A vertebral expandable implant (1, 101), comprising: at least one bearing surface which expands away from a central longitudinal axis (10, 110) of the implant (1, 101); a first implant end (20, 120) and an opposed second implant end (21, 121), wherein each of the first implant end (20, 120) and the second implant end (21, 121) includes an opening or recess, and wherein the first implant end (20, 120) and the second implant end (21, 121) are intended to move toward one another during expansion of the implant (1, 101); a retaining member comprising an elongate structure having a first retaining member end and second retaining member end, wherein each of the first retaining member end and the second retaining member end engages with a respective opening or recess of a respective implant end (20, 21), and wherein at least one of the first retaining member end and the second retaining member end comprises a plurality of ridges and corresponding grooves therebetween; characterized by at least one engagement member provided within a recess adjacent the first implant end (20, 120), wherein the engagement member fits within a groove of the plurality of grooves of the retaining member; wherein: the recess comprises a first recess end having sufficient space to allow passage of the engagement member therein when the engagement member is positioned on a ridge of the retaining member during expansion of the implant (1, 101), a second recess end lacks sufficient space to allow passage of the engagement member when the engagement member is positioned on a ridge of the retaining member; and the retaining member retains the implant (1, 101) in an expanded configuration by preventing contraction of the implant (1, 101) when expanded. at least one bearing surface which expands away from a central longitudinal axis (10, 110) of the implant (1, 101); a first implant end (20, 120) and an opposed second implant end (21, 121), wherein each of the first implant end (20, 120) and the second implant end (21, 121) includes an opening or recess, and wherein the first implant end (20, 120) and the second implant end (21, 121) are intended to move toward one another during expansion of the implant (1, 101); a retaining member comprising an elongate structure having a first retaining member end and second retaining member end, wherein each of the first retaining member end and the second retaining member end engages with a respective opening or recess of a respective implant end (20, 21), and wherein at least one of the first retaining member end and the second retaining member end comprises a plurality of ridges and corresponding grooves therebetween; characterized by at least one engagement member provided within a recess adjacent the first implant end (20, 120), wherein the engagement member fits within a groove of the plurality of grooves of the retaining member; the recess comprises a first recess end having sufficient space to allow passage of the engagement member therein when the engagement member is positioned on a ridge of the retaining member during expansion of the implant (1, 101), a second recess end lacks sufficient space to allow passage of the engagement member when the engagement member is positioned on a ridge of the retaining member; and the retaining member retains the implant (1, 101) in an expanded configuration by preventing contraction of the implant (1, 101) when expanded.