Sustained Release of Antifungal and Antibacterial Agents from Novel Hybrid Degradable Nanofibers for the Treatment of Polymicrobial Osteomyelitis.

This study aimed to develop a drug delivery system with hybrid biodegradable antifungal and antibacterial agents incorporated into poly lactic-co-glycolic acid (PLGA) nanofibers, facilitating an extended release of fluconazole, vancomycin, and ceftazidime to treat polymicrobial osteomyelitis. The nanofibers were assessed using scanning electron microscopy, tensile testing, water contact angle analysis, differential scanning calorimetry, and Fourier-transform infrared spectroscopy. The in vitro release of the antimicrobial agents was assessed using an elution method and a high-performance liquid chromatography assay. The in vivo elution pattern of nanofibrous mats was assessed using a rat femoral model. The experimental results demonstrated that the antimicrobial agent-loaded nanofibers released high levels of fluconazole, vancomycin, and ceftazidime for 30 and 56 days in vitro and in vivo, respectively. Histological assays revealed no notable tissue inflammation. Therefore, hybrid biodegradable PLGA nanofibers with a sustainable release of antifungal and antibacterial agents may be employed for the treatment of polymicrobial osteomyelitis.

Superior Survivorship of Cementless vs Cemented Diaphyseal Fixed Modular Rotating-Hinged Knee Megaprosthesis at 7 Years' Follow-Up.

BACKGROUND: Total knee arthroplasty in the presence of a huge bone and soft-tissue defect is always a challenge. A rotating-hinged (RH) megaprosthesis is indicated for extensive soft-tissue loss with a huge bone defect such as a primary or metastatic neoplasm of the bone, repeat periprosthetic joint infection, or extensive trauma of the knee. However, the reported survivorship of RH megaprostheses is unsatisfactory. The aim of this study was to evaluate the survivorship of megaprostheses and the factors that contribute to implant survival. METHODS: A total of 103 RH knee megaprostheses were implanted in 85 patients between January 2001 and June 2013. Each prosthesis was a modular custom-made (CM) cemented or cementless fixed total knee system (United USTAR system). Clinical results and prosthesis survivorship were evaluated between the 2 groups. RESULTS: The overall survivorship of this CM knee megaprosthesis was 91% at 2 years, 83% at 5 years, and 68% at 10 years. The cumulative component survivorship was 87% in the cemented group and 96% in the cementless group at 2 years compared with 75% in the cemented group and 94% in the cementless group at 5 years. The failure mechanism included loosening in 5 and breakage in 6 patients in the cemented stem group. The survivorship of the cementless fixed component was significantly superior to that of the cemented fixed component. CONCLUSION: Our data suggest that modular RHCM knee megaprosthesis provides an acceptable clinical result. A diaphyseal long stem with cementless fixation was more reliable and durable than its cemented counterpart.

Reliability and validity of the Nurse Practitioners' Roles and Competencies Scale.

AIMS AND OBJECTIVES: The objective of this study was to test the reliability and construct validity of the Nurse Practitioners' Roles and Competencies Scale. BACKGROUND: The role of nurse practitioners has attracted international attention. The advanced nursing role played by nurse practitioners varies with national conditions and medical environments. To date, no suitable measurement tool has been available for assessing the roles and competencies of nurse practitioners in Asian countries. DESIGN: Secondary analysis of data from three studies related to nurse practitioners' role competencies. METHODS: We analysed data from 563 valid questionnaires completed in three studies to identify the factor structure of the Nurse Practitioners' Roles and Competencies Scale. To this end, we performed exploratory factor analysis using principal component analysis extraction with varimax orthogonal rotation. The internal consistency reliabilities of the overall scale and its subscales were examined using Cronbach's alpha coefficient. RESULTS: The scale had six factors: professionalism, direct care, clinical research, practical guidance, medical assistance, as well as leadership and reform. These factors explained 67·5% of the total variance in nurse practitioners' role competencies. Cronbach's alpha coefficient for the overall scale was 0·98, and those of its subscales ranged from 0·83-0·97. CONCLUSION: The internal consistency reliability and construct validity of the Nurse Practitioners' Roles and Competencies Scale were good. The high internal consistency reliabilities suggest item redundancy, which should be minimised by using item response theory to enhance the applicability of this questionnaire for future academic and clinical studies. RELEVANCE TO CLINICAL PRACTICE: The Nurse Practitioners' Roles and Competencies Scale can be used as a tool for assessing the roles and competencies of nurse practitioners in Taiwan. Our findings can also serve as a reference for other Asian countries to develop the nurse practitioner role.

