Circulatory Diseases of Bone and Adjacent Soft Tissues

Abstract

The blood circulation of bone may be affected by a variety of insults, involving the arterial, capillary, sinusoidal or venous networks. Blood flow impedance may be due to mechanisms such as intraluminal obstruction, vascular compression or physical disruption of the vessel. In circulatory diseases of bone, imaging aims to demonstrate the reparative host response. Avascular necrosis (AVN) is a lesion in which an early diagnosis is vital in order that the appropriate management can be undertaken, with the femoral head being the most important affected site. There are numerous predisposing factors for AVN. The radiographic hallmark of femoral AVN is increased femoral head density in an otherwise normal joint. Established AVN is seen as collapse of the articular surface and fragmentation. MR imaging is the most accurate technique for diagnosing early AVN, demonstrating characteristic marrow changes. Trauma-induced AVN may affect specific sites, following injuries such as the scaphoid and lunate fractures, and slipped capital femoral epiphysis. Spontaneous osteonecrosis of the knee (SONK) affects the weight-bearing surface of the medial femoral condyle. AVN precursor syndromes include regional osteoporosis, reflex sympathetic dystrophy, transient osteoporosis and regional migratory osteoporosis. Osteochondroses related to osteonecrosis include Legg-Calve-Perthes disease, Kienbock disease, Freiberg infraction, Kohler disease and osteochondritis dissecans. Miscellaneous vascular disease that affects the musculoskeletal system encompass, frostbite, thermal and electrical injuries, compartment syndrome/myonecrosis, venous insufficiency of soft tissue, and ischemic fasciitis.