Infected Tibia Research Articles

Detecting Chronic Post-Traumatic Osteomyelitis of Mouse Tibia via an IL-13Rα2 Targeted Metallofullerene Magnetic Resonance Imaging Probe.

Differential diagnosis of chronic post-traumatic osteomyelitis (CPO) from aseptic inflammation remains challenging, since both pathological processes share similar clinical symptoms. Here we utilized a novel targeted metallofullerene nanoparticle based magnetic resonance imaging (MRI) probe IL-13-TAMRA-Gd3N@C80(OH)30(CH2CH2COOH)20 to detect CPO in mouse tibia via overexpressed IL-13Rα2 receptors. The functionalized metallofullerene was characterized by X-ray photoelectron spectroscopy. Upon lipopolysaccharide (LPS) stimulation, macrophage Raw 264.7 cells showed elevated IL-13Rα2 expression via immunofluorescence staining and increased MRI probe binding via built-in TAMRA fluorescence imaging. Trauma was induced in both tibia of mice and bacteria soaked suture was inserted into the right tibia to initiate infection. During the acute phase (1.5 weeks), luminol-bioluminescence imaging revealed much higher myeloperoxidase activity in the infected tibia compared to the sham. In the chronic phase (4 weeks), X-ray radiography illustrated bone deformation in the infected tibia compared to the sham. With T1 weighted sequences, the probe clearly exhibited hyperintensity in the infection foci at both acute and chronic phases, which was not observed in the sham tibia. Histological analysis revealed severe bone structural destruction and massive inflammatory cell infiltration in the infected tibia. Immunohistochemistry confirmed abundant expression of IL-13Rα2 in the infection site. In summary, we developed a noninvasive imaging approach to detect and differentiate CPO from aseptic inflammation using a new IL-13Rα2 targeted metallofullerene MRI probe. In addition, for the first time, IL-13Rα2 was investigated as a unique biomarker in the context of osteomyelitis. Our data established a foundation for the translational application of this MRI probe in the clinical differentiation of CPO.

Experience in fixation of infected non-union tibia by Ilizarov technique – a retrospective study of 42 cases

ObjectiveThe aim of the study is to evaluate the clinical and functional outcome in treatment of infected tibial nonunion by the Ilizarov method. MethodsThe authors retrospectively analyzed 42 patients with infected tibial nonunion with bone loss; shortening and deformity treated at this institution during the period of February 2012 to April 2015 were included in the study. The results were evaluated according to Association for the Study and Application of the Methods of Ilizarov (ASAMI) criteria. Pin tract infections were assessed by Moore and Dahl score. ResultsBone results were excellent in 60% of patients (n=25), good in 15% (n=6), fair in 25% (n=11), and poor in none. The functional results were excellent in 55% of patients, good in 30%, fair in 5%, and poor in 10%. The most common complication found in this study was pin tract infection. ConclusionIlizarov ring fixator still remains an excellent treatment modality for tibial nonunion, as it addresses the problems associated with the condition, although the procedure is cumbersome.

Successful management of infected tibia IL nail by debridement, lavage, and antibiotic impregnated v-nail

<p class="abstract"><strong>Background:</strong> Tibia is a most common subcutaneous long bone which is highly vulnerable for injury. Infected ILN tibia and non-union of tibia is much common in clinical practice which calls for challenging management protocols to control intramedullary infection. Considerable judgment is required to treat an infection in fracture with implant in situ. Mechanical stability and control of infections are two main factors in management of infected tibia with implant in situ. To remove infected material and bio-film by serial reaming of medullary canal, thorough lavage and local debridement of infected fracture site and sinuses is essential and must before inserting antibiotic impregnated nail. According to pharmacokinetic studies, antibiotic delivery from antibiotic impregnated bone cement is 200 times higher concentration than systemic administration without any systemic side effects. Local high antibiotic concentration not only prevents bacterial growth but also prevents bio-film formation by bacteria. The study was conducted to evaluate the efficacy of antibiotic-impregnated PMMA cemented v-nails in managing infected IL Nailing tibia without any bony defects.</p><p class="abstract"><strong>Methods:</strong> They were 10 males and 02 females, with a mean age of 38.5 years. Mean follow-up was of 24 months (range 15-30 months). Mean duration for union was patients were followed up at 4, 8, 12 weeks and 3, 6, 9 and 12 months interval. Functional results were evaluated with regards to control of infection, bony union, deformity, limb length discrepancy and complications (intra and post-operative).<strong></strong></p><p class="abstract"><strong>Results:</strong> Radiological and functional outcome assessed according to complications treated accordingly. </p><strong>Conclusions:</strong> IL nail tibia with infection can be treated effectively if control of infection by debridement and mechanical stability (by v-nail), prevention of bacterial growth by antibiotic impregnated V-nail. Control of infection after debridement is addressed by antibiotic impregnated v-nail is the main crux of treatment. After control of infection cemented V-nail is exchanged with standard IL-nail. Bone grafting is optional, if after exchange nailing there is no sign of union by 8 weeks. Insertion of antibiotic impregnated cemented V-nails combined with adequate debridement; lavage and systemic antibiotic administration significantly contribute to infection control after intramedullary nailing.

