Reverse Ponseti-type Method Combined With Minimally Invasive Approach For Children With Congenital Vertical Talus:Comparison Between Idiopathic And Non-idiopathic Patients

Background:Congenital vertical talus(CVT)is a rare rigid flatfoot disorder characterized by hindfoot valgus and equinus,with associated midfoot dorsiflexion and forefoot abduction caused by a fixed dorsal dislocation of the navicular on the head of the talus.In addition,the contracture of Achilles tendon and dorsolateral soft-tissue of the foot and dislocation and subluxation of calcaneocuboid joint can be also present at the same time.The estimated prevalence of vertical talus is one in 10,000[1].The etiology of vertical talus deformity remains unknown.It is estimated that,approximately one half of cases of vertical talus occur in conjunction with neurologic disorders(neuromuscular and central nervous system)or known genetic defects[2]and/or syndromes[3].The other half occur in children without other congenital anomalies and are considered idiopathic or isolated cases.For the treatment of CVT,currently consensus are:the earlier treatment applied,the better result will be achieved,and only simple conservative treatment cannot be effective,surgery may be the only effective method.The traditional surgical approach involving one-stage or two-stage extensive soft-tissue release[6-8],the dorsal or posterior approach[9-11],excision of the navicular[12],evensubtalar or triple arthrodesis[13,14]etc.while effective for gaining initial correction in many cases,is associated with several potential complications,including wound necrosis[1],avascular necrosis of the talus[5],recurrence of the deformity[5],stiffness of the ankle and subtalar joints[8],and amputation in extreme cases[15].In 2006,Dobbs et al[16]initiate a new and more simple method for CVT after acquiring the inspiration of Ponseti method for the treatment of clubfoot deformity.The new method,also calledReverse-type Ponseti method or Dobbs method,consistsof manipulation,serial casting immobilization,pinning of the talonavicular joint or minimally invasive approach reduce talonavicular joint and percutaneous tenotomy of the Achilles tendon,has successfully corrected all the component of CVT,and obtained satisfactoryshort and longterm outcome[16,18-23].However,lots of previous studies only reported the effect of idiopathic[16,24]or non-idiopathic[22]CVT,only few research[19,20,25]focus on the difference outcome between the two groups.Presently,there are very few study related to this new method for young children CVT,in addition,comparison between the two groups is blank in domestic.As a result,it is a meaningful to explore the approach in details as well as the effects and difference between the two groups.Objective:1.To explore the clinical effect and surgical skills of Reverse Ponseti-type method combined with minimally invasive approach for young children with congenital vertical talus(CVT).2.To investigate the difference effects between idiopathic andnon-idiopathic patients,using Reverse Ponseti-type method combined with minimally invasive approach.Methods:Between July 2012 and December 2015,11 consecutive patients who had a total of 18 feet with congenital vertical talus were retrospectively reviewed,following treatment with Dobbs method.There were 8 boys and 3 girls,including 5 patients(9 feet)with idiopathicCVT and 6 patients(9 feet)with non-idiopathic CVT,with average of 10.9 months(range,3.9-31.2 months).All of them had serial manipulations and casts followed by percutaneous Achilles tenotomy,casting or other limited surgeries if necessary.Comparison between idiopathic and non-idiopathic CVT on subtalar and ankle range of motion were made at the time of the latest follow-up.In addition,the Patients’ radiological measurements at the time of presentation,immediately postoperatively and the latest follow-up were compared with each other respectively.At last,Adelaar scoring system were used for evaluation of whole clinical effects at the latest follow-up.Results:11 consecutive patients with 18 feet obtained initial correction both clinically and radiographically with the average follow-up of 27months(range,12-57).However,there were only 2 patients with 4 feet in non-idiopathic group had recurrence of deformity within six months after the initial correction and were treated with repeat serial manipulations and casts followed by pinning of the talonavicular joint or limited procedure without the need for an extensive soft-tissue release.At the time of the latest follow-up,idiopathic group has a greater ankle range of motion than non-idiopathic group(P<0.05).There were significant difference(P<0.05)in all measured radiographic parameters compared with the preoperative values at the time of the latest follow-up,no significant difference were found between the two groups.According to the Adelaar scoring system,the results were excellent in 2 patients,good in 15 and fair in one.No complications such as wound necrosis,stiffness of the ankle and the subtalar joint,avascular necrosis of the talus etc.were found.Conclusions:The Dobbs method isa new and effective way for congenital vertical talus in young children,with obvious advantage of less invasive trauma,reliable result and lesser complication in the terms of clinical appearance,foot function and radiographic measured results,which can provides early excellent results for congenital vertical talus.