Development of a Three-Dimensional (3D) Printed Biodegradable Cage to Convert Morselized Corticocancellous Bone Chips into a Structured Cortical Bone Graft.

This study aimed to develop a new biodegradable polymeric cage to convert corticocancellous bone chips into a structured strut graft for treating segmental bone defects. A total of 24 adult New Zealand white rabbits underwent a left femoral segmental bone defect creation. Twelve rabbits in group A underwent three-dimensional (3D) printed cage insertion, corticocancellous chips implantation, and Kirschner-wire (K-wire) fixation, while the other 12 rabbits in group B received bone chips implantation and K-wire fixation only. All rabbits received a one-week activity assessment and the initial image study at postoperative 1 week. The final image study was repeated at postoperative 12 or 24 weeks before the rabbit scarification procedure on schedule. After the animals were sacrificed, both femurs of all the rabbits were prepared for leg length ratios and 3-point bending tests. The rabbits in group A showed an increase of activities during the first week postoperatively and decreased anterior cortical disruptions in the postoperative image assessments. Additionally, higher leg length ratios and 3-point bending strengths demonstrated improved final bony ingrowths within the bone defects for rabbits in group A. In conclusion, through this bone graft converting technique, orthopedic surgeons can treat segmental bone defects by using bone chips but with imitate characters of structured cortical bone graft.

Can Anthropometry and Body Composition Explain Physical Fitness Levels in School-Aged Children?

Physical fitness (PF) is closely related to various health outcomes and quality of life among children. However, the associations between anthropometry, body composition (BC), and PF are not fully elucidated. This cross-sectional study aimed to investigate the associations between demographic metrics (age, sex), anthropometric measures (body mass index z-score (BMI z-score) waist/height ratio (WHtR)), BC parameters (body-fat percentage (BF%), muscle weight), and PF levels (800-m run, sit-and-reach, 1-min sit-ups, standing long jump) in school-aged children. Continuous variables were dichotomized by median splits. The results of 180 girls and 180 boys (mean age: 10.0 ± 0.7 years; mean BMI z-score: 0.366 ± 1.216) were analyzed. Multivariable linear regressions revealed that BF% (regression coefficient (B) = 3.4, 95% confidence interval (CI) = 2.5-4.3) was independently correlated with the 800-m run. Sex (B = 4.6, 95% CI = 3.0-6.3), age (B = 3.1, 95% CI = 1.9-4.3), and BMI z-score (B = -0.7, 95% CI = -1.4--0.1) were independently related to sit-and-reach. Age (B = 3.3, 95% CI = 2.0-4.7), BF% (B = -0.3, 95% CI = -0.4--0.2), and muscle weight (B = 0.7, 95% CI = 0.2-1.2) were independently associated with 1-min sit-ups. In addition to demography, anthropometry and BC provided additional information concerning some PF levels in school-aged children. Weight management and PF promotion should be addressed simultaneously in terms of preventive medicine and health promotion for children.

The Association between Metabolic Syndrome and Related Factors among the Community-Dwelling Indigenous Population in Taiwan.

