Ponseti method in the management of clubfoot under 2 years of age: A systematic review

Search strategy

A systematic literature search was performed by three authors (BG, GRN, and SB) for articles published between from January 2000 to September 2015 in the following electronic databases: Medline, Cumulative Index to Nursing and Allied Health Literature (CINHAL), PubMed, Scopus for relevant articles to identify the Ponseti method of treatment to treat clubfoot. The process of literature search and articles selected for this study is illustrated in Fig 1.The flow chart summarizes the method of the literature search, inclusion and exclusion criteria for selecting articles, method of extraction of the articles, outcome of the articles, and results. The following key words were used in the electronic databases: "Clubfoot or CTEV or congenital talipes equinovarus", "Ponseti method or Ponseti treatment'', "clubfoot treatment or clubfoot management" (“S1 File"). The articles published in the English language were only considered for this review. In addition, we followed the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) in this systematic review study (“S2 File").

Study selection

The title and abstract of the Ponseti method for clubfoot related articles were reviewed and extracted by investigators (BG, AL, AA, and GRN) based on the inclusion criteria and exclusion criteria of this study. The following information was examined in the abstract and title for selecting the articles: Inclusion criteria: Articles were selected based on the following inclusion criteria: Studies with using the Ponseti method as an intervention for clubfoot deformities, articles restricted into the language of English with full text, clubfoot children with less than 2 years. According to the Ponseti classification, children with less than 2 years are considered as untreated clubfoot [47, 48]. Exclusion criteria: Articles published in other languages, neglected clubfoot, associated with other problems, survey studies, short-term outcome, surgical management of clubfoot and Ponseti method of intervention for testing the effectiveness of different casting materials were excluded in this systematic review.

Data extraction

Two authors extracted data on characteristics of clubfoot patients from the selected articles and recorded into the data extraction sheet, followed by the extracted data was reviewed by two authors for accuracy. The following characteristics of clubfoot patients and selected articles were included into the data extraction sheet: study design, sample size and number of children, number of feet, types of intervention, intervention groups, gender, affected side of the clubfoot (bilateral & unilateral clubfoot), age at initial casting, number of casting, schedule of bracing protocol, details of PAT, outcome measurement scale, results (mean), and the details of relapses rate and follow-up.

Outcome of study articles

In the initial literature search, from January 2000 to November 2015, 1095 articles were identified from the four databases: Medline (n = 260), Cumulative Index to Nursing and Allied Health Literature (CINHAL) (n = 80), PubMed (n = 346), Scopus (n = 408). In the first stages of the screening, 1050 articles were excluded through screening the title and abstract based on inclusion and exclusion criteria and we included 45 articles for further screening. At the second stages of screening process, we excluded 33 articles due to the following main reasons: full text was not available, full text articles was not in English, conference proceedings, duplication of articles, children over than 2 years of age, neglected clubfoot, clubfoot associated with other problems, survey studies, short-term outcome, other treatments such as operative treatment, Ponseti method with different casting materials, different purpose of the studies other than finding effectiveness of Ponseti method among children with clubfoot. As a result, 12 studies were satisfied our selection criteria for the systematic review study after application of all inclusion and exclusion criteria in 45 articles [49–60]. Among the twelve studies, there were four prospective studies [49–52], one multicenter clinical study [53], one consecutive clinical series [54], two randomized controlled study [55, 56], one cohort study [57] and other three clinical studies [58–60].

Patient characteristics

The summary of all articles is described in Table 1. There is a total of 852 clubfoot children with 1206 clubfeet were included in this review. In the 12 studies, a total of 293 bilateral clubfoot children are identified [49, 50, 52, 53, 55, 56, 58–60]. Few studies reported that the affected side of the foot is either right side or left side of the foot. [50, 51, 55, 60]. One of the study [54] did not mention the type of clubfoot (affected side). The number of castings, duration of treatment, follow-up is varied from one study to another study. The average initial presentation of casting would determine the effectiveness of the treatment. Therefore, the clubfoot intervention should be started as early as possible [3]. In most of the studies, Ponseti method of treatment was started after immediate birth