Prospective study of infected non-union of long bones treated by Antibiotic impregnated intramedullary nailing

Background: In a era of high velocity injuries, compound fractures are very common in orthopaedic practice n despite of preventive measures taken pre operatively and post operatively, infected non unions still common and they pose real challenge to the treating surgeon and makes the patient debilitating. In infected non-union case, the preference has to be given to eradication of the infection before aiming to achieve fracture union. Many methods of treatment have been described in the past including ilizarov fixator and Antibiotic cement impregnated intramedullary nailing(ACIIMN). Sustained and gradual release of heat stable antibiotics which are mixed with the bone cement at a high concentration and coating it on Intramedullary nail(ACIIMN) has gained popularity among the techniques used to treat infected non unions. Our study is aimed at summarizing our experience with the use of antibiotic cement-impregnated intramedullary nail (ACIIMN) for control of infection in cases of infected non-union. This is a report of series of 27 infected non union cases, both femur and tibia which were treated by Antibiotic cement impregnated intramedullary nailing(ACIIMN) in our institute. Aims and objectives: To evaluate the outcome of treatment of infected nonunions of long bones treated by Antibiotic cement impregnated intramedullary nailing(ACIIMN). Materials and Methods: Our’s is prospective study involving 27 cases of infected nonunions of long bones treated by Antibiotic cement impregnated intramedullary nailing(ACIIMN) at our institute from 2012- 2015. The outcome of procedure was evaluated with regards to infection control, deformity, bony union and limb length discrepancy etc. Results: Infection was eradicated in 23 cases with ACIIN and the fractures united. In 4 cases, though the infection was controlled with ACIIN, they required subsequent procedures like exchange nailing with bone grafting to achieve bony union. Conclusion: Antibiotic cement impregnated nailing is a very simple yet economical and very effective procedure than the other methods in treatment of infected non-unions of long bones. Keywords: long bones, Infected non-union, antibiotic cement impregnated intramedullary nail

Bifocal corticotomy and bone transport for large segmental defects of the infected tibia and soft tissue

Objective To evaluate the techniques of bifocal corticotomy and bone transport for large segmental defects of the infected tibia and soft tissue and their complications as well. Methods From May, 2009 to May, 2014, 25 patients with large segmental defects of the infected tibia and soft tissue were treated at our center. They were 23 males and 2 females, from 2 to 52 years of age (average, 31.2 years). All the cases were Gustilo type Ⅲ B. The defect size of the soft tissue ranged from 8 cm × 4 cm to 24 cm × 12 cm; the length of tibia defects was from 8.5 cm to 18.2 cm, averaging 12.3 cm. After debridement, the tibia was fixated with Ilizarov external fixator. Bifocal corticotomy was performed on the proximal and distal tibial metaphyses simultaneously. The transporting speeds for proximal and distal tibial segment were 1 mm/d and 0.6 mm/d initially, and lowered to 0.5~0.6 mm/d later until the 2 bone segments connected. The bone transport lasted for 40 to 150 days, averaging 69.6 days. Results The patients were followed up for 12 to 72 months (average, 26.6 months). The soft tissue wound healed uneventfully and the bone defects were reconstructed. Of the 25 cases, 22 obtained primary bone union. Nonunion of the bone segments occurred in one, wound infection and osteogenesis imperfect in bone lengthening area occurred in one, and cut and pull-out of K-wires in the osteoporotic tibial ends occurred in one. These complications were treated accordingly before bone union was achieved. The other complications were also treated accordingly, including serious pin tract infection in 2 cases, re-fracture after removal of the external fixator in one, and shift of the tibial alignment in 2 cases. Conclusions Bifocal corticotomy can decrease bone transport time for large segmental defects of the tibia and soft tissue. During the long treatment period, a surgeon must pay much attention to the technical details and management of complications. Key words: Tibia; Bone lengthening; Complications; Ilizarov technique

18-Fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography scan for monitoring the therapeutic response in experimental Staphylococcus aureus foreign-body osteomyelitis.

