone collectors can provide functions demonstrated in in vivo spinal fusion and femoral fracture surgeries with different bone grafting size requirements. CONCLUSIONS: The novel bone collector has been validated as a viable and effective surgical device, offering surgeons an additional option to enhance patient outcomes.

Early outcomes of the Oxford unicompartmental knee arthroplasty: 140 cases from a single institute in Taiwan.

BACKGROUND: The clinical and radiologic outcomes of the Oxford unicompartmental knee arthroplasty utilizing Microplasty® instrumentation have not been extensively investigated in Taiwanese patients. Despite the efficacy of this treatment for unicompartmental knee diseases, its specific impact on this population remains unknown. METHODS: We retrospectively analyzed prospectively collected data of patients who underwent OUKA with MP between 2018 and 2021, including demographic information, component position, preoperative and postoperative knee range of motion (ROM), numeric rating scale (NRS), and 2011 Knee Society Score-functional activity score (2011 KSS-FAS). We compared preoperative and postoperative data and analyzed the correlation between clinical and radiographic outcomes. RESULTS: Among 140 patients with an average age of 66.8 years, predominantly female, the majority exhibited components that fell within the radiographically acceptable tolerance ranges. The mean 2.5-year follow-up revealed significant improvements in knee ROM from 102.6° ± 12.9° to 127.3° ± 9.8° ( p < 0.05), pain reduction from 7.7 ± 0.8 to 0.4 ± 0.7 ( p < 0.001), and KSS-FAS from 30.7 ± 10.5 to 94.3 ± 5.2 ( p < 0.001). Notably, a tibial component medial overhang within tolerance predicted shorter hospital stays, and a higher preoperative KSS correlated with lower postoperative NRS. No independent variables were identified as predictors of a higher postoperative KSS. CONCLUSION: Our study on OUKA with MP in Taiwanese patients reveals promising early clinical and radiographic outcomes. Tibial component medial overhang <3 mm is associated with shorter hospital stays, and a higher preoperative KSS predicts lower NRS at 1 year postoperatively.

Arthroscopic Transosseous Superior Capsular Reconstruction.

Superior capsular reconstruction is a common treatment option for irreparable rotator cuffs. Arthroscopic surgery procedures mostly use anchor-based methods. However, difficulty in preoperative graft measurement and intra-articular knot-tying present an obstacle for most sport surgeons. Complementing the known advantages of the transosseous technique in rotator cuff repair, a feasible, economical arthroscopic transosseous superior capsular reconstruction technique is described in this Technical Note. This procedure results not only in similar fixation strength and stability and greater bone stock but also in greater cost effectiveness due to using fewer anchors. This Technical Note describes the procedure in detail and compares it with conventional procedures.

Supraclavicular nerve sparing versus sacrifice during open reduction internal fixation of acute midshaft clavicle fracture.

BACKGROUND: The branches of the supraclavicular nerve are often sacrificed during open reduction and internal fixation (ORIF) for clavicle fracture. No consensus exists on whether the supraclavicular nerve should be routinely identified and protected during ORIF. METHODS: We developed a simple method to make nerve sparing easier; Wide-Awake Local Anesthesia No Tourniquet (WALANT) solution is locally injected prior to the surgical incision being made. This retrospective study enrolled 340 patients and divided them into supraclavicular-nerve-sparing (n = 45) and supraclavicular-nerve-sacrifice (n = 295) groups. Surgical outcomes-including operative time, estimated blood loss, postoperative pain, union rate, time to union, functional score, paresthesia, complications, implant removal rate, and complication rate-were recorded. RESULTS: Incisional or anterior chest wall numbness and intraoperative blood loss were significantly less (p < 0.001) in the nerve-sparing group. The operative time was similar in the two groups. No significant differences were discovered in QuickDASH score, postoperative pain score, union rate, time to union, implant removal rate, complication rate, or revision rate. CONCLUSIONS: Our study demonstrated that the outcomes of supraclavicular nerve sparing during ORIF with WALANT can reduce postoperative incisional and anterior chest wall numbness and intraoperative blood loss without increasing the operative time or complication rate.

Mechanical Properties of Titanium/Nano-Fluorapatite Parts Produced by Laser Powder Bed Fusion.

