A computing system for planning shoulder stability enhancement surgery, the computing system comprising: a memory configured to store data describing a 3-dimensional model of a predicted premorbid humerus of a patient; and processing circuitry configured to: determine a first areal size as an areal size of a predicted premorbid glenoid bone of the patient; determine a second areal size as an areal size of a Bankart lesion on a morbid glenoid bone of the patient; determine a third areal size as an areal size of a geodesic surface on the 3D model of the predicted premorbid humerus of the patient, wherein the geodesic surface is defined at least in part by (i) a projected medial border of a Hill-Sachs lesion on a morbid humerus and (ii) a projected medial border of a footprint of a humeral head of the morbid humerus, wherein: the projected medial border of the Hill-Sachs lesion is a projection of a medial border of the Hill-Sachs lesion onto the 3D model of the predicted premorbid humerus, and the projected medial border of the footprint of the humeral head of the morbid humerus is a projection of a medial border of the footprint of the humeral head of the morbid humerus onto the 3D model of the predicted premorbid humerus; determine, based on the first, second, and third areal sizes, whether bone loss of the patient involves joint engagement; and based on a determination that the bone loss of the patient involves joint engagement, output an indication that a shoulder stability enhancement surgery that includes a bone graft is recommended for the patient. a memory configured to store data describing a 3-dimensional model of a predicted premorbid humerus of a patient; and processing circuitry configured to: determine a first areal size as an areal size of a predicted premorbid glenoid bone of the patient; determine a second areal size as an areal size of a Bankart lesion on a morbid glenoid bone of the patient; determine a third areal size as an areal size of a geodesic surface on the 3D model of the predicted premorbid humerus of the patient, wherein the geodesic surface is defined at least in part by (i) a projected medial border of a Hill-Sachs lesion on a morbid humerus and (ii) a projected medial border of a footprint of a humeral head of the morbid humerus, wherein: the projected medial border of the Hill-Sachs lesion is a projection of a medial border of the Hill-Sachs lesion onto the 3D model of the predicted premorbid humerus, and the projected medial border of the footprint of the humeral head of the morbid humerus is a projection of a medial border of the footprint of the humeral head of the morbid humerus onto the 3D model of the predicted premorbid humerus; determine, based on the first, second, and third areal sizes, whether bone loss of the patient involves joint engagement; and based on a determination that the bone loss of the patient involves joint engagement, output an indication that a shoulder stability enhancement surgery that includes a bone graft is recommended for the patient. determine a first areal size as an areal size of a predicted premorbid glenoid bone of the patient; determine a second areal size as an areal size of a Bankart lesion on a morbid glenoid bone of the patient; determine a third areal size as an areal size of a geodesic surface on the 3D model of the predicted premorbid humerus of the patient, wherein the geodesic surface is defined at least in part by (i) a projected medial border of a Hill-Sachs lesion on a morbid humerus and (ii) a projected medial border of a footprint of a humeral head of the morbid humerus, wherein: the projected medial border of the Hill-Sachs lesion is a projection of a medial border of the Hill-Sachs lesion onto the 3D model of the predicted premorbid humerus, and the projected medial border of the footprint of the humeral head of the morbid humerus is a projection of a medial border of the footprint of the humeral head of the morbid humerus onto the 3D model of the predicted premorbid humerus; the projected medial border of the Hill-Sachs lesion is a projection of a medial border of the Hill-Sachs lesion onto the 3D model of the predicted premorbid humerus, and the projected medial border of the footprint of the humeral head of the morbid humerus is a projection of a medial border of the footprint of the humeral head of the morbid humerus onto the 3D model of the predicted premorbid humerus; determine, based on the first, second, and third areal sizes, whether bone loss of the patient involves joint engagement; and based on a determination that the bone loss of the patient involves joint engagement, output an indication that a shoulder stability enhancement surgery that includes a bone graft is recommended for the patient.