Department of Radiology, Royal Orthopaedic Hospital, Birmingham, UK.
Clin Radiol. 2010 May;65(5):382-6. doi: 10.1016/j.crad.2010.01.014. Epub 2010 Mar 23.
To investigate the association of a fatigue-type stress fracture and a fibrous cortical defect/non-ossifying fibroma (FCD/NOF) of the lower limb long bones in skeletally immature patients.
The patient database of a specialist orthopaedic oncology centre was searched to determine the number of skeletally immature patients (<or=16 years of age) over an 18 year period with a lower limb long bone lesion ultimately shown to be a fatigue-type stress fracture. The diagnosis was established by a combination of typical imaging findings of a fatigue-type stress fracture, the absence of aggressive features suggestive of a sarcoma (e.g., interrupted periosteal reaction, cortical breach, and a soft-tissue mass) together with evidence of consolidation or healing on follow-up radiographs and resolution of symptoms over the subsequent weeks. The database was also used to determine the number of skeletally immature cases (<or=16 years of age) referred in the same period in which the principal lesion was shown to be a fibrous cortical defect (FCD) or non-ossifying fibroma (NOF) of the lower limb long bones. The clinical and imaging features of those cases common to both groups (i.e., with both a fatigue-type stress fracture and a FCD or NOF) were reviewed.
Six percent of patients (five cases) referred to an orthopaedic oncology unit, who were subsequently shown to have a stress fracture of the lower limb long bones, were found to have a related FCD/NOF. All had been referred with a suggested diagnosis of a bone sarcoma and/or osteomyelitis. The possibility of a stress fracture had been raised in only one case. Four cases involved the proximal tibia and one the distal femur. Radiographs revealed that both lesions arose in the posteromedial cortex in all but one of the cases. The radiographs and magnetic resonance imaging (MRI) features were considered typical of the overlapping pathological features of the lesions.
A sarcoma could be effectively excluded in the absence of true cortical destruction and soft-tissue extension. Both fatigue-type stress fractures and FCD/NOFs occur at similar sites in the long bones. It is postulated that the existence of the latter may cause localized weakening of the bone thereby predisposing to the development of a stress fracture. The co-existence of these two conditions in the skeletally immature should be recognized as the dual pathological processes may contribute to radiological misdiagnosis.
研究下肢长骨疲劳型应力性骨折与纤维皮质缺损/非骨化性纤维瘤（FCD/NOF）的相关性，这些病变均发生于未成熟骨骼的患者中。
通过对一家骨科肿瘤专科中心的患者数据库进行检索，确定了 18 年间患有下肢长骨病变的未成年患者（<16 岁）的数量，这些病变最终被证实为疲劳型应力性骨折。诊断的建立是基于典型的疲劳型应力性骨折影像学表现，缺乏提示肉瘤的侵袭性特征（例如，中断的骨膜反应、皮质破裂和软组织肿块），以及随访 X 线片上有愈合或修复的证据，且随后数周内症状缓解。该数据库还用于确定同一时期内就诊的未成年患者（<16 岁）数量，这些患者的主要病变被证实为下肢长骨纤维皮质缺损（FCD）或非骨化性纤维瘤（NOF）。回顾了这两个组（即既有疲劳型应力性骨折又有 FCD 或 NOF 的患者）中具有共同临床和影像学特征的病例。
在被转诊至骨科肿瘤专科的患者中，有 6%（5 例）被证实患有下肢长骨的应力性骨折，同时发现存在相关的 FCD/NOF。所有这些患者均被建议诊断为骨肉瘤和/或骨髓炎。仅有 1 例病例提出了应力性骨折的可能性。4 例涉及胫骨近端，1 例涉及股骨远端。X 线片显示，除 1 例外，所有病例的病变均起源于后内侧皮质。X 线片和磁共振成像（MRI）特征被认为是病变重叠病理特征的典型表现。
在没有真正的皮质破坏和软组织延伸的情况下，可以有效地排除肉瘤。疲劳型应力性骨折和 FCD/NOF 均发生在长骨的相似部位。据推测，后者的存在可能导致骨局部弱化，从而易发生应力性骨折。在未成熟骨骼中这两种情况同时存在，应认识到这两种病理过程可能导致影像学误诊。
