Introduction:

the rupture of the extensor pollicis longus (EPL) tendon is a rare pathology and usually occurs in adult women in relation to distal radius fractures.

Material and methods:

we present the case of an adolescent female patient who, after conservative treatment with splinting of a Peterson type I physeal fracture of the radius, suffered an acute extension deficit of the thumb at six weeks, diagnosed with clinical radiological examination as spontaneous rupture of the extensor pollicis longus (EPL). She was treated with extensor pollicis indicis propius (EIP) transfer with satisfactory results and recovering her usual activity one month after surgery.

Conclusion:

this kind of injuries are infrequent in pediatric ages and rarely described in a pediatric patient with immature skeleton, what makes this case something exceptional. It is necessary considering these complications in patients of low ages even with no other risk factors. The most frequent treatment applied in adults as in children is the EIP transference with good results in the long term.