Background18-Fluoro-2-deoxy-d-glucose positron emission tomography combined with computed tomography (18F-FDG PET/CT) scan is useful for diagnosis of osteoarticular infections. Whether 18F-FDG PET/CT scanning may be used for therapeutic monitoring is not clear. The objective of this study was to develop 18F-FDG PET/CT scanning for monitoring therapeutic response to antimicrobials in experimental Staphylococcus aureus osteomyelitis.MethodsA total of 22 rabbits were studied. In 20 animals, the right tibia was inoculated intraoperatively with S. aureus. Two control animals were inoculated with normal saline. A needle was placed in the tibia as a foreign body. Infection was allowed to develop for 21 days when 18F-FDG PET/CT was performed, the needle was removed, and bone specimens were cultured to confirm infection. Antimicrobial therapy with daptomycin was initiated in all successfully infected animals for 1, 3, or 6 weeks. Following completion of treatment, a second 18F-FDG PET/CT was performed, animals were euthanized, and infected tibias were harvested for quantitative cultures and histology. A positive scan was defined as 18F-FDG signal activity greater in the infected tibia than that of the contralateral non-infected control tibia. Therapeutic response was measured by the change of 18F-FDG signal activity in the infected tibia.ResultsAll successfully infected animals (n = 14), with microbiologically and/or histologically confirmed osteomyelitis, had positive 18F-FDG PET/CT scans, while the two control animals had negative scans despite the presence of the foreign body [mean maximum standardized uptake value (SUVmax) (±SD) values 2.96 (±0.80) vs. 1 (±1.10), respectively, P = 0.04]. In the 14 successfully infected animals, the mean SUVmax was significantly higher in the infected compared to the uninfected tibia (P < 0.0001). A SUVmax of 1.4, when used as a cutoff for infection, yielded a diagnostic accuracy of 93 %. At the end of treatment, successfully treated animals and saline controls had a negative 18F-FDG PET/CT scan (n = 4), while animals with persistent infection despite treatment (n = 12) had a positive 18F-FDG PET/CT scan (SUVmax 1.0–3.0) (p < 0.001). SUVmax values were significantly reduced after 42 days of treatment from 3.15 ± 0.5 (day 7) to 1.71 ± 0.37 (day 42) (p = 0.05).Conclusions18F-FDG PET/CT scan is a sensitive and specific tool in therapeutic monitoring of experimental foreign-body osteomyelitis.

Impact of prophylactic CpG Oligodeoxynucleotide application on implant-associated Staphylococcus aureus bone infection

TLR-9 ligand CpG oligodeoxynucleotide type B (CpG ODN) induces a proinflammatory environment. We evaluated the effects of a preoperative CpG ODN application in an implant-associated Staphylococcus aureus bone infection model by monitoring bacterial loads and cytokine and chemokine levels.A total of 95 rats were used in four different groups: CpG ODN group (group 1; n=25), non-CpG-ODN group (group 2; n=25); saline pretreatment (group 3; n=25), and one uninfected group (group 4; n=20). A single dose of CpG-ODN was administered to the left tibialis anterior muscle 3days prior to surgery and the tibia midshaft was osteotomized, stabilized by an intramedullary implant and subsequently contaminated with 103 colony forming units (CFUs) of S. aureus in groups 1–3. The osteotomy gap in animals of group 4 was not contaminated with S. aureus and those animals did not receive any pretreatment.CpG ODN administration resulted in significant reduction of the bacterial load in tibia tissue homogenate and on the implant surface on day 1 post-infection compared to non-CpG-ODN pretreatment (p<0.05; p<0.05). Reductions in bacterial CFUs, compared to non-treated (saline) controls, were approximately 67% and 77% for bone tissue homogenates and implants. No bacteria were detected in uninfected rats. Early reduction of bacterial CFUs in the tibia was accompanied by increased levels of proinflammatory mediators MIP-2, IL-1β and RANTES in bone tissue milieu of the CpG ODN treated group compared to controls.At day 42 post-infection, bone marrow tissue of rats pretreated with CpG ODN had comparable high bacterial CFU numbers as the non-CpG ODN or saline treated groups. Microbiological analysis of implants removed from CpG ODN treated rats showed high bacterial growth densities on their surfaces which were not different from those observed in controls. In histology, all animals of groups 1–3 showed established infected non-unions. Additionally, inflammatory mediator profiles in bone marrow homogenates of CpG ODN treated rats resembled those seen in infected controls.In this rat model, prophylactic administration of a single dose of CpG ODN, resulted in marked reduction of S. aureus load in the infected tibia during the initial stage of infection but failed to prevent development of chronic infection over time.

