An interbody fusion implant system according to the principles of the present disclosure includes a base member, a first guide, a second guide, and a closure member with a first thru-bore and a second thru-bore. The base member includes a first side wall, a second side wall, and an end wall to define an open trailing end and an interior bounded by the side walls and the end wall. Each guide includes length and has a first portion attached to the proximal end of the first side wall and a second portion extending freely away from the first portion. The closure member includes a first thru-bore configured to be received by the first guide to align the closure member with the first side wall and a second thru-bore configured to be received by the second guide to align the closure member with the second side wall.