Introduction
Talipes equinovarus, commonly referred to as congenital clubfoot, is a complex pediatric foot deformity with a global incidence ranging from 0.9 to 7 per 1000 live births, depending on the population studied [1]. Approximately 80% of cases occur in developing countries, and most epidemiological studies indicate a higher prevalence in males compared to females, with a male-to-female ratio of roughly 2:1 [2, 3]. Clubfoot is defined by four characteristic structural abnormalities: Cavus (increased medial longitudinal arch), forefoot adduction, hindfoot varus, and ankle equinus (collectively known by the acronym CAVE) [4]. If left untreated, clubfoot can lead to significant functional impairments, including abnormal gait patterns, social limitations, and physical complications. Affected children often walk on the dorsum of the foot, which can result in callus formation, skin breakdown, and infections [2].
Over the past decade, the Ponseti method has gained widespread acceptance as the preferred treatment for idiopathic clubfoot, replacing many surgical approaches. This conservative technique involves gentle manipulation of the foot followed by weekly application of long-leg casts to correct deformities gradually [5]. If ankle equinus persists before the final cast, a percutaneous Achilles tenotomy is typically performed to achieve full correction. After successful correction, a foot abduction brace must be worn full-time to maintain alignment [5-7]. While the standard Ponseti protocol involves cast changes every 5 to 7 days, several studies have explored a biweekly interval, particularly for neglected cases, with favorable clinical outcomes [8-10].
Given the logistical and financial barriers faced by many families (especially those who must travel long distances for weekly treatment), this study was designed to compare the clinical efficacy of biweekly versus weekly Ponseti casting in infants with congenital clubfoot. The trial was conducted at Hazrat Rasool Akram and Hazrat Ali Asghar hospitals, Tehran City, Iran, between 2024 and 2025.

Methods
This study was a randomized clinical trial designed to compare the effectiveness of the Ponseti casting method applied at weekly versus biweekly intervals. Ethical approval was obtained from the Ethics Committee of Iran University of Medical Sciences, and the study was registered with the Iranian Registry of Clinical Trials. The trial was conducted at the orthopedic clinics of Hazrat Rasool Akram and Hazrat Ali Asghar hospitals from March 2024 to May 2025. Infants and children up to 6 months of age diagnosed with idiopathic congenital clubfoot were eligible for inclusion. Patients with secondary causes of clubfoot (such as syndromic conditions or neurologic disorders, including arthrogryposis, spina bifida, or Charcot-Marie-Tooth disease) were excluded.
Eligible patients were randomly assigned to receive Ponseti casting at either a weekly or biweekly interval. All casting procedures were performed in the operating rooms of the participating hospitals without the administration of anesthesia or analgesia.
The Ponseti method involved gentle manipulations followed by the application of a long-leg cast with the knee flexed to 90 degrees. The first cast was applied with the forefoot in supination to correct the cavus deformity. Subsequent casts aimed to address adduction and varus through forefoot abduction and rotation of the navicular and cuboid bones around the talus. The final cast was applied with the ankle in 15 degrees of dorsiflexion. If 15 degrees of dorsiflexion could not be achieved, a percutaneous Achilles tenotomy was performed. Following tenotomy, the foot was immobilized in 60 degrees of abduction and maximum dorsiflexion for 21 days.
After successful correction of the deformity, patients were fitted with a foot abduction brace to be worn full-time (23 hours per day) for the first 12 weeks. Thereafter, the brace was used during sleep (nighttime and naps) until the child reached four years of age to prevent recurrence. The brace was initiated once the foot achieved approximately 60 to 70 degrees of abduction and 20 degrees of dorsiflexion. Informed written consent was obtained from the parents of all participants. Families retained the right to withdraw from the study at any time, and any patient whose parents declined continued participation was excluded from further follow-up.

