Final answer:
A fracture of the femoral neck can lead to avascular necrosis due to disrupted blood supply, often requiring surgical intervention and associating with high health care costs and increased morbidity and mortality.
Step-by-step explanation:
A possible consequence of a fracture of the femoral neck within the capsule of the hip joint is a serious complication known as avascular necrosis (AVN) or osteonecrosis. This occurs when there is a disruption of the blood supply to the femoral neck or head, which can lead to the death of bone and cartilage in these areas. Avascular necrosis may require surgical treatment, and is associated with high health care costs, increased morbidity and mortality rates, and the potential for life-threatening complications such as pneumonia, pressure ulcers, and thrombophlebitis leading to pulmonary embolism.