Infected nonunion of tibia and femur treated by bone transport.

ObjectiveThe objective of this study was to evaluate the effectiveness of the treatment of infected nonunion of tibia and femur by bone transport.Material and methodsWe retrospectively reviewed 110 patients with infected nonunion of tibia and femur treated by bone transport. Our study included 92 males and 18 females with a mean age of 38.90 years. The site of infected nonunion involved 72 tibias and 38 femurs. The mean length of the bone defects after radical debridement was 6.15 cm (range 3–13 cm).ResultsThe mean follow-up after removal of the apparatus was 23.12 months (14–46 months). Ten patients including seven patients with infected tibia nonunion and three patients with infected femur nonunion were lost to follow-up. All the patients achieved bone union, and no recurrence of infection was observed. The time of bone transport took a mean of 67.50 days (range 33 to 137 days), and the mean external fixation index was 1.48 months/cm (range 1.15–1.71 months/cm). According to Association for the Study and Application of the Method of Ilizarov (ASAMI) classification, bone results were excellent in 68, good in 28, fair in 12, and poor in 2; functional results were excellent in 37, good in 42, fair in 21, and no poor.ConclusionsOur study and the current evidence suggested that Ilizarov methods in the treatment of infected nonunion of tibia and femur acquired satisfied results. Radical debridement is the key step to control bone infection.

Cost of external fixation vs external fixation then nailing in bone infection.

To study the cost benefit of external fixation vs external fixation then nailing in treatment of bone infection by segment transfer. Out of 71 patients with infected nonunion tibia treated between 2003 and 2006, 50 patients fitted the inclusion criteria (26 patients were treated by external fixation only, and 24 patients were treated by external fixation early removal after segment transfer and replacement by internal fixation). Cost of inpatient treatment, total cost of inpatient and outpatient treatment till full healing, and the weeks of absence from school or work were calculated and compared between both groups. The cost of hospital stay and surgery in the group of external fixation only was 22.6 ± 3.3 while the cost of hospital stay and surgery in the group of early external fixation removal and replacement by intramedullary nail was 26.0 ± 3.2. The difference was statistically significant regarding the cost of hospital stay and surgery in favor of the group of external fixation only. The total cost of medical care (surgery, hospital stay, treatment outside the hospital including medications, dressing, physical therapy, outpatient laboratory work, etc.) in group of external fixation only was 63.3 ± 15.1, and total absence from work was 38.6 ± 6.6 wk. While the group of early removal of external fixation and replacement by IM nail, total cost of medical care was 38.3 ± 6.4 and total absence from work or school was 22.7 ± 4.1. The difference was statistically significant regarding the total cost and absence from work in favor of the group of early removal and replacement by IM nail. Early removal of external fixation and replacement by intramedullary nail in treatment of infected nonunion showed more cost effectiveness. Orthopaedic society needs to show the cost effectiveness of different procedures to the community, insurance, and health authorities.

Vancomycin containing PLLA/β-TCP controls experimental osteomyelitis in vivo.

BackgroundImplant-related osteomyelitis (IRO) is recently controlled with local antibiotic delivery systems to overcome conventional therapy disadvantages. In vivo evaluation of such systems is however too little.Questions/purposesWe asked whether vancomycin (V)-containing poly-l-lactic acid/β-tricalcium phosphate (PLLA/β-TCP) composites control experimental IRO and promote bone healing in vivo.MethodsFifty-six rats were distributed to five groups in this longitudinal controlled study. Experimental IRO was established at tibiae by injecting methicillin-resistant Staphylococcus aureus (MRSA) suspensions with titanium particles in 32 rats. Vancomycin-free PLLA/β-TCP composites were implanted into the normal and infected tibiae, whereas V-PLLA/β-TCP composites and coated (C)-V-PLLA/β-TCP composites were implanted into IRO sites. Sham-operated tibiae established the control group. Radiological and histological scores were quantified with microbiological findings on weeks 1 and 6.ResultsIRO is resolved in the CV- and the V-PLLA/β-TCP groups but not in the PLLA/β-TCP group. MRSA was not isolated in the CV- and the V-PLLA/β-TCP groups at all times whereas the bacteria were present in the PLLA/β-TCP group. Radiological signs secondary to infection are improved from 10.9 ± 0.9 to 3.0 ± 0.3 in the V-PLLA/β-TCP group but remained constant in the PLLA/β-TCP group. Histology scores are improved from 24.7 ± 6.5 to 17.6 ± 4.8 and from 27.6 ± 7.9 to 32.4 ± 8.9 in the CV-PLLA/β-TCP and the V-PLLA/β-TCP groups, respectively. New bone was formed in all the PLLA/β-TCP group at weeks 1 and 6.ConclusionsCV- and V-PLLA/β-TCP composites controlled experimental IRO and promoted bone healing.Clinical relevanceCV- and V-PLLA/β-TCP composites have the potential of controlling experimental IRO and promoting bone healing.

