When two or more cervical levels of the spine are fused, it is referred to as a multilevel cervical fusion, or multilevel ACDF. While a single-level cervical fusion is rarely a concern in terms of neck mobility after surgery, a multilevel fusion is more complex and has more considerations, especially with each additional level of fusion.
What Happens During a Multilevel ACDF?
A multilevel fusion is similar to a single-level fusion in the sense that it typically involves decompressing the spine (removing any material or structure that is inflaming a spinal nerve or the spinal cord) and then stabilizing the spine (setting up a bone graft for fusion). The main difference is that a multilevel fusion will involve at least two cervical levels instead of one.
How Multilevel Fusion Affects Overall Neck Mobility
Some studies have found that once a neck fusion has reached three or four cervical levels, significant range of motion may be lost. In particular, one small study found that a group of patients with three- or four-level cervical fusions had, compared to their preoperative cervical ranges of motion, lost an average of:
- More than 25% of extension/flexion (forward/backward)
- More than 25% of lateral bending (side to side)
- About 14% of rotation (turning left and right)1
However, even for these observed reductions in overall neck mobility, most daily tasks would not be impacted. It is rare for an activity during the day to require more than 30% to 50% of a healthy cervical spine’s overall range of motion.2
Compensating for Reduced Cervical Range of Motion
Even though people who have a three- or four-level cervical fusion will be able to perform most daily tasks without being hindered by a reduced cervical range of motion, they will still experience an adjustment period and some tasks may require new methods to manage.
People might take for granted their daily hygiene routine, but these movements may require more cervical range of motion than other tasks typically done throughout a day. For example, washing hair, shaving, and applying make-up can all involve lots of neck movements and could necessitate some adjustments after a multilevel fusion. Depending on the activity, some people might adjust by simply relying more on moving their eyes rather than their neck, or perhaps moving other regions of the body, such as the back.3
Backing up a car requires the most cervical range of motion for many people during a normal day—one estimate has this task requiring about 92% of the neck’s rotation.3 For people with reduced mobility in the neck, some possible ways to compensate could include modifying mirrors, twisting more with the back, backing up more slowly, and/or relying more on a vehicle backup camera and vehicle alerts when there is an obstruction in its path.
Can Hybrid Surgery Maintain More Neck Mobility?
For some patients who are considering surgery to address spinal degeneration at multiple levels, a newer option is called hybrid surgery. This procedure involves fusing one or more of the spinal levels and then using a cervical artificial disc at another level.
For example, someone with a three-level cervical fusion might opt for two levels to be fused and the third level to receive an artificial disc (instead of a three-level fusion).
In theory, a hybrid surgery has the potential to maintain more cervical range of motion and reduce the risk for an adjacent level (especially below) to wear out and require another surgery. Some studies have shown promising results with hybrid surgery achieving more cervical range of motion and less stress on adjacent joints.4 However, not everyone is a candidate for this surgery, and long-term data is still being collected.5