Evolution of clubfoot deformity and muscle abnormality in the Ponseti method: evaluation with the Dimeglio score.

Purpose: The modality of progression of the correction along casting sessions of Ponseti method has been poorly investigated and information regarding evolution of muscular abnormalities is missing. The aim of the study was to investigate dynamics of correction of the different components of clubfoot deformity in a clinical setting.

Methods: In a prospective study, 124 clubfeet consecutively treated by a single orthopaedic surgeon were evaluated with the Dimeglio system at each casting session and score progression was determined.

Results: For each component a typical pattern was recorded. Cavus and medial crease showed a rapid correction. Rotation, adduction and varus corrected gradually and simultaneously. The posterior crease usually persisted until final cast was discontinued. Equinus improved progressively after each cast and then to a larger extent with Achilles tenotomy. The parameter describing poor muscular condition, reported at presentation in 39 feet (31.5%), was the only item showing extremely different dynamics of correction (from rapid and complete resolution to persistence at last cast removal), which could be explained by the large diversity of entities included (hypertonia, imbalance, fatty infiltration, fibrosis, aplasia).

Conclusions: This study confirmed that dynamics of correction in clinical setting correspond essentially to theoretical principles of Ponseti method. Muscle abnormalities are not uncommon in clubfeet and have great influence on the progression of correction. If abnormalities are recorded, their evolution along the treatment should be monitored. A more objective evaluation would be required.