磁共振成像评估先天性马蹄内翻足经Ponseti方法治疗跗骨病理解剖关系

Evaluation of tarsal bone alignment and malformation by magnetic resonance imaging for congenital talipes equinovarus after Ponseti therapy

目的应用核磁共振评估经Ponseti方法治疗的先天性马蹄内翻足(congenital talipes equinovarus,CTEV)的跗骨病理解剖的恢复程度。方法收集2014年3月至2022年3月首都儿科研究所附属儿童医院收治的经Ponseti系列石膏矫形技术治疗先天性马蹄内翻足12例(15足)患儿的临床资料,其中男10例,女2例;做MRI扫描时患儿平均年龄为47.7个月,范围是8~96个月;单侧9例(9足),双侧3例(6足)。采用3.0T核磁共振成像扫描双足,获得标准的解剖矢状面、冠状面和横轴面的T1加权和T2加权图像。选择能够清晰显示解剖结构的最佳切面进行角度测量,包括矢状面:胫骨-跟骨角,距骨-跟骨角;冠状面:胫骨-跟骨角;横轴面:距骨颈角,距骨-舟骨角,距骨-跟骨角。Ponseti方法治疗的CTEV作为观察组,其余正常足作为对照组。采用t检验或非参数检验对CTEV观察组和对照组的数据进行统计学分析。同时采用Pirani评分系统对经Ponseti方法治疗后的CTEV进行临床评估。结果全部患足均达到柔软、无痛、灵活、功能正常的跖行足。Pirani评分:治疗前5~6分(平均5.5分),末次随访时0~0.5分(平均0.07分),其中0.5分2足,0分13足。MRI测量结果显示,矢状面:胫骨-跟骨角对照组平均为68.7°,观察组为72.4°(P=0.22),距骨-跟骨角对照组平均为27.4°,观察组为29.9°(P=0.74)。冠状面:胫骨-跟骨角对照组平均为12.2°,观察组为13.1°(P=0.53)。横轴面:距骨颈角对照组平均为28.8°,观察组为32.2°(P=0.30);距骨-舟骨角对照组平均为22.2°,观察组为43.2°(P<0.001);距骨-跟骨角对照组平均为9.8°,观察组为11.9°(P=0.26)。只有横轴面MRI距骨-舟骨角出现的差异有统计学意义(P<0.001)。1例矢状面MRI显示舟骨向距骨背侧半脱位,1例横轴面MRI显示舟骨向外侧脱位。结论CTEV经过Ponseti方法治疗后外观和功能恢复良好,MRI显示Ponseti系列石膏矫形技术成功矫正了CTEV的内翻、高弓和跖屈畸形。

Objective To objectively to evaluate the effectiveness of Ponseti method for correcting congenital talipes equinovarus(CTEV)and employ magnetic resonance imaging(MRI)for evaluating changes in tarsal bones relationship.Methods The relevant clinical data were reviewed for 12 CTEV children(15 clubfoot)on Ponseti therapy from March 2014 to March 2022.Magnetic resonance imaging(MRI)studies were performed with a 3.0 T machine.There were 10 boys and 2 girls with a mean examination age of 47.7(8-96)months.Involvement was unilateral(n=9)and bilateral(n=3).There were 8 left and 7 right clubfoot.T1/T2-weighted images were acquired on standard anatomic sagittal,transverse and coronal planes.The optimal slice demonstrating distinct anatomy was selected for measurement.Sagittal talocalcaneal,sagittal tibiocalcaneal,coronal tibiocalcaneal,transverse talar neck,transverse talonavicular and transverse talocalcaneal angles were measured.Fifteen corrected feet were compared with 9 unilateral normal feet at clinical and radiological levels using a Pirani scoring system and MRI,respectively.Results The recovery of affected feet fulfilled the goals of Ponseti therapy(functional,normal looking,pain-free,plantigrade foot).The mean Pirani score was 5.5(5-6)pre-treatment.During follow-ups,Pirani score was 0.07(0-0.05),of which 2 feet got 0.05 and 13 feet got 0.MRI indicated that sagittal talocalcaneal,sagittal tibiocalcaneal,coronal tibiocalcaneal,transverse talar neck and transverse talocalcaneal angles showed no significant difference between treated clubfoot and normal feet(P>0.05).Transverse talonavicular angle differed markedly between two groups(P<0.001).1/15 of corrected CTEV had dorsal talonavicular subluxation on sagittal plane and 1 had lateral navicular subluxation on transverse plane.Conclusions Appearance and function of CTEV recover well after Ponseti therapy.As indicated by MRI,Ponseti therapy has successfully corrected varus,cavus and equinus deformities and incompletely modified the adduction deformity regarding transverse talonavicular angle.Also it may cause dorsal talonavicular subluxation on sagittal plane and lateral subluxation of navicular on transverse plane on MRI.