Aims. This study aimed to explore the role of small colony variants (SCVs) of Staphylococcus aureus in intraosseous invasion and colonization in patients with periprosthetic joint infection (PJI). Methods. A PJI diagnosis was made according to the MusculoSkeletal Infection Society (MSIS) for PJI.
Background. Systemically administered vancomycin may provide insufficient target-site concentrations. Intraosseous vancomycin administration has the potential to overcome this concern by providing high target-site concentrations. Aim. To evaluate the local
Tourniquet is widely used in orthopedic surgery to reduce intraoperative bleeding and improve visualization. We evaluated the effect of tourniquet application on both peri- and postoperative cefuroxime concentrations in subcutaneous tissue, skeletal muscle, calcaneal cancellous bone, and plasma. The primary endpoint was the time for which the free drug concentration of cefuroxime was maintained above the clinical breakpoint minimal inhibitory concentration (T>MIC) for Ten patients scheduled for hallux valgus or hallux rigidus surgery were included. Microdialysis catheters were placed for sampling of cefuroxime concentrations bilaterally in subcutaneous tissue, skeletal muscle, and calcaneal cancellous bone. A tourniquet was applied on the thigh of the leg scheduled for surgery. Cefuroxime (1.5 g) was administered intravenously as a bolus 15 minutes prior to tourniquet inflation, followed by a second dose 6 hours later. The mean tourniquet duration (range) was 65 (58; 77) minutes. Dialysates and venous blood samples were collected for 12 hours. For cefuroxime the T>MIC (4 μg/mL) ranged between 4.8–5.4 hours across compartments, with similar results for the tourniquet and non-tourniquet leg. Comparable T>MIC and penetration ratios were found for the first and second dosing intervals. We concluded that administration of cefuroxime (1.5 g) 15 minutes prior to tourniquet inflation is safe in order to achieve tissue concentrations above 4 µg/mL throughout surgery. A tourniquet application time of approximately 1 hour did not affect the cefuroxime tissue penetration in the following dosing interval.
The course of secondary fracture healing typically consists of four major phases including inflammation, soft and hard callus formation, and bone remodeling. Callus formation is promoted by mechanical stimulation, yet little is known about the healing tissue response to strain stimuli over shorter timeframes on hourly and daily basis. The aim of this study was to explore the hourly, daily and weekly variations in bone healing progression and to analyze the short-term response of the repair tissue to well-controlled mechanical stimulation. A system for continuous monitoring of fracture healing was designed for implantation in sheep tibia. The experimental model was adapted from Tufekci et al. 2018 and consisted of 3 mm transverse osteotomy and 30 mm bone defect resulting in an intermediate mobile bone fragment in the tibial shaft. Whereas the distal and proximal parts of the tibia were fixed with external fixator, the mobile fragment was connected to the proximal part via a second, active fixator. A linear actuator embedded in the active fixator moved the mobile fragment axially, thus stimulating mechanically the tissue in the osteotomy gap via well-controlled displacement being independent from the sheep's functional weightbearing. A load sensor was integrated in the active fixation to measure the force acting in the osteotomy gap. During each stimulation cycle the displacement and force magnitudes were recorded to determine in vivo fracture stiffness. Following approval of the local ethics committee, experiments were conducted on four skeletally mature sheep. Starting from the first day after surgery, the daily stimulation protocols consisted of 1000 loading events equally distributed over 12 hours from 9:00 to 21:00 resulting in a single loading event every 44 seconds. No stimulation was performed overnight. One animal had to be excluded due to inconsistencies in the load sensor data. The onset of tissue stiffening was detected around the eleventh day post-op. However, on a daily basis, the stiffness was not steadily increasing, but instead, an abrupt drop was observed in the beginning of the daily stimulations. Following this initial drop, the stiffness increased until the last stimulation cycle of the day. The continuous measurements enabled resolving the tissue response to strain stimuli over hours and days. The presented data contributes to the understanding of the influence of patient activity on daily variations in tissue stiffness and can serve to optimize rehabilitation protocols post fractures.
