Sonication is superior to scraping for retrieval of bacteria in biofilm on titanium and steel surfaces in vitro

Background and purpose Low-virulence implant infections are characterized by bacterial colonization of the implant with subsequent biofilm formation. In these cases, soft tissue biopsies often prove to be culture negative. Consequently, detachment of the causative adherent bacteria is crucial for correct microbiological diagnosis. Using an in vitro model, we compared 4 methods of biofilm sampling from metal surfaces

Establishment of an in vivo rat model for chronic musculoskeletal implant infection

Background The aim of the study was to establish an experimental chronic musculoskeletal infection model in vivo characterized by (a) a small bacterial inoculum, (b) no general or local signs of infection, (c) several parallels (implants) in each animal and finally (d) a model that is technically easy to perform. Methods Bone xenografts with steel plates were implanted intramuscularly in rats. To the xenografts, different inocula of Staphylococcus aureus and two strains of Staphylococcus epidermidis were added. The animals were observed for different time periods before the removal of the xenografts. The xenografts and steel plates were subjected to quantitative bacterial culture after sonication. Additional steel plates were subjected to scanning electron microscopy (SEM) for visualization of biofilm formation. Results Inoculation of bone grafts with S. aureus did produce a pyogenic infection in all animals. A chronic infection was established in rats where the bone grafts were inoculated with S. epidermidis. A bacterial inoculum of 100 colony-forming units (CFU) of S. epidermidis was adequate as a minimum infective dose. During a period of up until 42 days, the animals infected with S. epidermidis had no general or local signs of infection. According to the results of the quantitative bacterial culture of sonicate fluid and SEM, a biofilm was developed on all implants. Conclusion In the present in vivo model, a very small bacterial inoculum succeeded in establishing a chronic musculoskeletal implant infection where a biofilm was formed on the implants. The experimental model is easy to perform and allows several implants in each animal. The model could be useful for the study of biofilm formation in vivo on different implants and different surfaces

NEW TECHNOLOGY FOR THE SUSPENSION OF TRANS-HUMERAL PROSTHESES – SISA (SUBFASCIAL IMPLANT SUPPORTED ATTACHMENT)

Trans-humeral amputees have for a long time had suspension methods that limit the functionality and use of the prosthesis. Due to the cone shape of the amputated stump, suspension of the prosthesis has mainly been done with harness securing the prosthesis to the body. The harness crosses the back and goes around the axilla of the contralateral shoulder. This may cause back and neck problems to-gether with pain in the contralateral axilla. The range of movement for positioning the prosthesis is also limited with the harnessed prosthesis. For the trans-humeral amputee, positioning the artificial arm is crucial to obtain the benefits the pros-thesis can give. Since the elbow joint is absent, the only way of positioning the prosthesis is by using the shoulder movements. If the prosthesis and its suspension limit the effective range of movement, the functionality of the prosthesis will be reduced. The prosthesis will in most cases hardly respond to internal - or external rotation of humerus due to the circular shape of the stump and no condyles at the distal end to effectuate the movement

Virus transmission during orthopedic surgery on patients with COVID-19 – a brief narrative review

Background and purpose — COVID-19 is among the most impactful pandemics that the society has experienced. Orthopedic surgery involves procedures generating droplets and aerosols and there is concern amongst surgeons that otherwise rational precautionary principles are being set aside due to lack of scientific evidence and a shortage of personal protective equipment (PPE). This narrative review attempts to translate relevant knowledge into practical recommendations for healthcare workers involved in orthopedic surgery on patients with known or suspected COVID-19. Patients and methods — We unsystematically searched in PubMed, reference lists, and the WHO’s web page for relevant publications concerning problems associated with the PPE used in perioperative practice when a patient is COVID-19 positive or suspected to be. A specific search for literature regarding COVID-19 was extended to include publications from the SARS epidemic in 2002/3. Results — Transmission of infectious viruses from patient to surgeon during surgery is possible, but does not appear to be a considerable problem in clinical practice. Seal-leakage is a problem with surgical masks. Due to the lack of studies and reports, the possibility of transmission of SARS-CoV-2 from patient to surgeon during droplet- and aerosol-generating procedures is unknown. Interpretation — Surgical masks should be used only in combination with a widely covering visor and when a respirator (N95, FFP2, P3) is not made available. Furthermore, basic measures to reduce shedding of droplets and aerosols during surgery and correct and consistent use of personal protective equipment is important

Virus transmission during orthopedic surgery on patients with COVID-19 – a brief narrative review

Background and purpose — COVID-19 is among the most impactful pandemics that the society has experienced. Orthopedic surgery involves procedures generating droplets and aerosols and there is concern amongst surgeons that otherwise rational precautionary principles are being set aside due to lack of scientific evidence and a shortage of personal protective equipment (PPE). This narrative review attempts to translate relevant knowledge into practical recommendations for healthcare workers involved in orthopedic surgery on patients with known or suspected COVID-19. Patients and methods — We unsystematically searched in PubMed, reference lists, and the WHO’s web page for relevant publications concerning problems associated with the PPE used in perioperative practice when a patient is COVID-19 positive or suspected to be. A specific search for literature regarding COVID-19 was extended to include publications from the SARS epidemic in 2002/3. Results — Transmission of infectious viruses from patient to surgeon during surgery is possible, but does not appear to be a considerable problem in clinical practice. Seal-leakage is a problem with surgical masks. Due to the lack of studies and reports, the possibility of transmission of SARS-CoV-2 from patient to surgeon during droplet- and aerosol-generating procedures is unknown. Interpretation — Surgical masks should be used only in combination with a widely covering visor and when a respirator (N95, FFP2, P3) is not made available. Furthermore, basic measures to reduce shedding of droplets and aerosols during surgery and correct and consistent use of personal protective equipment is important