Severity assessment using the Pirani scoring system
The Pirani scoring system is a widely used and validated tool for assessing the severity and monitoring the progress of clubfoot treatment, particularly in patients undergoing the Ponseti method. It is based on the clinical evaluation of 6 signs of foot morphology—three related to the hindfoot and three to the midfoot.
Hindfoot components include posterior crease, empty heel, and rigid equinus.
Midfoot components include lateral border curvature, medial (internal) crease, and palpable talar head laterally.
Each parameter is scored as 0=normal, 0.5=moderately abnormal, and 1=severely abnormal.
The total Pirani score ranges from 0 (no deformity) to 6 (severe deformity), with higher scores indicating more severe clubfoot [6].
The inclusion criteria were as follows: Term newborns (delivered via vaginal or cesarean section) whose parents or legal guardians provided informed consent for participation and infants diagnosed with idiopathic clubfoot and aged less than 6 months at the time of enrollment.
The exclusion criteria were as follows: Presence of atypical or non-idiopathic forms of clubfoot, associated congenital syndromes, such as arthrogryposis, Charcot-Marie-Tooth disease, or spina bifida, prior treatment for clubfoot before enrollment in the study, and incomplete treatment or failure to adhere to scheduled follow-up appointments (Figure 1).



Statistical analysis
Data were entered and analyzed using SPSS software, version 24 (IBM Corp., Armonk, NY). Descriptive statistics were calculated for baseline demographic and clinical characteristics. For the comparison of quantitative variables between groups, the independent t-test was used when data followed a normal distribution; otherwise, the Mann-Whitney U test was employed. Categorical variables were compared using the chi-square test or Fisher exact test when expected frequencies were small. The level of statistical significance was set at P<0.05, and all tests were two-tailed with a 95% confidence interval (CI).

Results

Demographic information
A total of 97 patients (155 feet) diagnosed with congenital clubfoot were initially assessed at the orthopedic clinics. Of these, 24 patients (41 feet) met the exclusion criteria and were removed from the study. Ultimately, 73 newborns (114 feet) were enrolled and randomized into two groups: 57 feet received Ponseti casting at weekly intervals, and the remaining 57 feet received Ponseti casting at biweekly intervals.
The mean age of the participants at the start of treatment was 10.05±3.06 days. Among the participants, 43 were male (58.9%) and 30 were female (41.1%). Bilateral clubfoot involvement was observed in 41 patients (56.2%), while 32 patients (43.8%) presented with unilateral involvement. Of the unilateral cases, 21 involved the right foot (28.8%) and 11 involved the left foot (15.1%) (Table 1).



Pirani score comparison
At the initial assessment before treatment, Pirani scores were recorded separately for the midfoot and hindfoot components. The mean midfoot score was 2.57±0.37, and the mean hindfoot score was 2.63±0.352, resulting in a total initial Pirani score of 5.21±0.483.
Following serial Ponseti casting, the final mean Pirani score was significantly reduced to 0.51±0.352 (P<0.05), indicating substantial clinical improvement. However, there was no significant difference in the final Pirani scores between the weekly and biweekly casting groups (P=0.791) (Table 2).



Other clinical findings
The mean number of casting sessions required to achieve full correction across all participants was 4.94±1.05. When comparing the two treatment groups, the biweekly casting group required significantly fewer cast applications than the weekly group (P<0.05).
Regarding the need for percutaneous Achilles tenotomy, 106 feet (92.98%) underwent the procedure, while 8 feet (7.02%) achieved full correction without it.
In terms of casting-related complications, the most frequently reported issues included plaster slippage/loosening in 24 feet (21.1%), erythema or skin irritation in 17 feet (14.9%), and pressure sores in 3 feet (2.6%).
Although plaster slippage and loosening were more commonly observed in the biweekly group, the difference compared to the weekly group was not statistically significant (P=0.461) (Table 3).



