Schallert Erica K, Kan J Herman, Monsalve Johanna, Zhang Wei, Bisset George S, Rosenfeld Scott
Department of Pediatric Radiology, Texas Children's Hospital, 6701 Fannin St., Suite 470, Houston, TX, 77030, USA,
Pediatr Radiol. 2015 Jul;45(8):1174-81. doi: 10.1007/s00247-015-3293-0. Epub 2015 Feb 20.
Joint effusions identified by MRI may accompany osteomyelitis and determining whether the joint effusion is septic or reactive has important implications on patient care.
Determine the incidence of epiphyseal marrow edema, joint effusions, perisynovial edema and epiphyseal non-enhancement in the setting of pediatric metaphyseal osteomyelitis and whether this may be used to predict coexisting septic arthritis.
Following IRB approval, we retrospectively evaluated children who underwent MRI and orthopedic surgical consultation for suspected musculoskeletal infection between January 2011 and September 2013. Criteria for inclusion in the study were microbiologically/pathologically proven infection, MRI prior to surgical intervention, long bone involvement and age 0-18 years. MRI exams were independently reviewed by two faculty pediatric radiologists to confirm the presence of appendicular metaphyseal osteomyelitis, to evaluate extent of edema, to determine subjective presence of a joint effusion and to assess perisynovial edema and epiphyseal non-enhancement. Any discrepant readings were reviewed in consensus. Charts and operative notes were reviewed to confirm the diagnosis of osteomyelitis and septic arthritis.
One hundred and three joints with metaphyseal osteomyelitis were identified (mean age: 7.1 years; M:F 1.3:1), of whom 53% (55/103) had joint effusions, and of those, 75% (41/55) had surgically confirmed septic arthritis. The incidence of coexisting septic arthritis was 40% in the setting of epiphyseal edema, 74% in epiphyseal edema and effusion, 75% with perisynovial edema, 76% with epiphyseal non-enhancement and 77% when all four variables were present. Of these, the only statistically significant variable, however, was the presence of a joint effusion with a P-value of <0.0001 via Fisher exact test. Statistical significance for coexisting septic arthritis was also encountered when cases were subdivided into intra-articular vs. extra-articular metaphyses (P-value = 0.0499). No statistically significant difference was found between patients younger than 24 months and those older than 24 months.
Patients with joint effusions identified by MRI, in the setting of metaphyseal osteomyelitis, should be presumed to have septic arthritis until proven otherwise. Epiphyseal extension of edema, perisynovial edema and epiphyseal non-enhancement in the setting of metaphyseal osteomyelitis are not helpful predictors in differentiating reactive and pyogenic joint effusions. Osteomyelitis at a site with an intra-articular metaphyses, however, is more likely to have concurrent septic arthritis.
MRI识别出的关节积液可能与骨髓炎同时存在，确定关节积液是感染性的还是反应性的对患者护理具有重要意义。
确定小儿干骺端骨髓炎情况下骨骺骨髓水肿、关节积液、滑膜周围水肿和骨骺无强化的发生率，以及这是否可用于预测并存的化脓性关节炎。
经机构审查委员会（IRB）批准后，我们回顾性评估了2011年1月至2013年9月间因疑似肌肉骨骼感染而接受MRI检查和骨科手术会诊的儿童。纳入本研究的标准为微生物学/病理学证实的感染、手术干预前的MRI检查、长骨受累以及年龄在0至18岁之间。两名儿科放射科教员独立审查MRI检查，以确认是否存在四肢干骺端骨髓炎、评估水肿程度、确定关节积液的主观存在情况，并评估滑膜周围水肿和骨骺无强化情况。任何有差异的读数均经共同商议审查。查阅病历和手术记录以确认骨髓炎和化脓性关节炎的诊断。
共识别出103例伴有干骺端骨髓炎的关节（平均年龄：7.1岁；男:女为1.3:1），其中53%（55/103）有关节积液，在这些有积液的病例中，75%（41/55）经手术证实为化脓性关节炎。在骨骺水肿的情况下并存化脓性关节炎的发生率为40%，在骨骺水肿和积液的情况下为74%，在有滑膜周围水肿时为75%，在骨骺无强化时为76%，当所有四个变量都存在时为77%。然而，其中唯一具有统计学意义的变量是存在关节积液，通过Fisher精确检验P值<0.0001。当病例分为关节内与关节外干骺端时，并存化脓性关节炎也具有统计学意义（P值 = 0.0499）。24个月以下的患者与24个月以上的患者之间未发现统计学上的显著差异。
在干骺端骨髓炎情况下，经MRI识别出有关节积液的患者，在未得到其他证实之前应被假定为患有化脓性关节炎。在干骺端骨髓炎情况下，水肿的骨骺延伸、滑膜周围水肿和骨骺无强化无助于区分反应性和化脓性关节积液。然而，关节内干骺端部位的骨髓炎更有可能并发化脓性关节炎。
