Hyun Bae, M.D., professor of Orthopaedic Surgery and co-director of Fellowship and Education at Cedars Sinai Medical Center in Los Angeles, describes hybrid spine surgery this way: “Cervical disc replacement procedures have traditionally been reserved for young patients where they have largely been successful,” explained Dr. Bae to OTW. “When we are working with older patients who have more degenerative disc disease and cervical spondylolisthesis, however, hybrid surgery should be considered.”
Hybrid surgery is, in effect, an approach which combines anterior cervical discectomy and fusion with cervical disc arthroplasty. “For patients with multilevel cervical degenerative disc disease (DDD), hybrid surgery is still relatively new,” says Dr. Bae. “But it does show promise for preserving motion at the mobile, nonspondylotic segments, while stabilizing the degenerated segments.”
Beyond Conventional Thinking
“The conventional thinking is that new artificial disc technology should be for young patients because they move more. However, the reality is that younger patients tend to tolerate fusion better because the other levels can compensate and the net effect for them is not as great as in older patients. The young patients are in peak condition and can tolerate a one- or two-level fusion.”
And what about those inching towards 60 or 70 years of age?
“If you try do a fusion in someone 60-70 years of age you often include other levels to negate the negative effects of the fusion. If this is such a good operation then why are we fusing level(s) that are not the true problem?”
“If you do a multilevel fusion in a 65-year-old with DDD that has huge impact because the other levels can’t compensate. That person might end up with other issues such as a loss of lordosis.”
“The problem is that a 65-year-old may only need a one- or two-level fusion because that’s where the disease is…but surgeons look at the disc and say, ‘If I fuse this, I have to fuse this.’ The pseudoarthrosis rate is very high at three- to four-level and you’re only getting about a 50-70% fusion rate. I think these are the patients who can greatly benefit from a hybrid approach.”
“Most surgeons think that if the disc is collapsed then you should fuse. But once you fuse, then you have to think about the adjacent levels. If only one disc is collapsed and there is minimal facet arthritis, then it is possible to remobilize the disc.”
“Why is the default to take a collapsed disc and advance it to fusion? Maybe we should try to remobilize it and not affect the adjacent level or levels.”
Indeed!
In terms of multiple level disc disease, Dr. Bae said, “Sometimes you have to do a multilevel procedure because the pathology is widespread. In those situations, it is best to treat each level independently. Look at each level and if it has collapsed and you are trying decompression and it has good alignment then that level could take an artificial disc.”
“Then look at the next level. You may have a disc collapse and facet arthritis or listhesis—in those cases, yes, you would fuse…and then go on to the next level.”
“The best thing about this is if you must treat four levels, you can do two artificial discs and two fusions, you have increased your fusion success rate to 90%. The fundamental issue is: Are we totally clear on what problem we are trying to fix?”
Yes, More Difficult Approach – But Not a 4-Level Fusion
Finally, Dr. Bae reminded OTW and all readers that the hybrid approach is difficult.
“Doing a hybrid multilevel approach in this patient population is more difficult and is not for everyone,” said Dr. Bae to OTW. “While there is a learning curve, detractors shouldn’t dismiss it as ‘crazy.’ I have a feeling that most spine surgeons would think twice if someone told them that they needed a four-level fusion.”
