27. A medical implant assembly comprising: a) first and second bone anchors cooperating with a longitudinal connecting member having a tensioned cord, each of the first and second bone anchors having a receiver with a first pair of opposed upstanding arms having inner surfaces and an insert, each insert being positioned within a respective receiver and having a channel formed by a second pair of upstanding arms; a) a sleeve for attachment to the first bone anchor and having a first end and a second end, the sleeve having a body positionable between the inner surfaces of the first pair of opposed upstanding arms of a respective bone anchor receiver, an elongate solid rod portion on and extending from the second end of the sleeve, and a longitudinal bore extending partially through the body for receiving the tensioned cord therein, the sleeve including first and second body portions, the first body portion sized and shaped for being closely received within the channel of a respective insert and the second body portion being sized and shaped to be received between the first pair of opposed upstanding arms of a respective bone anchor receiver, the second body portion also engaging top surfaces of the second pair of upstanding arms of the respective insert.
28. The assembly of claim 27 , wherein the sleeve further includes a longitudinally projecting central extension on the sleeve first end, the longitudinally projecting central extension projecting outwardly beyond the first pair of opposed upstanding arms of the respective bone anchor.