The aim of this study was to conduct a community-based study with a view to construct a detailed analysis about metabolic syndrome and the related risk factors of the indigenous population. This was an observational, population-based and cross-sectional study that was conducted in remote villages of an indigenous community in northern Taiwan between 2010 and 2013. A total of 586 participants, 275 men and 311 women, were eligible for analysis. The participants underwent a questionnaire survey that included demographic and health behavior issues. An anthropometric assessment and measurements of blood pressure were carried out including serum biochemical variables. Metabolic syndrome (MetS) was defined by following the criteria provided by the modified Adult Treatment Panel III (ATP III) criteria of the National Cholesterol Education Program (NCEP). Univariate and multiple logistic regressions were used to identify the risk factors for metabolic syndrome. The standardized prevalence rates of substance use (cigarette smoking, alcohol drinking and betel nut chewing) were significantly higher than the general population regardless of whether it was northern, central or southern Taiwan and this was especially the case with betel nut chewing in women. The prevalence rate of metabolic syndrome was 42.9% in the indigenous population with 41.3% in men and 44.4% in women, which was higher than for urban Taiwanese. In the multiple logistic regression models, we found that the significant associated factors for metabolic syndrome were older age, lower education level, high levels of uric acid, alanine transaminase (ALT), gamma-glutamyl transferase (γ-GT) and creatinine. A higher prevalence rate of metabolic syndrome and substance use were observed in the indigenous population compared with urban Taiwanese, especially in women.

Beneficial Effect of TaON-Ag Nanocomposite Titanium on Antibacterial Capacity in Orthopedic Application.

PURPOSE: In this study, a novel oxygenated nanocomposite thin film, TaON-Ag, was investigated in vitro and in vivo to evaluate its biocompatibility and antibacterial ability. MATERIAL AND METHODS: The antibacterial ability of TaON-Ag nanocomposite-coated titanium (Ti) was evaluated using the Kirby-Bauer disk diffusion susceptibility test. The effects of TaON-Ag nanocomposite-coated metal on osteogenesis were further evaluated in an in vitro osteogenic culture model with rat marrow-derived mesenchymal stem cells (rMSCs). Furthermore, titanium rods coated with TaON-Ag were implanted into a rat femur fracture model either with or without osteomyelitis to investigate the effects of TaON-Ag in osteogenesis. RESULTS: The TaON-Ag-coated Ti exhibited an effective antibacterial effect against Staphylococcus aureus, coagulase-negative Staphylococcus, and the Gram-negative strains Escherichia coli and Pseudomonas aeruginosa. Using an osteogenic culture with rMSCs and a rat femoral fracture model, the TaON-Ag-coated Ti did not interfere with the ossification of rMSCs in vitro or during fracture healing in vivo. Field-emission scanning electron microscopy (FE-SEM) revealed that coating with TaON-Ag could inhibit pathogen adhesion and biofilm formation in both Staphylococcus aureus and Escherichia coli. CONCLUSION: Using the proposed novel oxygenation process, TaON-Ag nanocomposite-coated Ti yielded robust biocompatibility and antibacterial ability against common microorganisms in orthopedic infections, thereby demonstrating potential for use in clinical applications.

Osteogenesis of prefabricated vascularized periosteal graft in rabbits.

BACKGROUND: The role of vascularized periosteum flap as a graft and the factors stimulating it into osteogenic activity remain obscure. Few articles recognized its osteogenic process without the dependence of stress stimulation or bony contact. METHODS: We analyzed the osteogenic capacity of the vascularized periosteum in an ectopic site via the method of histomorphologic assessment. Pedicled vascularized periosteum was taken from the proximal tibia in rabbits and transferred to the soft tissue pouch in the distal thigh. Specimen was harvested for osteogenesis assessment at 4 weeks, 8 weeks, and 16 weeks. RESULTS: During macroscopic examination, all rabbits were dissected along the previous surgical wound in the distal femur. Dense osseous-like tissue was found in the prefabricated vascularized periosteum. The tissue sections showed red-mineralized matrix of Alizarin Red S staining increased neovascularization. CONCLUSIONS: The study results revealed the osteogenic capacity of prefabricating vascularized periosteum without the dependence of stress stimulation or its proximity to viable bone.

Effectiveness of a multi-faceted intervention among elementary school children.

