MRI Area of Interest Without IV Contrast MRI is the most sensitive and specific imaging modality for the diagnosis of osteonecrosis, with a sensitivity and specificity nearing 100% [24,28,42]. A meta-analysis of 43 studies for early detection of femoral head osteonecrosis reported a sensitivity of 93% and specificity of 91% [43]. MRI allows for characterization of the osteonecrosis including location, volume, and presence of associated bone marrow edema or joint effusion [13,14]. MRI is also important for detecting asymptomatic osteonecrosis in the contralateral hip. Osteonecrosis chondrosarcoma in older adults or chondroblastoma in adolescents). Infarct-associated sarcomas (most commonly malignant fibrous histiocytomas and osteosarcomas) are extremely rare and total up to less than 80 cases in the literature [44,45]. Variant 3: Known osteonecrosis with articular collapse by radiographs. Surgery planned. Next imaging study. The body regions covered in this clinical scenario are ankle, elbow, hip, knee, shoulder, and wrist. Bone Scan Area of Interest There is limited evidence to support the use of bone scan for preoperative planning of osteonecrosis. CT Area of Interest With IV Contrast There is limited evidence to support the use of CT with IV contrast for preoperative planning of osteonecrosis. CT Area of Interest Without and With IV Contrast There is limited evidence to support the use of CT without and with IV contrast for preoperative planning of osteonecrosis. CT Area of Interest Without IV Contrast CT is superior to MRI in showing the location and extent of articular collapse [37,38] and, therefore, plays a critical role in surgical planning. Preoperative CT, before total hip arthroplasty, showed that 21% of femoral head osteonecrosis staged as ARCO stage I or II on radiographs to actually be stage III on CT [49]. With developing technologies in 3-D printing, CT also plays an important role.
Osteonecrosis PCAs. MRI Area of Interest Without IV Contrast MRI is the most sensitive and specific imaging modality for the diagnosis of osteonecrosis, with a sensitivity and specificity nearing 100% [24,28,42]. A meta-analysis of 43 studies for early detection of femoral head osteonecrosis reported a sensitivity of 93% and specificity of 91% [43]. MRI allows for characterization of the osteonecrosis including location, volume, and presence of associated bone marrow edema or joint effusion [13,14]. MRI is also important for detecting asymptomatic osteonecrosis in the contralateral hip. Osteonecrosis chondrosarcoma in older adults or chondroblastoma in adolescents). Infarct-associated sarcomas (most commonly malignant fibrous histiocytomas and osteosarcomas) are extremely rare and total up to less than 80 cases in the literature [44,45]. Variant 3: Known osteonecrosis with articular collapse by radiographs. Surgery planned. Next imaging study. The body regions covered in this clinical scenario are ankle, elbow, hip, knee, shoulder, and wrist. Bone Scan Area of Interest There is limited evidence to support the use of bone scan for preoperative planning of osteonecrosis. CT Area of Interest With IV Contrast There is limited evidence to support the use of CT with IV contrast for preoperative planning of osteonecrosis. CT Area of Interest Without and With IV Contrast There is limited evidence to support the use of CT without and with IV contrast for preoperative planning of osteonecrosis. CT Area of Interest Without IV Contrast CT is superior to MRI in showing the location and extent of articular collapse [37,38] and, therefore, plays a critical role in surgical planning. Preoperative CT, before total hip arthroplasty, showed that 21% of femoral head osteonecrosis staged as ARCO stage I or II on radiographs to actually be stage III on CT [49]. With developing technologies in 3-D printing, CT also plays an important role.