Shape of the lateral edge of the first metatarsal head changes depending on the rotation and inclination of the first metatarsal: a study using digitally reconstructed radiographs Satoshi Yamaguchi, Takahisa Sasho, Jun Endo, Yohei Yamamoto, Ryuichiro Akagi, Yasunori Sato, Kazuhisa Takahashi Journal of Orthopaedic Science; July 2015 Quote: Background Correction of pronation deformity and metatarsal primus varus is an important component of hallux valgus surgery, necessary to achieve a satisfactory correction and to prevent post-operative recurrence. Roundness of the lateral edge of the first metatarsal head (round sign) on the dorsoplantar radiograph of the foot has been empirically advocated as an indicator of first metatarsal pronation
Go here to see the original:
Shape of lateral first metatarsal head on x-ray
