| 摘要 |
<p>An interbody fusion device (10) includes a tapered body (11) defining a hollow interior for receiving bone graft or bone substitute material. The body (11) defines exterior threads (18,19) which are interrupted over portions (22) of the outer surface of the device. The fusion device (10) defines truncated side walls (22) so that on end view the body takes on a cylindrical form. The side walls are provided with vascularization openings, and the body wall device includes opposite bone ingrowth slots (27) extending through the interrupted thread (18,19) portion of the body. An implant driver is provided which engages the truncated side walls to complete the cylindrical form of the implant at the root diameter of the interrupted threads. The driver facilitates threaded insertion of the implant to the intra-discal space between adjacent vertebrae. The implant is tapered at a predetermined angle generally corresponding to a desired lordotic angle of the spine. The implant is inserted to a determinant depth into the intra-discal space to restore the normal lordosis of the particular vertebral level. The lordotic angle is restored not only by way of the taper of the implant itself, but also as a function of the depth of insertion of the implant into the space. The implant is readily adapted for insertion from either an anterior or a posterior approach. In the anterior approach, the implant is screw threaded into position, while in the posterior approach the implant operates as a cam to spread the vertebral bodies apart to an appropriate lordotic angle. <IMAGE></p> |