Laser powder bed fusion (L-PBF) has attracted great interest in recent years due to its ability to produce intricate parts beyond the capabilities of traditional manufacturing processes. L-PBF processed biomedical implants are usually made of commercial pure titanium (CP-Ti) or its alloys. However, both alloys are naturally bio-inert, and thus reduce the formation of apatite as implants are put into the human body. Accordingly, in an attempt to improve the bioactivity of the materials used for making orthopedic implants, the present study decomposed fluorapatite material (FA, (Ca10(PO4)6F2)) into the form of nano-powder and mixed this powder with CP-Ti powder in two different ratios (99%Ti + 1%FA (Ti-1%FA) and 98%Ti + 2%FA (Ti-2%FA)) to form powder material for the L-PBF process. Experimental trials were conducted to establish the optimal processing conditions (i.e., laser power, scanning speed and hatching space) of the L-PBF process for the two powder mixtures and the original CP-Ti powder with no FA addition. The optimal parameters were then used to produce tensile test specimens in order to evaluate the mechanical properties of the different samples. The hardness of the various samples was also examined by micro-Vickers hardness tests. The tensile strength of the Ti-1%FA sample (850 MPa) was found to be far higher than that of the CP-Ti sample (513 MPa). Furthermore, the yield strength of the Ti-1%FA sample (785 MPa) was also much higher than that of the CP-Ti sample (472 MPa). However, the elongation of the Ti-1%FA sample (6.27 %) was significantly lower than that of the CP-Ti sample (16.17%). Finally, the hardness values of the Ti-1%FA and Ti-2%FA samples were around 63.8% and 109.4%, respectively, higher than that of the CP-Ti sample.

Taiwanese translation and psychometric testing of the Revised Illness Perception Questionnaire for patients with traumatic injury.

AIMS: The purpose of this study was to undertake a cross-cultural adaptation, translation and psychometric analysis of the Illness Perception Questionnaire Revised for patients with traumatic injury in Taiwan. BACKGROUND: Illness representations are the cognitive understandings and emotional responses individuals develop, which help to determine their responses to health threats. METHODS: This methodological study involved four phases. First, two subscales, identity and causes were modified. Second, translation and back translation was undertaken by four translators, moderated by an expert committee. Third, ten patients with traumatic injury pilot tested the feasibility and readability of the Chinese Illness Perception Questionnaire Revised (Trauma), and three professionals assessed the scale for content validity, resulting in minor modifications. Finally, 173 patients with traumatic injury were recruited to the main study and completed the Chinese Illness Perception Questionnaire Revised (Trauma). Item analysis, factor analysis, Cronbach's alpha and split-half reliability were used to the psychometric properties of the Chinese Illness Perception Questionnaire Revised (Trauma). RESULTS: Eight items were removed from the scale as a result of the item analysis. The factor analysis demonstrated a six-factor structure explained 60.3% of the total item variance in the scale, which was very similar to the original scale. The Cronbach's alphas ranged from 0.69-0.80 for each subscale, and the split-half reliability coefficients were from 0.70-0.82. CONCLUSION: The Chinese Illness Perception Questionnaire Revised (Trauma) had good psychometric properties. RELEVANCE TO CLINICAL PRACTICE: Translation of the instrument into Chinese extends its utility to the traumatic injury population. Awareness of patients' illness representations can help clinicians provide appropriate interventions to patients.

A novel approach to distal femur: a minimally invasive technique for supracondylar and intercondylar fracture.

BACKGROUND: For treating distal femur fractures, minimally invasive plating techniques with indirect reduction of the metadiaphysis while minimizing the damage to the peripheral soft tissue has gradually become the standard. However, all the current approaches use a straight or lazy curved incision adjacent to the patella or along the lateral side of the femur, which allows for easier proximal extension but increases the incision length. METHODS: In order to achieve a more physiological and esthetic outcome while leaving the metadiaphysis untouched, we developed an approach using a lambda-shaped incision, which sacrifices the potential for proximal extension but preserves much more peripheral soft tissue. Here, we describe our technique and our experience with it in 19 patients (12 men and 7 women). RESULTS: Fractures healing by first intention was observed in all patients. The postoperative knee range of motion can reach up to 90° in most of the patient. Clinically, 9 patients had excellent results, 6 had good results, 3 had fair results, and 2 had loss of follow-up. CONCLUSIONS: Our minimally invasive lambda-incision approach allows sufficient visual access to almost the entire joint surface, including the entire lateral femoral condyle, trochlear surface, and distal medial condyle, where reduction is required. The lambda incision provides a much larger window than that offered by a same-length straight incision. The vertical turn at the mid-patellar level parallels the skin crease and geniculate artery, reducing soft tissue damage and resulting in a smooth healing wound. Moreover, plate and distal screw insertion is easier than that through a straight incision. Because the metadiaphysis region is mostly left untouched, ideal fracture-healing environment is preserved.

