SLR - April 2019 - Pooja Shah

Prognosticating Factors of Relapse in Clubfoot Management by Ponseti Method

Reference: Zhao D, Li H, Kuo K N, Yang X, Wu Z, Liu J, Zhu J. Prognosticating factors of relapse in clubfoot management by Ponseti method. J Pediatr Orthop. 2018 Nov–Dec; 38(10): 514–520.

Scientific Literature Review

Reviewed By: Pooja Shah, DPM
Residency Program: Montefiore Medical Center, NY

Podiatric Relevance: Clubfoot is a common deformity; however, there are no set protocols regarding treatment and recurrence. The first line of treatment is manual manipulation via Ponseti casting. However, given the spectrum of deformity, each patient undergoes a different treatment timeframe with a risk of relapse. This study tries to establish a new ratio to predict recurrence in patients who are high risk from initial presentation.

Methods:
A level II study was performed over a three-year timeframe for patients with idiopathic clubfoot. A total of 116 patients and 172 feet were analyzed on initial evaluation using a Pirani score. The treatment plan consisted of the Ponseti casting method. If there was residual equinus, a percutaneous achilles tenotomy (PAT) was performed. After correction was achieved, patients were placed in a brace, each following the same protocol until the end of four years of age. If recurrence occurred, repeat casting and, if necessary, a tibialis anterior tendon transfer were performed. Patients were followed up at three and six months and then annually until four years old, recording brace compliance. The number of casts needed from first manipulation, need for a PAT, recurrence of deformity and age of relapse were all recorded. The ratio of correction improvement (RCI) value was eventually calculated by using the initial Pirani score divided by the number of casts needed to achieve correction and using 1 as the dividing factor.

Results: The average age of initiation of treatment was 47.5 days, and average follow-up was 36.4 months. The average starting Pirani score was 4, and the average cast needed was 4.1. Only 13 patients did not receive a PAT. There were 30 patients where the deformity recurred, at an average of 22 months after wearing the brace. Of the recurrence group, they required an average of 4.9 additional casts. A repeat PAT was performed in 15 patients, and four patients received a tendon transfer. The RCI score showed a positive correlation between the initial Pirani score and the number of casts required to achieve correction. The lower the RCI value, the higher the risk of relapse.  

Conclusion: The basis of this study was to analyze the relationship between the initial Pirani score and the number of casts needed to correct the deformity and analyze noncompliance as a risk factor for recurrence. The authors provided a new parameter known as the RCI to create a relationship between the severity of the disease and length of treatment. Authors recognized the main limitation of this study as the subjective data regarding brace compliance. Since there was a positive correlation to the initial Pirani score and the number of casts needed for correction, it is important to educate patients on the length of their potential treatment plan and the multiple levels of compliance necessary for positive results. Currently, there are no set guidelines for the number of casts needed to achieve full correction. Hence, the RCI can be used as a parameter toward a future protocol.  

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