It’s true that one of the possible problems after spinal fusion is adjacent-segment deterioration (ASD). This doesn’t always happen. Scientists aren’t sure why it happens to some people but not to others.
In a recent study, surgeons in Korea compared two different fusion methods used to see if the type of fusion made a difference. Their patients either had a posterior lumbar interbody fusion (PLIF) or an anterior lumbar interbody fusion (ALIF).
Posterior means the operation is done from the back. Anterior is from the front. In both methods, the disc was removed. Bone chips and/or a tiny cage were used to fill the empty disc space. This graft material stimulates additional bone growth to occur. Screws were used to hold the spine stable until the fusion was complete.
Surgery done from the front (anterior) is less likely to cause ASD. This may be because damage to the posterior parts of the spine is avoided. The structures that hold the spine in place remain strong. No change in the alignment may be a protective factor.
One study comparing ALIF to PLIF showed that ASD is more likely to occur with PLIF. The posterior soft tissue structures are disrupted possibly contritbuting to the proglem. But even with ASD forming, the patients did not need additional surgery. They seemed just as happy with the results as the patients who had ALIF and no segmental degeneration.
More studies are needed to find ways to eliminate the complication of ASD after spinal fusion.