I have back pain that is so severe that I am unable to lift my children, play golf, or work in the yard without spending the next two or three days in bed. This problem has existed for a couple of years and seems to be getting worse. I have been told by other doctors that a spinal fusion may solve my problem. I have heard about a new device called a BAK fusion cage, which is expected to revolutionize spinal surgery. Do you have any experience with this device and could it solve my problem?

Low back pain can be caused by a number of problems, some of which are related to the spine. Of the spine problems, the most common is disc degeneration. The intervertebral disc is the ''shock absorber'' of the spine and acts as a spacer between the bones of the back. The disc is susceptible to injury and degeneration, which results in the disc being unable to perform its function as an adequate shock absorber. When this happens, motion of the bones above and below the disc can produce pain in a fashion similar to a painful arthritic joint. Additionally, when the disc degenerates, pain causing chemicals that normally are found within the center of the disc leak out and come in contact with nerves. The combination of motion and nerve irritation can cause severe back pain and/or leg pain. In a large majority of cases, physical therapy and conditioning will keep this problem under control. If the problem persists in spite of an aggressive rehabilitation program, a surgical fusion may be an option. A fusion forms a solid bond between the bone above the disc and the bone below the disc, eliminating motion. When the motion is eliminated, pain coming from the disc should disappear. A number of operations are used to accomplish a spinal fusion, one of which utilizes a device known as the BAK fusion cage. A fusion cage is a metal box that is filled with bone or bonelike substance. This box is inserted into the disc and acts as a spacer, replacing the soft damaged disc with bone that will bond to the bones above.