Table 1.

Etiology, current treatments, and role of vasculature in the main pathologies affecting bone

	Etiology/risk factors	Current treatments	Role of vasculature
Osteoporosis, loss of bone density	Altered balance of bone remodeling: greater bone removal by osteoclasts and then production by osteoblasts [18]	Administration of bisphosphonates, which shorten osteoclast life span and inhibit bone resorption [19]	Possible link between decreased production of vasodilator molecules by endothelial cells and increased bone loss [20]
Osteoarthritis, progressive degeneration of cartilage and bone	Traumatic, congenital, postoperative, metabolic, endocrine; age, joint overuse, obesity are common risk factors [274]	Symptomatic treatments through physiotherapy, orthopedic aids and orthoses, pharmacotherapy, total joint replacement [275]	Increased vascularization and neoangiogenesis in the joint; increase in VEGF level in osteoarthritic chondrocytes [43]
Osteomyelitis, infection within bone	Infection by Staphylococcus aureus, but also by other Gram-negative cocci and Gram-positive bacilli [45]	Parenteral course of broad-spectrum antibiotics and surgical debridement[46]	Poor vascularity can cause both development of the infection and resistance to antibiotics [46]
Osteonecrosis, death of bone cells, arthritis, and destruction of bone	Inadequate vascular supply to the bone; long-term steroid treatment, alcohol abuse, joint injury, arthritis, cancer are common risk factors [52]	Nonsteroidal anti-inflammatory drugs to reduce pain and inflammation; bone surgery, grafting, and joint replacement [276]	Compromised subchondral microcirculation, vascular interruption, intravascular occlusion, and extravascular compression [277]
Fractures, loss of bone contiguity	Mainly trauma; osteoporosis, low mineral density, age, tumors are common risk factors [278–280]	Fracture reduction and immobilization; bone autograft, allograft, or synthetic materials [59]	Vascular supply is critical for fracture healing; VEGF treatment can enhance fracture repair [57]
Osteosarcoma, bone malignancy	Occurring mostly in the medullary cavity of long bones: environmental factors, chromosomal abnormalities, p53 mutation are common risk factors [72]	Depending on the stage, chemotherapy, radiation therapy, surgery (amputation, grafting, local excision) [281]	Vasculature is critical for tumor survival, osteosarcoma generally involves downregulation of anti-angiogenic factors [73, 74]

VEGF vascular endothelial growth factor