Which long bone most commonly suffers a compound fracture and is notable for its poor blood supply?

The tibia is the long bone most commonly associated with compound fractures, particularly due to its anatomical position and the nature of activities that can lead to injuries. Its location in the lower leg makes it susceptible to high-impact trauma from falls, sports injuries, or vehicular accidents, which can easily result in an open fracture where the bone breaks through the skin.

Moreover, the tibia is noted for having a relatively poor blood supply compared to other long bones, especially in its mid-shaft region. This limited vascularity can impact healing and recovery, making fractures in this area particularly concerning. A reduced blood flow means that the healing process can be slower, and there is a higher risk for complications such as non-union or delayed healing.

In contrast, while the femur and humerus can also sustain compound fractures, they typically have better vascular supply thanks to their location and the surrounding musculature, which enhances blood flow. The fibula, although it can fracture as well, is smaller and more commonly involved in injuries that do not result in a compound fracture as often as the tibia. Therefore, the tibia is the best choice given its susceptibility to compound fractures alongside its poor blood supply.