The formation of biomimetic environments using scaffolds containing cell recognition sequence and osteo-inductive factors in combination with bone cells offers tremendous potential for bone and cartilage regeneration. In tissues, collagen forms the scaffold by mediating the flux of chemical and mechanical stimuli. Recently, a synthetic 15-residue peptide P-15, related biologically to the active domain of type I collagen, has been found to promote attachment and the osteoblast phenotype of human dermal fibroblasts and periodontal ligament fibroblasts on particulate anorganic bone mineral (ABM). The aim of this study was to exam the ability of the collagen peptide, P-15, to promote human osteoprogenitor attachment, proliferation and differentiation on cell culture surfaces and 3-D scaffolds. Selected human bone marrow cells were cultured on particulate microporous anorganic bone mineral (‘pure ‘ hydroxyapatite based on x-ray diffraction standard JCPDS9-432) phase and polygalactin vicryl mesh adsorbed with or without P-15 in basal or osteogenic conditions. Cell adhesion, spreading and patterning were examined by light and confocal microscopy following incorporation of cell tracker green and ethidium homodimer fluorescent labels. Osteoprogenitor proliferation and differentiation was assessed by DNA content and alkaline phosphatase specific activity. Growth and differentiation on 3-D ABM structures were examined by confocal and scanning electron microscopy (SEM). P-15 promoted human osteoprogenitor cell attachment and patterning on particulate bovine anorganic bone mineral phase and polygalactin vicryl mesh over 5–24 hours compared to culture on ABM and vicryl mesh alone as observed by photomicroscopy. Increased alkaline phosphatase specific activity was enhanced following culture on P-15 adsorbed matrices as recognized by enhanced expression of alkaline phosphatase, type I collagen, osteocalcin and cfba-1. The presence of mineralised bone matrix and extensive cell ingrowth and cellular bridging between 3-D ABM matrices and polygalactin vicryl mesh adsorbed with P-15 was observed by confocal microscopy and alizarin red staining. SEM confirmed the 3-D structure of newly formed cell constructs and cellular ingrowth on and between the P-15 modified inorganic bone mineral materials. Negligible cell growth was observed on ABM alone or polygalactin vicryl mesh alone. These observations demonstrate that the synthetic 15-residue collagen peptide, P-15, when adsorbed to ABM or polygalactin vicryl mesh, can stimulate human osteoprogenitor attachment and spreading. They also demonstrated that P-15 coupled 3-D matrices stimulate human osteoprogenitor differentiation and materialisation. The studies indicate that a synthetic analogue of collagen provides a biomimetic environment supportive for cell differentiation and tissue regeneration and indicate a potential for the use of extracellular matrix cue in the development of biomimetic environments for bone tissue engineering.
