POP-ON-CAP ASSEMBLIES HAVING SPLAY-RESISTING FEATURES AND ANTI-SPLAY FEATURES FOR SPINAL SURGERY WITH WIDE FEATURES ALLOWING PURPOSEFUL SPLAY BY TRANS-CAP DISTAL FORCE

摘要

A spinal-surgery system having a receiver for receiving a rod and/or a receiver cap. The cap has a generally cylindrical body and a set of opposing splay-resisting flanges extending radially from the body. The receiver has arms each having an inner proximal protrusion at or adjacent the proximal end, and an inner sloped splaying surface distal of the proximal protrusion. Each cap flange has a proximal-facing cap splay-prevent surface, and a distal-facing cap pop-on surface. Each receiver proximal protrusion has a proximal-facing sloped receiver pop-on surface, and a distal-facing sloped receiver splay-prevent surface. The receiver pop-on surfaces are spaced so each cap pop-on surface contacts a respective receiver pop-on surface in operation. Each splaying revision surface extends distally and radially inward toward the longitudinal axis and into a cylindrical plane defined by an inner diameter of the cap. The cap inner diameter is greater than a rod width.