Childhood obesity has been shown to be closely related to future obesity and comorbidities. As its prevalence and impact has increased significantly worldwide, researchers have focused on prevention and intervention. This study assessed a multifaceted intervention for elementary school children.A retrospective data collection with a cohort analysis was employed. A 16-week school-based intervention with nutritional intervention, physical activity, and behavioral education was designed and conducted by a multidisciplinary team for 1860 children aged 6 to 13 years. Basic information, anthropometrics, and physical fitness (PF) were recorded before and after the intervention. The differences compared with a reference group, and compared between subgroups, were analyzed.Significant favorable changes in body weight and composition were found. Children's height, weight, and muscle weight increased, whereas BMI, BMI z-score (zBMI), waist circumference, hip circumference, waist-hip ratio, waist-height ratio, body fat percentage, and visceral fat area decreased. Sit-ups and 800-m run time significantly improved. Girls exhibited a greater reduction in body weight outcomes; boys improved more in body composition and PF. Students with higher zBMI had a greater reduction in all anthropometrics; students with lower zBMI showed greater PF improvement, except for the 800-m run.The intervention improved weight measures, body composition, and PF. Subgroup differences suggested the need for sex- and weight-specific interventions.

Resorbable Beads Provide Extended Release of Antifungal Medication: In Vitro and In Vivo Analyses.

Fungal osteomyelitis has been difficult to treat, with first-line treatments consisting of implant excision, radical debridement, and local release of high-dose antifungal agents. Locally impregnated antifungal beads are another popular treatment option. This study aimed to develop biodegradable antifungal-agent-loaded Poly(d,l-lactide-co-glycolide) (PLGA) beads and evaluate the in vitro/in vivo release patterns of amphotericin B and fluconazole from the beads. Beads of different sizes were formed using a compression-molding method, and their morphology was evaluated via scanning electron microscopy. Intrabead incorporation of antifungal agents was evaluated via Fourier-transform infrared spectroscopy, and in vitro fluconazole liberation curves of PLGA beads were inspected via high-performance liquid chromatography. When we implanted the drug-incorporated beads into the bone cavity of rabbits, we found that a high level of fluconazole (beyond the minimum therapeutic concentration [MTC]) was released for more than 49 d in vivo. Our results indicate that compression-molded PLGA/fluconazole beads have potential applications in treating bone infections.

Two-stage revision arthroplasty for Mycobacterium Tuberculosis periprosthetic joint infection: An outcome analysis.

BACKGROUND: Mycobacterium tuberculosis periprosthetic joint infection (TBPJI) is a rare complication of hip/knee joint arthroplasty. The outcomes of hip/knee TBPJI treatment are still unreported. The objective of this study was to investigate the outcomes of hip/knee TBPJI following treatment with two-stage exchange arthroplasty. MATERIALS AND METHODS: From 2003 to 2013, 11 patients with TBPJI (six hips and five knees) were treated with two-stage exchange arthroplasty at our institution. We collected and analyzed variables including demographic data, comorbidities, microbiological data, duration of symptoms, and types of antibiotic used in bone cement. RESULTS: At the most recent follow-up, the success rate of two-stage exchange arthroplasty was 63.3% (7 of 11). All five knee treatments resulted in infection eradication and successful prosthesis reimplantation. However, only two hip TBPJI treatments resulted in successful outcomes; two patients died and two experienced chronic infection. Overall, secondary bacterial infections were common in patients with TBPJI (5 of 11 cases, 45.5%). Streptomycin in bone cement increased the success rate (83.33% vs. 40%). CONCLUSION: More than one third of the patients treated with two-stage exchange arthroplasty for TBPJI showed infection relapse or uncontrolled infection. Streptomycin-loaded interim cement spacers appeared to help ensure successful treatment. Routine M. tuberculosis culture is recommended when treating TBPJI in areas of high tuberculosis prevalence.

Novel solvent-free fabrication of biodegradable poly-lactic-glycolic acid (PLGA) capsules for antibiotics and rhBMP-2 delivery.

