Ischemic necrosis following clubfoot surgery: the purple hallux sign

Ischemic necrosis, which develops rarely after clubfoot surgery, may have a vascular etiology, since many idiopathic and neurogenic clubfeet have congenital deficiency of the anterior tibial and dorsalis pedis arteries. Dorsalis pedis deficiency is demonstrated more frequently in those clubfeet showing greater deformity. Substantial hypoplasia of the profunda femoris and posterior and anterior tibial arteries was evident in the affected limb of a patient in this series who underwent postoperative arteriography. Herein, we report massive necrosis in seven limbs of six patients after clubfoot surgery and have combined this series with seven previously published cases. Additional cases support our hypothesis that arterial deficiencies put some postoperative clubfeet at risk of perioperative ischemic necrosis. Necrosis occurs in those regions supplied by the congenitally diminished anterior tibial and dorsalis pedis arteries. Knowing that children with congenital vascular deficiency are at risk for ischemic necrosis, surgeons should be alert to the subtle, early signs of ischemia and be prepared to prevent or ameliorate the consequences of this condition. Since hypoperfusion in these postoperative feet is a surgical emergency, we propose clinical guidelines for treatment for this phenomenon, which we have named the purple hallux sign.