Casting techniques and numbers of casts

In this review, we assessed the number of castings used in the studies, and all of the selected 12 studies reported the number of casts used to achieve the full correction of clubfoot (35–46). Five studies [50, 55–57, 59] used Kite method techniques to compare with the Ponseti method in the correction of clubfoot. These studies reported that Ponseti method achieved the initial correction in shorter time and used fewer casts than the Kite method. The percentages of Ponseti method’s correction success rate was 96% (follow-up time- 36.2 months) and the Kite’s method full correction success rate was 74.3% at the time of an average of 35.1 months [59]; Another study by Sud et al.2008, achieved 91.7% in Ponseti method (Average of 27.24 follow-up) and Kite method 67.7% at time of 24.8 months follow-up [50]. Although the achievement of correction rate was similar in each group (Ponseti-87% & Kite method-79%), the average of casting was less in Ponseti group (7 casts in Ponseti and 10 casts in Kite’s method) and the duration of treatment took only 10 weeks in the Ponseti method and 13 weeks for Kite method [55]. In Elgohary and Abulsaad (49) study, an average of 4.88 ± 0.88 castings (4–7 casts) were used to achieve the full correction of the clubfoot for traditional Ponseti method group and the average of 5.16 ± 0.72 cast (4–7 casts) in the accelerated Ponseti group, in which 84.8% feet required less than 5 casts in both groups. Another study [59]reported that an average 4–12 casting was only used to get the full correction of clubfoot, but, in the Kite method took an average of 4–20 castings; and also between the casting duration periods varied in their study (7 to 10 days per casting).

On the other hand, the accelerated group achieved full correction of clubfoot from 11 to 12 days (castings twice per week) and for the traditional ponseti method group was 21–42 days. Also, the accelerated group achieved nearly same as a traditional ponseti group in a short period of time [49]. However, in the accelerated Ponseti technique, the casting was performed two times a week. Previously, Morcuende et al. 2005 studies tried the accelerated Ponseti techniques with every 5 days casting instead of 7 days once, and Xu [61] studied with casting twice a week, and the results of both studies showed successful correction as same as traditional method and also the duration of the treatment period was less than the original method. Of these 12 selected studies, one study achieved the full clubfoot correction with less than 5 casts (average of 4.9 casts) in 75% of the cases [52]. Only one study described about the casting procedure time, and it took 5 to 9 minutes for each casting (Average 4–8 casting) and for Achilles tenotomy with last casting ranged from 6 to 11 minutes [51]. In Morcuende, Abbasi (18) study, the following steps of casting procedures were performed to maintain the correction of clubfoot: in the first step casting was performed from toe to lower knee and in the second step casting was performed from the knee to thigh area, and 90% of patients were treated with less than 5 casts. Among the selected studies, one of the study [50] stated that the casting treatment is considered as failure if not achieved full correction within a year, and these patients referred to surgery after obtaining the consent from the patient. In this study, Ponseti method was compared with Kite method, in which the Ponseti method took less casting ranged from 3–12 for achieving full correction of the clubfoot. At the same time, 3–23 casts were used in the Kite method. According to the Pavone, Testa (60) more casting is required if the initial deformity is severe or initial treatment is started after 15 weeks of birth. However, there is a still controversy in the impact of late presentation of treatment and outcome of the results. Some authors reported that late presentation of treatment does not affect the outcome of the results [54, 62–65]. At the same time, the study of Abdelgawad et al. stated that 6.6% failure rate of Ponseti treatment due to the late presentation of the treatment. But one of the selected studies for this review, Pavone, Testa (60) reported that there is no correlation between age of presentation and final outcome of range of motion of the feet even though taking more casts, and the clubfoot was corrected with the range of 5–10 casts in their study. Only two of the studies [56, 59] from this review conducted post casting checking such as margin of the cast, neurovascular assessments, as well as the patients were instructed to see other complications: swelling, discoloration of the skin of the toes and baby’s excessive crying. Out of 12 selected studies, only one study [53] treated the clubfoot children with two different types of casting materials, in which 78% clubfoot children were treated with semi-rigid fibreglass cast and 22% of them were plaster of Paris. However, the results of these casting materials are still controversial based on the report of [53]. In addition, the average of 7.2 casts (total of 162 feet) was used in this study to achieve full initial correction including the final cast after tenotomy. Only 3–5 casts were used for 4 children those had a mild foot deformity. Among 162 feet treated in this study, 15 feet (10 bilateral brace & 5 unilateral brace) were treated with recasting and also this study reported that those who are treated with unilateral brace had more casts than bilateral brace. At the same time, the corrected clubfoot should be maintained by foot abduction braces to prevent the relapses or recurrences of clubfoot [30, 64, 66–70].

