OBJECTIVE: When the pedicle screw insertion technique is failed or not applicable, C7 intralaminar screw insertion method has been used as an alternative or salvage fixation method recently. However, profound understanding of anatomy is required for safe application of the bilaterally crossing laminar screw at C7 in clinic. In this cadaveric study, we evaluated the anatomic feasibility of the bilateral crossing intralaminar screw insertion and especially focused on determination of proper screw entry point. METHODS: The C7 vertebrae from 18 adult specimens were studied. Morphometric measurements of the mid-laminar height, the minimum laminar thickness, the maximal screw length, and spino-laminar angle were performed and cross-sectioned vertically at the screw entry point (spino-laminar junction). The sectioned surface was equally divided into 3 parts and maximal thickness and surface area of the parts were measured. All measurements were obtained bilaterally. RESULTS: The mean mid-laminar height was 13.7 mm, mean minimal laminar thickness was 6.6 mm, mean maximal screw length was 24.6 mm, and mean spinolaminar angle was 50.8+/-4.7degrees. Based on the measured laminar thickness, the feasibility of 3.5 mm diameter intralaminar screw application was 83.3% (30 sides laminae out of total 36) when assuming a tolerance of 1 mm on each side. Cross-sectional measurement results showed that the mean maximal thickness of upper, middle, and lower thirds was 5.0 mm, 7.5 mm, and 7.3 mm, respectively, and mean surface area for each part was 21.2 mm2, 46.8 mm2, and 34.7 mm2, respectively. Fourteen (38.9%) sides of laminae would be feasible for 3.5 mm intralaminar screw insertion when upper thirds of C7 spino-laminar junction is the screw entry point. In case of middle and lower thirds of C7 spino-laminar junction, 32 (88.9%) and 28 (77.8%) sides of laminae were feasible for 3.5 mm screw insertion, respectively. CONCLUSION: The vertical cross-sectioned area of middle thirds at C7 spinolaminar junction was the largest area and 3.5 mm screw can be accommodated with 77.8% of feasibility when lower thirds were the screw entry point. Thus, selection of middle and lower thirds for each side of screw entry point in spino-laminar junction would be the safest way to place bilateral crossing laminar screw within the entire lamina. This anatomic study result will help surgeons to place the screw safely and accurately.
Adult ; Cadaver* ; Humans ; Spine

BACKGROUND: It is important that hospitals conduct disaster drills to ensure prompt response in case of a pandemic and thereby prevent a biological disaster. METHODS: In a university hospital of Seoul, a drill was arranged by the members of the drill preparation team who were a part of the response team for infection control of novel influenza A (H1N1). The drill preparation team designed the scenario for the drill, made plans to resolve the potential problems that could occur during that scenario, and organized a survey team and a survey methodology. The scenario consisted of 2 modules: (1) for an intensive care unit and (2) for an emergency care center. The surveyors and field participants were evaluated after the drill exercise. RESULTS: This drill was conducted to improve the response to outbreaks of new infectious diseases. The drill event showed that the communication among the members responsible for the infection control was effective. However, the drill revealed certain drawbacks in the process; this drawbacks involved availability of adequate quarantine space, education on using personal protective equipments, assignment of medical and nonmedical staff, management of visitors, and installment of air-conditioners, heaters, and ventilation units in the areas with H1N1 outbreak. CONCLUSION: This drill helped to improve the process of infection control and overcome the drawbacks in the current process, and thereby helped in achieving positive outcome during the actual pandemic situation when the number of hospital visits and admissions because of H1N1 pandemic had rapidly increased. Although disaster plans and drills are not actively performed, the drill for infection control is essential because the risk for an outbreak of a new infectious disease is increasing.
Communicable Diseases ; Surveys and Questionnaires ; Dietary Sucrose ; Disasters ; Disease Outbreaks ; Emergency Medical Services ; Humans ; Infection Control ; Influenza, Human ; Intensive Care Units ; Mandrillus ; Pandemics ; Quarantine ; Ventilation