Final answer:
The proximal tibia physis displaced fracture risks damaging the growth plate, leading to potential growth disturbances or angular deformities.
Step-by-step explanation:
When considering a proximal tibia physis displaced fracture, the structure that is at risk is the growth plate (physis), which is essential for the normal growth and development of the tibia. This type of fracture in the proximal tibia, which includes the medial and lateral condyles, tibial tuberosity, intercondylar eminence, and the soleal line, could potentially damage the growth plate leading to improper or stunted bone growth in a young patient. It is crucial to manage such fractures with care to prevent growth disturbances or angular deformities.