A previously unreported complication of the AO cannulated 4.0- and 4.5-mm screw systems: a review of three cases.

Cannulated screws are utilized widely in the management of periarticular fractures and osteotomies. Reports of complications related to these screws have increased as use has become more commonplace. A novel mode of mechanical failure of 4.0-mm and 4.5-mm A-O cannulated screws is described in three patients, as well as hypotheses regarding possible causes of the failure. It may be prudent to predrill and tap dense cortical bone when such devices are used in teenagers and young adults patients in an attempt to avoid similar damage to the screw during insertion.