Treatment of acute distal radioulnar joint instability with distal oblique bundle augmentation of the interosseous membrane by suture-button suspension: A case series.

The stability of distal radioulnar joints is afforded by bony radioulnar articulation and peripheral soft-tissue stabilizers. The primary soft-tissue stabilizers are structures that surround the distal radioulnar joint and are collectively referred to as the triangular fibrocartilaginous complex. Among the stabilizers, the volar and dorsal radioulnar ligaments contribute the most to the stability of distal radioulnar joints. For acute traumatic distal radioulnar joint instability accompanied by purely ligamentous injury, traditional surgical treatments involve the repair or reconstruction of the distal radioulnar ligament; however, these intra-articular procedures are highly invasive and difficult. The extra-articular reconstruction of the secondary stabilizer such as the distal oblique bundle of the interosseous membrane has attracted significant attention in recent years; however, most studies have only conducted cadaveric or laboratory modelbased investigations. In this article, we present three patients who suffered from acute dorsal wrist pain after a trauma event. Radiographic and physical examinations revealed distal radioulnar joint instability. All patients were treated with minimally invasive suture-button suspension augmentation in the direction of distal oblique bundle of the interosseous membrane. The instability was resolved after the surgical procedure, but two patients developed ulnar wrist pain and one patient underwent implant removal. All patients have been continually followed at our outpatient department and exhibited stable wrists, despite mild limitation in the range of motion after the procedure. In conclusion, acute traumatic distal radioulnar joint instability may be sufficiently treated with suture-button suspension for augmentation of the distal oblique bundle; however, some obstacles impede the in vivo adoption of this treatment.

Effects of Micro-Arc Oxidation Discharge Parameters on Formation and Biomedical Properties of Hydroxyapatite-Containing Flower-like Structure Coatings.

The micro-arc oxidation (MAO) process was used to prepare hydroxyapatite-containing flower-like structure coatings on commercially pure titanium substrates with various values of the applied voltage (330, 390, 450 V), applied current (0.4, 0.5, 0.6 A), and duration time (1, 3, 5 min). It was found that the surface morphology of the coatings was determined primarily by the applied voltage. A voltage of 330 V yielded a flower-like/plate-like structure, while voltages of 390 V and 450 V produced a flower-like structure and a porous morphology, respectively. The applied current and duration time mainly affected the coating formation speed and petal size of the flower-like structures, respectively. The coatings prepared using voltages of 330 V and 390 V (0.6 A, 5 min) both contained Ti, TiO2-A (anatase), TiO2-R (rutile), DCPD (CaHPO4·2H2O, calcium hydrogen phosphate), and hydroxyapatite (HA). However, the latter coating contained less DCPD and had a higher HA/DCPD ratio and a Ca/P ratio closer to the ideal value of HA. The coating prepared with a voltage of 450 V consisted mainly of Ti, TiO2-A, TiO2-R, and CaTiO3. For the coatings prepared with a voltage of 390 V, the flower-like structures consisted mainly of HA-containing compounds. DCPD plate-like structures were observed either between the HA-containing flower-like structures (330 V samples) or within the flower-like structures themselves (390 V samples). The coating surfaces with flower-like/plate-like or flower-like structures had a greater roughness, which increased their hydrophilicity and resulted in superior bioactivity (SBF immersion) and biocompatibility (MG-63 cell culture). The optimal biomedical performance was found in the 390 V coating due to its flower-like structure and high HA/DCPD ratio.

A Novel Arthroscopic Transosseous Procedure for Rotator Cuff Repair: An Economical Freehand Method.

Open transosseous repair was historically considered the gold-standard surgical solution for rotator cuff tears; however, with advancements in arthroscopic surgery, this procedure was largely replaced by anchor-based techniques. Yet, the ability of anchor-based techniques to achieve similar biomechanical fixation remains uncertain.In this article, we describe a reproducible, economical, arthroscopic anchorless transosseous rotator cuff repair technique that uses an Omega configuration. This technique involves two bone tunnels and four high-strength polyethylene sutures and is suitable for medium-to-large rotator cuff tears that would alternatively need multiple anchors. This procedure not only maximizes the tendon-footprint contact area without using any implanted device but also theoretically lowers the bone laceration rate and is cost effective. In the current Technical Note, the procedure is described in detail along with several tips and tricks. CLASSIFICATIONS: Level I, shoulder; Level II, rotator cuff.