There has been significant advancement in the principles and practices of Tissue Banking in Australia over the last two years. Those advances relate to scientific development, regulatory modulation and inter-relationships between both Federal and State governments. Licencing issues
The Therapeutic Goods Administration of the Federal Department of Health and Aged Care Prior to 1997, Code of Ethics Formal government regulations Code for Good Manufacturing Practice Freeze dried materials First national licence Synthetic osteogenic proteins Centralisation of processing Number of Tissue Banks in Australia Considerable variation amongst Tissue Banks Financial statistics Difficulty in attaining and maintaining TGA licence Inherent inefficiencies Core activities Nonstandardisation of processing regimen International precedence Further potential benefits Consideration by Federal Government through Health Minister’s Advisory Council Probable end point
Aims. Flucloxacillin is commonly administered intravenously for perioperative antimicrobial prophylaxis, while oral administration is typical for prophylaxis following smaller traumatic wounds. We assessed the time, for which the free flucloxacillin concentration was maintained above the minimum inhibitory concentration (fT > MIC) for methicillin-susceptible Staphylococcus aureus in soft and bone tissue, after intravenous and oral administration, using microdialysis in a porcine model. Methods. A total of 16 pigs were randomly allocated to either intravenous (Group IV) or oral (Group PO) flucloxacillin 1 g every six hours during a 24-hour period. Microdialysis was used for sampling in cancellous and cortical
Aim. The incidence of orthopaedic methicillin-resistant staphylococcus aureus infections is increasing. Vancomycin may therefore play an increasingly important role in orthopaedic perioperative antimicrobial prophylaxis. Adequate antimicrobial concentrations at target site is essential for prevention of orthopaedic infections. Current studies investigating perioperative
Purpose: The purpose of this study was to determine the rate of clinically detected deep venous thrombosis and pulmonary embolism in patients with trunk or extremity
Introduction: Local recurrence of tumour following definitive treatment of
The aims of the treatment of tibial infected nonunions with
This study investigates the experience of one treatment centre with routine surveillance MRI following excision of sarcoma. Casenotes, MRI and histology reports for fifty-nine patients were reviewed. The primary outcome was the presence of local tumour recurrence and whether this was identified on surveillance or interval scanning. Forty-eight patients had a diagnosis of soft tissue sarcoma, the remaining 11 a primary bone tumour. Fifteen patients had local recurrence (25%). Eight were identified on surveillance scan, and the remaining 7 required interval scans. Surveillance scanning has a role in the early detection of local recurrence of
Introduction: The ‘Two Week Wait’ (2ww) process has been in force since the year 2000, with the subsequent implementation of 32-day diagnosis and 62-day treatment ‘rules’ in 2005. The aims of this study were to compile a definitive diagnostic profile of 2ww referrals, establish whether a histological biopsy was required for diagnosis and consider the current 2ww impact on services in our centre. Materials and Methods: Two hundred and nine patients were referred under 2ww to the North of England Bone and Soft Tissue Tumour service and prospectively recorded on a computerised multidisciplinary tumour database from 2006–8. The data was reviewed and verified using pathology, radiology reports and patient records. Results: Malignancy was diagnosed in 41(20%) patients. This comprised 21 soft tissue sarcomas (10%), 11 primary bone tumours (5%), and 9 metastatic bone tumours (4%). 63 (30%) benign
Introduction: The ‘Two Week Wait’ (2ww) process has been in force since the year 2000, with the subsequent implementation of 32-day diagnosis and 62-day treatment ‘rules’, as part of reforms to NHS cancer services. The aims of this study were to compile a definitive diagnostic profile of 2ww referrals, establish whether a histological diagnosis was required and consider the current 2ww impact on services in our centre. Methods: Two hundred and nine patients were referred to the North of England Bone and Soft Tissue Tumour service and prospectively recorded on a computerised multidisciplinary tumour database from 2006–8. The data was reviewed and verified using pathology, radiology reports and patient records. Results: Malignancy was diagnosed in 41(20%) patients (n=209). This comprised 21 soft tissue sarcomas (10%), 11 primary bone tumours (5%), and 9 metastatic bone tumours (4%). 63 (30%) benign
Introduction. The reduction of intraoperative blood loss during total knee arthroplasty (TKA) and total hip arthroplasty (THA) and even organ resection is an important factor for surgeons as well as the patient. In order to cauterize blood vessels to stop bleeding diathermy is commonly used and involves the use of high frequency and induces localized tissue damage and burning. Saline-coupled bipolar sealing RFE technology however has been shown to reduce tissue carbonization, however the dosage effects of RFE are not well known for both
Aims: Surgical treatment big defect of long
Purpose: Management of extensive tibial loss raises the question of indications for vascularised grafts. These techniques depend on the number of functional vascular trunks available. We developed a modified technique which allows using this type of graft without sacrificing the tibial pedicle, making it usable when only one trunk remains functional. We use the fibular arterial supply to bridge the remaining axis. The purpose of this work was to detail the modalities of this technique and provide early results. Material and method: Since 2000, we have reserved this technique for infected nonunion with loss of tibial tissue extending over 5 cm in patients who decline amputation. Four patients (four men, mean age 30 years) underwent the procedure. The initial trauma resulted from a motorcycle (n=3) or firearm (n=1) accident. The patients were referred to our unit within three months on the average. Prior treatments (cancellous graft in an open or intrafocal procedure) had failed in all patients who presented persistent infection. Antibiotics were administered until bone healing in all patients. Mean length of the gap was 10 cm (7 – 15 cm). The composite graft (skin and fibula with a vascularised fibular bundle) was raised from the contralateral limb and cross-leg anastomosed proximally and distally on the receiver anterior tibial bundle (all four cases). Results: All fractures consolidated between six and twelve months after initiating management of this technique.
