Touloupakis, G.; Stuflesser, W.; Ferrara, F.; Maione, A.; Antonini, G.; Crippa, C. Early-Stage Radiological Critical Analysis of Unsuccessful Cases Following a Four-Part Fracture Osteosynthesis of the Proximal Humerus: Focus on the “P” Sign. Acta Biomed 2017, 88 (2), 178-184. https://doi.org/10.23750/abm.v88i2.5295.