Daptomycin plus fosfomycin, a synergistic combination in experimental implant-associated osteomyelitis due to methicillin-resistant Staphylococcus aureus in rats.

The aim of this study was to evaluate the combination of daptomycin and fosfomycin in experimental chronic implant-associated osteomyelitis due to methicillin-resistant Staphylococcus aureus (MRSA). Infection was induced in the tibiae of rats by the insertion of a bacterial inoculum (1 to 5×10(8) CFU/ml) of a clinical MRSA isolate and a titanium wire. Four weeks after infection, each animal was assigned to a treatment group: daptomycin monotherapy at 60 mg/kg of body weight once daily (n=10), fosfomycin monotherapy at 40 mg/kg once daily (n=10), or daptomycin and fosfomycin combined at 60 mg/kg and 40 mg/kg, respectively, once daily (n=9). Ten animals were left untreated. After a 3-week treatment period, the animals were euthanized, and the infected tibiae and implants were processed for quantitative bacterial cultures. The bacterial cultures from bones were positive for MRSA in all animals in the untreated group, the daptomycin group, and the fosfomycin group, with median bacterial counts of 2.34×10(6) CFU/g bone, 1.57×10(6) CFU/g bone, and 3.48×10(2) CFU/g bone, respectively. In the daptomycin-fosfomycin group, 6 out of 9 animals were positive for MRSA, with a median count of 7.92 CFU/g bone. Bacterial cultures derived from the titanium wires were negative in the fosfomycin- and daptomycin-fosfomycin-treated groups. Based on bacterial counts in bones, treatment with daptomycin-fosfomycin was statistically significantly superior to all that of the other groups (P≤0.003). Fosfomycin was superior to daptomycin and no treatment (P<0.0001). No development of resistance was observed in any treatment arm. The combination of daptomycin and fosfomycin demonstrated synergism against MRSA in experimental implant-associated osteomyelitis.

99mTc]cFLFLF for Early Diagnosis and Therapeutic Evaluation in a Rat Model of Acute Osteomyelitis.

Early diagnosis and therapeutic monitoring of acute osteomyelitis (AO) is challenging. Here, we use a polyethylene glycol (PEG)ylated chemotactic peptide cinnamoyl-F-(D)L-F-(D)L-F (cFLFLF) conjugated with hydrazinonicotinamide (HYNIC) and labeled with Tc-99m ([(99m)Tc]cFLFLF) to image AO in a rat model and to validate its efficacy in early diagnosis and therapeutic evaluation of AO. Forty rats were divided into eight groups of five each. Groups A, B, C, G, and H were AO models, and D, E, and F were sham controls. Groups A and D underwent [(99m)Tc]cFLFLF scintigraphy, groups B and E underwent [(99m)Tc]methylene diphosphonate ([(99m)Tc]MDP) bone scan, and groups C and F underwent 2-deoxy-2-[(18)F]fluoro-D-glucose ([(18)F]FDG) positron emission tomography (PET)/computed tomography (CT) scan. [(99m)Tc]cFLFLF biodistribution was assessed in group G. The response to antibiotic therapy was evaluated using [(99m)Tc]cFLFLF scintigraphy in group H. Conventional radiographs were obtained following scintigraphy. Ratios of infected or sham-operated tibia to the opposite tibia (T/B) were calculated. Immediately after the imaging studies, infected tibias were excised and underwent histopathological analysis and immunohistochemistry staining. AO was present in all rats of groups A, B, C, G, and H. Total histological scores were not significantly different among groups A, B, and C (F = 0.34, p = 0.71). The biodistribution results revealed significant uptake and excellent retention of [(99m)Tc]cFLFLF in the infected tibia. [(99m)Tc]cFLFLF scintigraphy and [(99m)Tc]MDP bone scan both detected AO. The mean T/B ratio of [(99m)Tc]cFLFLF scintigraphy 1 h postinjection was 2.09-fold higher than that of [(99m)Tc]MDP bone scan (t = 13.81, p <0.001). The mean T/B ratio of [(18)F]FDG PET/CT scan was not significantly different from the control group F (t = 2.17, p = 0.062). [(99m)Tc]cFLFLF scintigraphy revealed a significant attenuation of inflammation in group H following a 3-week antibiotic treatment, which was verified by histopathological analysis and immunohistochemistry staining. Our results suggest that the specificity and image quality of [(99m)Tc]cFLFLF are superior to those of the [(99m)Tc]MDP and [(18)F]DFG imaging probes currently used for early diagnosis of AO. Furthermore, [(99m)Tc]cFLFLF was able to effectively evaluate the therapeutic response to antibiotic treatment of AO. Our data suggest that [(99m)Tc]cFLFLF is a promising imaging agent for detection of infectious diseases.

