Purpose: Congenital idiopathic clubfoot is the most common congenital deformity in children and can be a major cause of disability for the child as well as an emotional stress for the parents. The Ponseti method of club-foot correction, consisting of serial manipulations and casting, is now the gold standard of treatment. It has traditionally been described using plaster of Paris (POP) above-knee casts, which are affordable, stiff, and easily moldable. Recently, semi-rigid fiberglass softcast (FSC, 3M Scotchcast) has grown in popularity due to ease of removal, durability, lighter weight, better appearance, ease of cleaning, and water resistance. There are currently no randomized controlled trials to prove its efficacy with respect to POP. The purpose of this study was to determine the influence of choice of cast material on the correction of congenital idiopathic clubfeet using the Ponseti method.

Method: A prospective, randomized controlled trial. Based on the results of a pilot study performed at our centre, a sample size of 30 patients was determined to be appropriate. Thirty consecutive patients presenting with congenital idiopathic clubfoot were randomized into POP and FSC groups prior to commencement of treatment with the Ponseti Method. Clubfeet secondary to non-idiopathic diagnoses were excluded. The Pirani classification was used to determine clubfoot severity (less severe, < =4; severe > 4), and for surveillance during casting. The primary outcome measure was the number of casts required to correct the clubfoot deformities to the point where the foot was ready for a percutaneous tendo-achilles tenotomy (TAL) or when the foot was completely corrected (Pirani=0). Secondary outcome measures include: number of casts by clubfoot severity, ease of cast removal, number of methods needed to remove casts, need for percutaneous tendo-achilles tenotomy.

Results: Of the 30 patients enrolled, 13 (40%) were randomized to POP and 18 (60%) to FSC. No patients were lost to follow-up. In the POP and FSC groups, eight (67%) and 11 patients (61%) underwent a TAL, respectively. In general, there were no differences in the mean number of casts required for clubfoot correction between the two groups (p=0.13). When analyzed by clubfoot severity, the mean number of casts for each material in the less severe group was equal (3 casts). In the severe group, the mean number of casts in the FSC group (6.4 casts) was considerably higher than for the POP group (4.7 casts) but our study was underpowered to verify this result. According to parents, POP was harder to remove than FSC (p< 0.001).

Conclusion: In general, FSC was found to be as efficacious as POP in the correction of idiopathic clubfeet by the Ponseti Method and was the preferred cast material by parents. For stiffer, more severe feet, POP seemed to show a faster correction time than FSC.