Bracing

Foot abduction braces (FAB) of the Ponseti method protocol are essential to maintain the corrected clubfoot and to avoid the relapses. In these 12 studies, we noticed variations in the bracing protocol schedule and it ranges from 2–6 months for full time or 23 hours, and then followed by 2–5 years in night time [49–60]. Several studies reported that braces need to wear for full time or 24 hours per day up to 2–3 months [51, 54, 60].]. All these moreover, Hallaj-Moghaddam, Moradi (51) study reported that they used full time abduction brace up to 6 months. Three studies stated that full time abduction braces need to wear 23 hours per day up to 2–3 months [52, 56, 58]. Two of the authors from this review reported that the children (clubfoot) used the splint up to the walking age, and then worn the braces night time for up to four years [55, 59]. However, originally the Ponseti method suggested wearing the full time brace up to two to three months and thereafter at night time for up to 3–4 years. One study [53] used different types of braces and changed their brace type in the bracing protocol: 62% of children were used FAB, then 30% user changed into Mitchell from Markell, and 12% user changed into flexible custom-made unilateral above-the-knee brace from bilateral FAB, and 3% are changed into a softcast or scotchcast removable brace/cast. Moreover, we observed that a change in the position of correcting foot varies in the bracing regime. For example, one of the study used 70 degrees of external rotation of clubfoot [49]; another study positioned the feet in a 60–70 degrees of external rotation in their bracing protocol. Non-compliance brace causes the relapse of correcting clubfoot, which affects the success of the Ponseti treatment [71].

Relapses and its characteristics

Several studies reported that Ponseti method is a successful conservative method to correct the clubfoot deformity [57, 72, 73]. However, previous literatures reported that 10–30 percentages of the relapses are very common [74, 75]. In this review, of the 12 studies, we found that relapses in nine studies [49–52, 54, 57–60, 62]. The maximum of relapse rate was 27.1% [51] and the lowest relapse rate (two relapses) was observed in Pulak and Swamy [52]study. From the selected 12 articles, one of the study [51], stated that maximum relapses rate (27.1%) at the end of the follow-up (average of 5–72 months) period. Total of 76 patients (89.4%) underwent the tenotomy surgical procedures in this study. Few studies reported the relapse pattern of the clubfoot after the initial correction such as fore foot adductus, hindfoot varus, midfoot cavus and ankle equinus [49, 51, 57, 59]. For example, Pavone et.al. [60] reported in their study about 3% of relapses rate, one foot was relapsed by adductus and varus relapse pattern, another foot was affected by equinus, and one foot was totally relapsed with all four components of clubfoot. These relapses occur due to non-compliance with Denis browne splint, and infrequently use of splint because of lack of education and socioeconomic status of parents of clubfoot children [60]. But, in few studies, clubfoot relapse pattern is not clearly described [53, 58]. We observed in Morcuende et.al. study, 11% of the clubfoot children had relapses, and relapses are corrected by manipulation, re-casting, and tendoachilles tenotomy. However, 2.5% of the relapses patients were treated by tibialis tendon transfer and lengthening of Achilles tendon. In Elgohary and Abulsaad (49) study, 14.7% of clubfeet had relapsed due to non-compliance of brace, with 90% of relapses cases had initial high Pirani score (90%). At the same time, Dobbs et al. reported that relapses are not dependent on the initial severity of the clubfoot. Other studies, relapses: 6 cases [58], 27.1% [51], 21.7%[50], 27 feet [53], 13.2% [59], and 2 cases [52] were noticed in the selected articles for our review.

