Evolution of Technology

Lumbar Disc Arthroplasty

Lumbar disc arthroplasty started in Europe with metallic spheres used to replace the disc. This however had mixed outcomes, and was largely not accepted within the spine surgery field. However, in the mid-1980s two scientists developed the Charite artificial disc, which has provided the basis of all disc arthroplasty since.

As with joint arthroplasty throughout the body, many current versions of disc arthroplasty use metallic endplates which affix to the vertebral bodies with plastic polymer interposition piece which allows for smooth movement in flexion and extension, as well as, side bending and rotation. The metallic implants now have rough texture and teeth on the back side of the implant to ensure that it does move from its intended position after implantation. Disc replacement surgery is done via an anterior approach (from the front) to the lumbar spine. This is due to the typically small space available in the posterior spine.

Evolution of Procedure

Lumbar Disc Replacement

Surgical treatment of lumbar disc degeneration has been rooted in removing the pain generator, which in this instance is the disc. Historically, and still commonly performed, the treatment has been in lumbar interbody fusion. In this procedure, the disc is removed surgically, and a metal or bone device is placed to fill the gap. This device helps fuse the two vertebral levels thereby preventing motion. However, the spine is a very mobile part of the body, and relies on small motion at each level of the lumbar spine to produce the large amount of lumbar spine motion overall.

What has been found is that if you fuse two or more levels of the spine, there are increased forces across the remaining levels with motion. This causes a more rapid degeneration of the other levels and can necessitate further surgical intervention. Around 25% of people require re-operation within 10 years of the original surgery. These problems prompted the development of lumbar disc arthroplasty in order to remove the pain generating disc, while maintaining motion of the lumbar spine and to try and prevent adjacent level secondary degeneration.