Bilateral Sever's Disease in Identical Twin Sisters: A Case Report.

Sever's disease, or calcaneal apophysitis, is the primary cause of heel pain in pediatric patients. However, its simultaneous occurrence in monozygotic twin siblings is rarely documented. It is commonly seen in children aged between 8 and 15 years with skeletal immaturity. This case report presents 10-year-old Indian monozygotic twin sisters from a lower socioeconomic background in a rural area who simultaneously developed bilateral Sever's disease. Both twins reported a gradual onset of bilateral heel pain over seven months, which was exacerbated by walking and physical activity. On examination, both twins exhibited a moderate build, weighing 26 kg and 27 kg, respectively. They displayed bilateral hallux varus deformities, and the calcaneal squeeze test was positive bilaterally, which was sufficient to establish the diagnosis. Radiological evaluation, including digital X-rays of the bilateral feet in anteroposterior and lateral views, confirmed the presence of calcaneal apophysitis. Given the identical clinical presentation and radiographic findings in both twins, this case raises the possibility of an underlying genetic predisposition or shared biomechanical risk factors. This report highlights the need for further research into potential hereditary influences contributing to Sever's disease and suggests that genetic, environmental, and mechanical stressors may synergistically contribute to its pathogenesis.