After my laminectomy, I had a bone graft fusion at the L45 level. It’s been 12 months, and the X-ray shows there is still some movement at that level. Does this mean the surgery was a failure?

Not necessarily. Movement at a fused site can create what looks like (and acts like) a joint. This is called a pseudoarthrosis or false joint. It’s unclear just what constitutes a pseudoarthrosis. Is it any amount of motion (one degree)? Two degrees of motion?

Some experts suggest more than five degrees of movement seen on side views of X-rays may be considered a fusion failure. But it’s difficult to tell how much motion is really present without an open incision. And most surgeons are not in favor of operative exploration to confirm a pseudoarthrosis.

Studies show that lumbar fusions often deteriorate over time. Long-term fusion is not always maintained. Up to 25 per cent of all cases eventually deteriorate. Patients may or may not be aware of any problems. They may not have any symptoms to alert them of a problem. Or they can suffer from back pain and loss of stability requiring additional surgery.

Your surgeon is the best one to advise you about your current status. Dynamic X-rays taken of the moving spine are often helpful in making the diagnosis. Short of doing exploratory surgery, it isn’t always possible to tell what’s going on at the fused site.