Ponseti and Becker [4] found that nearly 90 % of patients with MA achieve spontaneous resolution with time. The authors advised that passively correctable MA did not require any treatment but recommended casting for feet that were not passively correctable. They reported good results from casting of semi-rigid or rigid feet. Rushforth [5] followed 130 MA of all grades of severity for a mean follow up of 7 years and found 86 % were normal or mildly deformed but fully mobile; 10 % were still moderately deformed but were asymptomatic and 4 % remained deformed and stiff. It was not possible to detect these resistant cases before the age of 3 years, but the low failure rate would seem to justify a policy of expectant treatment. Ghali et al. [6] presented a small series of both untreated (31) and surgically treated (38) MA at a median follow-up of 4 years. Surgical treatment involved antero-medial release. Patients were assessed both clinically and radiologically. He reported “excellent” results in both groups. [7] presented a follow up study of 243 feet with MA. It is not clear what the length of follow up was. He treated flexible feet with stretching and semi-rigid or rigid feet with casting. He found a favourable outcome and commented that children with residual deformity had “no difficulties with function or shoe wear”. However Bohne also offered surgery to 9 feet with “severe residual deformity”. The Scandinavian series of [8] reported on 76 patients with MA at 6 years follow-up and found that 13 % of children had a persistent MA. Widhe subsequently published a longer follow up of the same cohort at 16 years [9]. Those with persistent MA at 6 years continued to improve and only three patients had a persistent MA deformity at 16 years. All of them were asymptomatic despite the deformity. The initial grade of severity of the MA patients in this series is not known. Widhe also compared gait analysis and dynamic foot pressure at 16 years between those with normal feet at birth and those with MA and found no difference between the two groups. Ponseti’s group published a 32-year follow up of patients with MA [10]. The cohort included 16 passively correctable feet that had no treatment. The rest had semi-rigid or rigid deformity and were treated with serial manipulation and casting. The authors used a functional rating system to assess functional outcome and also performed radiological assessment. No one had poor results and none required subsequent surgery. All the feet that were initially passively correctable went on to achieve spontaneous resolution. There was only a single case of hallux valgus at final follow up. The authors advised against surgical treatment of rigid MA.

Evidence from the published literature appears to suggest a favourable outcome for untreated MA. Most will resolve without treatment by early childhood and those that persist are likely to improve with age. A small minority of MA may persist but are unlikely to give any functional problem. There is enough evidence to suggest that passively correctable MA deformity does not require any treatment apart from parental reassurances. Manipulation and casting is an option in feet that do not correct passively although no treatment is probably equally feasible.