Rossi Ignacio, Rosenberg Zehava, Zember Jonathan
Musculoskeletal Research Fellow at NYU Langone Medical Center, 333 E 38th St, New York, NY, 10016, USA.
Centro de Diagnostico Dr. Enrique Rossi, Arenales 2777, Buenos Aires, 1425, Argentina.
Skeletal Radiol. 2016 Apr;45(4):483-93. doi: 10.1007/s00256-015-2320-4. Epub 2016 Jan 9.
Heel pain in children and secondary MR imaging (MRI) of the hindfoot have been increasing in incidence. Our purpose is to illustrate the, previously unreported, MRI stages in development of the posterior calcaneal apophysis, with attention to imaging pitfalls. This should aid in distinguishing normal growth from true disease.
Consecutive ankle MRIs in children <18 years, from 2008-2014, were subdivided into 0≤5, 5≤10, 10≤15 and 15≤18 age groups and retrospectively reviewed for development of the calcaneal apophysis.
204 ankle MRI studies in 188 children were identified. 40 studies were excluded with final cohort of 164 studies in 154 patients (82 boys, 72 girls). The calcaneal apophysis was cartilaginous until age 5. Foci of decreased as well as increased signal were embedded in cartilage, prior to ossification. Early, secondary ossification centers appeared in plantar third of the apophysis in 100% of children by age 7. Increased T2 signal in the ossifications was seen in 30% of children. Apohyseal fusion began at 12 and was complete in 78% of 14≤15 year olds and in 88% of 15≤18 year olds. Curvilinear low signal in the ossification centers, paralleling, but distinguished from growth plate, and not be confused with fracture line, was common.
Development of the posterior calcaneus follows a unique sequence. Apophyseal fusion occurs earlier than reported in the literature. Familiarity with this maturation pattern, in particular the apophyseal increased T2 signal and the linear low signal paralleling the growth plate, will avoid misinterpreting it for pathology.
儿童足跟痛及后足的二次磁共振成像（MRI）发病率一直在上升。我们的目的是阐述跟骨后突发育过程中此前未报道过的MRI分期，并关注成像陷阱。这有助于区分正常生长与真正的疾病。
对2008年至2014年间18岁以下儿童的连续踝关节MRI进行回顾性研究，将其分为0≤5岁、5≤10岁、10≤15岁和15≤18岁年龄组，观察跟骨后突的发育情况。
共确定了188名儿童的204例踝关节MRI研究。排除40例研究，最终纳入154例患者的164例研究（82名男孩，72名女孩）。跟骨后突在5岁前为软骨性。在骨化之前，信号减低及增高的病灶均位于软骨内。到7岁时，100%的儿童在跟骨后突的跖侧三分之一处出现早期继发骨化中心。30%的儿童在骨化中心可见T2信号增高。跟骨后突融合始于12岁，在14≤15岁的儿童中78%完成融合，在15≤18岁的儿童中88%完成融合。骨化中心出现的曲线状低信号与生长板平行，但可与之区分，且不应与骨折线混淆，这种情况很常见。
跟骨后部的发育遵循独特的顺序。跟骨后突融合比文献报道的时间更早。熟悉这种成熟模式，尤其是跟骨后突T2信号增高以及与生长板平行的线状低信号，将避免将其误判为病变。