A modified chronic infection model for testing treatment of Staphylococcus aureus biofilms on implants.

Bacterial biofilms causing implant-associated osteomyelitis is a severe complication with limited antimicrobial therapy options. We designed an animal model, in which implant associated osteomyelitis arise from a Staphylococcus aureus biofilm on a tibia implant. Two bioluminescently engineered (luxA-E transformed), strains of S. aureus were utilized, Xen29 and Xen31. Biofilm formation was assessed with epifluorescence microscopy. Quantitative measurements were performed day 4, 6, 8, 11 and 15 post-surgery. Bacteria were extracted from the biofilm by sonication and the bacterial load quantified by culturing. Biofilm formation was evident from day 6 post-implantation. Mean bacterial load from implants was ∼1×104 CFU/implant, while mean bacterial load from infected tibias were 1×106 CFU/bone. Bioluminesence imaging revealed decreasing activity throughout the 15-day observation period, with signal intensity for both strains reaching that of the negative control by day 15 while there was no significant reduction in bacterial load. The model is suitable for testing antimicrobial treatment options for implant associated OM, as treatment efficacy on both biofilm and viable counts can be assessed.

In vivo expression of Streptococcus pyogenes immunogenic proteins during tibial foreign body infection.

Group A streptococcus (GAS) is an important human pathogen that causes a number of diseases with a wide range of severities. While all known strains of GAS are still sensitive to penicillin, there have been reports of antibiotic treatment failure in as many as 20% to 40% of cases. Biofilm formation has been implicated as a possible cause for these failures. A biofilm is a microbially derived, sessile community where cells grow attached to a surface or as a bacterial conglomerate and surrounded by a complex extracellular matrix. While the ability of group A streptococcus to form biofilms in the laboratory has been shown, there is a lack of understanding of the role of GAS biofilms during an infection. We hypothesized that during infections, GAS exhibits a biofilm phenotype, complete with unique protein expression. To test this hypothesis, a rabbit model of GAS osteomyelitis was developed. A rabbit was inoculated with GAS using an infected indwelling device. Following the infection, blood and tissue samples were collected. Histological samples of the infected tibia were prepared, and the formation of a biofilm in vivo was visualized using peptide nucleic acid fluorescent in situ hybridization (PNA-FISH) and confocal microscopy. In addition, Western blotting with convalescent rabbit serum detected cell wall proteins expressed in vitro under biofilm and planktonic growth conditions. Immunogenic proteins were then identified using matrix-assisted laser desorption ionization-time of flight tandem mass spectrometry (MALDI-TOF/TOF MS). These identities, along with the in vivo results, support the hypothesis that GAS forms biofilms during an infection. This unique phenotype should be taken into consideration when designing a vaccine or any other treatment for group A streptococcus infections.