Tibial fractures complicated by bone and/or soft tissue loss present a great challenge. Traditional methods of limb reconstruction are lengthy and may not yield satisfactory functional results. Despite its tremendous contribution to the management of this condition, the Ilizarov technique of bone transport has several problems and difficulties. The present study was carried out between 1997 and 2002 and included 21 patients with tibial fractures complicated by
Disease-free survival and local relapse rates in patients with malignant bone tumors are similar following limb salvage and amputation. However, while there has been considerable interest in comparative function after surgery, as assessed by clinicians, there is less information on patient-reported outcomes (PROs). Interest in PROs has evolved from recognizing the usefulness of measures of (health-related) quality of life (HRQL) and the acceptance that the “gold standard” in such assessments is provided by the individual reporting on his/her own health status. In the context of cancer and cancer-treatment, the importance of PROs is firmly embedded in the conduct of clinical trials, as documented by the Cancer Outcomes Working Group of the National Cancer Institute (NCI) in the USA. The NCI has promoted the development of appropriate instruments for eliciting and evaluating PROs through the Patient Reported Outcomes Measurement Information System (PROMIS). Similar initiatives have been undertaken in Canada, the United Kingdom, Western Europe and elsewhere. This topic was the subject of a series of reviews in a recent issue of the Journal of Clinical Oncology. Large studies in the United States and Canada revealed that, among survivors of cancer in childhood and adolescence, those who had had brain or bone tumors experienced the greatest compromise in physical performance, psychosocial outcomes and HRQL. Inclusion of PROs and measures of HRQL are still not routine in the design and conduct of clinical trials, and these are seldom used in regular day-to-day practice by clinical oncologists who have yet to be sufficiently persuaded of the added value provided by such determinations. However, the orthopedic community lead the way more than 25 years ago with an assessment of HRQL following treatment of sarcomas of the extremities (at that time refuting the commonly held belief that any therapy, no matter how “aggressive”, was better than limb amputation). That study enrolled only a small number of patients and the therapeutic (especially surgical) options have changed substantially in a generation, but a “marker” was established and the challenge to provide current evidence remains. Measures of HRQL that focus on orthopedic problems have been developed and subjected to recent rigorous review. But assessments are subject to many confounding factors such as age, gender, diagnosticdetails (tumor type, size and location), prior (neo-adjuvant) and subsequent therapy, the era of treatment and the time elapsed since surgical intervention. Sample sizes will need to be very large to address these variables. Despite the almost consistent problem of small samples, some common findings emerge. Females experience poorer outcomes than males; there can be improvement over time; and, insofar as they are comparable (candidates for amputation are seldom candidates for limb salvage surgery), the differences in HRQL among amputees, patients who had rotationplasties, and those who underwent limb salvage (with endoprostheses or bone grafts) are small. Measures of functional outcome and HRQL are neither fully inter-changeable nor mutually exclusive, and much remains to be learned from the measurement of PROs in patients with