The Canadian Orthopaedic Trauma Society.

The Canadian Orthopaedic Trauma Society was started in an endeavour to answer the difficult problem of obtaining enough patients to perform top-quality research into fractures. By maintaining a high standard, including randomised study design, inclusivity, open discussion among surgeons and excellent long-term follow-up, this group has become a leader in the orthopaedic research community. This annotation describes the short history, important components and spirit necessary to build a research community or team which will function well despite the difficult research environment facing individual surgeons.

Assessment of fragment micromotion in distal femur fracture fixation with RSA.

To assess fragment micromotion in three fracture fixation constructs 18 composite femur models were sectioned to create AO-C3 fractures and fixed using the Less Invasive Stabilization System (LISS), Dynamic Condylar Screw (DCS), or the Condylar Buttress Plate (CBP). Tantalum beads were attached to each fracture fragment. The constructs were tested for permanent deformation after cyclical loading (amplitude = 242.2N) and elastic deformation during static loading with 490.5N. Radiographs were taken before loading and then after unloading to determine permanent deformation or during loading to determine elastic deformation. We used RSA to quantify the six degrees of freedom interfragmentary maximum total motion, strain, and stress. For maximum total motion the CBP had more permanent deformation and two failures, whereas the LISS underwent the greatest elastic deformation. LISS and CBP had the highest strain conditions in the fracture gap and LISS had the greatest stress movements between fragments, all of which exceeded the upper limits for bone healing. LISS and CBP may not be indicated for comminuted fractures due to the high degree of flexibility of the LISS, resulting in high stress and strain conditions and susceptibility to catastrophic failure and high strain conditions with the CBP.

The challenges of teaching universal precautions to multicultural, diverse patients and their family members.

Teaching universal precautions to culturally diverse groups, whether healthcare workers, patients, or family members, is a unique challenge. In the environment of acquired immune deficiency syndrome, it involves honest and realistic appraisal of the modes of transmission and the risks involved. In addition, we must understand the fears involved, as well as the cultural perspectives that may alter the perception of the situation. This article will discuss the many cultural problems, briefly review what information needs to be included in any educational program, and focus on how we can realistically assess the risks involved and communicate those risks to healthcare workers, patients, and family members. When these risks are addressed honestly and without fear, implementation of and compliance with universal precautions will become easier, both in acute care and home care settings.

Technetium pyrophosphate labelling following catheter shock: potential for a new intraoperative mapping technique.

Technetium pyrophosphate uptake at the site of catheter shock was studied in four patients and seven experimental dogs. Technetium pyrophosphate scintigraphy was performed following five catheter ablation attempts in humans at different cardiac sites, and following 24 J catheter shocks delivered in the right and left ventricles of seven dogs. In the patients, gamma camera imaging with tomographic reconstruction showed intense focal uptake at the sites of shock. The scans were positive from 1.5 to 5.5 h following ablation and stayed positive for up to five days. In the animals, the low energy shocks produced circumscribed areas of coagulation and contraction band necrosis. The binding of technetium pyrophosphate at these sites was confirmed by in vivo gamma camera imaging, epicardial counting with a 1.2 cm scintillation probe and ex vivo imaging. Ratios of focal binding to normal myocardial uptake of technetium pyrophosphate were calculated from the digital gamma camera images. In all cases, technetium pyrophosphate was bound to myocardial sites where transcatheter energies were delivered in both humans and dogs. Intraoperative localization of the origin of tachycardia in man may be facilitated by combining preoperative endocardial catheter mapping, catheter shock, radionuclide labelling of the site of shock and a search for the focus of radionuclide concentration during subsequent surgery.