When one has a screw loose, there can be medical implications. This study documents one such:
“Spontaneous expulsion of a screw: An unusual complication 3 years after internal fixation of posterior acetabular wall fracture,” Francisco Chana-Rodríguez, José Matías Tabernero Fernández, Manuel Villanueva-Martínez, José Rojo-Manaute, Javier Vaquero-Martín, Injury Extra, vol. 43, no. 9, September 2012, Pages 63–64. The authors, at General University Hospital Gregorio Marañón [the hospital is pictured here], Madrid, Spain, report:
“we present a novel case in which an acetabular screw spontaneously migrated 3 years after the surgery, undergoing subsequent transcutaneous expulsion”
BONUS: “Screw Fixation of Acetabular Components“