Relapsing factors

Ponseti practitioners recommended that clubfoot should be treated as early as possible after birth to avoid the relapses and to achieve the full correction of clubfoot [7,16, 26, 28, 59]. Especially, to avoid the recurrence or relapse pattern of the clubfoot, compliance of foot abduction braces is necessary in the Ponseti treatment [30, 54]. The relapses of clubfoot are evaluated by either foot morphology or Dimeglio score or Pirani scoring system [72–75]. It can also be evaluated or classified as minor or major relapses based on how much necessity of surgical release requirement [67].

Approximately 78% of the clubfoot relapses occur due to the reason of non-compliance foot abduction braces, and 7% of relapses occur with compliance of foot abduction braces [72]. Non-compliance of foot abduction braces is having a tendency to induce the relapse of the patient [30, 54]. Relapses are not associated at age of presentation, numbers of casting, and previous history of unsuccessful treatment. It is observed that the noncompliance bracing is being the main issue for relapses for the clubfoot and bracing protocol was not strictly followed by caregivers or family members [70]. Although non adherence of bracing is the leading cause of relapse, number of researches suggested other different causative or risk factors for relapses of correcting clubfoot such as low educational level of parents, low income (< US $20,000), and Native American ethnicity [71]. In our selected review articles, Morcuende et al. study [54] states that noncompliance is 17 times greater than compliance of braces for occurrence of relapses and their study referred 2.5 patients (Children with non-compliance of FAB) for anterior tibial tendon transfer to the third cuneiform surgery to avoid additional relapses. Poor socio-economic status and lack of understanding causes relapses in two patients [60]. Three studies [52,55–56] do not describe the causes of relapses in their studies. Three studies were only described the compliance of braces [58– 60]. Some authors suggested that poor experience in casting techniques, improper tenotomy surgeries, ill-fitting of FAB as well as poor education and socioeconomic status of parents for the reason of recurrence [54,60,76], short term follow-up [57]. One selected article in our study reported that 13.7 percentages of relapses occurred in the first year of age in follow-up [59] and so that they are drawn a conclusion relapses is not related to age factor or severity of the foot [50,59]. Of twelve study, only one study [51] was tried to analyze the relapsing related to different factors such as gender, age, age at first casting, clubfoot with other deformities, walking age, number of castings, initial severity score (Dimeglio score), tenotomy, and satisfaction. However, the brace compliance was 97 percentages but the relapse occurred in 27% of the patients and this study suggested that relapse rate might be due to noncompliance of braces, initial severity, below knee casting, and low education level of level of parent’s. Previous literatures have only been discussed about the relationship between the compliance of braces and relapses. According to the Morcuende et al. “Compliance” defined as the children not wearing the foot abduction orthosis for a period of 10 hours per day consider as compliance [54] and Dobbs et al. defined as “complete discontinuation of FAB” [30]. However, there were no studies described about the grade of compliance of braces in details in our selected studies except Sætersdal et al. study [53]. In our selected study for this review[53] graded the compliance of brace as Excellent: use the braces continually until the follow up (4 years of age) or at least 10 hours every day for night time regime; Good: use the braces continually until the follow up (2 years of age) or at least 6 to 8 hours every day for night time regime; Fair: If the braces used less than 2 years of age or less than 6 hours; Non-compliant: If the braces discounted before the age of one year. However, there is no studies described the any grade of compliance for relapses in our selected studies. Identification of relapse pattern, and adherence to the original protocol of the Ponseti method with understanding of detailed manipulation, casting, bracing is necessary to prevent the relapses [3, 19, 38].

