Endoscopic Bertolotti Pseudoarthrosis Excision

At the base of the spine, some people are born with a transitional vertebra: the lowest lumbar vertebra is partly "sacralised", with one or both transverse processes enlarged. When an enlarged transverse process meets the wing of the sacrum, it can form a false joint — a pseudoarticulation — rather than fusing solidly. In a proportion of people this false joint becomes painful, producing low back pain typically felt to one side, sometimes worse on bending or twisting. This is Bertolotti syndrome. It is often missed because the anatomy is dismissed as an incidental finding, so confirming that the pseudoarticulation is genuinely the source of pain — frequently with a targeted diagnostic injection into the false joint — is an essential first step before any surgery.

Where the false joint is confirmed as the pain generator and non-operative measures have not helped, the operation removes it — resecting the enlarged transverse process and the pseudoarticulation so that the abnormal, painful joint no longer exists. Done endoscopically, this is a targeted keyhole procedure: the endoscope is docked directly onto the pseudoarticulation through a small portal, and the abnormal bony bridge is taken down with a fine burr under continuous irrigation and magnified vision, with care to protect the nearby L5 nerve, which runs close to this region. The aim is to free the painful joint completely while disturbing as little surrounding muscle and bone as possible.

The pseudoarticulation is a small, deep, out-of-the-way target, and reaching it through open surgery means a fair amount of muscle dissection. A targeted endoscopic approach goes straight to the spot with far less collateral disturbance, which is well suited to what is essentially a focused bone-resection task in a young, otherwise healthy patient. I am careful, though, to be honest about selection: the single most important thing in Bertolotti syndrome is being sure the false joint really is the cause of the pain before operating, because the anatomy is common and not always symptomatic. Careful assessment, imaging and a confirmatory injection guide that decision, and in some cases — particularly where there is associated instability — a fusion rather than a simple excision may be the better option. Making that judgement openly with each patient is part of good care.

The evidence on Bertolotti syndrome comprises reviews, classification systems and surgical series rather than large trials. Classification work — relating the exact anatomy of the transitional vertebra to the best treatment — has helped guide whether resection of the pseudoarticulation or a fusion is more appropriate. Surgical series of resection, including minimally invasive tubular and microendoscopic approaches and, more recently, full-endoscopic resection of the pseudoarticulation, report meaningful improvements in pain and quality of life in well-selected patients, while consistently emphasising the importance of confirming the false joint as the pain source first. Longer-term comparative work using anatomical classification to choose between resection and fusion supports individualising the operation to each person's anatomy — which is exactly my approach.

Because the endoscopic approach is a targeted keyhole, recovery is generally quicker and more comfortable than an equivalent open resection, with relief of the localised back pain expected as the false joint is removed. It is honest to say that outcomes depend heavily on correct selection — on the pseudoarticulation genuinely being the source of the pain. Activity is built back up over the following weeks, and the spine is followed up over the longer term.

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• —A review of symptomatic lumbosacral transitional vertebrae: Bertolotti's syndrome. (PMID 26484005)
• —Redefining the classification for Bertolotti syndrome: anatomical findings guide treatment selection. (PMID 36965661)
• —Minimally invasive tubular resection of the anomalous transverse process in Bertolotti's syndrome. (PMID 24358999)
• —Quality-of-life and satisfaction following pseudoarthrectomy in Bertolotti syndrome. (PMID 35189349)
• —Long-term outcomes using the Jenkins classification to determine treatment of transitional vertebrae in Bertolotti syndrome. (PMID 36898630)
• —Systematic review and bibliometric study of Bertolotti's syndrome. (PMID 37318877 / PMC10583961)