A spinal implant (110; 310) for placement between first and second vertebral bodies, comprising: a body (111; 311) having a first surface (108; 308) for engaging a first vertebral body; a first movable member (122a; 326a) having a first end movable away from the body at a first location; a second movable member (122b; 326b) having a second end movable away from the body at a second location; at least one extendable support element (122a, 116a; 322) connected to the body, the at least one extendable support element being actuatable to expand so as to induce movement of at least one of the first and second ends of the respective first and second movable members away from the body; a first locking element (120a; 320a) at the first location; and a second locking element (120b; 320b) at the second location; wherein the first locking element is selectively lockable between an unlocked configuration and a locked configuration, such that, when in the locked configuration, the first locking element restrains movement of the first movable member away from the body without restraining movement of the second movable member away from the body; and wherein the second locking element is selectively lockable between an unlocked configuration and a locked configuration, such that, when in the locked configuration, the second locking element restrains movement of the second movable member away from the body without restraining movement of the first movable member away from the body, and wherein, when in the locked configuration, the first locking element restrains movement of the first movable member away from the body by defining a maximum amount of permitted movement of the first movable member away from the body; and wherein, when in the locked configuration, the second locking element restrains movement of the second movable member away from the body by defining a maximum amount of permitted movement of the second movable member away from the body. a body (111; 311) having a first surface (108; 308) for engaging a first vertebral body; a first movable member (122a; 326a) having a first end movable away from the body at a first location; a second movable member (122b; 326b) having a second end movable away from the body at a second location; at least one extendable support element (122a, 116a; 322) connected to the body, the at least one extendable support element being actuatable to expand so as to induce movement of at least one of the first and second ends of the respective first and second movable members away from the body; a first locking element (120a; 320a) at the first location; and a second locking element (120b; 320b) at the second location; wherein the first locking element is selectively lockable between an unlocked configuration and a locked configuration, such that, when in the locked configuration, the first locking element restrains movement of the first movable member away from the body without restraining movement of the second movable member away from the body; and wherein the second locking element is selectively lockable between an unlocked configuration and a locked configuration, such that, when in the locked configuration, the second locking element restrains movement of the second movable member away from the body without restraining movement of the first movable member away from the body, and wherein, when in the locked configuration, the first locking element restrains movement of the first movable member away from the body by defining a maximum amount of permitted movement of the first movable member away from the body; and wherein, when in the locked configuration, the second locking element restrains movement of the second movable member away from the body by defining a maximum amount of permitted movement of the second movable member away from the body.