Synergistic Antibacterial Effect of Casein-AgNPs Combined with Tigecycline against Acinetobacter baumannii.

Acinetobacter baumannii (A. baumannii) is a common and challenging pathogen of nosocomial infections, due to its ability to survive on inanimate objects, desiccation tolerance, and resistance to disinfectants. In this study, we investigated an antibacterial strategy to combat A. baumannii via the combination of antibiotics and silver protein. This strategy used a functional platform consisting of silver nanoparticles (AgNPs) resurrected from silver-based calcium thiophosphate (SSCP) through casein and arginine. Then, the silver protein was combined with tigecycline, the first drug in glycylcycline antibiotic, to synergistically inhibit the viability of A. baumannii. The synergistic antibacterial activity was confirmed by the 96-well checkerboard method to determine their minimum inhibitory concentrations (MIC) and calculated for the combination index (CI). The MIC of the combination of silver protein and tigecycline (0.31 mg/mL, 0.16 µg/mL) was significantly lower than that of the individual MIC, and the CI was 0.59, which indicates a synergistic effect. Consequently, we integrated the detailed synergistic antibacterial properties when silver protein was combined with tigecycline. The result could make for a promising approach for the treatment of A. baumannii.

Antimetastatic potential of fisetin involves inactivation of the PI3K/Akt and JNK signaling pathways with downregulation of MMP-2/9 expressions in prostate cancer PC-3 cells.

Fisetin (3,3',4',7-tetrahydroxyflavone), a naturally occurring flavonoid, has been reported to possess some anti-cancer and anti-inflammation capabilities. In this study, fisetin has exhibited inhibitory effects on the adhesion, migration, and invasion ability of a highly metastatic PC-3 cells under non-cytotoxic concentrations. Gelatin zymography assay showed that fisetin inhibited the matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) activities. Our result also showed that fisetin could inhibit the phosphorylation of c-Jun N-terminal kinase 1 and 2 (JNK1/2) and Akt. Moreover, fisetin significantly decreased the nuclear levels of nuclear factor kappa B (NF-kappaB), c-Fos, and c-Jun, and the binding abilities of NF-kappaB and activator protein-1 (AP-1). Also, the results showed that the protein and mRNA levels of MMP-2 and MMP-9 were significantly reduced by Western blot and semi-quantitative RT-PCR. Further, treating specific inhibitors for PI3K (Wortmannin) or JNK (SP600125) to PC-3 cells could reduce the protein expressions of MMP-2 and MMP-9. These results showed fisetin could inhibit the metastatic ability of PC-3 by reducing MMP-2 and MMP-9 expressions through suppressing phosphoinositide 3-kinase/Akt (PI3K/Akt) and JNK signaling pathways. This suggested fisetin can serve as a potential candidate for treating cancer metastasis.

Microwave assisted synthesis of negative-charge carbon dots with potential antibacterial activity against multi-drug resistant bacteria.

In this research, negative-charge carbon dots (CDs) were synthesized in one-step using a microwave and found to have potential antibacterial ability against multi-drug resistant bacteria. The CDs were synthesized by using citric acid and urea as precursors, and characterized by FT-IR, TEM and fluorescence spectrophotometry. The average size of CDs was about 2.5 nm, and the ζ potential was -11.06 mV. In the following antibacterial activity test, time-killing curve experiments and colony-forming assay were carried out to determine the minimum bactericidal concentration (MBC) and minimum inhibitory concentration (MIC) of the CDs against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-intermediate Staphylococcus aureus (VISA). The data showed the MBC of the CDs against MRSA is 2.5 mg mL-1, and the MIC of the CDs against MRSA is 0.63 mg mL-1; the MBC of the CDs against VISA is 1.25 mg mL-1, and the MIC of the CDs against VISA is 0.63 mg mL-1. The results demonstrated that the negative-charge CDs have potential against multi-drug resistant Staphylococcus aureus (S. aureus), and may serve as alternatives for therapy in the future.