Role of Ilizarov Ring Fixator in Infected Non Union Tibia

Background: The main surgical principle in the management of diaphyseal bone infection is thorough debridement of all nonviable tissue. None of the previously mentioned techniques afford surgeon the ability to correct deformities, eliminate antibiotic therapy, regenerate new bone without grafts and allow weight bearing during treatment. Objectives: The present study was conducted to evaluate the clinical follow-up results with Ilizarov technique using three parameters: union, infection and function and to know the complications if any faced by the patients. Material and Methods: This was a prospective study planned to evaluate the results of Ilizarov ring fixator on follow-up of 18 cases of either sex with infected non-union tibia. Average age of presentation was 34.5 years. Follow-up roentgenographs were used to assess alignment, bone contact and later callus formation. Healing status of the fracture was monitored using biplane roentgenographs, unchanged fracture alignment with loosening of the frame, absence of pain during ambulation with the frame destabilized. The data thus collected were analysed by using percentage and valid conclusions were drawn. Result: Pain and swelling were the most common complication after application of ilizarov ring fixator. In this study of 18 cases, 11 (61.11%) patients had excellent, 2 (11.11%) good, 5 (27.77%) fair and none had poor results as per criterion laid down by Catteneo et al. Conclusion: Ilizarov technique was found to be useful to progressively lengthen the extremity, achieve union without bone grafting and to correct deformities in infected non-union with or without bone gap.

Expanding the utility of modified vascularized femoral periosteal bone-flaps: An analysis of its form and a comparison with a conventional-bone-graft.

Vascularized medial femoral condyle (MFC) corticoperiosteal bone-flap is a well-accepted technique when dealing with tissue defects or infection. Its role in refractory conditions and in the possible use for options concerning modifications of this bone-flap compared to a conventional iliac bone graft (conventional-graft) are rarely discussed. We reviewed 21 consecutive cases concerning alternatives with some modifications of original MFC bone-flap surgery used to treat refractory conditions with bone defects, necrosis, or infection in the extremities. We present our devised approaches for this boneflap, and especially modifications of the grafted bone (including strut bone, perforator to the vastus medialis muscle, and the use of one vascular pedicle for some bone flaps) as well as the combined use of artificial bone as hybrid bone transplantation. We also compared the clinical results of 21 cases that received a conventional-graft. Following flap placement, 100% of the nonunion sites healed in an average of 2 months, which was significantly shorter than 5.5 months for the conventional-graft. The results showed the expanding possibility for options with regard to the form and options of this bone-flap as well as the shortening the duration of treatment, especially at the site of an infected distal tibia, insertion of the Achilles tendon on the posterior aspect of calcaneal osteomyelitis, distal end of the clavicle, clavicle or forearm with a bone defect, small bones with refractory conditions, and a femur without implant failure. However, it was not efficient for treating a forearm without bone defect.

Clinical course, complication rate and outcome of segmental resection and distraction osteogenesis after chronic tibial osteitis

IntroductionRadical segmental resection and subsequent distraction osteogenesis are considered the gold standard in the treatment of chronic tibial osteitis. We investigated the clinical course of treatment, particularly with respect to patients’ quality of life, and the complication rate associated with this technique. MethodsIn this prospective case series, 25 patients (22 men, 3 women, average age: 46 years) with chronic post-traumatic tibial osteitis were managed operatively from 2006 to 2009. Standardised treatment included bacterial eradication by segmental resection, bone transport using Ilizarov apparatus, and docking manoeuvre. The follow-up rates during bacterial eradication, bone transport, post docking, and complete osseous consolidation were 100% while follow-up two years after completed consolidation was 76%. The main outcome measurements consisted of the quality of life (Medical Outcomes Study 36-Item Short Form Health Survey (SF-36 score)) and the virtual analogue scale (VAS) of pain during the five stages of therapy. Additionally, all complications and difficulties were documented. ResultsThe average defect size was 5.3cm (range: 3–13). The healing index was 57 days per cm transport (range: 18–172). The overall treatment time averaged 93 weeks (range: 38–183). Patients suffered 22 minor and 13 major complications including one amputation. The average complication rate per patient consisted of 0.88 minor and 0.52 major complications. After the period of bone transport, the physical and mental component summary scores increased continuously. After completed consolidation, the average mental summary score was comparable to a normal collective. ConclusionsDistraction osteogenesis is challenging for both the patient and the surgeon. The arduous and demanding nature of the clinical course subjects the patient to considerable mental and physical stress. Thankfully, the average physical and mental status of health continues to improve during the clinical course of treatment. The 2-year success rate of the distraction osteogenesis in an infected tibia is 96%.

