SLR - May 2019 - Jordan W. Crafton

Development and Validation of a Delayed Presenting Clubfoot Score to Predict the Response to Ponseti Casting for Children Aged 2–10

Reference: Nunn TR, Etsub M, Gardner ROE, Allgar V, Wainwright AM, Lavy CBD Development and Validation of a Delayed Presenting Clubfoot Score to Predict the Response to Ponseti Casting for Children Aged 2–10. Strategies in Trauma and Limb Reconstruction. 2018 Nov;13:171–177.

Scientific Literature Review

Reviewed By: Jordan W. Crafton, DPM
Residency Program: Mount Auburn Hospital, Cambridge, MA

Podiatric Relevance: The treatment options for children aged two to 10 with unfortunate, but all too common, delayed diagnosis of clubfoot has limited treatment options. Ponseti casting for delayed presentation clubfoot has not been fully postulated for this treatment group. Scoring systems for response to clubfoot casting have been developed for infantile clubfoot, but a validated scoring system for delayed clubfoot presentation to predict response to clubfoot casting has not been developed. Treating a patient with delayed diagnosis of clubfoot can be difficult; however, with utilization of this new scoring system, our treatment can become more focused and effective.

Methods: The PAVER scoring system was developed to predict outcomes of delayed presentation of clubfoot. PAVER stands for the five angles evaluated, including plantaris (midfoot plantarflexion), adductus, varus, equinus of the ankle and rotation around the talar head. Angles were measured after treatment that consisted of Ponseti casting for a maximum of nine outpatient casts changed every two weeks (~4.5 months). Minimal surgical intervention was utilized consisting of possible percutaneous tendoachilles lengthening, Tibialis anterior tendon transfer, abductor hallucis release and cuboid decancellation. Angle measurements were converted via algorithm to a point system. Correction to <0 degrees=0 points, 0–20 degrees=1 point, 21–45 degrees=2 points, >45 degrees=3 points. Given that increase in age causes patient resistance to casting, a multiplier was developed as part of the scoring system. For ages 2–4, 5–7 and 8–10, a multiplier of 1, 1.5 and 2, respectively, for a total of 30 points was utilized. Foot pressures were also evaluated using pedobarography. Failure was defined in those with uncorrected deformity of the midfoot in any plane.

Results: One hundred feet in 62 patients were identified to have delayed presenting clubfoot, were treated with Ponseti casting and minimal surgery and were scored with the PAVER system. Casting and limited surgical approach occurred in 89 percent of patients. One hundred percent of patients had a percutaneous TAL, 95 percent had a Tibialis anterior transfer and 8 percent had cuboid decancellation. Overall, total PAVER score was correlated with higher peak pressures on pedobarographic exam (tau=0.36, p<0.05) and negatively correlated with total footprint area (tau=-0.39, p<0.05). Severity of score was positively correlated with total number of casts needed for correction (tau=0.43, p<0.05). Fair correlation between age and the number of casts needed for correction (tau=0.43. p<0.05). PAVER score with age multiplier had good association with total cast number (tau=0.71, p<0.05). The probability of failure with a score >18 was 90 percent. There was a 97 percent success rate with PAVER scores of <18.

Conclusions: The PAVER score proved to be a useful tool in predicting success rate with Ponseti casting and minimal surgery in patients with delayed clubfoot presentation. Patients with a PAVER score above 18 will likely not respond to casting and minimal surgery (90 percent failure). Those with scores <18 have a 97 percent success rate with Ponseti casting and minimal surgery. When a patient presents with a PAVER score above 18, forgoing casting and proceeding to more invasive surgery may be of more benefit in lieu of ~4.5 months of casting that will likely lead to failure. 

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