In patients who were later found to have osteomyelitis, 11% had contralateral extremity findings, including contralateral osteomyelitis, and 20% had ipsilateral septic arthritis. Among patients who did not have osteomyelitis, 20% had contralateral abnormalities, most commonly stress reaction, soft-tissue edema, myositis, joint effusion (not septic), and leukemia. US Area of Interest US is a highly sensitive method of diagnosing hip joint effusion, and the absence of hip joint effusion virtually excludes septic arthritis; a false negative rate of 5% has been described, noted in patients with a shorter duration of symptoms (<1 day) [40,43,45-47]. US can reportedly detect hip effusions as small as 1 mL [44]. Hip US for the purpose of identifying joint effusion can be performed with high sensitivity and specificity [48]. In one study, nearly 80% of pediatric patients with hip septic arthritis required US imaging alone to guide their management [45]. US in evaluation of osteomyelitis is limited in its ability to assess the osseous structures but can identify abutting inflammatory changes affecting the soft tissues such as periosteal elevation and subperiosteal collections [40,49,50]. 3-Phase Bone Scan Area of Interest There is limited data regarding the use of 3-phase bone scan of area of interest as the next imaging study in evaluation of septic arthritis. In one study in which blood pool and delayed imaging of only the area of interest were performed, 8 of 9 cases of septic arthritis were identified [51]. Bone Scan Whole Body There is limited data regarding the use of whole-body bone scan as the next imaging study in the evaluation of septic arthritis. One study assessed the accuracy of bone scan for the diagnosis of suspected acute hematogenous osteomyelitis and septic arthritis in 86 children, using whole-body and selected static images, without blood flow or blood pool views [55].
Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs. In patients who were later found to have osteomyelitis, 11% had contralateral extremity findings, including contralateral osteomyelitis, and 20% had ipsilateral septic arthritis. Among patients who did not have osteomyelitis, 20% had contralateral abnormalities, most commonly stress reaction, soft-tissue edema, myositis, joint effusion (not septic), and leukemia. US Area of Interest US is a highly sensitive method of diagnosing hip joint effusion, and the absence of hip joint effusion virtually excludes septic arthritis; a false negative rate of 5% has been described, noted in patients with a shorter duration of symptoms (<1 day) [40,43,45-47]. US can reportedly detect hip effusions as small as 1 mL [44]. Hip US for the purpose of identifying joint effusion can be performed with high sensitivity and specificity [48]. In one study, nearly 80% of pediatric patients with hip septic arthritis required US imaging alone to guide their management [45]. US in evaluation of osteomyelitis is limited in its ability to assess the osseous structures but can identify abutting inflammatory changes affecting the soft tissues such as periosteal elevation and subperiosteal collections [40,49,50]. 3-Phase Bone Scan Area of Interest There is limited data regarding the use of 3-phase bone scan of area of interest as the next imaging study in evaluation of septic arthritis. In one study in which blood pool and delayed imaging of only the area of interest were performed, 8 of 9 cases of septic arthritis were identified [51]. Bone Scan Whole Body There is limited data regarding the use of whole-body bone scan as the next imaging study in the evaluation of septic arthritis. One study assessed the accuracy of bone scan for the diagnosis of suspected acute hematogenous osteomyelitis and septic arthritis in 86 children, using whole-body and selected static images, without blood flow or blood pool views [55].