Discussion
This randomized controlled trial (RCT) was conducted to evaluate the therapeutic efficacy of biweekly Ponseti casting and compare it with the conventional weekly approach using the Pirani scoring system. The findings indicated no significant difference in treatment outcomes between the two groups. However, the mean number of casts required in the biweekly group was significantly lower than that of the weekly group. Although complications such as cast slippage were more frequent in the biweekly group, the difference was not statistically significant.
In a prospective study, Harnett et al. evaluated 40 patients (61 feet) to assess the outcomes of an accelerated Ponseti regimen (three times per week) [11]. The initial Pirani scores were 5.5 in the accelerated group and 5 in the standard group, with no statistically significant difference. Similarly, the final Pirani scores did not differ significantly between groups (P=0.308). However, the mean treatment duration was significantly shorter in the accelerated group (16 days vs 42 days; P<0.001). These results suggest that the accelerated method can achieve comparable therapeutic outcomes with reduced treatment duration, offering advantages for patients facing logistical challenges. Similarly, the current study found that therapeutic efficacy and final Pirani scores were comparable between biweekly and weekly casting groups. Furthermore, the mean number of casts needed for correction was lower in the biweekly group, suggesting that this method may be more practical for patients with limited access to healthcare facilities or financial constraints.
Barik et al. conducted a prospective study in Southern India with a minimum follow-up of five years. The patients underwent Ponseti casting either weekly or every three days [12]. The accelerated group required significantly fewer casts (P<0.01) and achieved correction more quickly, while final Pirani scores did not significantly differ. These results reinforce the efficacy of accelerated casting protocols in expediting correction.
Singh evaluated 40 patients with idiopathic clubfoot using both standard and accelerated Ponseti methods [13]. The accelerated group demonstrated significantly shorter treatment durations (P<0.05), and there was a significant difference in Pirani scores post-treatment. The need for Achilles tenotomy was marginally higher in the accelerated group.
In an RCT, Islam et al. studied 100 patients (158 feet) and compared standard and accelerated Ponseti techniques [14]. Both groups exhibited significant improvement in Pirani scores, with no notable differences between them post-treatment. The mean number of casts was similar (6.2), while the mean duration of casting was significantly shorter in the accelerated group (39 days vs 58 days). The rate of Achilles tenotomy was approximately 86%, with no significant intergroup differences. Minor complications such as rash (8%) and cast slippage (4%) were reported. The higher mean number of casts in the Islam study may be attributed to the shorter casting intervals, which necessitate more frequent adjustments. The shorter total casting duration in the accelerated method might be explained by enhanced soft tissue stretching and correction in each session. Longer casting intervals, such as those in the biweekly approach, may increase the risk of cast loosening and reduce the treatment’s effectiveness.
In a retrospective investigation, Lourenço et al. applied biweekly Ponseti casting in neglected clubfoot and found it effective in improving Pirani scores [10]. However, the absence of a control group using weekly or more frequent casting limits the conclusions. In a prospective study by Hassan et al., the biweekly method was applied to children aged 1–3 years with clubfoot, demonstrating significant improvements in Pirani scores [9]. The mean number of casts was 6, slightly higher than the present study’s 5, possibly due to the older age and reduced soft tissue flexibility of participants. Similarly, Ayana et al. studied children aged 2–10 years with neglected clubfoot and found significant Pirani score improvements using biweekly casting [8]. However, the mean number of casts was 8, again likely due to the older age group.
In the current study, the complication rate—specifically, cast loosening and slippage—was 21%. This rate may represent a drawback of the biweekly casting interval, as such complications could hinder optimal correction of the clubfoot deformity.

Conclusion
This study demonstrated that biweekly Ponseti casting for the treatment of idiopathic clubfoot in infants yields clinical outcomes comparable to the standard weekly method in terms of Pirani score improvement—notably, the biweekly protocol required significantly fewer cast applications to achieve full correction. To our knowledge, this is the first randomized clinical trial comparing weekly and biweekly casting intervals in infants with idiopathic clubfoot using a control group. These findings suggest that a biweekly casting schedule may serve as a practical alternative for patients in remote areas or those facing logistical and financial barriers to frequent hospital visits. However, further investigations with larger sample sizes and longer follow-up periods are warranted to validate these results and assess long-term outcomes.

Ethical Considerations

Compliance with ethical guidelines
This study was approved by the Ethics Committee of Iran University of Medical Sciences, Tehran, Iran (Code: IR.IUMS.FMD.REC.1403.286), and the study was registered with the Iranian Registry of Clinical Trials (IRCT), Tehran, Iran (Code: IRCT20240624062245N1).

Funding
The paper was extracted from the master thesis of the Morteza Behjat, approved by Iran University of Medical Sciences, Tehran, Iran.

Authors' contributions
Software, validation, formal analysis, investigation, resources, data curation, Writing the original draft and Funding Acquisition: Morteza Behjat; Review & editing, visualization,  project administration: Alireza Pahlevansabagh; Supervision, conceptualization and methodology: Alireza Ghaznavi.

Conflict of interest
The authors declared no conflict of interest.





References