Evaluation of treatment outcome and surgical recommendations

In the evaluation or outcome of the clubfoot treatment by Ponseti method, most of the studies, using Pirani scoring system or Dimeglio scoring system as outcome measurement scale for assessing the clubfoot deformity. In addition, these measurement scales are also helps to predict whether the percutaneous Achilles tenotomy is needed or not to correct the equinus [77–78]. If the initial score of Pirani is greater than 5, then it should be corrected with Achilles tenotomy to correct the equinus but the score is less than 3, there is no requirement of this surgery [78]. On the other hand, Morcuende et al.[54], used initial correction of the clubfoot, the rate of extensive corrective surgery, and relapses rate as an outcome measures to evaluate the effectiveness of intervention. The results of Morcuende et al. study [54] showed are: Average achievement of dorsiflexion at ankle is 20 degrees, and initial correction was achieved in 20 days, and relapses were noticed about 10% followed by initial treatment. Some studies, used goniometry to assess the ankle range of motion (ROM) such as dorsiflexion and planter flexion to find out the effectiveness [52] of clubfoot deformities. The results and measurement outcomes of the selected 12 studies are described in the Table 1. The Dimeglio score was reduced from 16 ± 3.4 to 1.6 ± 6.2 at the end of the follow-up [51]; and was an average of 11.2 (received no previous treatment and received previous treatment) before the casting at Colburn & Williams study. However, the Colburn & Williams study does not explain how much the Dimeglio score reduced after casting and follow-up, and this study stated that performed posteromedial release surgery for 3 children (received previous treatment group) [58]. Some of the studies used Pirani scoring system for evaluation but in the outcome evaluation the study did not clearly described the pre and post or follow-up of Pirani scoring outcome [59]. In Pavone et al. study [60], the Pirani score was an average of 5.56 before the casting treatment, and thereafter the results suggested that 82.93% for percutaneous tenotomy after the casting. However, this study also not described about the post Pirani scores but in the follow-up (mean of 4 years follow-up), 98.78% patients had normal passive range of motion, achieved good to excellent results (96.34%) in the functional Ponseti scoring system score [60]. Some studies reported the all parts of the Pirani score including total score (5.6) and the hindfoot score and midfoot score was at 2.9 and 2.8 respectively, and 94.3% of the cases were referred to tenotomy [52], and in another study the hindfoot Pirani score reduced from 2.62 to 0.7 in Ponseti method and 2.79 to 1.31 Kite's method at the 10^th weeks of follow-up. Also, the midfoot score of Ponseti method and Kite method’s decreased from 2.62 and 2.7 to 0.5 and 1.04 respectively, and 96% went for tenotomy surgery in the Ponseti method [56]. One study [53] reported the range of motion as well as Pirani score, the mean Pirani score was 4.8 before the treatment. Thereafter, Pirani score of 0 or 0.5 in 78% of the patients, 1 or 1.5 in 22% of the patients, 3.5 score was noted only one patients. In addition, we observed in their study is about 92% achieved more than 15 degrees of dorsiflexion, 84% of feet freed from adduction deformities, and 93% had more than 40 degrees of external rotation, and 4% feet had adducted deformity. Only one study [55] used the following measurements method to assess the outcome: a) Clinical assessments (relapses, passive ROM, appearance of the foot, muscle power, calf muscle atrophy, size of the foot size, and other complications); b) Functional assessments (Gait pattern, functional limitation, pain, satisfaction of the patients and shoe comfort wear); c) Radiological assessments- talocalcaneal angle, talo first metatarsal angle, and talocalcaneal index. All these three components together graded as excellent-85 to 100 points; good -70 to 84 points); fair—60 to 69 points; poor <60 points. The overall results of this study showed 87% success rate in Ponseti method and 79% in Kite method. In Segev study, 94% of the feet corrected successfully in the Ponseti method (the average of Dimeglio score reduced from 11.9 to 3.2), and tenotomy was performed in 47 feet. At the same time, 6% had residual deformity [57].

Strength and limitations of this systematic review

The main strength of this review is that it thoroughly followed a systematic method and analysis method than previous published few systematic review articles and several reviews on clubfoot with Ponseti method. Also, this review study found that 2 or 3 articles selected in this review, even though they compared the Ponseti method with Kite method and showed that Ponseti techniques are superior to the Kite method, the publications were same as other ones without changing the written script (protocol, some of the results and discussion parts of the articles), and other details.