SLR - April 2016 - David Arens

Title: Initial Correction Predicts the Need for Secondary Achilles Tendon Procedures in Patients With Idiopathic Clubfoot Treated With Ponseti Casting

Reference: Hosseinzadeh P, Steiner RB, Hayes CB, Muchow RD, Iwinski HJ, Walker JL, Talwalkar VR, Milbrandt TA. Initial Correction Predicts the Need for Secondary Achilles Tendon Procedures in Patients With Idiopathic Clubfoot Treated With Ponseti Casting. J Pediatr Orthop. 2016 Jan;36(1):80-3.
Scientific Literature Review
Reviewed By: David Arens, DPM
Residency Program: Hennepin County Medical Center
Podiatric Relevance: Congenital clubfoot is seen in one to twoinfants per 1000 live births. The Ponseti serial casting has become the primary treatment with beneficial short and long term results. The casting will correct the cavus and adductus deformity but 72-90 percent will need Achilles tenotomy to reduce the dorsiflexion. Despite good initial correction, recurrence of some aspect of clubfoot may occur which could need further surgical correction. The authors of this study wanted to evaluate the predictive value of initial correction of the equinus deformity after Achilles tenotomy on the need for repeat procedures to address equinus. They hypothesized that a less than adequate initial correction of equinus would correlate with a higher rate of further surgical procedures.

Methods: The study included patients who were treated with Ponseti technique with a percutaneous Achilles tenotomy followed by bracing. All patients had digital photos directly before and after the tenotomy procedure. The photos and a digital goniometer was used measure the amount of dorsiflexion correction gained from the Achilles tenotomy. All measurements were done by one author. The feet were divided into two groups: those not needing further procedures to address equinus and those needing another procedure to address equinus. The amount of post operative equinus after initial procedure was compared between the two groups. The feet were then re-divided into three groups based on the amount of dorsiflexion after the tenotomy. The first group had greater than 10 degrees of dorsiflexion, Group 2 had dorsiflexion between 1 and 10 degrees, and Group 3 had neutral dorsiflexion or residual equinus. The rate of future procedures was calculated for each group and compared between groups.

Results: One-hundred-forty-eight feet were included in this study and average follow up was 3.5 years. One-hundred-and-six feet did not need any further procedures and forty-two feet did need further procedures. These procedures included percutaneous and open procedures regarding equinus. Average time to second procedure after initial was 22.6 months. Average dorsiflexion after initial procedure was 14 degrees in the initial-procedure-only group and 5.1 degrees in those needing further procedures, which was significant. Sixty feet had > 10 degrees of dorsiflexion after tenotomy (Group 1), 55 feet had between 1 and 10 (Group 2), and 33 had neutral or residual equinus (Groups 3). Group 1 had a 12 percent recurrence (8 feet) after initial tenotomy, Group 2 had 24 percent (13 recurrences) and Group 3 had 64 percent (21 recurrences). The rate of surgery was higher in Group 3 when comparing to Group 1 and 2. There was no significant difference between Group 1 and 2.  

Conclusions: The authors concluded that residual equinus deformity before bracing has a high rate of re-operation. They suggested that this deformity could possibly be corrected with serial casting before going to bracing to help prevent further operations. The data revealed there was a high amount of overestimation of the amount of initial correction. This was seen because 20 percent of feet had neutral dorsiflexion or residual equinus immediately after the initial tenotomy. The authors cautioned clinicians to be sure to get the proper correction initially to try to limit further operation. This information was very useful for any clinician treating clubfoot as it marks the importance of proper initial correction of the equinus deformity. It would be very beneficial for anyone doing an Achilles tenotomy to measure the amount of correction to make certain you performed the tenotomy correctly or if there is a need for any further procedure to be done such as a posterior capsule release. It also informs clinicians that if equinus deformity was not sufficient then they should have a high index of suspicion for secondary procedures. 

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