MULTI-VARIABLE HEIGHT FUSION DEVICE

摘要

An apparatus (10) promoting a spinal fusion between neighboring vertebrae (16, 18) is disclosed. Apparatus (10) may be located within the intervertebral disc space and preferably includes a pair of engaging plates (12, 14) for contacting the vertebrae (16, 18). An alignment device may be used to alter the vertical height (20) between the engaging plates (12, 14) to customize the apparatus (10) to fit a given patient. In one embodiment, the alignment device includes two turnbuckles (250, 270) and two pairs of cam blocks (260, 261; 280, 281) for adjusting the height between the engaging plates (202, 204). In another embodiment, the alignment device includes three turnbuckles (540, 550, 560) and three pairs of cam blocks (544, 545; 554, 555; 564, 565) for adjusting the height between the engaging plates (502, 504). In another embodiment, the alignment device includes three screws (640, 650, 660) and three cam blocks (644, 654, 664) for adjusting the height between the engaging plates (602, 604). In another embodiment, the alignment device includes four screws and four cam blocks for adjusting the height between the engaging plates. The alignment device may be adapted to vary the height (20) between the engaging plates (12, 14) such that the height of the apparatus (10) proximate the anterior end (22) is greater than that proximate the posterior end (24), whereby the natural lordosis of the spine is maintained after the apparatus (10) is installed, and such that the height (20) of the apparatus (10) proximate the first side edge (26) is substantially different from the height of the apparatus (10) proximate the second side edge (28), whereby the natural lateral alignment of the spine is maintained after the apparatus (10) is installed. In an alternate embodiment, the apparatus includes a single alignment device that may be used to alter the vertical distance between the engaging plates. The alignment device may include a turnbuckle and a single pair of cam blocks for adjusting the height between the engaging plates (12, 14).