An expandable inter-body fusion device for use in surgery comprising: a first plate having a first plate longitudinal axis, an upper bone contact surface and an opposed first plate inner surface ; a second plate having a second plate longitudinal axis, a lower bone contact surface and an opposed second plate inner surface , wherein the second plate underlies at least a portion of the first plate ; and an insert positioned therebetween the first plate and the second plate , wherein the insert has an insert longitudinal axis and comprises a first member and a second member spaced from the first member a predetermined distance, and wherein the first member and the second member are each rotatable about the insert longitudinal axis and relative to the first plate and the second plate between a first insert position and a second insert position and, wherein the device is selectively adjustable about and between a first unexpanded position, in which the first member and the second member of the insert are in the first insert position and a second expanded position, in which at least one of the first member and the second member are in the second insert position, and wherein rotation of at least one of the first member and the second member from the first insert position towards the second insert position comprises at least one of the first member and the second member camming a portion of the first plate away from the second plate , and wherein in the second expanded position, the first plate inner surface is spaced therefrom the second plate inner surface a distance greater than in the first, unexpanded position, characterized in that said first member comprises a first retainer configured to couple a portion of the first member to at least one of the first plate and the second plate . a first plate having a first plate longitudinal axis, an upper bone contact surface and an opposed first plate inner surface ; a second plate having a second plate longitudinal axis, a lower bone contact surface and an opposed second plate inner surface , wherein the second plate underlies at least a portion of the first plate ; and an insert positioned therebetween the first plate and the second plate , wherein the insert has an insert longitudinal axis and comprises a first member and a second member spaced from the first member a predetermined distance, and wherein the first member and the second member are each rotatable about the insert longitudinal axis and relative to the first plate and the second plate between a first insert position and a second insert position and, wherein the device is selectively adjustable about and between a first unexpanded position, in which the first member and the second member of the insert are in the first insert position and a second expanded position, in which at least one of the first member and the second member are in the second insert position, and wherein rotation of at least one of the first member and the second member from the first insert position towards the second insert position comprises at least one of the first member and the second member camming a portion of the first plate away from the second plate , and wherein in the second expanded position, the first plate inner surface is spaced therefrom the second plate inner surface a distance greater than in the first, unexpanded position, characterized in that said first member comprises a first retainer configured to couple a portion of the first member to at least one of the first plate and the second plate . <EOS>