What is the primary risk associated with sedentary behavior during recovery from a hip fracture in older patients?

The primary risk associated with sedentary behavior during recovery from a hip fracture in older patients is blood clots. After a hip fracture, especially in the elderly, immobility can significantly increase the risk of venous thromboembolism (VTE), which includes deep vein thrombosis (DVT) and pulmonary embolism (PE). When a patient remains inactive, the normal blood flow in the legs decreases, which can lead to clot formation in the veins.

While pneumonia, muscle atrophy, and joint stiffness are important secondary complications that can arise from prolonged immobility and lack of physical activity, they do not pose the immediate, life-threatening risk that blood clots do. For instance, pneumonia can occur due to reduced lung ventilation from lying supine for extended periods, but it typically develops over a longer time frame. Muscle atrophy might be a concern as well, since inactivity can lead to the wasting of muscle tissue, yet this is a gradual process rather than an acute risk. Joint stiffness can result from lack of movement, affecting the range of motion, but again, it is a lesser concern compared to the critical and potentially fatal ramifications of blood clots developing due to inactivity post-fracture.