Comparative investigation into effects of ZrO2 and Al2O3 addition in fluorapatite laser-clad composite coatings on Ti6Al4V alloy.

Composite coatings consisting of fluorapatite mixed with 20 wt% yttria (3 mol%) stabilized cubic phase zirconia (c-ZrO2, 3Y-TZP) or 20 wt% alumina (α-Al2O3) were deposited on Ti6Al4V substrates using a Nd:YAG laser cladding system. The interface morphology, phase composition, micro-hardness and biological properties of the two coatings were examined and compared. The results showed that the fluorapatite/Al2O3 specimen underwent a greater inter-diffusion at the interface between the coating layer and the transition layer than the fluorapatite/ZrO2 specimen. During the cladding process, the ZrO2 and Al2O3 components of the coating were completely decomposed or underwent phase transformation. In addition, the fluorapatite was partially decomposed. For both specimens, the coating layers contained fluorapatite, CaF2 and CaTiO3 phases. The coating layer of the fluorapatite/ZrO2 specimen additionally contained TTCP, CaO, CaZrO3 and m-ZrO2 (monoclinic phase), while that of the fluorapatite/Al2O3 specimen contained ß-TCP, CaAl2O4 and θ-Al2O3. The average micro-hardness of the fluorapatite/ZrO2 coating layer (1300 HV) was approximately 200 HV higher than that of the fluorapatite/Al2O3 coating layer (1100 HV). Both specimens generated dense bone-like apatite following immersion in simulated body fluid for 3 days. In other words, both specimens had a good in vitro bioactivity. However, the fluorapatite/ZrO2 specimen showed a better initial attachment and spread of osteoblast-like osteosarcoma MG63 cells than the fluorapatite/Al2O3 specimen in in vitro biocompatibility tests performed for 24 h.

Comparison of EMG activity between maximal manual muscle testing and cybex maximal isometric testing of the quadriceps femoris.

Two methods have been used to produce a maximal voluntary isometric contraction (MVIC) of the superficial quadriceps femoris muscles for normalization of electromyographic (EMG) data. The purposes of this study were to compare the myoelectic activity of MVIC of manual muscle testing (MMT) versus Cybex maximal isometric testing. Eighteen normal subjects were recruited. MMT and Cybex testing for MVIC of the dominant leg were performed. EMG activities of the vastus medialis, vastus lateralis and rectus femoris were recorded during MMT and Cybex trials. EMG amplitude and median frequency obtained from the two methods (MMT and Cybex testing) were used for statistical analysis of these three muscles. Statistically, the difference in the mean of the EMG signal amplitude and median frequency between MMT and Cybex testing were not significant. Considering cost and time, MMT for MVIC technique appears to be reliable and highly valuable.

Effects of Laser Power Level on Microstructural Properties and Phase Composition of Laser-Clad Fluorapatite/Zirconia Composite Coatings on Ti6Al4V Substrates.

Hydroxyapatite (HA) is one of the most commonly used materials for the coating of bioceramic titanium (Ti) alloys. However, HA has poor mechanical properties and a low bonding strength. Accordingly, the present study replaces HA with a composite coating material consisting of fluorapatite (FA) and 20 wt % yttria (3 mol %) stabilized zirconia (ZrO2, 3Y-TZP). The FA/ZrO2 coatings are deposited on Ti6Al4V substrates using a Nd:YAG laser cladding system with laser powers and travel speeds of 400 W/200 mm/min, 800 W/400 mm/min, and 1200 W/600 mm/min, respectively. The experimental results show that a significant inter-diffusion of the alloying elements occurs between the coating layer (CL) and the transition layer (TL). Consequently, a strong metallurgical bond is formed between them. During the cladding process, the ZrO2 is completely decomposed, while the FA is partially decomposed. As a result, the CLs of all the specimens consist mainly of FA, Ca4(PO4)2O (TTCP), CaF2, CaZrO3, CaTiO3 and monoclinic phase ZrO2 (m-ZrO2), together with a small amount of θ-Al2O3. As the laser power is increased, CaO, CaCO3 and trace amounts of tetragonal phase ZrO2 (t-ZrO2) also appear. As the laser power increases from 400 to 800 W, the CL hardness also increases as a result of microstructural refinement and densification. However, at the highest laser power of 1200 W, the CL hardness reduces significantly due to the formation of large amounts of relatively soft CaO and CaCO3 phase.