Avascular necrosis of the proximal epiphysis of the first metatarsal bone in childhood. Long-term outcome.

Ten-year old boy with an 8-month history of limping for pain in the dorsomedial region of the right midfoot. At examination, there were signs of local swelling and tenderness to palpation, as well as antalgic gait with internal rotation. X-ray results showed widening of the proximal epiphysis of the first metatarsal. One month later, local fragmentation with hypodense and sclerotic areas was observed. MRI showed fragmentation, sclerosis, and collapse in the proximal epiphysis consistent with avascular necrosis of the proximal epiphysis of the first metatarsal bone. Patient was only recommended to avoid any physical activity that could increase the load on the foot, without pharmacological treatment. Symptoms spontaneously subsided over the course of six weeks and local pain disappeared after four months. Four years later, the patient remains asymptomatic, playing sports. A high index of suspicion is needed to avoid superfluous diagnostic tests, as it is a self-resolving lesion.