Can we make a diagnosis with radiographic examination alone in calcaneal apophysitis (Sever's disease)?

The purpose of this study was to investigate whether the identification of Sever's disease is reliable with radiographs alone. Eighty foot radiographs (50 boys with calcaneal apophysitis and 30 healthy boys) were included in this study. Two consultant orthopaedic surgeons were instructed to make a diagnosis without clinical information on the patients. Radiologic assessments were performed in random order by each observer on two separate occasions, at least 3 weeks later. kappa-statistics were used to establish a relative level of agreement between observers for the two readings and between separate readings by the same observer. Observer A made 22 true (27.5%) diagnoses, whereas observer B made 56 true (70%) diagnoses at the first assessment. Interobserver agreement was rated as slight (kappa-value, 0.190). Observer A made 40 true (50%) diagnoses, whereas observer B made 52 true (65%) diagnoses at the second assessment. Interobserver agreement was rated as slight (kappa-value, 0.039). Intraobserver reproducibility was rated as fair for both observers (kappa-value, 0.369 for observer A and 0.253 for observer B). The results of this study showed that the radiologic identification of calcaneal apophysitis without the absence of clinical information was not reliable. Radiologic findings that were attributed to Sever's disease showed a wide variation between independent observers and between separate readings by the same observer. The diagnosis of calcaneal apophysitis is a clinical decision and radiographic assessment seems to be unnecessary.