Knapik Derrick M, Guraya Sahejmeet S, Jones Jessica A, Cooperman Daniel R, Liu Raymond W
Department of Orthopaedic Surgery, University Hospitals Cleveland Medical Center.
Rainbow Babies and Children's Hospital at Case Western Reserve University, School of Medicine, Cleveland.
J Pediatr Orthop. 2019 Oct;39(9):e718-e721. doi: 10.1097/BPO.0000000000001016.
Accessory ossicles off the talus (os trigonum) are a common radiographic finding seen within the foot with variable symptomatology in adult and pediatric patients. Although most studies have examined the incidence of these anatomic variants in a retrospective manner, few have longitudinally followed the behavior of os trigonum over time. The aim of this study was to investigate the incidence, mean age of appearance and fusion, and fusion rate of os trigonum in a large cohort of asymptomatic pediatric patients.
A total of 2620 serial digitized unilateral foot and ankle radiographs from 261 healthy white children (age range, 0.25 to 7 y at enrollment) were retrospectively reviewed. Radiographs were examined to determine the incidence of os trigonum, noting age of appearance and if present, the age of fusion. Skeletal maturity was graded based on ossification pattern of the calcaneal apophysis.
Radiographic evidence of os trigonum was present in 18% of patients (n=16 females, n=15 males) with radiographs extending 1 SD beyond the average age of os trigonum appearance. There was no difference in incidence between females and males (P=0.27), and os trigonum was found to appear at a significantly younger age in females (9.1±1.8 y) than males (10.4±2.0 y, P=0.04). Overall, 70% (n=26) of subjects with os trigonum achieved fusion by age 17 (mean, 9.5±1.6 y in females, 11.2±1.6 in males) with no significant difference between sexes (P=0.61). Grading of skeletal maturity at the time of fusion showed that both male and female subjects underwent fusion on average between calcaneal stages 2 and 3 (P=0.5).
This study confirms a relatively large prevalence of os trigonum in a random pediatric population, and clarifies both the average age of onset and high rate of fusion at a relatively narrow range of skeletal maturity.
Prognostic level II-retrospective study.
距骨附属骨（三角骨）是足部常见的影像学表现，在成人和儿童患者中症状各异。尽管大多数研究以回顾性方式研究了这些解剖变异的发生率，但很少有研究对三角骨随时间的变化进行纵向跟踪。本研究的目的是调查一大群无症状儿童患者中三角骨的发生率、平均出现年龄和融合年龄以及融合率。
回顾性分析了261名健康白人儿童（入组时年龄范围为0.25至7岁）的2620张系列数字化单侧足踝部X线片。检查X线片以确定三角骨的发生率，记录出现年龄，若存在则记录融合年龄。根据跟骨骨骺的骨化模式对骨骼成熟度进行分级。
18%的患者（n = 16名女性，n = 15名男性）有三角骨的影像学证据，其X线片超出三角骨平均出现年龄1个标准差。女性和男性的发生率无差异（P = 0.27），且发现女性三角骨出现的年龄（9.1±1.8岁）明显低于男性（10.4±2.0岁，P = 0.04）。总体而言，70%（n = 26）有三角骨的受试者在17岁时实现融合（女性平均为9.5±1.6岁，男性为11.2±1.6岁），两性之间无显著差异（P = 0.61）。融合时的骨骼成熟度分级显示，男性和女性受试者平均在跟骨2期和3期之间实现融合（P = 0.5）。
本研究证实了在随机儿童人群中三角骨的患病率相对较高，并明确了在相对较窄的骨骼成熟度范围内的平均发病年龄和高融合率。
预后II级——回顾性研究。