Osteomyelitis has been one of the most common causes of post-operative problems and complications despite the advances in surgical techniques and the availability of newly developed antibiotics. Local antibiotic and growth factor delivery devices for treatment of various surgical infections have been studied recently, especially in the case of orthopedic infections. The report was to develop novel solvent-free biodegradable capsules for antibiotics and growth factors delivery. To fabricate a biodegradable capsule, polylactide-polyglycolide copolymers were pre-mixed with vancomycin. The mixture was then compression molded and sintered to form a cylinder with a cover of 8 mm in diameter. After the addition of 1 and 10 microg recombinant bone morphogenetic protein (rhBMP-2) into the core, an ultrasonic welder was used to seal the capsules. An elution method was employed to characterize the in vitro release characteristics of the antibiotics and the rhBMP-2 over a 30-day period. The HPLC analysis and the bacterial inhibition test showed that biodegradable capsules released high concentrations and activity of vancomycin (well above the minimum inhibition concentration) in vitro for the period of time needed to treat bone infection; i.e. 4-6 weeks. In addition, the results of ELISA and ALP tests also suggested that the capsules released active rhBMP-2 for up to 30 days. By adopting this novel technique, we will be able to fabricate biodegradable capsules of various medicines for long-term drug deliveries.

The release of cefazolin and gentamicin from biodegradable PLA/PGA beads.

Infection has been one of the most common causes of problems and complications after the operation despite the advance in surgical techniques and the availability of newly developed antibiotics. Local antibiotic delivery beads for treatment of various surgical infections had been studied recently especially in osteomyelitis. This current paper used cefazolin sodium and gentamicin sulfate combined with biodegradable polymers (50:50 poly(DL-lactide):co-glycolide) as antibiotic beads for a long-term drug release. To manufacture an antibiotic bead, polylactide-polyglycolide copolymers were mixed with the antibiotics. The mixture was compressed and sintered at 55 degrees C to form beads of different sizes. The beads were placed in 3 ml of phosphate buffered saline and incubated at 37 degrees C. An elution method combined with a bacterial inhibitory test was employed to characterize the release rate of the antibiotics over a 30-day period. The results suggested that the biodegradable beads released high concentrations of antibiotic (well above the minimum inhibitory concentration) in vitro for the period of time needed to treat bone infection; i.e. 2-4 weeks. This provides advantages as a first line choice of long-term antibiotics for patients with osteomyelitis and various infections such as thoracic, abdominal, and pelvic infections, as well as for the prophylaxis of these infections.

Biodegradable drug-eluting nanofiber-enveloped implants for sustained release of high bactericidal concentrations of vancomycin and ceftazidime: in vitro and in vivo studies.

We developed biodegradable drug-eluting nanofiber-enveloped implants that provided sustained release of vancomycin and ceftazidime. To prepare the biodegradable nanofibrous membranes, poly(D,L)-lactide-co-glycolide and the antibiotics were first dissolved in 1,1,1,3,3,3-hexafluoro-2-propanol. They were electrospun into biodegradable drug-eluting membranes, which were then enveloped on the surface of stainless plates. An elution method and a high-performance liquid chromatography assay were employed to characterize the in vivo and in vitro release rates of the antibiotics from the nanofiber-enveloped plates. The results showed that the biodegradable nanofiber-enveloped plates released high concentrations of vancomycin and ceftazidime (well above the minimum inhibitory concentration) for more than 3 and 8 weeks in vitro and in vivo, respectively. A bacterial inhibition test was carried out to determine the relative activity of the released antibiotics. The bioactivity ranged from 25% to 100%. In addition, the serum creatinine level remained within the normal range, suggesting that the high vancomycin concentration did not affect renal function. By adopting the electrospinning technique, we will be able to manufacture biodegradable drug-eluting implants for the long-term drug delivery of different antibiotics.

Steady antibiotic release from biodegradable beads in the pleural cavity: an in vitro and in vivo study.

BACKGROUND: Inadequate localized drug concentrations and systemic adverse effects are among the concerns when regional infections are treated with systemic antibiotics. We designed and fabricated a poly(D,L)-lactide-co-glycolide (PLGA)-based biodegradable drug delivery system and evaluated the release of antibiotics both in vitro and in vivo. METHODS: PLGA copolymer and penicillin G sodium were mixed, compressed, and sintered to fabricate biodegradable antibiotic beads. The beads were placed in phosphate-buffered saline to test the characteristics of in vitro drug release. The beads then were introduced into the pleural cavities through chest tubes of six New Zealand white rabbits. Daily pleural effusion was collected to measure the antibiotic concentration and bacterial inhibitory characteristics. RESULTS: Forty percent of the penicillin was released in the first day in the in vitro study. The rest of the antibiotic was then gradually released in the following 30 days. All six animals survived the experiment. The initial surge of drug release was less significant in the pleural cavity than in the phosphate-buffered saline. The drug concentrations were well above the minimum inhibitory concentration breakpoint for penicillin susceptibility throughout the study period in both in vitro (30 days) and in vivo (14 days) studies. CONCLUSIONS: These preliminary findings demonstrated that the biodegradable PLGA antibiotic beads could achieve a fairly steady antibiotic release in the pleural cavity for at least 2 weeks. This drug delivery system may have the potential to serve as an adjuvant treatment of pleural cavity infection.

