Minimally invasive lumbar fusion (MI-TLIF)

Replacing the worn disc with an interbody implant and fixing the two vertebrae with screws so that, over time, they knit into a single unit. It is considered when the problem is not only that something is compressing the nerve, but that the segment is moving abnormally.

Fusion rates match those of the open technique, but with far less muscle damage and a shorter recovery: the implant goes in through a lateral corridor and the screws are placed percutaneously, without stripping the muscles off the whole spine.

The fused level stops moving, and that is exactly the aim when abnormal movement is what hurts. That is why fusion only makes sense when it is genuinely indicated: if the case allows movement to be preserved, there are other options — disc replacement, dynamic stabilisation — and they are considered first.

In spondylolisthesis, segmental instability and foraminal stenosis that requires fusion. A herniation or a stenosis without instability is dealt with by decompressing and preserving the stabilising structures, without fixing anything.