The Arterial Supply to the Foot and its Correlation With Return of Capillary Filling Post-Achilles Tenotomy in Congenital Clubfoot.

Abstract

Background: Congenital clubfoot is a common idiopathic foot abnormality that manifests in newborns. Vascular deficiencies have been suggested as one of the underlying etiologies of clubfoot. The question in hand was: "Is the return of capillary filling to the foot post-Achilles tenotomy correlated with both the arterial supply to the foot and degree of ankle equinus"?

Methods: This clinical study included 30 unilateral idiopathic clubfeet. All patients were assessed clinically using the Pirani score, then manipulation using the Ponseti technique, followed by examination of the infragenicular arterial system using Doppler ultrasound in both the affected and the normal control limbs. After Achilles tenotomy and reaching dorsiflexion of 10 to 20 degrees, the time-lapse till complete return of capillary filling to the foot was recorded. Both the radiologist and the surgeon were blinded to each other's assessment.

Results: The mean postoperative time-lapse to complete return of capillary filling after the maintenance of dorsiflexion at the start of cast application was 3.53±5.56 minutes (range: 0 to 26.59). The anterior tibial artery (ATA) on the affected side was found to be completely attenuated distally in 24 out of 30 feet (80%), while the mean caliber of the posterior tibial artery (PTA) (1.09±0.18 mm) on the affected side was found to be increased compared with the normal side (0.99±0.20 mm) (P=0.042). Also, cases with hypoplastic PTAs needed more time for the return of capillary filling (mean: 8.71±8.88 min) compared with those with normal PTAs (mean: 1.95±2.83 min), (P=0.007). Also, there was a direct positive correlation between postoperative complete return of capillary filling and preoperative degree of equinus (P<0.001).

Conclusion: Delay of the postoperative complete return of capillary filling to the foot after maximum dorsiflexion post Achilles tenotomy is related to both the degree of preoperative equinus and insufficiency/hypoplasia of the posterior tibial artery. This expected delay should not rush the surgeons to remove the cast before the lapse of 30 minutes.

Level of evidence: Level III.