Algorithm-based quantitative analysis of lower-extremity alignment in representative patients reflective of the spectrum of clinical indications. A, Female adult patient with bilateral medial compartmental osteoarthritis of the knee joints. B, Male adolescent patient with bilateral valgus deformity. C, Female adult patient with valgus deformity and morbid obesity. D, Female child with dysplasia of the right hip, pelvic obliquity, and leg-length discrepancy. Although the algorithm-based identification of the mechanical (blue) and anatomic axes (orange) was robust and not affected by joint degeneration, A, incomplete bone maturation, B, D, eccentric projection of both patellae, B, C, excess skin folds, C, displaced gonad shields, C, or open epiphysial plates, D, segmentation outlines were rendered focally imprecise. Corresponding original radiographs and segmentation outlines are detailed in Figure E2 (supplement). Units of scales, if present, are centimeters.