Evaluation Of Tarsal Bones Alignment And Malformation By Magnetic Resonance Imaging In Congenital Talipes Equinovarus Treated With The Ponseti Method

Objective:To objectively evaluate the effectiveness of Ponseti method for the correction of congenital talipes equinovarus(CTEV),we decided to use magnetic resonance imaging(MRI)to evaluate changes in the tarsal bones relationship.Methods: This is a retrospective study of 12 children with CTEV treated with the Ponseti method.MRI studies were obtained using a 3.0T machine.T1-weighted and T2-weighted images were obtained in the standard anatomic sagittal,transverse and coronal planes.The best slice demonstrating the anatomy clearly was selected for measurement.Sagittal talocalcaneal angle,sagittal tibiocalcaneal angle,coronal tibiocalcaneal angle,transverse talar neck angle,transverse talonavicular angle and transverse talocalcaneal angle were measured.The 15 corrected feet were compared with the 9 unilateral normal feet at clinical and radiological levels using a Pirani scoring system and MRI,respectively.Results: 12 patients(10 boys,2 girls)with CTEV were examined by using MRI.Nine cases had unilateral and three had bilateral involvement(8 left clubfoot,7 right clubfoot),giving a total of fifteen CTEV compared with nine normal feet.The mean age of patients at examination was 47.7months(8-96).The recovery of the affected feet in these patients met the goals of the Ponseti treatment(functional,normal looking,pain-free,plantigrade foot).The mean Pirani score was 5.5(5-6)before Ponseti treatment.During this follow up,the Pirani score was 0.07(0-0.5),of which 2feet got 0.05 and 13 feet got 0.The results of MRI indicated that the sagittal talocalcaneal angle,sagittal tibiocalcaneal angle,coronal tibiocalcaneal angle,transverse talar neck angle and transverse talocalcaneal angle showed no significant difference between treated clubfoot and normal feet(p>0.05).The transverse talonavicular angle showed significant difference between two groups(p<?0.001).1 of15 of the corrected CTEV had dorsal talonavicular subluxation in sagittal plane and 1had lateral subluxation of the navicular in transverse plane.Conclusions: Although the appearance and function of CTEV recovered well after Ponseti method,The results of MRI indicated that Ponseti method successfully corrected the varus,cavus and equinus deformities and incompletely corrected the adduction deformity regarding transverse talonavicular angle.At the same time,the Ponseti method may cause dorsal talonavicular subluxation in the sagittal plane and lateral subluxation of the navicular in the transverse plane on MRI.