Aims. This study aims to define a set of core outcomes (COS) to allow consistent reporting in order to compare results and assist in treatment decisions for idiopathic clubfoot. Methods. A list of outcomes will be obtained in a three-stage process from the literature and from key stakeholders (patients, parents, surgeons, and healthcare professionals). Important outcomes for patients and parents will be collected from a group of children with idiopathic clubfoot and their parents through questionnaires and interviews. The outcomes identified during this process will be combined with the list of outcomes previously obtained from a systematic review, with each outcome assigned to one of the five core areas defined by the Outcome Measures Recommended for use in Randomized Clinical Trials (OMERACT). This stage will be followed by a two round Delphi survey aimed at key stakeholders in the management of idiopathic clubfoot. The final outcomes list obtained will then be discussed in a consensus meeting of representative key stakeholders. Conclusion. The inconsistency in outcomes reporting in studies investigating idiopathic clubfoot has made it difficult to define the success rate of treatments and to compare findings between studies. The development of a COS seeks to define a minimum standard set of outcomes to collect in all future clinical trials for this condition, to facilitate comparisons between studies and to aid decisions in treatment. Cite this article: Bone Jt Open 2021;2(4):255–260

Aims. To identify the minimum set of outcomes that should be collected in clinical practice and reported in research related to the care of children with idiopathic congenital talipes equinovarus (CTEV). Methods. A list of outcome measurement tools (OMTs) was obtained from the literature through a systematic review. Further outcomes were collected from patients and families through a questionnaire and interview process. The combined list, as well as the appropriate follow-up timepoint, was rated for importance in a two-round Delphi process that included an international group of orthopaedic surgeons, physiotherapists, nurse practitioners, patients, and families. Outcomes that reached no consensus during the Delphi process were further discussed and scored for inclusion/exclusion in a final consensus meeting involving international stakeholder representatives of practitioners, families, and patient charities. Results. In total, 39 OMTs were included from the systematic review. Two additional OMTs were identified from the interviews and questionnaires, and four were added after round one Delphi. Overall, 22 OMTs reached ‘consensus in’ during the Delphi and two reached ‘consensus out’; 21 OMTs reached ‘no consensus’ and were included in the final consensus meeting. In all, 21 participants attended the consensus meeting, including a wide diversity of clubfoot practitioners, parent/patient representative, and an independent chair. A total of 21 outcomes were discussed and voted upon; six were voted ‘in’ and 15 were voted ‘out’. The final COS document includes nine OMTs and two existing outcome scores with a total of 31 outcome parameters to be collected after a minimum follow-up of five years. It incorporates static and dynamic clinical findings, patient-reported outcome measures, and a definition of CTEV relapse. Conclusion. We have defined a minimum set of outcomes to draw comparisons between centres and studies in the treatment of CTEV. With the use of these outcomes, we hope to allow more meaningful research and a better clinical management of CTEV. Cite this article: Bone Jt Open 2022;3(1):98–106