Background: Iatrogenic intraoperative fractures are preventable complications in total knee arthroplasty. As press-fit fixation becomes more popular, further investigation into risk factors is needed. Some authors have suggested that smaller femurs may be at higher risk in posterior-stabilized constructs owing to industry designs trending toward larger, constant box sizes that increase the amount of bone resection relative to bone stock. Methods: Finite element analysis (FEA) was used to investigate the effect of insertion of posteriorstabilized femoral components on stress distributions in small femurs and whether common bony preparation techniques could further affect risk for intraoperative fracture. The FEA results were validated with mechanical testing by loading to failure with varying resection depths of the distal femur and varying lateralization of the box cut. Results: With a standard distal resection depth and neutral box position, a decrease in femur size led to an increase in maximal von Mises stresses by 43.6% medially and 44.3% laterally. Box lateralization and increased distal resection depth had minimal changes on the maximal stresses (3.3% medially and À0.4% laterally) on average-sized femurs while having a much larger effect on the stress distribution in small femurs (118.3% medially and 6.7% laterally). Conclusions: A subset of intraoperative femur fractures is potentially preventable. Small femur sizes, especially ones that would require increased distal resection or change in implant positioning, may benefit from an alternative design without the need for a cam/post mechanism.

Previous studies have demonstrated that sterile equipment is frequently contaminated intraoperatively, yet the incidence of miniature c-arm (MCA) contamination in hand and upper extremity surgery is unclear. To examine this incidence, a prospective study of MCA sterility in hand and upper extremity cases was performed in a hospital main operating room (MOR) (n = 13) or an ambulatory surgery center operating room (AOR) (n = 16) at a single tertiary care center. Case length, MCA usage parameters, and sterility of the MCA through the case were examined. We found that MOR surgical times trended toward significance (p = 0.055) and that MOR MCAs had significantly more contamination prior to draping than AOR MCAs (p < 0.001). In MORs and AORs, 46.2 and 37.5% of MCAs respectively were contaminated intraoperatively. In MORs and AORs, 85.7 and 80% of noncontaminated cases, respectively, used the above hand-table technique, while 50 and 83.3% of contaminated MOR and AOR cases, respectively, used a below hand-table technique. Similar CPT codes were noted in both settings. Thus, a high-rate of MCA intraoperative contamination occurs in both settings. MCA placement below the hand-table may impact intraoperative contamination, even to distant MCA areas. Regular sterilization of equipment and awareness of these possible risk factors could lower bacterial burden.

Рязанский государственный медицинский университет им. акад. И.П. Павлова, г. Рязань В данной статье авторы сравнивают качество жизни пациентов после эндопротезирования тазобедренного сустава при бесцементной (группа 1) и цементной (группа 2) фиксации компонентов протеза. Получены схожие данные в обеих группах. Авторы рекомендуют бесцементное эндопротезирование тазобедренного сустава при переломе шейки бедренной кости как альтернативу цементному способу фиксации в условиях остеопороза.Ключевые слова: эндопротезирование тазобедренного сустава, качество жизни после эндопротезирования, бесцементная фиксация, цементная фиксация.