Evaluating musculoskeletal conditions of the lower limb and understanding the pathophysiology of complex bone kinematics is challenging. Static images do not take into account the dynamic component of relative bone motion and muscle activation. Fluoroscopy and dynamic MRI have important limitations. Dynamic CT (4D-CT) is an emerging alternative that combines high spatial and temporal resolution, with an increased availability in clinical practice. 4D-CT allows simultaneous visualization of bone morphology and joint kinematics. This unique combination makes it an ideal tool to evaluate functional disorders of the musculoskeletal system. In the lower limb, 4D-CT has been used to diagnose femoroacetabular impingement, patellofemoral, ankle and subtalar joint instability, or reduced range of motion. 4D-CT has also been used to demonstrate the effect of surgery, mainly on patellar instability. 4D-CT will need further research and validation before it can be widely used in clinical practice. We believe, however, it is here to stay, and will become a reference in the diagnosis of lower limb conditions and the evaluation of treatment options. Cite this article:
The COVID-19 virus is a tremendous burden for the Italian health system. The regionally-based Italian National Health System has been reorganized. Hospitals' biggest challenge was to create new intensive care unit (ICU) beds, as the existing system was insufficient to meet new demand, especially in the most affected areas. Our institution in the Milan metropolitan area of Lombardy, the epicentre of the infection, was selected as one of the three regional hub for major trauma, serving a population of more than three million people. The aims were the increase the ICU beds and the rationalization of human and structural resources available for treating COVID-19 patients. In our hub hospital, the reorganization aimed to reduce the risk of infection and to obtained resources, in terms of beds and healthcare personnel to be use in the COVID-19 emergency. Non-urgent outpatient orthopaedic activity and elective surgery was also suspended. A training programme for healthcare personnel started immediately. Orthopaedic and radiological pathways dedicated to COVID-19 patients, or with possible infection, have been established. In our orthopaedic department, we passed from 70 to 26 beds. Our goal is to treat trauma surgery's patient in the “golden 72 hours” in order to reduce the overall hospital length of stay. We applied an objective priority system to manage the flow of surgical procedures in the emergency room based on clinical outcomes and guidelines. Organizing the present to face the emergency is a challenge, but in the global plan of changes in hospital management one must also think about the near future. We reported the Milan metropolitan area orthopaedic surgery management during the COVID-19 pandemic. Our decisions are not based on scientific evidence; therefore, the decision on how reorganize hospitals will likely remain in the hands of individual countries.