Here are five studies on cervical and lumbar artificial disc replacement. The studies were published in Spine, unless otherwise noted.
1. Artificial disc replacements may be more cost-effective than spinal fusion. Richard Delamarter, MD, co-director of the Cedars-Sinai Spine Center, reported a study earlier this year in which he found that artificial disc replacement for patients with degenerative disc disease had a more positive economic impact than spinal fusions. The study examined 209 patients with damaged cervical spine discs who underwent either cervical disc replacement or spinal fusion. Four years after the surgery, the fusion patients were four times more likely to need additional surgery and half of those operations were necessary because of new disc complications occurring at levels adjacent to the fusion.
Another study focused on patients suffering from three-level lower back disc disease, comparing the cost of care between disc replacement and fusion. The total hospital costs for the disc replacement patients were, on average, 49 percent lower than fusion patients.
2. Cervical disc arthroplasty better than ACDF. A recent study of 187 patients who either received cervical disc arthroplasty or anterior cervical discectomy and fusion for one-level cervical disc disease showed cervical disc arthroplasty had better outcomes. Two years after surgery, the arthroplasty group experienced significantly greater improvement in cervical spine range of motion when compared with the ACDF group. The ACDF patients also reported significantly elevated contribution from caudal adjacent level, as well as first, second and third cranial adjacent level.
3. Lumbar disc arthroplasty has better results than fusion for DDD. In a randomized study of 577 patients with degenerative disc disorders, surgeons either treated the patients with a stand-alone interbody fusion or lumbar disc arthroplasty using the Maverick disc. The arthroplasty patients reported better outcomes on the Oswestry Disability Index scores, back pain scores and patient satisfaction. Hospital stays were similar for both groups and the arthroplasty patients reported fewer implant- or procedure-related adverse events. However, surgical time and blood loss rates were higher among the arthroplasty group.
4. Disc arthroplasty successful for military patients. The success rate for total disc arthroplasty for military patients is now approaching 80 percent, according to a study published in the Journal of Spinal Disorders & Techniques. In a study of 38 military members who underwent single or two-level total disc arthroplasty for degenerative disc disorder after failing at least six months of conservative treatment. The patients showed an improvement in the Oswestry Disability Index from 53.6 to 27.7 postoperatively. In addition to symptom relief, the average disc height of the patients increased by 69 percent for the patients. Nearly 70 percent of the patients were able to return to their position within the military.
5. Cervical spine biomechanics are better after disc replacement adjacent to fusion. Researchers examined nine cadaveric cervical spines under load- and displacement-control testing. The test was meant to replicate either a two-level fusion or a cervical disc replacement adjacent to fusion. The external fixator device simulating fusion significantly reduced the range of motion at C4-C5 and C6-C7, and the range of motion returned after removing the fusion construct. However, arthroplasty using the porous-coated motion disc at C5-C6 maintained total flexion-extension ROM. The arthroplasty model also showed significantly decreased demand on the adjacent segments when compared with fusion.
Written by Laura Miller