Method for computing and displaying a virtual resection of a bone for planning a treatment of a pathological deformity of said bone, said bone having a rim bounding a substantially hemispherical cavity of the bone, comprising: - receiving a set of 3D medical images of said bone, - defining from said 3D medical images patient anatomical landmark data comprising a center of said substantially hemispherical cavity in a patient referential, a rim axis being the medial-lateral anatomic axis of the bone comprising the substantially hemispherical cavity, a circumferential coordinate system assigned to said rim and a plurality of points located along the rim, - determining from said patient anatomical landmark data a 3D patient coverage curve comprising, in the circumferential coordinate system assigned to the rim, a plurality of points representing a coverage parameter of the bone with respect to the substantially hemispherical cavity at a plurality of points along the rim, wherein, for each of said plurality of rim points, said coverage parameter is computed from the coverage angle between (i) the rim axis and (ii) a radius connecting the center of the substantially hemispherical cavity and the respective rim point, - receiving reference data corresponding to a reference rim morphology, said data comprising a 3D reference coverage curve defined by a plurality of points representing a reference coverage parameter of the bone with respect to the substantially hemispherical cavity at a plurality of points along the rim, - creating: • a 3D reference rim morphology model from the 3D reference coverage curve and from a radius extending from the center of the substantially hemispherical cavity to the rim, and • a 3D surface model of at least a part of the bone including the rim from said set of 3D images, wherein regions of the 3D surface model are over-covered or under-covered with respect to the 3D reference rim morphology model, - computing and displaying a virtual resection of the bone onto the 3D surface model to simulate removal of over-covered bone portions. - receiving a set of 3D medical images of said bone, - defining from said 3D medical images patient anatomical landmark data comprising a center of said substantially hemispherical cavity in a patient referential, a rim axis being the medial-lateral anatomic axis of the bone comprising the substantially hemispherical cavity, a circumferential coordinate system assigned to said rim and a plurality of points located along the rim, - determining from said patient anatomical landmark data a 3D patient coverage curve comprising, in the circumferential coordinate system assigned to the rim, a plurality of points representing a coverage parameter of the bone with respect to the substantially hemispherical cavity at a plurality of points along the rim, wherein, for each of said plurality of rim points, said coverage parameter is computed from the coverage angle between (i) the rim axis and (ii) a radius connecting the center of the substantially hemispherical cavity and the respective rim point, - receiving reference data corresponding to a reference rim morphology, said data comprising a 3D reference coverage curve defined by a plurality of points representing a reference coverage parameter of the bone with respect to the substantially hemispherical cavity at a plurality of points along the rim, - creating: • a 3D reference rim morphology model from the 3D reference coverage curve and from a radius extending from the center of the substantially hemispherical cavity to the rim, and • a 3D surface model of at least a part of the bone including the rim from said set of 3D images, wherein regions of the 3D surface model are over-covered or under-covered with respect to the 3D reference rim morphology model, • a 3D reference rim morphology model from the 3D reference coverage curve and from a radius extending from the center of the substantially hemispherical cavity to the rim, and • a 3D surface model of at least a part of the bone including the rim from said set of 3D images, wherein regions of the 3D surface model are over-covered or under-covered with respect to the 3D reference rim morphology model, - computing and displaying a virtual resection of the bone onto the 3D surface model to simulate removal of over-covered bone portions.