Automated decision support for Hallux Valgus treatment options using anteroposterior foot radiographs

Figure 5 Determining reference points of first and second metatarsals and hallucial proximal phalanx. A: Input radiograph; B: Three bones of interest: 1,2MT, and hallucial PP were approximated by ellipses to estimate bone axes, which were then used to determine bone endpoints; C: The elliptical axes were split into three parts with specific proportions to determine segment endpoints (marked by black dots) and reference points of the respective bone being established on a transverse line perpendicular to the longitudinal at a point equidistant from the outer border of the medial and lateral cortices (black crosses). Brown color show unsegmented (bone overlap) areas of the proximal epiphyseal of the second metatarsal bone; D: The central axes (white lines) were automatically determined through reference points (marked by black dots).