Sustainable release of vancomycin, gentamicin and lidocaine from novel electrospun sandwich-structured PLGA/collagen nanofibrous membranes.

This study investigated the in vitro release of vancomycin, gentamicin, and lidocaine from novel electrospun sandwich-structured polylactide-polyglycolide (PLGA)/collagen nanofibrous membranes. For the electrospinning of biodegradable membranes, PLGA/collagen and PLGA/vancomycin/gentamicin/lidocaine were separately dissolved in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP). They were then electrospun into sandwich structured membranes, with PLGA/collagen for the surface layers and PLGA/drugs for the core layer. After electrospinning, an elution method and HPLC assay were employed to characterize the in vitro release rates of the pharmaceutics over a 30-day period. The experiment showed that biodegradable nanofibrous membranes released high concentrations of vancomycin and gentamicin (well above the minimum inhibition concentration) for 4 and 3 weeks, respectively, and lidocaine for 2 weeks. A bacterial inhibition test was carried out to determine the relative activity of the released antibiotics. The bioactivity of vancomycin and gentamicin ranged from 30% to 100% and 37% to 100%, respectively. In addition, results indicated that the nanofibrous membranes were functionally active in responses in human fibroblasts. By adopting the electrospinning technique, we will be able to manufacture biodegradable biomimetic nanofibrous extracellular membranes for long-term drug delivery of various pharmaceuticals.

Augmentation of osteochondral repair with hyperbaric oxygenation: a rabbit study.

BACKGROUND: Current treatments for osteochondral injuries often result in suboptimal healing. We hypothesized that the combination of hyperbaric oxygen (HBO) and fibrin would be superior to either method alone in treating full-thickness osteochondral defects. METHODS: Osteochondral repair was evaluated in 4 treatment groups (control, fibrin, HBO, and HBO+fibrin groups) at 2-12 weeks after surgical injury. Forty adult male New Zealand white rabbits underwent arthrotomy and osteochondral surgery on both knees. Two osteochondral defects were created in each femoral condyle, one in a weight-bearing area and the other in a non-weight-bearing area. An exogenous fibrin clot was placed in each defect in the right knee. Left knee defects were left empty. Half of the rabbits then underwent hyperbaric oxygen therapy. The defects in the 4 treatment groups were then examined histologically at 2, 4, 6, 8, and 12 weeks after surgery. RESULTS: The HBO+fibrin group showed more rapid and more uniform repair than the control and fibrin only groups, but was not significantly different from the group receiving HBO alone. In the 2 HBO groups, organized repair and good integration with adjacent cartilage were seen at 8 weeks; complete regeneration was observed at 12 weeks. CONCLUSIONS: HBO significantly accelerated the repair of osteochondral defects in this rabbit model; however, the addition of fibrin produced no further improvement.

Management of late-diagnosed scaphoid fractures.

BACKGROUND: Scaphoid fractures are among the most common types of carpal bone injury; they can be easily overlooked in the acute stage. Scaphoid fractures detected in the subacute stage require a more meticulous and prompt approach, to prevent chronicity and regain wrist function. METHODS: The records of 30 patients were selected from 97 with scaphoid fractures surgically treated between 1994 and 2002. Fractures that were diagnosed between 2 weeks and 5 months (average, 2.2 months) after the injury were included. We report the fracture patterns and locations, as determined from radiographs, as well as the surgical methods used. The mean follow-up was 2.5 years. RESULTS: Oblique fractures (60%) were the most commonly overlooked fractures. Twenty-six patients (87%) underwent open surgery, and 23 (77%) required bone grafts. Percutaneous fixation was indicated for only four patients, whose fractures were reducible via either fluoroscopic or arthroscopic guidance. Osseous unions were achieved for 29 (97%) patients; these patients returned to their pre-injury level of activity. The average union time was 10.6 weeks. CONCLUSION: Oblique-type scaphoid fractures are potentially unstable and may result in detrimental sequelae if overlooked in the acute stage. Accurate diagnosis is possible through critical skepticism and the meticulous scrutiny of radiographs. Prompt surgical intervention is associated with promising outcomes.