Knee extensor loss and proximal tibial soft tissue defect managed successfully with simultaneous medial gastrocnemius flap, saphenous fasciocutaneous flap and medial hemisoleus flap: a case report

IntroductionOpen fractures of the proximal tibia often pose serious challenges to the treating orthopedic surgeon. Management of these complex injuries becomes difficult if they are associated with damage to the extensor mechanism and an exposed knee joint. The scenario becomes more difficult to manage when the soft tissue defect extends to the middle third of the leg. We report a case where we used an extended medial gastrocnemius flap in combination with a saphenous artery fasciocutaneous flap and a medial hemisoleus flap for treatment of an infected proximal tibia fracture with loss of the extensor mechanism and soft tissue defect. To the best of our knowledge, combined use of these three flaps for the management of such injuries has not been reported elsewhere to date.Case presentationA 28-year-old Indian man presented to our Out-patient Department with complaints of pain and pus discharge from his left proximal leg for four weeks. He had sustained an open fracture of his left proximal tibia in a road traffic accident five weeks ago and had been operated on elsewhere. He had a stiff, painful knee with an infected wound of 4×4cm over the proximal third of his leg exposing infected, necrotic patellar tendon. He was successfully managed with debridement and simultaneously elevated flaps as described.ConclusionsThis procedure avoids the donor site morbidity associated with free flaps harvested from sites distant from the site of injury, and also does not need the expertise of microvascular reconstruction. To the best of our knowledge, this is also the first report of the combined use of three local flaps for knee extensor reconstruction and soft tissue coverage around the knee.

Treatment of infected non union tibia: A novel technique - lengthening using limb reconstruction system over intramedullary nail

Background: To assess combination of an intramedullary interlocking (IMIL) nail with limb reconstruction system (LRS) in cases of infected nonunion tibia and to show influence of nail in predicting good outcome. Materials and Methods: From 2009 to 2011, records of 20 patients (17 men and three women) aged 18 to 65 years (mean, 38.4 years) with infected nonunion of the tibia treated with the LRS over IMIL Nail technique were prospectively reviewed. According to Jain et al., patients were classified into five cases of A1, five cases of type A2, seven cases of type B1, and three cases of type B2. All cases underwent LRS and IMIL. Mean amount of target lengthening was 54.65 mm. The mean follow-up was 14 months. Results: Mean amount of tibia lengthening was 51.70 mm. Leg length equalization was achieved in 19 cases (±5). According to modified scoring by Paley et al., 12 patients had excellent results, three patients had good, four patients had fair outcome, and one patient had poor outcome. Mean distraction index was 0.97. Mean maturation index was 2.43. Mean consolidation index was 3.47. Mean healing index was 1.40. One case had proximal locking screw failure. One case developed pre mature consolidation as distraction was started at delayed period due to non-compliance. Two cases developed decreased dorsi flexion of ankle. Two cases required flap surgeries for cover of bone. One case had pin breakage, which had to be exchanged. One case developed re-infection. Conclusion: The advantages of this technique include complete eradication of infective foci, reduced risk of deformity during lengthening, decrease risk of fractures post external fixator removal and reduction of time required for external fixator use thus decreasing healing index: Number of days of external fixation required per centimetre of lengthening.

Daptomycin, Fosfomycin, or Both for Treatment of Methicillin-Resistant Staphylococcus aureus Osteomyelitis in an Experimental Rat Model

The in vivo activities of daptomycin, fosfomycin, and a combination of both antibiotics against a clinical isolate of methicillin-resistant Staphylococcus aureus (daptomycin MIC, 0.25 μg/ml; fosfomycin MIC, 0.5 μg/ml) were evaluated in a rat model of osteomyelitis. A total of 37 rats with experimental osteomyelitis were treated for 4 weeks with either 60 mg/kg of body weight of daptomycin subcutaneously once daily, 75 mg/kg fosfomycin intraperitoneally once daily, a combination of both drugs, or a saline placebo. After the completion of treatment, animals were euthanized, and the infected tibiae were processed for quantitative bacterial culture. Bone cultures were found to be positive for methicillin-resistant S. aureus in 9 of 9 (100%) animals of the placebo group, in 9 of 9 (100%) animals treated with daptomycin, in 1 of 10 (10%) fosfomycin-treated rats, and in 1 of 9 (22.2%) rats comprising the combination group. Results of bacterial counts in the bone samples were expressed as log(10) CFU/g of bone and analyzed by using the Mann-Whitney U test followed by Bonferroni's multiple-comparison test. Based on bacterial counts, treatment with daptomycin was significantly superior to placebo, although it remained inferior to treatment with fosfomycin. No synergistic or antagonistic effect was observed for the combination therapy. No development of resistance against daptomycin or fosfomycin was observed after the 4-week treatment period.