SLR - January 2023 - Rekha Kouri, DPM, PGY-3
Title: Ultrasound measurements in clubfoot treated with the Ponseti method and risk factors for recurrence: A retrospective studyReference: Nahle IS, Miron MC, Grimard G, Abu Zeid A, Glavas PP. Ultrasound measurements in clubfoot treated with the Ponseti method and risk factors for recurrence: A retrospective study. J Child Orthop. 2022 Feb;16(1):46-54.
Level of Evidence: Prognostic study, Level III
Reviewed by: Rekha Kouri, DPM PGY-3
Residency Program: SSM Health DePaul, Bridgeton MO
Podiatric Relevance: Idiopathic congenital talipes equinovarus (clubfoot) occurs in 1 per 1000 live births and fifty percent of the time it is bilateral. Currently, the Ponseti method is regarded as the gold standard of care for management of clubfoot. Even though success rate is high with this management, the recurrence of the deformity is still a challenge for the treating surgeons. One of the limitations is that the clinical response of the foot in infants cannot be adequately assessed by radiographs. The authors of this study believe an ultrasound can be used instead. The purpose of their study was to identify which ultrasound measurements can be associated with risk of recurrence in clubfoot. They also investigated factors that can influence the risk of recurrence such as demographic data, compliance with foot abduction bracing and performance of an Achilles tenotomy.
Methods: This was a level III retrospective study. The study was conducted at a single site over a six-year period. The inclusion criteria consisted of clubfoot deformity, no previous treatment, use of Ponseti method and the ultrasound after starting casting, and minimum of three year clinical follow up. Other factors measured included use of percutaneous Achilles tenotomy and compliance with the use of the brace. The quantitative measurements obtained with the ultrasound included the medial talo-navicular displacement (MTaN), medial malleolus to navicular distance (MM-N), talo-calcaneal angle (Ta-C) and distal tibial physis to proximal calcaneal apophysis distance (Ti-C). They used Mann-Whitney U tests for analyzing comparative groups, recurrence (R) and non-recurrence (NR); and multivariate logistic regression analysis for factors influencing the recurrence group.
Results: Overall, a total of 76 patients with 114 clubfeet were treated. Treatment on these patients, on average, started at 28 days of age and included the application of six casts to obtain correction. Recurrence of the deformity occurred in 17 (22%) of these patients. The factors that influenced recurrence rate included the use of a percutaneous Achilles tenotomy and noncompliance with the use of bracing. They found these to be the strongest predictors for recurrent deformity. The ultrasound measurement that showed significant correlation between deformity recurrence was the Ti-C distance, this distance was noted to be significantly shorter in the R group compared to the NR group (p=0.023).
Conclusion: This study assessed the relationship between the use of ultrasound for quantitative patho-anatomy and recurrence of clubfoot deformity. Based on their results, the Ti-C measurement can be useful to predict recurrence. They also found the factor that most affected recurrence rate was noncompliance with the brace. The article provided a good indication for the use of ultrasound and how it can be used to prevent the recurrence of clubfoot. Even though it is a good indicator, there is still a large learning curve compared to the use of radiographs. However, the use might progress with further studies indicating at what threshold values of the TiC distance affect recurrence rate and also how the progression of the quantitative measurements with ultrasound varies from birth.