Using low-intensity pulsed ultrasound to improve muscle healing after laceration injury: an in vitro and in vivo study.

The purpose of this study was to determine whether low-intensity pulsed ultrasound (LIPUS) could enhance the regeneration of myofibers and shorten the healing time in injured muscle. NIH C2C12 cells, a well-known myoblastic cell line, are subclones derived from the mouse myoblast cell line established from normal adult C3H mouse leg muscle. The cells differentiate rapidly and produce extensive contracting myotubes expressing characteristic muscle proteins. We exposed C2C12 cells to LIPUS therapy using the EXOGEN 2000+ system ultrasound apparatus (Exogen Inc., Piscataway, NJ, USA) with a total treatment of 20 min every 24 h. At intervals of 2, 4, 6 and 8 days, cell growth was measured by the increase in cell number and western blot analysis of myogenin and actin. Forty mice (C57BL10J+/+) were divided into five groups of eight animals each and used in the published laceration injury model. The gastrocnemius muscle of the left leg was lacerated in all the animals. The control group (sham ultrasound) did not undergo LIPUS therapy. The ultrasound 7-, 14-, 21- and 28-day groups (only changing the number of days during which the ultrasound was applied to the injured muscle) were treated with LIPUS (20 min/day) for 7, 14, 21 and 28 consecutive days, respectively. All animals were sacrificed at 4 weeks after the injury. Evaluation methods included muscle regeneration and muscle contractile properties. LIPUS therapy produced a significantly higher proliferative rate and cell number at days 6 and 8 (p < 0.05). Densitometric evaluation revealed an increase in myogenin and actin proteins in cells treated with LIPUS in the 4-, 6- and 8-day groups. The regeneration of myofibers, fast-twitch and tetanus of LIPUS-treated muscles (21 and 28 days) was significantly greater relative to control muscles. There was no major strength difference between the normal non-injured muscle and the group treated with LIPUS for 28 days. In conclusion, this was the first experimental study to show that LIPUS therapy is able to enhance the regeneration of myofibers with better physiologic performance in injured mice muscles after laceration, especially prior to postoperative week 4. Findings of this study demonstrate a scientific basis for future clinical trials and establish an indication for LIPUS in enhancing muscle healing after laceration injury.

Soft-tissue injury management and flap reconstruction for mangled lower extremities.

SUMMARY: The treatment for mangled lower extremities poses a clinical challenge for orthopaedic surgeons. The complexities of soft-tissue injury combined with open fractures and osteomyelitis have frequently resulted in amputation of the lower extremity. The current advances in soft-tissue flap reconstruction techniques have significantly improved the results of limb-salvage attempts. Understanding the reconstructive ladders around the zone of injury, debridement, timing and nuances of techniques regarding skin graft, local and distant flaps and microsurgical reconstruction is necessary to complete limb salvage in a timely and appropriate fashion. Various soft-tissue flap applications have been described, including emergent flow-through flap, acute soft-tissue flap, acute combined soft-tissue and bone flap, pedicle gastrocnemius/soleus flap, pedicle sural artery flap, soft-tissue flap for chronic osteomyelitis, composite osseous-myocutaneous flap for chronic osteomyelitis and free functioning muscle flap for functional reconstruction of mangled lower limbs. Clinical experience of 850 flaps reconstructions for mangled lower limbs in both acute and chronic stages has revealed that adequate application of flap technique was able to achieve quite acceptable results. This article provides a comprehensive review of the soft-tissue injury management and flap reconstruction for mangled lower limbs.